MGTA / Magenta Therapeutics Inc - تصريحات هيئة الأوراق المالية والبورصات، التقرير السنوي، بيان الوكيل

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US ˙ NASDAQ ˙ US55910K1088
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الإحصائيات الأساسية
LEI 549300Z3N6ODPCOFC890
CIK 1690585
SEC Filings
All companies that sell securities in the United States must register with the Securities and Exchange Commission (SEC) and file reports on a regular basis. These reports include company annual reports (10K, 10Q), news updates (8K), investor presentations (found in 8Ks), insider trades (form 4), ownership reports (13D, and 13G), and reports related to the specific securities sold, such as registration statements and prospectus. This page shows recent SEC filings related to Magenta Therapeutics Inc
SEC Filings (Chronological Order)
توفر هذه الصفحة قائمة كاملة ومرتبة ترتيبًا زمنيًا لتصريحات هيئة الأوراق المالية والبورصات، باستثناء تصريحات الملكية التي نقدمها في مكان آخر.
August 7, 2025 EX-99.1

DIANTHUS THERAPEUTICS HIGHLIGHTS RECENT BUSINESS ACHIEVEMENTS AND REPORTS Q2 FINANCIAL RESULTS

Exhibit 99.1 DIANTHUS THERAPEUTICS HIGHLIGHTS RECENT BUSINESS ACHIEVEMENTS AND REPORTS Q2 FINANCIAL RESULTS Phase 2 MaGic trial of claseprubart (DNTH103) in generalized Myasthenia Gravis (gMG) top-line results anticipated in September 2025; the first of three catalysts for the claseprubart neuromuscular franchise by YE’26 Phase 3 CAPTIVATE trial of claseprubart in Chronic Inflammatory Demyelinatin

August 7, 2025 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2025 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001-38541 Dianthus Therapeutics, Inc.

August 7, 2025 8-K

FORM 8-K Item 2.02 Results of Operations and Financial Condition. Item 9.01 Financial Statements and Exhibits.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): August 7, 2025 DIANTHUS THERAPEUTICS, INC. (Exact name of Registrant as Specified in Its Charter) Delaware 001-38541 81-0724163 (State or Other Jurisdiction of Incorporation) (Commiss

May 22, 2025 8-K

FORM 8-K Item 5.07 Submission of Matters to a Vote of Security Holders.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 22, 2025 DIANTHUS THERAPEUTICS, INC. (Exact name of Registrant as Specified in Its Charter) Delaware 001-38541 81-0724163 (State or Other Jurisdiction of Incorporation) (Commissio

May 12, 2025 EX-99.1

DIANTHUS THERAPEUTICS HIGHLIGHTS RECENT BUSINESS ACHIEVEMENTS AND REPORTS Q1 FINANCIAL RESULTS

Exhibit 99.1 DIANTHUS THERAPEUTICS HIGHLIGHTS RECENT BUSINESS ACHIEVEMENTS AND REPORTS Q1 FINANCIAL RESULTS Completed enrollment in Phase 2 MaGic trial of DNTH103 in generalized Myasthenia Gravis (gMG)s Top-line MaGic results anticipated in September 2025 to be the first of three catalysts for the DNTH103 neuromuscular franchise by YE’26 Phase 3 CAPTIVATE trial of DNTH103 in Chronic Inflammatory D

May 12, 2025 8-K

FORM 8-K Item 2.02 Results of Operations and Financial Condition. Item 9.01 Financial Statements and Exhibits.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 12, 2025 DIANTHUS THERAPEUTICS, INC. (Exact name of Registrant as Specified in Its Charter) Delaware 001-38541 81-0724163 (State or Other Jurisdiction of Incorporation) (Commissio

May 12, 2025 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2025 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001-38541 Dianthus Therapeutics, Inc.

April 10, 2025 DEF 14A

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. )

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. ) Filed by the Registrant ☒ Filed by a Party other than the Registrant ☐ Check the appropriate box: ☐ Preliminary Proxy Statement ☐ Confidential, for Use of the Commission Only (as permitte

April 10, 2025 DEFA14A

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. )

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. ) Filed by the Registrant ☒ Filed by a Party other than the Registrant ☐ Check the appropriate box: ☐ Preliminary Proxy Statement ☐ Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)

March 11, 2025 EX-FILING FEES

Filing Fee Table

Exhibit 107.1 Calculation of Filing Fee Tables Form S-8 (Form Type) Dianthus Therapeutics, Inc. (Exact Name of Registrant as Specified in its Charter) Table 1: Newly Registered Securities Security Type Security Class Title Fee Calculation Rule Amount Registered(1) Proposed Maximum Offering Price Per Unit Maximum Aggregate Offering Price Fee Rate Amount of Registration Fee Equity Common stock, $0.0

March 11, 2025 10-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K (Mark One) ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2024 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001-38

March 11, 2025 EX-19.1

Dianthus Therapeutics, Inc. Insider Trading Policy.

Exhibit 19.1 INSIDER TRADING POLICY (dated September 11, 2023) I. INTRODUCTION Dianthus Therapeutics, Inc. (the “Company”) is listed on the Nasdaq Stock Market (“Nasdaq”), and is subject to its rules, as well as the rules and regulations of the U.S. Securities and Exchange Commission (the “SEC”). U.S. federal and state laws prohibit buying, selling, gifting or making other transfers of securities

March 11, 2025 EX-99.1

DIANTHUS THERAPEUTICS HIGHLIGHTS RECENT BUSINESS ACHIEVEMENTS AND REPORTS Q4 AND FY 2024 FINANCIAL RESULTS Phase 2 MaGic trial of DNTH103 in generalized Myasthenia Gravis (gMG) ongoing; top-line results on track for 2H’25 Phase 3 CAPTIVATE trial of D

DIANTHUS THERAPEUTICS HIGHLIGHTS RECENT BUSINESS ACHIEVEMENTS AND REPORTS Q4 AND FY 2024 FINANCIAL RESULTS Phase 2 MaGic trial of DNTH103 in generalized Myasthenia Gravis (gMG) ongoing; top-line results on track for 2H’25 Phase 3 CAPTIVATE trial of DNTH103 in Chronic Inflammatory Demyelinating Polyneuropathy (CIDP) ongoing; interim responder analysis anticipated in 2H’26 Phase 2 MoMeNtum trial of DNTH103 in Multifocal Motor Neuropathy (MMN) ongoing; top-line results anticipated in 2H’26 $357.

March 11, 2025 8-K

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): March 11, 2025 DIANTHUS THERAPEUTICS, INC. (Exact name of Registrant as Specified in Its Charter) Delaware 001-38541 81-0724163 (State or Other Jurisdiction of Incorporation) (Commiss

March 11, 2025 S-8

As filed with the Securities and Exchange Commission on March 11, 2025

As filed with the Securities and Exchange Commission on March 11, 2025 Registration No.

March 5, 2025 8-K

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): March 4, 2025 DIANTHUS THERAPEUTICS, INC. (Exact name of Registrant as Specified in Its Charter) Delaware 001-38541 81-0724163 (State or Other Jurisdiction of Incorporation) (Commissi

February 14, 2025 EX-99.1

JOINT FILING AGREEMENT

EXHIBIT 99.1 JOINT FILING AGREEMENT This Joint Filing Agreement, dated as of February 14, 2025, is by and among RA Capital Management, L.P., Peter Kolchinsky, Rajeev Shah, and RA Capital Healthcare Fund, L.P. (the foregoing are collectively referred to herein as the “Filers”). Each of the Filers may be required to file with the United States Securities and Exchange Commission a statement on Schedu

December 12, 2024 8-K

Financial Statements and Exhibits, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): December 12, 2024 DIANTHUS THERAPEUTICS, INC. (Exact name of Registrant as Specified in Its Charter) Delaware 001-38541 81-0724163 (State or Other Jurisdiction of Incorporation) (Comm

December 12, 2024 EX-99.1

FORWARD-LOOKING STATEMENTS Certain statements in this presentation (“Presentation”), other than purely historical information, may constitute “forward-looking statements” within the meaning of the federal securities laws, including for purposes of th

Corporate Presentation December 2024 Exhibit 99.1 FORWARD-LOOKING STATEMENTS Certain statements in this presentation (“Presentation”), other than purely historical information, may constitute “forward-looking statements” within the meaning of the federal securities laws, including for purposes of the safe harbor provisions under the United Stated Private Securities Litigation Reform Act of 1995, c

December 3, 2024 SC 13D/A

DNTH / Dianthus Therapeutics, Inc. / Avidity Partners Management LP Activist Investment

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D Under the Securities Exchange Act of 1934 (Amendment No. 1) Dianthus Therapeutics, Inc. (Name of Issuer) Dee Raibourn, Esq. c/o Avidity Partners Management LP 2828 N Harwood Street, Suite 1220 Dallas, Texas 75201 United State of America 214-550-1934 (Name, Address and Telephone Number of Person Authorized to Recei

November 22, 2024 EX-99.1

JOINT FILING AGREEMENT

EX-99.1 2 d845832dex991.htm EX-99.1 Exhibit 1 JOINT FILING AGREEMENT The undersigned hereby agree that the foregoing statement on Schedule 13G is filed on behalf of each of the undersigned, and any amendments thereto executed by the undersigned shall be filed on behalf of each of the undersigned without the necessity of filing any additional joint filing agreement. The undersigned acknowledge that

November 22, 2024 SC 13G

DNTH / Dianthus Therapeutics, Inc. / TCG Crossover GP II, LLC - SC 13G Passive Investment

SC 13G 1 d845832dsc13g.htm SC 13G UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. )* Dianthus Therapeutics, Inc. (Name of Issuer) Common Stock, $0.001 par value per share (Title of Class of Securities) 252828108 (CUSIP Number) November 15, 2024 (Date of Event Which Requires Filing of This Statement) Check

November 14, 2024 SC 13G/A

DNTH / Dianthus Therapeutics, Inc. / 5AM Partners VII, LLC - SC 13G/A Passive Investment

SC 13G/A 1 tm2427620d23sc13ga.htm SC 13G/A UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G/A Under the Securities Exchange Act of 1934 (Amendment No. 2)* Dianthus Therapeutics, Inc. (Name of Issuer) Common stock, $0.001 par value per share (Title of Class of Securities) 252828108 (CUSIP Number) September 30, 2024 (Date of Event Which Requires Filing of this Sta

November 14, 2024 SC 13G/A

DNTH / Dianthus Therapeutics, Inc. / Venrock Healthcare Capital Partners III, L.P. - SC 13G/A Passive Investment

SC 13G/A 1 tm2428137d6sc13ga.htm SC 13G/A UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G/A Under the Securities Exchange Act of 1934 (Amendment No. 1)* Dianthus Therapeutics, Inc. (Name of Issuer) Common stock, $0.001 par value per share (Title of Class of Securities) 252828108 (CUSIP Number) September 30, 2024 (Date of Event Which Requires Filing of this Stat

November 7, 2024 EX-99.1

DIANTHUS THERAPEUTICS HIGHLIGHTS RECENT BUSINESS ACHIEVEMENTS AND REPORTS Q3 FINANCIAL RESULTS Initiation of a single, two-part, pivotal Phase 3 trial of DNTH103 in Chronic Inflammatory Demyelinating Polyneuropathy (CIDP) anticipated by YE’24 Phase 2

DIANTHUS THERAPEUTICS HIGHLIGHTS RECENT BUSINESS ACHIEVEMENTS AND REPORTS Q3 FINANCIAL RESULTS Initiation of a single, two-part, pivotal Phase 3 trial of DNTH103 in Chronic Inflammatory Demyelinating Polyneuropathy (CIDP) anticipated by YE’24 Phase 2 MaGic trial of DNTH103 in generalized Myasthenia Gravis (gMG) ongoing; top-line results anticipated in 2H’25 Phase 2 MoMeNtum trial of DNTH103 in Multifocal Motor Neuropathy (MMN) ongoing; top-line results anticipated in 2H’26 Approximately $343 million of cash provides runway into 2H’27 New York City and Waltham, Mass.

November 7, 2024 8-K

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): November 7, 2024 DIANTHUS THERAPEUTICS, INC. (Exact name of Registrant as Specified in Its Charter) Delaware 001-38541 81-0724163 (State or Other Jurisdiction of Incorporation) (Commi

November 7, 2024 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended September 30, 2024 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001-38541 Dianthus Therapeutics, Inc.

October 21, 2024 RW

October 21, 2024

October 21, 2024 VIA EDGAR Division of Corporate Finance Securities and Exchange Commission 100 F Street, N.

October 11, 2024 424B3

Dianthus Therapeutics, Inc. 23,655,372 Shares Common Stock Offered by the Selling Stockholders

Table of Contents Filed Pursuant to Rule 424(b)(3) Registration No. 333-282443 PROSPECTUS Dianthus Therapeutics, Inc. 23,655,372 Shares Common Stock Offered by the Selling Stockholders Pursuant to this prospectus, the selling stockholders identified herein (the “Selling Stockholders”) are offering (the “Offering”) on a resale basis an aggregate of up to 23,655,372 shares of common stock, par value

October 11, 2024 424B5

$200,000,000 Dianthus Therapeutics, Inc. Common Stock

Table of Contents Filed Pursuant to Rule 424(b)(5) Registration No. 333-282446 PROSPECTUS SUPPLEMENT (To Prospectus dated October 9, 2024) $200,000,000 Dianthus Therapeutics, Inc. Common Stock We have entered into a sales agreement (the “Sales Agreement”) with TD Securities (USA) LLC (“TD Cowen”), relating to shares of our common stock, par value $0.001 per share (“common stock”), offered by this

October 11, 2024 SC 13G

DNTH / Dianthus Therapeutics, Inc. / Octagon Capital Advisors LP Passive Investment

SC 13G 1 dnth1011240sc13g.htm UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. )* Dianthus Therapeutics, Inc. (Name of Issuer) Common Stock, $0.001 par value (Title of Class of Securities) 252828108 (CUSIP Number) September 30, 2024 (Date of Event Which Requires Filing of This Statement) Check the appropri

October 7, 2024 CORRESP

October 7, 2024

October 7, 2024 VIA EDGAR AND EMAIL United States Securities and Exchange Commission Division of Corporation Finance 100 F Street, N.

October 7, 2024 CORRESP

October 7, 2024

October 7, 2024 VIA EDGAR AND EMAIL United States Securities and Exchange Commission Division of Corporation Finance 100 F Street, N.

October 1, 2024 EX-4.8

Form of Debt Indenture.

Exhibit 4.8 DIANTHUS THERAPEUTICS, INC. Debt Securities Indenture Dated as of    , 202 [    ], as Trustee CROSS-REFERENCE TABLE This Cross-Reference Table is not a part of the Indenture TIA Section Indenture Section 310(a)(1) 7.10 (a)(2) 7.10 (a)(3) N.A. (a)(4) N.A. (b) 7.08; 7.10; 12.02 311(a) 7.11 (b) 7.11 (c) N.A. 312(a) 2.05 (b) 12.03 (c) 12.03 313(a) 7.06 (b)(1) N.A. (b)(2) 7.06 (c) 12.02 (d)

October 1, 2024 EX-1.2

Sales Agreement, dated October 1, 2024, by and between Dianthus Therapeutics, Inc. and TD Securities (USA) LLC.

Exhibit 1.2 DIANTHUS THERAPEUTICS, INC. $200,000,000 COMMON STOCK SALES AGREEMENT October 1, 2024 TD Securities (USA) LLC 1 Vanderbilt Avenue New York, New York 10017 Ladies and Gentlemen: Dianthus Therapeutics, Inc., a Delaware corporation (the “Company”), confirms its agreement (this “Agreement”) with TD Securities (USA) LLC (“TD Cowen”), as follows: 1. Issuance and Sale of Shares. The Company a

October 1, 2024 S-3

As filed with the Securities and Exchange Commission on October 1, 2024

Table of Contents As filed with the Securities and Exchange Commission on October 1, 2024 Registration No.

October 1, 2024 EX-FILING FEES

Filing Fee Table.

Exhibit 107 Calculation of Filing Fee Tables Form S-3 (Form Type) Dianthus Therapeutics, Inc.

October 1, 2024 EX-FILING FEES

Filing Fee Table.

Exhibit 107 Calculation of Filing Fee Tables FORM S-3 (Form Type) Dianthus Therapeutics, Inc.

October 1, 2024 S-3

As filed with the Securities and Exchange Commission on October 1, 2024.

Table of Contents As filed with the Securities and Exchange Commission on October 1, 2024.

September 16, 2024 8-K

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): September 16, 2024 DIANTHUS THERAPEUTICS, INC. (Exact name of Registrant as Specified in Its Charter) Delaware 001-38541 81-0724163 (State or Other Jurisdiction of Incorporation) (Com

September 16, 2024 424B3

DIANTHUS THERAPEUTICS, INC. 21,326,988 Shares Common Stock Offered by the Selling Stockholders

Prospectus Supplement No. 4 (to prospectus dated March 27, 2024) Filed pursuant to Rule 424(b)(3) Registration No. 333-274863 DIANTHUS THERAPEUTICS, INC. 21,326,988 Shares Common Stock Offered by the Selling Stockholders This prospectus supplement no. 4 is being filed to update and supplement information contained in the prospectus dated March 27, 2024 (the “Prospectus”) related to the offering on

September 12, 2024 SC 13D/A

DNTH / Dianthus Therapeutics, Inc. / Viridian, LLC - SC 13D/A Activist Investment

SC 13D/A 1 tm2423966d1sc13d.htm SC 13D/A UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D Under the Securities Exchange Act of 1934 (Amendment No. 1) DIANTHUS THERAPEUTICS, INC. (Name of Issuer) Common Stock, $0.001 par value (Title of Class of Securities) 252828 108 (CUSIP Number) Ryan A. Murr Gibson, Dunn & Crutcher LLP One Embarcadero Center, Suite 2600 San F

August 8, 2024 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2024 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001-38541 Dianthus Therapeutics, Inc.

August 8, 2024 424B3

DIANTHUS THERAPEUTICS, INC. 21,326,988 Shares Common Stock Offered by the Selling Stockholders

Prospectus Supplement No. 3 (to prospectus dated March 27, 2024) Filed pursuant to Rule 424(b)(3) Registration No. 333-274863 DIANTHUS THERAPEUTICS, INC. 21,326,988 Shares Common Stock Offered by the Selling Stockholders This prospectus supplement no. 3 is being filed to update and supplement information contained in the prospectus dated March 27, 2024 (the “Prospectus”) related to the offering on

August 8, 2024 8-K

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): August 8, 2024 DIANTHUS THERAPEUTICS, INC. (Exact name of Registrant as Specified in Its Charter) Delaware 001-38541 81-0724163 (State or Other Jurisdiction of Incorporation) (Commiss

August 8, 2024 S-8

As filed with the Securities and Exchange Commission on August 8, 2024

As filed with the Securities and Exchange Commission on August 8, 2024 Registration No.

August 8, 2024 EX-FILING FEES

Filing Fee Table

Exhibit 107.1 Calculation of Filing Fee Tables Form S-8 (Form Type) Dianthus Therapeutics, Inc. (Exact Name of Registrant as Specified in its Charter) Table 1: Newly Registered Securities Security Type Security Class Title Fee Calculation Rule Amount Registered(1) Proposed Maximum Offering Price Per Unit Maximum Aggregate Offering Price Fee Rate Amount of Registration Fee Equity Common stock, $0.0

August 8, 2024 EX-99.1

DIANTHUS THERAPEUTICS HIGHLIGHTS RECENT BUSINESS ACHIEVEMENTS AND REPORTS Q2 FINANCIAL RESULTS Phase 2 MaGic trial in generalized Myasthenia Gravis (gMG) ongoing; top-line results anticipated in 2H’25 IND for Phase 2 MoMeNtum trial in Multifocal Moto

DIANTHUS THERAPEUTICS HIGHLIGHTS RECENT BUSINESS ACHIEVEMENTS AND REPORTS Q2 FINANCIAL RESULTS Phase 2 MaGic trial in generalized Myasthenia Gravis (gMG) ongoing; top-line results anticipated in 2H’25 IND for Phase 2 MoMeNtum trial in Multifocal Motor Neuropathy (MMN) cleared by FDA in June; top-line results anticipated in 2H’26 Phase 2 trial in Chronic Inflammatory Demyelinating Polyneuropathy (CIDP) to initiate 2H’24 Approximately $361 million of cash provides runway into 2H’27 New York City and Waltham, Mass.

August 8, 2024 EX-10.1

Dianthus Therapeutics, Inc. 2019 Employee Stock Purchase Plan, as amended.

Exhibit 10.1 DIANTHUS THERAPEUTICS, INC. 2019 EMPLOYEE STOCK PURCHASE PLAN The purpose of the Dianthus Therapeutics, Inc. 2019 Employee Stock Purchase Plan (“the Plan”) is to provide eligible employees of Dianthus Therapeutics, Inc. (the “Company”) and each Designated Subsidiary (as defined in Section 11) with opportunities to purchase shares of the Company’s common stock, par value $0.001 per sha

June 6, 2024 EX-99.1

FORWARD-LOOKING STATEMENTS Certain statements in this presentation (“Presentation”), other than purely historical information, may constitute “forward-looking statements” within the meaning of the federal securities laws, including for purposes of th

Corporate Presentation June 2024 Exhibit 99.1 FORWARD-LOOKING STATEMENTS Certain statements in this presentation (“Presentation”), other than purely historical information, may constitute “forward-looking statements” within the meaning of the federal securities laws, including for purposes of the safe harbor provisions under the United Stated Private Securities Litigation Reform Act of 1995, conce

June 6, 2024 8-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): June 6, 2024 DIANTHUS THERAPEUTICS, INC. (Exact name of Registrant as Specified in Its Charter) Delaware 001-38541 81-0724163 (State or Other Jurisdiction of Incorporation) (Commissio

May 28, 2024 8-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 23, 2024 DIANTHUS THERAPEUTICS, INC. (Exact name of Registrant as Specified in Its Charter) Delaware 001-38541 81-0724163 (State or Other Jurisdiction of Incorporation) (Commissio

May 28, 2024 EX-10.1

Second Amended and Restated Dianthus Therapeutics, Inc. Stock Option and Incentive Plan

Exhibit 10.1 SECOND AMENDED AND RESTATED DIANTHUS THERAPEUTICS, INC. STOCK OPTION AND INCENTIVE PLAN Section 1. GENERAL PURPOSE OF THE PLAN; DEFINITIONS The Second Amended and Restated Dianthus Therapeutics, Inc. Stock Option and Incentive Plan (the “Plan”) was originally adopted as the Magenta Therapeutics, Inc. 2018 Stock Option and Incentive Plan (the “Original Plan”), effective as of June 19,

May 28, 2024 424B3

DIANTHUS THERAPEUTICS, INC. 21,326,988 Shares Common Stock Offered by the Selling Stockholders

Prospectus Supplement No. 2 (to prospectus dated March 27, 2024) Filed pursuant to Rule 424(b)(3) Registration No. 333-274863 DIANTHUS THERAPEUTICS, INC. 21,326,988 Shares Common Stock Offered by the Selling Stockholders This prospectus supplement no. 2 is being filed to update and supplement information contained in the prospectus dated March 27, 2024 (the “Prospectus”) related to the offering on

May 9, 2024 8-K

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 9, 2024 DIANTHUS THERAPEUTICS, INC. (Exact name of Registrant as Specified in Its Charter) Delaware 001-38541 81-0724163 (State or Other Jurisdiction of Incorporation) (Commission

May 9, 2024 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2024 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001-38541 Dianthus Therapeutics, Inc.

May 9, 2024 EX-99.1

Phase 2 MaGic trial in generalized Myasthenia Gravis (gMG) ongoing, with top-line results anticipated in 2H’25 Building a neuromuscular franchise with DNTH103; Phase 2 trial in Multifocal Motor Neuropathy (MMN) to initiate 2Q’24 and Phase 2 trial in

Exhibit 99.1 DIANTHUS THERAPEUTICS HIGHLIGHTS RECENT BUSINESS ACHIEVEMENTS AND REPORTS Q1 FINANCIAL RESULTS Phase 2 MaGic trial in generalized Myasthenia Gravis (gMG) ongoing, with top-line results anticipated in 2H’25 Building a neuromuscular franchise with DNTH103; Phase 2 trial in Multifocal Motor Neuropathy (MMN) to initiate 2Q’24 and Phase 2 trial in Chronic Inflammatory Demyelinating Polyneu

May 9, 2024 424B3

DIANTHUS THERAPEUTICS, INC. 21,326,988 Shares Common Stock Offered by the Selling Stockholders

Prospectus Supplement No. 1 (to prospectus dated March 27, 2024) Filed pursuant to Rule 424(b)(3) Registration No. 333-274863 DIANTHUS THERAPEUTICS, INC. 21,326,988 Shares Common Stock Offered by the Selling Stockholders This prospectus supplement no. 1 is being filed to update and supplement information contained in the prospectus dated March 27, 2024 (the “Prospectus”) related to the offering on

April 11, 2024 DEF 14A

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. )

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. ) Filed by the Registrant ☒ Filed by a Party other than the Registrant ☐ Check the appropriate box: ☐ Preliminary Proxy Statement ☐ Confidential, for Use of the Commission Only (as permitte

April 11, 2024 DEFA14A

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. )

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. ) Filed by the Registrant ☒ Filed by a Party other than the Registrant ☐ Check the appropriate box: ☐ Preliminary Proxy Statement ☐ Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)

April 1, 2024 SC 13D/A

DNTH / Dianthus Therapeutics, Inc. / Fairmount Funds Management LLC - SC 13D/A Activist Investment

SC 13D/A 1 d814099dsc13da.htm SC 13D/A UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D Under the Securities Exchange Act of 1934 (Amendment No. 2) DIANTHUS THERAPEUTICS, INC. (Name of Issuer) Common Stock, $0.001 par value (Title of Class of Securities) 252828 108 (CUSIP Number) Ms. Erin O’Connor Fairmount Funds Management LLC 200 Barr Harbor Drive, Suite 400 W

March 25, 2024 CORRESP

March 25, 2024

March 25, 2024 VIA EDGAR AND EMAIL United States Securities and Exchange Commission Division of Corporation Finance 100 F Street, N.

March 21, 2024 EX-21.1

Subsidiaries of the Registrant (incorporated by reference to Exhibit 21.1 to the Registrant’s Annual Report on Form 10-K filed with the SEC on March 21, 2024).

Exhibit 21.1 SUBSIDIARIES Legal Name State of Organization Magenta Securities Corporation Massachusetts Dianthus Therapeutics OpCo, Inc. Delaware

March 21, 2024 EX-10.22

Separation Agreement, dated September 11, 2023, by and between Magenta Therapeutics, Inc. and Thomas Beetham.

Exhibit 10.22 September 11, 2023 Thomas Beetham Dear Tom: The purpose of this letter agreement (“Agreement”) is to confirm the terms of your separation of employment from Magenta Therapeutics, Inc. (“Magenta” or the “Company”).1 The Consideration being offered below is contingent on your agreement to and compliance with the provisions of this Agreement. This Agreement shall be effective on the eig

March 21, 2024 EX-10.8

Form of Stock Option Agreement for Executives under the Amended and Restated Dianthus Therapeutics, Inc. Stock Option and Incentive Plan (incorporated by reference to Exhibit 10.8 to the Registrant’s Annual Report on Form 10-K filed with the SEC on March 21, 2024).

Exhibit 10.8 EXECUTIVE FORM Amended and Restated DIANTHUS THERAPEUTICS, INC. STOCK OPTION AND INCENTIVE PLAN STOCK OPTION AGREEMENT Pursuant to the Amended and Restated Dianthus Therapeutics, Inc. Stock Option and Incentive Plan (the “Plan”), Dianthus Therapeutics, Inc. (the “Company”) hereby grants to the Optionee named below an option (the “Stock Option”) to purchase on or prior to the Expiratio

March 21, 2024 EX-10.20

Separation Agreement, dated May 12, 2023, by and between Magenta Therapeutics, Inc. and Lisa Olson.

Exhibit 10.20 May 12, 2023 Lisa Olson Dear Lisa: The purpose of this letter agreement (“Agreement”) is to confirm the terms of your separation of employment from Magenta Therapeutics, Inc. (“Magenta” or the “Company”).1 The Consideration being offered below is contingent on your agreement to and compliance with the provisions of this Agreement. This Agreement shall be effective on the eighth (8th)

March 21, 2024 EX-10.15

Amendment to Offer Letter, dated September 11, 2023, by and between Dianthus Therapeutics OpCo, Inc. and Simrat Randhawa (incorporated by reference to Exhibit 10.15 to the Registrant’s Annual Report on Form 10-K filed with the SEC on March 21, 2024).

Exhibit 10.15 September 11, 2023 Simrat Randhawa, MD, MBA Re: Amendment to Offer Letter Dear Sim: By way of this letter, Section 5 of your Offer Letter dated January 17, 2022 (the “Offer Letter”) by and between you and Dianthus Therapeutics OpCo, Inc. (f/k/a Dianthus Therapeutics, Inc.) (the “Company”) is hereby amended to and restated in its entirety to read as follows: “5. Severance Benefits. (a

March 21, 2024 EX-99.3

Form of Dianthus Therapeutics, Inc. Inducement Stock Option Agreement

Exhibit 99.3 DIANTHUS THERAPEUTICS, INC. INDUCEMENT STOCK OPTION AGREEMENT Dianthus Therapeutics, Inc. (the “Company”) hereby grants to the Optionee named below an option (the “Stock Option”) to purchase on or prior to the Expiration Date set forth below all or part of the number of shares of Common Stock, par value $0.001 per share, of the Company (the “Stock”) set forth below (the “Option Shares

March 21, 2024 EX-99.1

Phase 2 MaGic trial in generalized Myasthenia Gravis (gMG) initiated in Q1’24 with top-line results anticipated in 2H’25 $389 million of pro forma cash, including $216 million of net proceeds from a successful PIPE financing completed in January 2024

Exhibit 99.1 DIANTHUS THERAPEUTICS HIGHLIGHTS RECENT BUSINESS ACHIEVEMENTS AND REPORTS Q4 AND FY2023 FINANCIAL RESULTS Phase 2 MaGic trial in generalized Myasthenia Gravis (gMG) initiated in Q1’24 with top-line results anticipated in 2H’25 $389 million of pro forma cash, including $216 million of net proceeds from a successful PIPE financing completed in January 2024, provides runway into 2H 2027

March 21, 2024 EX-10.19

Separation Agreement, dated February 7, 2023, by and between Magenta Therapeutics, Inc. and Jason Gardner.

Exhibit 10.19 February 7, 2023 Jason Gardner Dear Jason: The purpose of this letter agreement (“Agreement”) is to confirm the terms of your separation of employment from Magenta Therapeutics, Inc. (“Magenta” or the “Company”).1 The Consideration being offered below is contingent on your agreement to and compliance with the provisions of this Agreement. This Agreement shall be effective on the eigh

March 21, 2024 EX-99.2

Dianthus Therapeutics, Inc. Equity Inducement Plan (incorporated by reference to Exhibit 99.2 to the Registrant’s Registration Statement on Form S-8 filed with the SEC on March 21, 2024).

Exhibit 99.2 DIANTHUS THERAPEUTICS, INC. EQUITY INDUCEMENT PLAN Section 1. GENERAL PURPOSE OF THE PLAN; DEFINITIONS Dianthus Therapeutics, Inc., a Delaware corporation (the “Company”), hereby establishes an equity inducement plan known as the Dianthus Therapeutics, Inc. Equity Inducement Plan (the “Plan”) effective as of February 7, 2024 (the “Effective Date”). The purpose of the Plan is to advanc

March 21, 2024 S-1/A

As filed with the Securities and Exchange Commission on March 21, 2024 Registration No. 333-274863 UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20459 AMENDMENT No. 2 TO FORM S-1 REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF

Table of Contents As filed with the Securities and Exchange Commission on March 21, 2024 Registration No.

March 21, 2024 8-K

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): March 21, 2024 DIANTHUS THERAPEUTICS, INC. (Exact name of Registrant as Specified in Its Charter) Delaware 001-38541 81-0724163 (State or Other Jurisdiction of Incorporation) (Commiss

March 21, 2024 EX-97.1

Dianthus Therapeutics, Inc. Rule 10D-1 Clawback Policy.

Exhibit 97.1 RULE 10D-1 CLAWBACK POLICY (September 11, 2023) I. Recoupment of Incentive-Based Compensation It is the policy of Dianthus Therapeutics, Inc. (the “Company”) that, in the event the Company is required to prepare an accounting restatement of the Company’s financial statements due to material non-compliance with any financial reporting requirement under the federal securities laws (incl

March 21, 2024 EX-FILING FEES

Filing Fee Table.

Exhibit 107 Calculation of Filing Fee Tables FORM S-1 (Form Type) Dianthus Therapeutics, Inc.

March 21, 2024 EX-3.2

Third Amended and Restated By-laws (incorporated by reference to Exhibit 3.2 to the Registrant’s Annual Report on Form 10-K filed with the SEC on March 21, 2024).

Exhibit 3.2 THIRD AMENDED AND RESTATED BY-LAWS OF DIANTHUS THERAPEUTICS, INC. (the “Corporation”) ARTICLE I Stockholders SECTION 1. Annual Meeting. The annual meeting of stockholders (any such meeting being referred to in these By-laws as an “Annual Meeting”) shall be held at the hour, date and place within or without the United States which is fixed by the Board of Directors, which time, date and

March 21, 2024 S-8

As filed with the Securities and Exchange Commission on March 21, 2024

As filed with the Securities and Exchange Commission on March 21, 2024 Registration No.

March 21, 2024 EX-FILING FEES

Filing Fee Table

Exhibit 107.1 Calculation of Filing Fee Tables Form S-8 (Form Type) Dianthus Therapeutics, Inc. (Exact Name of Registrant as Specified in its Charter) Table 1: Newly Registered Securities Security Type Security Class Title Fee Calculation Rule Amount Registered(1) Proposed Maximum Offering Price Per Unit Maximum Aggregate Offering Price Fee Rate Amount of Registration Fee Equity Common stock, $0.0

March 21, 2024 10-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K (Mark One) ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2023 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001-38

March 21, 2024 EX-4.5

Description of the Registrant’s Securities Registered Pursuant to Section 12 of the Securities Exchange Act of 1934, as amended (incorporated by reference to Exhibit 4.5 to the Registrant’s Annual Report on Form 10-K filed with the SEC on March 21, 2024).

Exhibit 4.5 Description of the Registrant’s Securities Registered Pursuant to Section 12 of the Securities Exchange Act of 1934, as amended The common stock, par value $0.001 per share (“Common Stock”), of Dianthus Therapeutics, Inc. (“Dianthus,” “we,” or “our”) is registered under Section 12 of the Securities Exchange Act of 1934, as amended. The following is a description of our capital stock an

March 21, 2024 EX-10.6

Dianthus Therapeutics, Inc. 2019 Employee Stock Purchase Plan (incorporated by reference to Exhibit 10.6 to the Registrant's Annual Report on Form 10-K filed with the SEC on March 21, 2024)

Exhibit 10.6 DIANTHUS THERAPEUTICS, INC. 2019 EMPLOYEE STOCK PURCHASE PLAN The purpose of the Dianthus Therapeutics, Inc. 2019 Employee Stock Purchase Plan (“the Plan”) is to provide eligible employees of Dianthus Therapeutics, Inc. (the “Company”) and each Designated Subsidiary (as defined in Section 11) with opportunities to purchase shares of the Company’s common stock, par value $0.001 per sha

February 14, 2024 SC 13G/A

DNTH / Dianthus Therapeutics, Inc. / 5AM Partners VII, LLC - SC 13G/A Passive Investment

SC 13G/A 1 tm245429d5sc13ga.htm SC 13G/A UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. 1)* Dianthus Therapeutics, Inc. (Name of Issuer) Common stock, $0.001 par value per share (Title of Class of Securities) 252828108 (CUSIP Number) December 31, 2023 (Date of Event Which Requires Filing of this Statemen

February 14, 2024 SC 13G/A

DNTH / Dianthus Therapeutics, Inc. / CITADEL ADVISORS LLC - SC 13G/A Passive Investment

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G* (Rule 13d-102) INFORMATION TO BE INCLUDED IN STATEMENTS FILED PURSUANT TO § 240.13d-1(b), (c), AND (d) AND AMENDMENTS THERETO FILED PURSUANT TO § 240.13d-2 (Amendment No. 1)* Dianthus Therapeutics, Inc. (Name of Issuer) Common Stock, par value $0.001 per share (the “Shares”) (Title of Class of Securities) 2528281

February 14, 2024 SC 13G/A

DNTH / Dianthus Therapeutics, Inc. / Third Rock Ventures IV, L.P. - SC 13G/A Passive Investment

SC 13G/A 1 d786707dsc13ga.htm SC 13G/A UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G UNDER THE SECURITIES EXCHANGE ACT OF 1934 (Amendment No. 2)* Dianthus Therapeutics, Inc. (Name of Issuer) COMMON STOCK, $0.001 PAR VALUE PER SHARE (Title of Class of Securities) 252828108** (CUSIP Number) December 31, 2023 (Date of Event Which Requires Filing of this Statemen

February 9, 2024 SC 13G/A

DNTH / Dianthus Therapeutics, Inc. / GV 2016, L.P. - SC 13G/A Passive Investment

SC 13G/A 1 tm244701-4sc13ga.htm SC 13G/A UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Schedule 13G Under the Securities Exchange Act of 1934 (Amendment No. 1)* Dianthus Therapeutics, Inc. (f/k/a Magenta Therapeutics, Inc.) (Name of Issuer) Common Stock, par value $0.001 per share (Title of Class of Securities) 252828108 (CUSIP Number) December 31, 2023 (Date of Event Whi

February 7, 2024 EX-FILING FEES

Filing Fee Table.

Exhibit 107 Calculation of Filing Fee Tables FORM S-1 (Form Type) Dianthus Therapeutics, Inc.

February 7, 2024 S-1/A

As filed with the Securities and Exchange Commission on February 7, 2024

Table of Contents As filed with the Securities and Exchange Commission on February 7, 2024 Registration No.

February 7, 2024 EX-21.1

Subsidiaries of the Registrant.

Exhibit 21.1 SUBSIDIARIES Legal Name State of Organization Magenta Securities Corporation Massachusetts Dianthus Therapeutics OpCo, Inc. Delaware

February 7, 2024 CORRESP

Abu Dhabi • Beijing • Brussels • Century City • Dallas • Denver • Dubai • Frankfurt • Hong Kong • Houston • London • Los Angeles Munich • New York • Orange County • Palo Alto • Paris • San Francisco • Singapore • Washington, D.C.

Gibson, Dunn & Crutcher LLP One Embarcadero, Suite 2600 San Francisco, CA 94111-3715 Tel 415.

February 2, 2024 SC 13G

DNTH / Dianthus Therapeutics, Inc. / BCLS Fund III Investments, LP - SC 13G Passive Investment

SC 13G 1 d649448dsc13g.htm SC 13G UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 SCHEDULE 13G (Rule 13d-102) Information to be Included in Statements Filed Pursuant to § 240.13d-1(b), (c) and (d) and Amendments Thereto Filed Pursuant to § 240.13d-2 Under the Securities Exchange Act of 1934 (Amendment No.  ) DIANTHUS THERAPEUTICS, INC. (Name of Issuer) Common Stock, $0.001 pa

February 2, 2024 SC 13G

DNTH / Dianthus Therapeutics, Inc. / RA CAPITAL MANAGEMENT, L.P. - SC 13G Passive Investment

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. )* DIANTHUS THERAPEUTICS, INC. (Name of Issuer) Common Stock, $0.001 Par Value (Title of Class of Securities) 252828108 (CUSIP Number) January 22, 2024 (Date of Event Which Requires Filing of this Statement) Check the appropriate box to designate the rule pu

January 31, 2024 SC 13D

DNTH / Dianthus Therapeutics, Inc. / Avidity Partners Management LP Activist Investment

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D Under the Securities Exchange Act of 1934 Dianthus Therapeutics, Inc. (Name of Issuer) Dee Raibourn, Esq. c/o Avidity Partners Management LP 2828 N Harwood Street, Suite 1220 Dallas, Texas 75201 United State of America 214-550-1934 (Name, Address and Telephone Number of Person Authorized to Receive Notice and Comm

January 24, 2024 SC 13D/A

DNTH / Dianthus Therapeutics, Inc. / Fairmount Funds Management LLC - SC 13D/A Activist Investment

SC 13D/A 1 d922138dsc13da.htm SC 13D/A UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D Under the Securities Exchange Act of 1934 (Amendment No. 1) DIANTHUS THERAPEUTICS, INC. (Name of Issuer) Common Stock, $0.001 par value (Title of Class of Securities) 252828 108 (CUSIP Number) Ms. Erin O’Connor Fairmount Funds Management LLC 200 Barr Harbor Drive, Suite 400 W

January 22, 2024 EX-10.1

Securities Purchase Agreement, dated as of January 22, 2024, by and between the Company and each purchaser identified in Annex A thereto (incorporated by reference to Exhibit 10.1 to the Registrant’s Current Report on Form 8-K filed with the SEC on January 22, 2024).

EX-10.1 Exhibit 10.1 SECURITIES PURCHASE AGREEMENT This SECURITIES PURCHASE AGREEMENT (this “Agreement”) is dated as of January 22, 2024, by and among DIANTHUS THERAPEUTICS, INC., a Delaware corporation (the “Company”), and each purchaser identified on Annex A hereto (each, including its successors and assigns, a “Purchaser” and collectively, the “Purchasers”). RECITALS A. The Company and each Pur

January 22, 2024 EX-4.1

Form of Pre-Funded Warrant of Dianthus Therapeutics, Inc. (incorporated by reference to Exhibit 4.1 to the Registrant’s Current Report on Form 8-K filed with the SEC on January 22, 2024).

Exhibit 4.1 THE OFFER AND SALE OF THESE SECURITIES AND THE SECURITIES ISSUABLE UPON EXERCISE OF THESE SECURITIES HAVE NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE “SECURITIES ACT”), OR ANY APPLICABLE STATE SECURITIES LAWS. THE SECURITIES MAY NOT BE OFFERED FOR SALE, SOLD, TRANSFERRED, ASSIGNED OR OTHERWISE DISPOSED OF (I) IN THE ABSENCE OF (A) AN EFFECTIVE REGISTRATION STA

January 22, 2024 EX-99.1

www.dianthustx.com 7 Times Square, Floor 43 New York, NY 10036

Exhibit 99.1 Dianthus Therapeutics Announces $230 Million Private Placement NEW YORK and WALTHAM, Mass., January 22, 2024 – Dianthus Therapeutics, Inc. (“Dianthus” or the “Company”) (NASDAQ: DNTH), a clinical-stage biotechnology company dedicated to advancing the next generation of antibody complement therapeutics to treat severe autoimmune diseases, today announced that it has entered into a secu

January 22, 2024 8-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): January 22, 2024 DIANTHUS THERAPE

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): January 22, 2024 DIANTHUS THERAPEUTICS, INC. (Exact name of Registrant as Specified in Its Charter) Delaware 001-38541 81-0724163 (State or Other Jurisdiction of Incorporation) (Commi

January 22, 2024 EX-10.2

Registration Rights Agreement, dated January 22, 2024, by and among Dianthus Therapeutics, Inc. and certain parties thereto (incorporated by reference to Exhibit 10.2 to the Registrant’s Current Report on Form 8-K filed with the SEC on January 22, 2024).

Exhibit 10.2 REGISTRATION RIGHTS AGREEMENT This Registration Rights Agreement (this “Agreement”) is dated as of January 22, 2024, by and among Dianthus Therapeutics, Inc., a Delaware corporation (the “Company”), and the several purchasers signatory hereto (each, including its successors and assigns, a “Purchaser” and collectively, the “Purchasers”). This Agreement is made pursuant to the Securitie

January 8, 2024 8-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): January 8, 2024 DIANTHUS THERAPEUTICS, INC. (Exact name of Registrant as Specified in Its Charter) Delaware 001-38541 81-0724163 (State or Other Jurisdiction of Incorporation) (Commis

January 8, 2024 EX-99.1

Lead program, DNTH103, is a potent investigational monoclonal antibody that targets the classical complement pathway by selectively inhibiting active C1s protein Top-line Ph. 1 data confirm a ~60-day half-life, potent classical pathway inhibition, an

Corporate Presentation January 2024 Exhibit 99.1 FORWARD-LOOKING STATEMENTS Certain statements in this presentation (“Presentation”), other than purely historical information, may constitute “forward-looking statements” within the meaning of the federal securities laws, including for purposes of the safe harbor provisions under the United Stated Private Securities Litigation Reform Act of 1995, co

December 21, 2023 S-1/A

As filed with the Securities and Exchange Commission on December 21, 2023 Registration No. 333-274863 UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20459 PRE-EFFECTIVE AMENDMENT No. 1 TO FORM S-3 ON FORM S-1 REGISTRATION STATEMENT

Table of Contents As filed with the Securities and Exchange Commission on December 21, 2023 Registration No.

December 21, 2023 EX-21.1

Subsidiaries of the Registrant.

Exhibit 21.1 SUBSIDIARIES Legal Name State of Organization Magenta Securities Corporation Massachusetts Dianthus Therapeutics OpCo, Inc. Delaware

December 21, 2023 EX-99.1

INDEX TO FI NAN CIAL STATEMENTS

Exhibit 99.1 INDEX TO FI NAN CIAL STATEMENTS In connection with the closing of the Merger (as defined below in Note 1) Dianthus Therapeutics, Inc. changed its name to Dianthus Therapeutics OpCo, Inc. on September 11, 2023. For the purposes of these Financial Statements, Dianthus Therapeutics, Inc. is referring to the company prior to the Merger. DIANTHUS THERAPEUTICS, INC. Page(s) Years ended Dece

December 21, 2023 EX-FILING FEES

Filing Fee Table.

Exhibit 107 Calculation of Filing Fee Tables FORM S-1 (Form Type) Dianthus Therapeutics, Inc.

December 21, 2023 8-K

Financial Statements and Exhibits, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): December 21, 2023 DIANTHUS THERAPEUTICS, INC. (Exact name of Registrant as Specified in Its Charter) Delaware 001-38541 81-0724163 (State or Other Jurisdiction of Incorporation) (Comm

November 9, 2023 EX-99.1

Dianthus Therapeutics Highlights Recent Business Achievements and Third Quarter 2023 Financial Results Began trading on Nasdaq under the ticker symbol DNTH following the successful completion of our merger with Magenta Therapeutics Completed concurre

Exhibit 99.1 Dianthus Therapeutics Highlights Recent Business Achievements and Third Quarter 2023 Financial Results Began trading on Nasdaq under the ticker symbol DNTH following the successful completion of our merger with Magenta Therapeutics Completed concurrent $72 million financing with a syndicate of leading life-science investors Announced positive top-line Phase 1 data for lead clinical pr

November 9, 2023 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended September 30, 2023 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001-38541 Dianthus Therapeutics, Inc.

November 9, 2023 8-K

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): November 9, 2023 DIANTHUS THERAPEUTICS, INC. (Exact name of Registrant as Specified in Its Charter) Delaware 001-38541 81-0724163 (State or Other Jurisdiction of Incorporation) (Commi

November 9, 2023 EX-10.12

Separation Agreement, dated September 11, 2023, by and between Magenta Therapeutics, Inc. and Stephen Mahoney (incorporated by reference to Exhibit 10.12 to the Company’s Quarterly Report on Form 10-Q filed with the SEC on November 9, 2023).

Exhibit 10.12 September 11, 2023 Stephen Mahoney Dear Steve: The purpose of this letter agreement (“Agreement”) is to confirm the terms of your separation of employment from Magenta Therapeutics, Inc. (“Magenta” or the “Company”)1. The Consideration being offered below is contingent on your agreement to and compliance with the provisions of this Agreement. This Agreement shall be effective on the

October 25, 2023 8-K

Changes in Registrant's Certifying Accountant

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): October 19, 2023 DIANTHUS THERAPEUTICS, INC. (Exact name of Registrant as Specified in Its Charter) Delaware 001-38541 81-0724163 (State or Other Jurisdiction of Incorporation) (Commi

October 4, 2023 S-3

As filed with the Securities and Exchange Commission on October 4, 2023

S-3 Table of Contents As filed with the Securities and Exchange Commission on October 4, 2023 Registration No.

October 4, 2023 EX-FILING FEES

Filing Fee Table

Exhibit 107.1 Calculation of Filing Fee Tables FORM S-8 (Form Type) DIANTHUS THERAPEUTICS, INC. (Exact Name of Registrant as Specified in its Charter) Table 1: Newly Registered Securities Security Type Security Class Title (1) Fee Calculation Rule Amount Registered Proposed Maximum Offering Price Per Unit Maximum Aggregate Offering Price Fee Rate Amount of Registration Fee Equity Common stock, $0.

October 4, 2023 EX-99.2

Form of Stock Option Agreement for Directors under the Amended and Restated Dianthus Therapeutics, Inc. Stock Option and Incentive Plan (incorporated by reference to Exhibit 99.2 to the Company’s Registration Statement on Form S-8 filed with the SEC on October 4, 2023).

Exhibit 99.2 DIRECTOR FORM AMENDED AND RESTATED DIANTHUS THERAPEUTICS, INC. STOCK OPTION AND INCENTIVE PLAN STOCK OPTION AGREEMENT Pursuant to the Amended and Restated Dianthus Therapeutics, Inc. Stock Option and Incentive Plan (the “Plan”), Dianthus Therapeutics, Inc. (the “Company”) hereby grants to the Optionee named below an option (the “Stock Option”) to purchase on or prior to the Expiration

October 4, 2023 S-8

As filed with the Securities and Exchange Commission on October 4, 2023

S-8 As filed with the Securities and Exchange Commission on October 4, 2023 Registration No.

October 4, 2023 EX-FILING FEES

Filing Fee Table

Exhibit 107 Calculation of Filing Fee Tables FORM S-3 (Form Type) Dianthus Therapeutics, Inc.

September 21, 2023 EX-99.4

Dianthus Therapeutics, Inc. Unaudited Interim Condensed Financial Statements

Exhibit 99.4 Dianthus Therapeutics, Inc. Unaudited Interim Condensed Financial Statements INDEX TO UNAUDITED INTERIM CONDENSED FINANCIAL STATEMENTS Unaudited Interim Condensed Financial Statements: Condensed Balance Sheets as of June 30, 2023 and December 31, 2022 1 Condensed Statements of Operations and Comprehensive Loss for the six months ended June 30, 2023 and 2022 2 Condensed Statements of C

September 21, 2023 EX-99.1

RISK FACTORS

Exhibit 99.1 RISK FACTORS Investing in Dianthus Therapeutics, Inc., or Dianthus, securities involves a high degree of risk. You should carefully consider the risk factors set forth below and under “Risk Factors” in Dianthus’ Annual Report on Form 10-K for the year ended December 31, 2022 as updated by subsequent filings under the U.S. Securities Exchange Act of 1934, as amended, or the Exchange Ac

September 21, 2023 SC 13G

DE:3MT / Magenta Therapeutics Inc / Venrock Healthcare Capital Partners III, L.P. - SC 13G Passive Investment

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. )* Dianthus Therapeutics, Inc. (Name of Issuer) Common stock, $0.001 par value per share (Title of Class of Securities) 252828108 (CUSIP Number) September 11, 2023 (Date of Event Which Requires Filing of this Statement) Check the appropriate box to designate

September 21, 2023 EX-99.6

SELECTED HISTORICAL FINANCIAL DATA AND UNAUDITED PRO FORMA CONDENSED COMBINED FINANCIAL INFORMATION

Exhibit 99.6 SELECTED HISTORICAL FINANCIAL DATA AND UNAUDITED PRO FORMA CONDENSED COMBINED FINANCIAL INFORMATION Terms not defined herein shall have the meanings ascribed to them in the Company’s definitive proxy statement/prospectus filed with the U.S. Securities and Exchange Commission (the “SEC”) on August 1, 2023. Selected Historical Consolidated Financial Data of Magenta The following tables

September 21, 2023 EX-99.3

DIANTHUS MANAGEMENT’S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS

Exhibit 99.3 DIANTHUS MANAGEMENT’S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS On September 11, 2023, Dianthus Therapeutics, Inc. (formerly Magenta Therapeutics, Inc.) (the “Company”) completed its business combination with Dianthus Therapeutics OpCo, Inc. (formerly Dianthus Therapeutics, Inc.) (“Dianthus”) in accordance with the terms of the Agreement and Plan of Merg

September 21, 2023 SC 13G

DE:3MT / Magenta Therapeutics Inc / 5AM Partners VII, LLC - SC 13G Passive Investment

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. )* Dianthus Therapeutics, Inc. (Name of Issuer) Common stock, $0.001 par value per share (Title of Class of Securities) 252828108 (CUSIP Number) September 11, 2023 (Date of Event Which Requires Filing of this Statement) Check the appropriate box to designate

September 21, 2023 8-K/A

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Results of Operations and Financial Condition, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K/A (Amendment No. 1) CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): September 11, 2023 DIANTHUS THERAPEUTICS, INC. (Exact name of registrant as specified in its charter) Delaware 001-38541 81-0724163 (State or other jurisdiction of

September 21, 2023 SC 13D

DE:3MT / Magenta Therapeutics Inc / Viridian, LLC - SC 13D Activist Investment

SC 13D UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D Under the Securities Exchange Act of 1934 (Amendment No. ) DIANTHUS THERAPEUTICS, INC. (Name of Issuer) Common Stock, $0.001 par value (Title of Class of Securities) 252828 108 (CUSIP Number) Ryan A. Murr Gibson, Dunn & Crutcher LLP 555 Mission Street, Suite 3000 San Francisco, CA 94105 (415) 393-8373 (Name

September 21, 2023 SC 13D

DE:3MT / Magenta Therapeutics Inc / Fairmount Funds Management LLC - SC 13D Activist Investment

SC 13D UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D Under the Securities Exchange Act of 1934 (Amendment No. ) DIANTHUS THERAPEUTICS, INC. (Name of Issuer) Common Stock, $0.001 par value (Title of Class of Securities) 252828 108 (CUSIP Number) Ms. Erin O’Connor Fairmount Funds Management LLC 200 Barr Harbor Drive, Suite 400 West Conshohocken, PA 19428 (267)

September 21, 2023 EX-99.2

2

Exhibit 99.2 DIANTHUS’ BUSINESS Terms not defined herein shall have the meanings ascribed to them in Dianthus’ definitive proxy statement/prospectus filed with the U.S. Securities and Exchange Commission on August 1, 2023. Overview Dianthus Therapeutics, Inc., or Dianthus, is a clinical-stage biotechnology company focused on developing next-generation complement therapeutics for patients living wi

September 21, 2023 EX-99.5

REPORT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

EXHIBIT 99.5 REPORT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM To the shareholders and the Board of Directors of Dianthus Therapeutics, Inc. Opinion on the Financial Statements We have audited the accompanying balance sheets of Dianthus Therapeutics, Inc. (the “Company”) as of December 31, 2022 and 2021, the related statements of operations and comprehensive loss, changes in convertible pref

September 21, 2023 EX-99.1

JOINT FILING AGREEMENT

EX-99.1 2 d495884dex991.htm EX-99.1 EXHIBIT 99.1 JOINT FILING AGREEMENT In accordance with Rule 13d-1(k) under the Securities Exchange Act of 1934, as amended, the undersigned agree to the joint filing on behalf of each of them of a Statement on Schedule 13D (including any and all amendments thereto) with respect to the Common Stock, $0.001 par value per share, of Dianthus Therapeutics, Inc. and f

September 15, 2023 SC 13D/A

DE:3MT / Magenta Therapeutics Inc / Atlas Venture Fund X, L.P. - SC 13D/A Activist Investment

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D/A Under the Securities Exchange Act of 1934 (Amendment No. 3)* Dianthus Therapeutics, Inc. (Name of Issuer) Common Stock, $0.001 par value per share (Title of Class of Securities) 252828 108 (CUSIP Number) Atlas Venture Attention: Ommer Chohan, Chief Financial Officer 300 Technology Square, 8th Floor Cambridge, MA

September 12, 2023 EX-99.1

Magenta Therapeutics Announces Completion of Merger with Dianthus Therapeutics and Implementation of Reverse Stock Split The combined company will operate as “Dianthus Therapeutics, Inc.” with its common stock traded on Nasdaq under trading symbol “D

Exhibit 99.1 Magenta Therapeutics Announces Completion of Merger with Dianthus Therapeutics and Implementation of Reverse Stock Split The combined company will operate as “Dianthus Therapeutics, Inc.” with its common stock traded on Nasdaq under trading symbol “DNTH” effective Tuesday, September 12, 2023 CAMBRIDGE, Mass., Sep. 11, 2023 (GLOBE NEWSWIRE) — Magenta Therapeutics, Inc. (Nasdaq: MGTA) (

September 12, 2023 EX-10.2

Form of Indemnification Agreements for Directors of the Company (incorporated by reference to Exhibit 10.2 to the Company’s Current Report on Form 8-K filed with the SEC on September 12, 2023).

Exhibit 10.2 DIANTHUS THERAPEUTICS, INC. FORM OF DIRECTOR INDEMNIFICATION AGREEMENT This Indemnification Agreement (“Agreement”) is made as of by and between Dianthus Therapeutics, Inc., a Delaware corporation (the “Company”), and [Director] (“Indemnitee”). RECITALS WHEREAS, the Company desires to attract and retain the services of highly qualified individuals, such as Indemnitee, to serve the Com

September 12, 2023 EX-10.5

Amendment to Offer Letter, dated September 11, 2023, by and between Dianthus Therapeutics OpCo, Inc. and Marino Garcia (incorporated by reference to Exhibit 10.5 to the Company’s Current Report on Form 8-K filed with the SEC on September 12, 2023).

Exhibit 10.5 SEPTEMBER 11, 2023 Marino Garcia Re: Amendment to Offer Letter Dear Marino: By way of this letter, Section 5 of your Offer Letter dated October 31, 2021 (the “Offer Letter”) by and between you and Dianthus Therapeutics OpCo, Inc. (f/k/a Dianthus Therapeutics, Inc.) (the “Company”) is hereby amended to and restated in its entirety to read as follows: “5. Severance Benefits. (a) General

September 12, 2023 EX-14.1

Code of Business Conduct and Ethics of the Company.

Exhibit 14.1 CODE OF BUSINESS CONDUCT AND ETHICS (September 11, 2023) I. INTRODUCTION This Code of Business Conduct and Ethics (this “Code”) provides a general statement of the expectations of Dianthus Therapeutics, Inc. (the “Company”) regarding the ethical standards to which each director, officer and employee should adhere while acting on behalf of the Company. You are expected to read and beco

September 12, 2023 EX-10.4

Amended and Restated Dianthus Therapeutics, Inc. Stock Option and Incentive Plan (incorporated by reference to Exhibit 10.4 to the Company’s Current Report on Form 8-K filed with the SEC on September 12, 2023).

Exhibit 10.4 AMENDED AND RESTATED DIANTHUS THERAPEUTICS, INC. STOCK OPTION AND INCENTIVE PLAN SECTION 1. GENERAL PURPOSE OF THE PLAN; DEFINITIONS The Amended and Restated Dianthus Therapeutics, Inc. Stock Option and Incentive Plan (the “Plan”) was originally adopted as the Magenta Therapeutics, Inc. 2018 Stock Option and Incentive Plan (the “Original Plan”), effective as of June 19, 2018 (the “Ori

September 12, 2023 EX-10.7

Amendment to Offer Letter, dated September 11, 2023, by and between Dianthus Therapeutics OpCo, Inc. and Edward Carr (incorporated by reference to Exhibit 10.7 to the Company’s Current Report on Form 8-K filed with the SEC on September 12, 2023).

Exhibit 10.7 SEPTEMBER 11, 2023 Edward Carr Re: Termination of Severance Letter and Amendment to Offer Letter Dear Ed: By way of this letter, your Severance Letter Agreement dated April 3, 2023 (the “Severance Letter”) by and between you and Dianthus Therapeutics OpCo, Inc. (f/k/a Dianthus Therapeutics, Inc.) (the “Company”) is hereby terminated, and Section 5 of your Offer Letter dated January 20

September 12, 2023 EX-10.3

Form of Indemnification Agreements for Officers of the Company (incorporated by reference to Exhibit 10.3 to the Company’s Current Report on Form 8-K filed with the SEC on September 12, 2023).

Exhibit 10.3 DIANTHUS THERAPEUTICS, INC. FORM OF OFFICER INDEMNIFICATION AGREEMENT This Indemnification Agreement (“Agreement”) is made as of by and between Dianthus Therapeutics, Inc., a Delaware corporation (the “Company”), and [Officer] (“Indemnitee”).1 RECITALS WHEREAS, the Company desires to attract and retain the services of highly qualified individuals, such as Indemnitee, to serve the Comp

September 12, 2023 EX-3.1

Fifth Amended and Restated Certificate of Incorporation (incorporated by reference to Exhibit 3.1 to the Registrant’s Current Report on Form 8-K filed with the SEC on September 12, 2023).

Exhibit 3.1 FIFTH AMENDED AND RESTATED CERTIFICATE OF INCORPORATION OF MAGENTA THERAPEUTICS, INC. Magenta Therapeutics, Inc., a corporation organized and existing under the laws of the State of Delaware (the “Corporation”), hereby certifies as follows: 1. The name of the Corporation is Magenta Therapeutics, Inc. The date of the filing of its original Certificate of Incorporation with the Secretary

September 12, 2023 EX-16.1

Letter from KPMG, LLP, dated September 12, 2023 (incorporated by reference to Exhibit 16.1 to the Company’s Current Report on Form 8-K filed with the SEC on September 12, 2023).

Exhibit 16.1 September 12, 2023 Securities and Exchange Commission Washington, D.C. 20549 Ladies and Gentlemen: We were previously principal accountants for Magenta Therapeutics, Inc. and, under the date of March 23, 2023, we reported on the consolidated financial statements of Magenta Therapeutics, Inc. as of and for the years ended December 31, 2022 and 2021. On September 11, 2023, we were dismi

September 12, 2023 EX-4.1

Form of Pre-Funded Warrant of Dianthus Therapeutics, Inc. (incorporated by reference to Exhibit 4.1 to the Registrant’s Current Report on Form 8-K filed with the SEC on September 12, 2023).

Exhibit 4.1 THE OFFER AND SALE OF THESE SECURITIES AND THE SECURITIES ISSUABLE UPON EXERCISE OF THESE SECURITIES HAVE NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE “SECURITIES ACT”), OR ANY APPLICABLE STATE SECURITIES LAWS. THE SECURITIES MAY NOT BE OFFERED FOR SALE, SOLD, TRANSFERRED, ASSIGNED OR OTHERWISE DISPOSED OF (I) IN THE ABSENCE OF (A) AN EFFECTIVE REGISTRATION STA

September 12, 2023 EX-10.6

Amendment to Offer Letter, dated September 11, 2023, by and between Dianthus Therapeutics OpCo, Inc. and Ryan Savitz (incorporated by reference to Exhibit 10.6 to the Company’s Current Report on Form 8-K filed with the SEC on September 12, 2023).

Exhibit 10.6 SEPTEMBER 11, 2023 Ryan Savitz Re: Amendment to Offer Letter Dear Ryan: By way of this letter, Section 5 of your Offer Letter dated January 18, 2022 (the “Offer Letter”) by and between you and Dianthus Therapeutics OpCo, Inc. (f/k/a Dianthus Therapeutics, Inc.) (the “Company”) is hereby amended to and restated in its entirety to read as follows: “5. Severance Benefits. (a) General. If

September 12, 2023 EX-10.1

Contingent Value Rights Agreement, dated September 11, 2023, by and between Dianthus Therapeutics, Inc. and the Rights Agent (incorporated by reference to Exhibit 10.1 to the Company’s Current Report on Form 8-K filed with the SEC on September 12, 2023).

Exhibit 10.1 CONTINGENT VALUE RIGHTS AGREEMENT THIS CONTINGENT VALUE RIGHTS AGREEMENT (this “Agreement”), dated as of September 11, 2023, is entered into by and among Magenta Therapeutics, Inc., a Delaware corporation (the “Company”) and Computershare Inc., a Delaware corporation (“Computershare”), and its affiliate, Computershare Trust Company, N.A., a federally chartered trust company (collectiv

September 12, 2023 8-K

Regulation FD Disclosure, Changes in Control of Registrant, Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Amendments to Articles of Incorporation or Bylaws; Change in Fiscal Year, Amendment to Registrant's Code of Ethics, or Waiver of a Provision of the Code of Ethics, Entry into a Material Definitive Agreement, Material Modification to Rights of Security Holders, Unregistered Sales of Equity Securities, Financial Statements and Exhibits, Changes in Registrant's Certifying Accountant, Completion of Acquisition or Disposition of Assets, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): September 11, 2023 DIANTHUS THERAPEUTICS, INC. (Exact name of registrant as specified in its charter) Delaware 001-38541 81-0724163 (State or other jurisdiction of incorporation) (Com

September 12, 2023 EX-4.2

Registration Rights Agreement, dated September 11, 2023, by and among Dianthus Therapeutics, Inc., Dianthus Therapeutics OpCo, Inc. and certain parties thereto (incorporated by reference to Exhibit 4.2 to the Company’s Current Report on Form 8-K filed with the SEC on September 12, 2023).

Exhibit 4.2 REGISTRATION RIGHTS AGREEMENT This Registration Rights Agreement (this “Agreement”) is made and entered into as of September 11, 2023, among Dianthus Therapeutics, Inc., a Delaware corporation, Magenta Therapeutics, Inc. (“Magenta”), a Delaware corporation, and each of the several purchasers signatory hereto (each such purchaser, a “Purchaser” and, collectively, the “Purchasers”). WHER

September 8, 2023 8-K

Other Events, Submission of Matters to a Vote of Security Holders

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): September 8, 2023 MAGENTA THERAPEUTICS, INC. (Exact name of registrant as specified in its charter) Delaware 001-38541 81-0724163 (State or other jurisdiction of incorporation) (Commi

August 31, 2023 425

Filed by Magenta Therapeutics, Inc. Pursuant to Rule 425 under the Securities Act of 1933, as amended, and deemed filed pursuant to Rule 14a-12 of the Securities Exchange Act of 1934, as amended Subject Company: Magenta Therapeutics, Inc. (Commission

425 Filed by Magenta Therapeutics, Inc. Pursuant to Rule 425 under the Securities Act of 1933, as amended, and deemed filed pursuant to Rule 14a-12 of the Securities Exchange Act of 1934, as amended Subject Company: Magenta Therapeutics, Inc. (Commission File No. 333-271917) Corporate Presentation August 2023 DISCLAIMER Forward Looking Statements Certain statements in this presentation (“Presentat

August 3, 2023 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2023 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001-38541 Mag

August 1, 2023 424B3

PROPOSED MERGER YOUR VOTE IS VERY IMPORTANT

Table of Contents Filed Pursuant to Rule 424(b)(3) Registration No. 333-271917 PROPOSED MERGER YOUR VOTE IS VERY IMPORTANT To the Stockholders of Magenta Therapeutics, Inc. and Dianthus Therapeutics, Inc., Magenta Therapeutics, Inc., a Delaware corporation (“Magenta”), and Dianthus Therapeutics, Inc., a Delaware corporation (“Dianthus”), entered into an Agreement and Plan of Merger (the “Merger Ag

July 31, 2023 EX-99.10

Consent of Houlihan Lokey Capital, Inc.

EX-99.10 Exhibit 99.10 CONSENT OF HOULIHAN LOKEY CAPITAL, INC. July 31, 2023 Magenta Therapeutics, Inc. 100 Technology Square 5th Floor Cambridge, MA 02139 Attn: Board of Directors RE: Proxy Statement / Prospectus of Magenta Therapeutics, Inc. (“Magenta”), which forms part of Amendment No. 3 to the Registration Statement on Form S-4 of Magenta (the “Registration Statement”). Dear Members of the Bo

July 31, 2023 S-4/A

As filed with the Securities and Exchange Commission on July 31, 2023 No. 333-271917 UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 AMENDMENT NO. 3 to FORM S-4 REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933 MAGENTA T

Table of Contents As filed with the Securities and Exchange Commission on July 31, 2023 No.

July 31, 2023 CORRESP

Magenta Therapeutics, Inc. 300 Technology Square, 8th Floor Cambridge, MA 02139

Magenta Therapeutics, Inc. 300 Technology Square, 8th Floor Cambridge, MA 02139 July 31, 2023 VIA EDGAR Office of Life Sciences Division of Corporation Finance U.S. Securities and Exchange Commission 100 F Street NE Washington, DC 20549 Attention: Ms. Doris Stacey Gama Mr. Jason Drory Ms. Jenn Do Mr. Kevin Vaughn Re: Magenta Therapeutics, Inc. Acceleration Request for Registration Statement on For

July 31, 2023 EX-99.1

Form of Magenta Therapeutics, Inc. proxy card.

EX-99.1 Exhibit 99.1 Exhibit 99.1 [Graphic Appears Here] YOUR VOTE IS IMPORTANT! PLEASE VOTE BY: INTERNET Go • To: www.proxypush.com/MGTA • Cast your vote online • Have your Proxy Card ready Follow the simple instructions to record your vote PHONE Call 1-866-230-6343 • • Use any touch-tone telephone • Have your Proxy Card ready Follow the simple recorded instructions MAIL • • Mark, sign and date y

July 17, 2023 EX-10.25

Cell Line License Agreement, dated as of March 22, 2021, by and between Dianthus Therapeutics, Inc. and WuXi Biologics (Hong Kong) Limited (incorporated by reference to Exhibit 10.25 to Amendment No. 2 to the Registrant’s Registration Statement on Form S-4 filed with the SEC on July 17, 2023).

EX-10.25 Exhibit 10.25 [***] = CERTAIN CONFIDENTIAL INFORMATION CONTAINED IN THIS DOCUMENT, MARKED BY BRACKETS, HAS BEEN OMITTED BECAUSE THE INFORMATION (I) IS NOT MATERIAL AND (II) WOULD BE COMPETITIVELY HARMFUL IF PUBLICLY DISCLOSED. CELL LINE LICENSE AGREEMENT This Cell Line License Agreement (“Agreement”), effective as of March 22, 2021 (“EFFECTIVE DATE”), is entered and made by and between Wu

July 17, 2023 S-4/A

As filed with the Securities and Exchange Commission on July 17, 2023 No. 333-271917 UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 AMENDMENT NO. 2 to FORM S-4 REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933 MAGENTA T

Table of Contents As filed with the Securities and Exchange Commission on July 17, 2023 No.

July 17, 2023 EX-99.1

Form of Magenta Therapeutics, Inc. proxy card.

EX-99.1 PRELIMINARY COPY, SUBJECT TO COMPLETION P.O. BOX 8016, CARY, NC 27512-9903 Exhibit 99.1 YOUR VOTE IS IMPORTANT! PLEASE VOTE BY: INTERNET Go To: www.proxypush.com/MGTA • Cast your vote online • Have your Proxy Card ready • Follow the simple instructions to record your vote PHONE Call 1-866-230-6343 • Use any touch-tone telephone • Have your Proxy Card ready • Follow the simple recorded inst

July 17, 2023 EX-4.6

Amended and Restated Investors’ Rights Agreement, dated April 6, 2022, by and among Dianthus Therapeutics, Inc. and certain parties thereto.

EX-4.6 Exhibit 4.6 AMENDED AND RESTATED INVESTORS’ RIGHTS AGREEMENT TABLE OF CONTENTS Page 1.   Definitions 1 2.   Registration Rights 5 2.1  Demand Registration 5 2.2  Company Registration 7 2.3  Underwriting Requirements 7 2.4  Obligations of the Company 9 2.5  Furnish Information 10 2.6  Expenses of Registration 10 2.7  Delay of Registration 11 2.8  Indemnification 11 2.9  Reports Under Exchang

July 17, 2023 EX-10.24

Biologics Master Services Agreement, dated as of March 22, 2021, by and between Dianthus Therapeutics, Inc. and WuXi Biologics (Hong Kong) Limited (incorporated by reference to Exhibit 10.24 to Amendment No. 2 to the Registrant’s Registration Statement on Form S-4 filed with the SEC on July 17, 2023).

EX-10.24 Exhibit 10.24 [***] = CERTAIN CONFIDENTIAL INFORMATION CONTAINED IN THIS DOCUMENT, MARKED BY BRACKETS, HAS BEEN OMITTED BECAUSE THE INFORMATION (I) IS NOT MATERIAL AND (II) WOULD BE COMPETITIVELY HARMFUL IF PUBLICLY DISCLOSED. BIOLOGICS MASTER SERVICES AGREEMENT This Biologics Master Services Agreement (this “Agreement”) is dated as of March 22, 2021 (the “Effective Date”) and is between

July 17, 2023 CORRESP

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Goodwin Procter LLP Three Embarcadero Center, 28th Floor San Francisco, CA 94111 goodwinlaw.

July 17, 2023 EX-10.20

Subscription Agreement, dated May 2, 2023, by and among Dianthus Therapeutics, Inc., Magenta Therapeutics, Inc., Dio Merger Sub, Inc. and certain parties thereto.

EX-10.20 Exhibit 10.20 SUBSCRIPTION AGREEMENT This Subscription Agreement (this “Agreement”) is made and entered into as of May 2, 2023 (the “Effective Date”) by and among Dianthus Therapeutics, Inc., a Delaware corporation (the “Company”), and each of the purchasers listed on the signature pages hereto, severally and not jointly (each a “Purchaser” and together the “Purchasers”). Certain terms us

July 17, 2023 EX-99.10

Consent of Houlihan Lokey Capital, Inc.

EX-99.10 Exhibit 99.10 CONSENT OF HOULIHAN LOKEY CAPITAL, INC. July 17, 2023 Magenta Therapeutics, Inc. 100 Technology Square 5th Floor Cambridge, MA 02139 Attn: Board of Directors RE: Proxy Statement / Prospectus of Magenta Therapeutics, Inc. (“Magenta”), which forms part of Amendment No. 2 to the Registration Statement on Form S-4 of Magenta (the “Registration Statement”). Dear Members of the Bo

June 22, 2023 EX-10.18

Form of Nonstatutory Stock Option Agreement under the Dianthus Therapeutics, Inc. 2019 Stock Plan (incorporated by reference to Exhibit 10.18 to Amendment No. 1 to the Company’s Registration Statement on Form S-4 filed with the SEC on June 22, 2023).

Exhibit 10.18 DIANTHUS THERAPEUTICS, INC. NONSTATUTORY STOCK OPTION AGREEMENT Granted Under 2019 Stock Plan 1. Grant of Option. This agreement evidences the grant by Dianthus Therapeutics, Inc., a Delaware corporation (the “Company”) on the “Grant date” (as set forth in the Carta Electronic Notice that is delivered electronically concurrent with this agreement (the “Carta Notice”)) to the individu

June 22, 2023 EX-10.19

Form of Incentive Stock Option Agreement under the Dianthus Therapeutics, Inc. 2019 Stock Plan (incorporated by reference to Exhibit 10.19 to Amendment No. 1 to the Company’s Registration Statement on Form S-4 filed with the SEC on June 22, 2023).

Exhibit 10.19 DIANTHUS THERAPEUTICS, INC. INCENTIVE STOCK OPTION AGREEMENT Granted Under 2019 Stock Plan 1. Grant of Option. This agreement evidences the grant by Dianthus Therapeutics, Inc., a Delaware corporation (the “Company”) on the “Grant date” (as set forth in the Carta Electronic Notice that is delivered electronically concurrent with this agreement (the “Carta Notice”)) to the individual

June 22, 2023 EX-10.15

Offer Letter, dated January 18, 2022, by and between Dianthus Therapeutics, Inc. and Ryan Savitz (incorporated by reference to Exhibit 10.15 to Amendment No. 1 to the Registrant’s Registration Statement on Form S-4 filed with the SEC on June 22, 2023).

EX-10.15 Exhibit 10.15 DIANTHUS THERAPEUTICS, INC. 203 Crescent Street, Bldg. #4, Suite #205 Waltham, MA 02453 JANUARY 18, 2022 Ryan Savitz Dear Ryan: Dianthus Therapeutics, Inc. (the “Company”) is pleased to offer you employment on the following terms contingent upon the closing of the Company’s Series A financing pursuant to which the Company raises not less than $80 million (the “Closing”): 1.

June 22, 2023 EX-10.16

Director Compensation Letter, dated May 6, 2022, by and between Dianthus Therapeutics, Inc. and Paula Soteropoulos (incorporated by reference to Exhibit 10.16 to Amendment No. 1 to the Registrant’s Registration Statement on Form S-4 filed with the SEC on June 22, 2023).

EX-10.16 Exhibit 10.16 DIANTHUS THERAPEUTICS, INC. May 6, 2022 Paula Soteropoulos Dear Paula: Dianthus Therapeutics, Inc. (the “Company”) is excited that you have recently joined us as a member of the Company’s Board of Directors (the “Board”). The following is some information on the terms of your Board membership. Subject to the approval of the Company’s Board or its Compensation Committee, you

June 22, 2023 EX-99.10

Consent of Houlihan Lokey Capital, Inc.

EX-99.10 Exhibit 99.10 CONSENT OF HOULIHAN LOKEY CAPITAL, INC. June 22, 2023 Magenta Therapeutics, Inc. 100 Technology Square 5th Floor Cambridge, MA 02139 Attn: Board of Directors RE: Proxy Statement / Prospectus of Magenta Therapeutics, Inc. (“Magenta”), which forms part of Amendment No. 1 to the Registration Statement on Form S-4 of Magenta (the “Registration Statement”). Dear Members of the Bo

June 22, 2023 EX-10.14

Offer Letter, as amended, dated March 11, 2022, by and between Dianthus Therapeutics, Inc. and Simrat Randhawa (incorporated by reference to Exhibit 10.14 to Amendment No. 1 to the Registrant’s Registration Statement on Form S-4 filed with the SEC on June 22, 2023).

EX-10.14 Exhibit 10.14 DIANTHUS THERAPEUTICS, INC. 203 Crescent Street, Bldg. #4, Suite #205 Waltham, MA 02453 JANUARY 17, 2022 Simrat Randhawa, MD, MBA Dear Simrat: Dianthus Therapeutics, Inc. (the “Company”) is pleased to offer you employment on the following terms contingent upon the closing of the Company’s Series A financing pursuant to which the Company raises not less than $100 million (the

June 22, 2023 S-4/A

As filed with the Securities and Exchange Commission on June 2 2 , 2023 No. 333-271917 UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 AMENDMENT NO. 1 to FORM S-4 REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933 MAGENTA

Table of Contents As filed with the Securities and Exchange Commission on June 2 2 , 2023 No.

June 22, 2023 EX-10.13

Employment Agreement, dated October 23, 2021, by and between Dianthus Therapeutics, Inc. and Marino Garcia (incorporated by reference to Exhibit 10.13 to Amendment No. 1 to the Registrant’s Registration Statement on Form S-4 filed with the SEC on June 22, 2023).

EX-10.13 Exhibit 10.13 DIANTHUS THERAPEUTICS, INC. 203 Crescent Street, Bldg. #4, Suite #205 Waltham, MA 02453 OCTOBER 23, 2021 Marino Garcia Dear Marino: Dianthus Therapeutics, Inc. (the “Company”) is pleased to offer you employment on the following terms: 1. Position. Your employment will be effective as of November 4, 2021. Your initial title will be President and Chief Executive Officer, and y

June 22, 2023 CORRESP

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Goodwin Procter LLP Three Embarcadero Center, 28th Floor San Francisco, CA 94111 goodwinlaw.

June 22, 2023 EX-10.17

Dianthus Therapeutics, Inc. 2019 Stock Plan (incorporated by reference to Exhibit 10.17 to Amendment No. 1 to the Company’s Registration Statement on Form S-4 filed with the SEC on June 22, 2023).

EX-10.17 Exhibit 10.17 DIANTHUS THERAPEUTICS, INC. 2019 STOCK PLAN 1. Purpose. The purpose of this 2019 Stock Plan (the “Plan”) of Dianthus Therapeutics, Inc., a Delaware corporation (the “Company”), is to advance the interests of the Company’s stockholders by enhancing the Company’s ability to attract, retain and motivate persons who are expected to make important contributions to the Company and

May 19, 2023 8-K

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 15, 2023 MAGENTA THERAPEUTICS, INC. (Exact name of registrant as specified in its charter) Delaware 001-38541 81-0724163 (State or other jurisdiction of incorporation) (Commission

May 19, 2023 425

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 15, 2023 MAGENTA THERAPEUTICS

425 UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 15, 2023 MAGENTA THERAPEUTICS, INC. (Exact name of registrant as specified in its charter) Delaware 001-38541 81-0724163 (State or other jurisdiction of incorporation) (Commis

May 15, 2023 EX-21.2

List of Subsidiaries of Magenta Therapeutics, Inc. (previously filed as Exhibit 21.2 to the Registration Statement on Form S-4 of Magenta Therapeutics, Inc. filed with the Securities and Exchange Commission on May 15, 2023).

EX-21.2 Exhibit 21.2 SUBSIDIARIES Legal Name State of Organization Magenta Securities Corporation Massachusetts Dio Merger Sub, Inc. Delaware

May 15, 2023 EX-99.4

Consent of Marino Garcia to serve as a director of Magenta Therapeutics, Inc., to be renamed Dianthus Therapeutics, Inc.

EX-99.4 Exhibit 99.4 Consent to be Named as a Director In connection with the filing by Magenta Therapeutics, Inc. (the “Company”) of the Registration Statement on Form S-4 with the Securities and Exchange Commission under the Securities Act of 1933, as amended (the “Securities Act”), I hereby consent, pursuant to Rule 438 of the Securities Act, to being named in the Registration Statement and any

May 15, 2023 EX-3.1

Amended and Restated Certificate of Incorporation of Dianthus Therapeutics, Inc., as currently in effect.

EX-3.1 Exhibit 3.1 AMENDED AND RESTATED CERTIFICATE OF INCORPORATION OF DIANTHUS THERAPEUTICS, INC. (Pursuant to Sections 242 and 245 of the General Corporation Law of the State of Delaware) Dianthus Therapeutics, Inc., a corporation organized and existing under and by virtue of the provisions of the General Corporation Law of the State of Delaware (the “General Corporation Law”), DOES HEREBY CERT

May 15, 2023 EX-99.5

Consent of Leon O. Moulder, Jr. to serve as a director of Magenta Therapeutics, Inc., to be renamed Dianthus Therapeutics, Inc.

EX-99.5 Exhibit 99.5 Consent to be Named as a Director In connection with the filing by Magenta Therapeutics, Inc. (the “Company”) of the Registration Statement on Form S-4 with the Securities and Exchange Commission under the Securities Act of 1933, as amended (the “Securities Act”), I hereby consent, pursuant to Rule 438 of the Securities Act, to being named in the Registration Statement and any

May 15, 2023 EX-3.2

Certificate of Amendment of Amended and Restated Certificate of Incorporation of Dianthus Therapeutics, Inc., as currently in effect.

EX-3.2 Exhibit 3.2 CERTIFICATE OF AMENDMENT OF AMENDED AND RESTATED CERTIFICATE OF INCORPORATION OF DIANTHUS THERAPEUTICS, INC. Dianthus Therapeutics, Inc., a corporation organized and existing under and by virtue of the provisions of the General Corporation Law of the State of Delaware (the “General Corporation Law”), DOES HEREBY CERTIFY: FIRST: That the name of this Corporation is Dianthus Thera

May 15, 2023 EX-99.7

Consent of Lei Meng to serve as a director of Magenta Therapeutics, Inc., to be renamed Dianthus Therapeutics, Inc.

Exhibit 99.7 Consent to be Named as a Director In connection with the filing by Magenta Therapeutics, Inc. (the “Company”) of the Registration Statement on Form S-4 with the Securities and Exchange Commission under the Securities Act of 1933, as amended (the “Securities Act”), I hereby consent, pursuant to Rule 438 of the Securities Act, to being named in the Registration Statement and any and all

May 15, 2023 EX-FILING FEES

Filing fee table.

EX-FILING FEES Exhibit 107 Calculation of Filing Fee Tables Form S-4 (Form Type) MAGENTA THERAPEUTICS, INC.

May 15, 2023 EX-99.9

Consent of Jonathan Violin to serve as a director of Magenta Therapeutics, Inc., to be renamed Dianthus Therapeutics, Inc.

EX-99.9 Exhibit 99.9 Consent to be Named as a Director In connection with the filing by Magenta Therapeutics, Inc. (the “Company”) of the Registration Statement on Form S-4 with the Securities and Exchange Commission under the Securities Act of 1933, as amended (the “Securities Act”), I hereby consent, pursuant to Rule 438 of the Securities Act, to being named in the Registration Statement and any

May 15, 2023 EX-99.10

Consent of Houlihan Lokey Capital, Inc.

EX-99.10 Exhibit 99.10 CONSENT OF HOULIHAN LOKEY CAPITAL, INC. May 15, 2023 Magenta Therapeutics, Inc. 100 Technology Square 5th Floor Cambridge, MA 02139 Attn: Board of Directors RE: Proxy Statement / Prospectus of Magenta Therapeutics, Inc. (“Magenta”), which forms part of the Registration Statement on Form S-4 of Magenta (the “Registration Statement”). Dear Members of the Board: Reference is ma

May 15, 2023 EX-99.6

Consent of Tomas Kiselak to serve as a director of Magenta Therapeutics, Inc., to be renamed Dianthus Therapeutics, Inc.

EX-99.6 Exhibit 99.6 Consent to be Named as a Director In connection with the filing by Magenta Therapeutics, Inc. (the “Company”) of the Registration Statement on Form S-4 with the Securities and Exchange Commission under the Securities Act of 1933, as amended (the “Securities Act”), I hereby consent, pursuant to Rule 438 of the Securities Act, to being named in the Registration Statement and any

May 15, 2023 EX-3.3

Bylaws of Dianthus Therapeutics, Inc., as currently in effect.

EX-3.3 Exhibit 3.3 BY-LAWS OF DIANTHUS THERAPEUTICS, INC. TABLE OF CONTENTS Page ARTICLE I STOCKHOLDERS 1 1.1 Place of Meetings 1 1.2 Annual Meeting 1 1.3 Special Meetings 1 1.4 Notice of Meetings 1 1.5 Voting List 1 1.6 Quorum 2 1.7 Adjournments 2 1.8 Voting and Proxies 2 1.9 Action at Meeting 2 1.10 Conduct of Meetings 3 1.11 Action without Meeting 3 ARTICLE II DIRECTORS 4 2.1 General Powers 4 2

May 15, 2023 EX-10.7

Sublease Termination and Release Agreement by and between the Registrant and Novartis Institutes for Biomedical Research, Inc., dated as of March 31, 2023.

EX-10.7 Exhibit 10.7 SUBLEASE TERMINATION AND RELEASE AGREEMENT This Sublease Termination and Release Agreement (“Agreement”) is entered into as of March 31, 2023, by and between NOVARTIS INSTITUTES FOR BIOMEDICAL RESEARCH, INC., a Delaware corporation, having an address at 100 Technology Square, Cambridge, Massachusetts 02139 (“Novartis”), and MAGENTA THERAPEUTICS, INC., a Delaware corporation, h

May 15, 2023 EX-99.8

Consent of Paula Soteropoulos to serve as a director of Magenta Therapeutics, Inc., to be renamed Dianthus Therapeutics, Inc.

EX-99.8 Exhibit 99.8 Consent to be Named as a Director In connection with the filing by Magenta Therapeutics, Inc. (the “Company”) of the Registration Statement on Form S-4 with the Securities and Exchange Commission under the Securities Act of 1933, as amended (the “Securities Act”), I hereby consent, pursuant to Rule 438 of the Securities Act, to being named in the Registration Statement and any

May 15, 2023 S-4

Power of Attorney (included on signature page of Form S-4 (No. 333-271917) filed on May 15, 2023).

Table of Contents As filed with the Securities and Exchange Commission on May 15, 2023 No.

May 15, 2023 SC 13G

MGTA / Magenta Therapeutics Inc / CITADEL ADVISORS LLC - SC 13G Passive Investment

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G* (Rule 13d-102) INFORMATION TO BE INCLUDED IN STATEMENTS FILED PURSUANT TO § 240.13d-1(b), (c), AND (d) AND AMENDMENTS THERETO FILED PURSUANT TO § 240.13d-2 (Amendment No. )* Magenta Therapeutics, Inc. (Name of Issuer) Common Stock, par value $0.001 per share (the “Shares”) (Title of Class of Securities) 55910K108

May 15, 2023 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2023 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001-38541 Ma

May 15, 2023 EX-99.1

JOINT FILING AGREEMENT

EXHIBIT 99.1 JOINT FILING AGREEMENT The undersigned hereby agree that the Statement on Schedule 13G filed herewith (and any amendments thereto), relating to the Shares of Magenta Therapeutics, Inc., a Massachusetts corporation, is being filed jointly with the Securities and Exchange Commission pursuant to Rule 13d-1(c) under the Securities Exchange Act of 1934, as amended, on behalf of each of the

May 3, 2023 425

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 2, 2023 MAGENTA THERAPEUTICS,

425 UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 2, 2023 MAGENTA THERAPEUTICS, INC. (Exact name of registrant as specified in its charter) Delaware 001-38541 81-0724163 (State or other jurisdiction of incorporation) (Commiss

May 3, 2023 EX-99.3

Magenta Therapeutics and Dianthus Therapeutics Merger Agreement Announcement Webcast Call Transcript WEDNESDAY, MAY 3, 2023 8:30am

EX-99.3 Exhibit 99.3 Magenta Therapeutics and Dianthus Therapeutics Merger Agreement Announcement Webcast Call Transcript WEDNESDAY, MAY 3, 2023 8:30am CORPORATE PARTICIPANTS Steve Mahoney, President and Chief Financial and Operating Officer of Magenta Marino Garcia, President and Chief Executive Officer of Dianthus Therapeutics Sim Randhawa, Chief Medical Officer of Dianthus Therapeutics PRESENTA

May 3, 2023 EX-2.1

Agreement and Plan of Merger, dated as of May 2, 2023, by and among Magenta Therapeutics, Inc., Dio Merger Sub, Inc. and Dianthus Therapeutics, Inc. (incorporated by reference to Exhibit 2.1 to the Registrant's Current Report on Form 8-K filed with the SEC on May 3, 2023).

Exhibit 2.1 AGREEMENT AND PLAN OF MERGER among: MAGENTA THERAPEUTICS, INC.; DIO MERGER SUB, INC.; and DIANTHUS THERAPEUTICS, INC. Dated as of May 2, 2023 Table of Contents Section 1. Definitions and Interpretative Provisions 2 1.1 Definitions 2 1.2 Other Definitional and Interpretative Provisions 17 Section 2. Description of Transaction 18 2.1 The Merger 18 2.2 Effects of the Merger 18 2.3 Closing

May 3, 2023 8-A12B

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-A/A (Amendment No. 1) FOR REGISTRATION OF CERTAIN CLASSES OF SECURITIES PURSUANT TO SECTION 12(b) OR 12(g) OF THE SECURITIES EXCHANGE ACT OF 1934 Magenta Therapeutics, Inc

8-A12B UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-A/A (Amendment No. 1) FOR REGISTRATION OF CERTAIN CLASSES OF SECURITIES PURSUANT TO SECTION 12(b) OR 12(g) OF THE SECURITIES EXCHANGE ACT OF 1934 Magenta Therapeutics, Inc. (Exact name of registrant as specified in its charter) Delaware 81-0724163 (State or other jurisdiction of incorporation or organization) (IR

May 3, 2023 EX-10.2

Form of Magenta Therapeutics, Inc. Stockholder Support Agreement. (Incorporated by reference to Exhibit 10.2 to Magenta Therapeutics, Inc.’s Form 8-K filed with the Securities and Exchange Commission on May 3, 2023).

EX-10.2 Exhibit 10.2 FORM OF MAGENTA STOCKHOLDER SUPPORT AGREEMENT This Support Agreement (this “Agreement”) is made and entered into as of May 2, 2023, by and among Dianthus Therapeutics, Inc., a Delaware corporation (the “Company”), Magenta Therapeutics, Inc., a Delaware corporation (“Magenta”), and the undersigned stockholder (the “Stockholder”) of Magenta. Capitalized terms used herein but not

May 3, 2023 EX-4.2

Amendment No. 1 to Stockholder Rights Agreement, dated as of May 2, 2023, by and between Magenta Therapeutics, Inc. and Computershare Trust Company, N.A., as Rights Agent (Incorporated by reference to Exhibit 4.2 to Magenta Therapeutics, Inc.’s Current Report on Form 8-K filed with the Securities and Exchange Commission on May 3, 2023).

EX-4.2 Exhibit 4.2 AMENDMENT NO. 1 TO STOCKHOLDER RIGHTS AGREEMENT This AMENDMENT NO. 1 TO STOCKHOLDER RIGHTS AGREEMENT (this “Amendment”) is dated as of May 2, 2023 (the “Effective Date”), and amends that certain Stockholder Rights Agreement, dated as of March 31, 2023 (the “Rights Agreement”), by and between Magenta Therapeutics, Inc., a Delaware corporation (the “Company”), and Computershare Tr

May 3, 2023 EX-99.2

Agenda | Merger Announcement Introductions & Steve Mahoney, President, Chief Financial and Operating Officer Transaction of Magenta Therapeutics Overview Dianthus Marino Garcia, President and Chief Executive Officer of Dianthus Overview Therapeutics

EX-99.2 Exhibit 99.2 Merger Announcement May 3, 2023 Agenda | Merger Announcement Introductions & Steve Mahoney, President, Chief Financial and Operating Officer Transaction of Magenta Therapeutics Overview Dianthus Marino Garcia, President and Chief Executive Officer of Dianthus Overview Therapeutics DNTH103 Simrat Randhawa, M.D., Chief Medical Officer of Dianthus Overview Therapeutics 2 DISCLAIM

May 3, 2023 8-K

Regulation FD Disclosure, Changes in Control of Registrant, Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Entry into a Material Definitive Agreement, Material Modification to Rights of Security Holders, Unregistered Sales of Equity Securities, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 2, 2023 MAGENTA THERAPEUTICS, INC. (Exact name of registrant as specified in its charter) Delaware 001-38541 81-0724163 (State or other jurisdiction of incorporation) (Commission

May 3, 2023 EX-10.4

Form of Contingent Value Rights Agreement

EX-10.4 Exhibit 10.4 FORM OF CONTINGENT VALUE RIGHTS AGREEMENT THIS CONTINGENT VALUE RIGHTS AGREEMENT (this “Agreement”), dated as of [], 2023, is entered into by and among Magenta Therapeutics, Inc., a Delaware corporation (the “Company”) and Computershare Inc., a Delaware corporation (“Computershare”), and its wholly-owned subsidiary, Computershare Trust Company, N.A., a federally chartered trus

May 3, 2023 EX-10.3

Form of Lock-Up Agreement. (Incorporated by reference to Exhibit 10.3 to Magenta Therapeutics, Inc.’s Form 8-K filed with the Securities and Exchange Commission on May 3, 2023).

EX-10.3 Exhibit 10.3 FORM OF LOCK-UP AGREEMENT May 2, 2023 Magenta Therapeutics, Inc. 300 Technology Square, 8th Floor Cambridge, Massachusetts 02139 Ladies and Gentlemen: The undersigned signatory of this lock-up agreement (this “Lock-Up Agreement”) understands that Magenta Therapeutics, Inc., a Delaware corporation (“Magenta”), has entered into an Agreement and Plan of Merger, dated as of May 2,

May 3, 2023 EX-10.1

Form of Dianthus Therapeutics, Inc. Stockholder Support Agreement. (Incorporated by reference to Exhibit 10.1 to Magenta Therapeutics, Inc.’s Form 8-K filed with the Securities and Exchange Commission on May 3, 2023).

EX-10.1 Exhibit 10.1 FORM OF COMPANY STOCKHOLDER SUPPORT AGREEMENT This Support Agreement (this “Agreement”) is made and entered into as of May 2, 2023, by and among Dianthus Therapeutics, Inc., a Delaware corporation (the “Company”), Magenta Therapeutics, Inc., a Delaware corporation (“Magenta”), and the undersigned stockholder (the “Stockholder”) of the Company. Capitalized terms used herein but

May 3, 2023 EX-99.1

Magenta Therapeutics and Dianthus Therapeutics Announce Merger Agreement Merger to create Nasdaq-listed, clinical-stage biotechnology company focused on advancing Dianthus’ portfolio of next-generation antibody complement therapeutics Combined compan

EX-99.1 Exhibit 99.1 Magenta Therapeutics and Dianthus Therapeutics Announce Merger Agreement Merger to create Nasdaq-listed, clinical-stage biotechnology company focused on advancing Dianthus’ portfolio of next-generation antibody complement therapeutics Combined company is expected to have approximately $180 million of cash or cash equivalents at close, including approximately $70 million from a

May 1, 2023 10-K/A

UNITED S TATES SECURITIES AND EXCHAN G E COMMISSION Washington, D.C. 20549 FORM 10-K/A (Amendment No. 1) (Mark One) ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2022 OR

Table of Contents UNITED S TATES SECURITIES AND EXCHAN G E COMMISSION Washington, D.

April 6, 2023 8-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): March 31, 2023 MAGENTA THERAPEUTI

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): March 31, 2023 MAGENTA THERAPEUTICS, INC. (Exact name of registrant as specified in its charter) Delaware 001-38541 81-0724163 (State or other jurisdiction of incorporation) (Commissi

March 31, 2023 8-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): March 31, 2023 MAGENTA THERAPEUTI

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): March 31, 2023 MAGENTA THERAPEUTICS, INC. (Exact name of registrant as specified in its charter) Delaware 001-38541 81-0724163 (State or other jurisdiction of incorporation) (Commissi

March 31, 2023 EX-99.1

Magenta Therapeutics Adopts Limited Duration Stockholder Rights Plan

EX-99.1 2 d436260dex991.htm EX-99.1 Exhibit 99.1 Magenta Therapeutics Adopts Limited Duration Stockholder Rights Plan Cambridge, MA – March 31, 2023 – Magenta Therapeutics, Inc. (Nasdaq: MGTA) (“Magenta” or the “Company”) today announced that its Board of Directors (the “Board”) has unanimously adopted a limited duration stockholder rights plan (the “Rights Plan”). The Rights Plan will give the Bo

March 31, 2023 EX-4.1

Stockholder Rights Agreement, dated as of March 31, 2023, by and between the Registrant and Computershare Trust Company, N.A., as Rights Agent (Incorporated by reference to Exhibit 4.1 to Magenta Therapeutics, Inc.’s Registration Statement on Form 8-A filed with the Securities and Exchange Commission on March 31, 2023).

EX-4.1 Exhibit 4.1 MAGENTA THERAPEUTICS, INC. AND COMPUTERSHARE TRUST COMPANY, N.A. AS RIGHTS AGENT STOCKHOLDER RIGHTS AGREEMENT DATED AS OF MARCH 31, 2023 Table of Contents Page Section 1. Certain Definitions 1 Section 2. Appointment of Rights Agent 11 Section 3. Issue of Right Certificates 12 Section 4. Form of Right Certificates 14 Section 5. Countersignature and Registration 15 Section 6. Tran

March 31, 2023 8-A12B

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-A FOR REGISTRATION OF CERTAIN CLASSES OF SECURITIES PURSUANT TO SECTION 12(b) OR 12(g) OF THE SECURITIES EXCHANGE ACT OF 1934 MAGENTA THERAPEUTICS, INC. (Exact name of reg

8-A12B UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-A FOR REGISTRATION OF CERTAIN CLASSES OF SECURITIES PURSUANT TO SECTION 12(b) OR 12(g) OF THE SECURITIES EXCHANGE ACT OF 1934 MAGENTA THERAPEUTICS, INC. (Exact name of registrant as specified in its charter) Delaware 81-0724163 (State of incorporation or organization) (I.R.S. Employer Identification No.) 100 Tech

March 31, 2023 EX-3.1

Certificate of Designations of Series A Junior Participating Cumulative Preferred Stock of Magenta Therapeutics, Inc. classifying and designating Series A Junior Participating Cumulative Preferred Stock (Incorporated by reference to Exhibit 3.1 to Magenta Therapeutics, Inc.’s Registration Statement on Form 8-A filed with the Securities and Exchange Commission on March 31, 2023).

EX-3.1 Exhibit 3.1 CERTIFICATE OF DESIGNATIONS of SERIES A JUNIOR PARTICIPATING CUMULATIVE PREFERRED STOCK of MAGENTA THERAPEUTICS, INC. MAGENTA THERAPEUTICS, INC. a corporation organized and existing under the General Corporation Law of the State of Delaware (the “Corporation”), in accordance with the provisions of Section 103 thereof, DOES HEREBY CERTIFY: Pursuant to the authority conferred upon

March 23, 2023 EX-10

Amended and Restated Employment Agreement by and between Magenta Therapeutics, Inc. and Lisa Olson, effective May 2, 2022 (Incorporated by reference to Exhibit 10.11 to Magenta Therapeutics, Inc.’s Annual Report on Form 10-K filed with the Securities and Exchange Commission on March 23, 2023).

EX-10 4 mgta-ex1011.htm EX-10.11 EXHIBIT 10.11 AMENDED AND RESTATED EMPLOYMENT AGREEMENT This Amended and Restated Employment Agreement (“Agreement”) is made by and between Magenta Therapeutics, Inc., a Delaware corporation (the “Company”), and Lisa Olson (the “Executive”) and is effective as of May 2, 2022 (the “Effective Date”). WHEREAS, the Executive is currently serving as the Company’s Chief

March 23, 2023 EX-10

Amended and Restated Employment Agreement by and between Magenta Therapeutics, Inc. and Jeffrey Humphrey, effective May 2, 2022 (Incorporated by reference to Exhibit 10.10 to Magenta Therapeutics, Inc.’s Annual Report on Form 10-K filed with the Securities and Exchange Commission on March 23, 2023).

EXHIBIT 10.10 AMENDED AND RESTATED EMPLOYMENT AGREEMENT This Amended and Restated Employment Agreement (“Agreement”) is made by and between Magenta Therapeutics, Inc., a Delaware corporation (the “Company”), and Jeffrey Humphrey (the “Executive”) and is effective as of May 2, 2022 (the “Effective Date”). WHEREAS, the Executive is currently serving as the Company’s Chief Medical Officer and possess

March 23, 2023 EX-21

List of Subsidiaries of the Registrant.

Exhibit 21.1 SUBSIDIARIES Legal Name State of Organization Magenta Securities Corporation Massachusetts

March 23, 2023 10-K

Power of Attorney (included on signature page to this Annual Report on Form 10-K).

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K (Mark One) ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2022 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to . Commission file number: 001-

March 23, 2023 EX-4

Description of Securities of the Registrant.

Exhibit 4.3 Description of the Registrant’s Securities Registered Pursuant to Section 12 of the Securities Exchange Act of 1934, as amended The common stock, par value $0.001 per share (“Common Stock”), of Magenta Therapeutics, Inc. (“Magenta,” “we,” or “our”) is registered under Section 12 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”). The following description sets fort

February 14, 2023 SC 13G/A

MGTA / Magenta Therapeutics Inc / RA CAPITAL MANAGEMENT, L.P. - SC 13G/A Passive Investment

SC 13G/A 1 tm236221d6sc13ga.htm SC 13G/A UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 SCHEDULE 13G/A Under the Securities Exchange Act of 1934 (Amendment No. 2)* MAGENTA THERAPEUTICS, INC. (Name of Issuer) Common Stock, $0.001 par value per share (Title of Class of Securities) 55910K108 (CUSIP Number) December 31, 2022 (Date of Event Which Requires Filing of this Stateme

February 14, 2023 SC 13G/A

MGTA / Magenta Therapeutics Inc / Deep Track Capital, LP Passive Investment

SC 13G/A 1 deeptrack-mgta123122a2.htm UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 SCHEDULE 13G/A Under the Securities Exchange Act of 1934 (Amendment No. 2)* Magenta Therapeutics, Inc. (Name of Issuer) Common Stock, $0.001 par value (Title of Class of Securities) 55910K108 (CUSIP Number) December 31, 2022 (Date of Event Which Requires Filing of this Statement) Check the a

February 14, 2023 SC 13G/A

MGTA / Magenta Therapeutics Inc / Casdin Capital, LLC Passive Investment

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No.

February 14, 2023 SC 13G/A

MGTA / Magenta Therapeutics Inc / GILDER GAGNON HOWE & CO LLC - SC 13G/A Passive Investment

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G (RULE 13d - 102) INFORMATION TO BE INCLUDED IN STATEMENTS FILED PURSUANT TO 13d-1(b), (c) AND (d) AND AMENDMENTS THERETO FILED PURSUANT TO 13d-2 (Amendment No. 3)* Magenta Therapeutics, Inc. (Name of Issuer) Common Stock, $0.001 par value per share (Title of Class of Securities) 55910K108 (CUSIP Number) December 31, 2022 (Date

February 14, 2023 SC 13G/A

MGTA / Magenta Therapeutics Inc / Aquilo Capital Management, LLC Passive Investment

SC 13G/A 1 MGTA13gv5.htm UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G/A Under the Securities Exchange Act of 1934 (Amendment No. 1)* Magenta Therapeutics, Inc. (Name of Issuer) Common Stock, $0.001 par value (Title of Class of Securities) 55910K108 (CUSIP Number) December 31, 2022 (Date of Event Which Requires Filing of this Statement) Check the appropriate

February 13, 2023 SC 13G

MGTA / Magenta Therapeutics Inc / TANG CAPITAL PARTNERS LP Passive Investment

SC 13G 1 mgta28234sc13g.htm Securities and Exchange Commission Washington, DC 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. )* Magenta Therapeutics, Inc. (Name of Issuer) Common Stock, par value $0.001 per share (Title of Class of Securities) 55910K108 (CUSIP Number) February 3, 2023 (Date of Event Which Requires Filing of This Statement) Check the appropriate box to

February 13, 2023 EX-99.1

JOINT FILING AGREEMENT

EX-99.1 2 ex991.htm EXHIBIT 99.1 Exhibit 99.1 JOINT FILING AGREEMENT In accordance with Rule 13d-1(k)(1) promulgated under the Securities Exchange Act of 1934, the undersigned agree to the joint filing of a Statement on Schedule 13G (including any and all amendments thereto) with respect to the Common Stock, $0.001 par value per share, of Magenta Therapeutics, Inc. and further agree to the filing

February 7, 2023 8-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): February 6, 2023 MAGENTA THERAPEU

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): February 6, 2023 MAGENTA THERAPEUTICS, INC. (Exact name of registrant as specified in its charter) Delaware 001-38541 81-0724163 (State or other jurisdiction of incorporation) (Commis

February 2, 2023 EX-99.1

Magenta Therapeutics to Explore Strategic Alternatives

Exhibit 99.1 Magenta Therapeutics to Explore Strategic Alternatives Cambridge, MA – February 2, 2023 – Magenta Therapeutics (Nasdaq: MGTA), a clinical-stage biotechnology company focused on improving stem cell transplantation, today announced that it has completed a review of its business, including the status of its programs, resources, and capabilities. Magenta has made the determination to halt

February 2, 2023 8-K

Regulation FD Disclosure, Notice of Delisting or Failure to Satisfy a Continued Listing Rule or Standard; Transfer of Listing, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): January 31, 2023 MAGENTA THERAPEUTICS, INC. (Exact name of registrant as specified in its charter) Delaware 001-38541 81-0724163 (State or other jurisdiction of incorporation) (Commis

January 25, 2023 8-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): January 25, 2023 MAGENTA THERAPEU

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): January 25, 2023 MAGENTA THERAPEUTICS, INC. (Exact name of registrant as specified in its charter) Delaware 001-38541 81-0724163 (State or other jurisdiction of incorporation) (Commis

January 25, 2023 EX-99.1

Magenta Therapeutics Voluntarily Pauses the MGTA-117 Phase 1/2 Dose-Escalation Clinical Trial to Investigate Drug Safety

EX-99.1 Exhibit 99.1 Magenta Therapeutics Voluntarily Pauses the MGTA-117 Phase 1/2 Dose-Escalation Clinical Trial to Investigate Drug Safety Cambridge, MA – January 25, 2023 – Magenta Therapeutics (Nasdaq: MGTA) today announced that the latest participant dosed at the Cohort 3 level (0.08 mg/kg) in the ongoing MGTA-117 Phase 1/2 Dose-Escalation Clinical Trial in relapsed/refractory acute myeloid

December 20, 2022 EX-99.1

Magenta Therapeutics Provides Update for MGTA-117 Phase 1/2 Dose Escalation Clinical Trial – Cohort 4 Dosing Stopped per Clinical Trial Protocol due to Dose-Limiting Toxicities – – Plan to Dose Additional Participants in Cohort 3 per Clinical Trial P

EX-99.1 Exhibit 99.1 Magenta Therapeutics Provides Update for MGTA-117 Phase 1/2 Dose Escalation Clinical Trial – Cohort 4 Dosing Stopped per Clinical Trial Protocol due to Dose-Limiting Toxicities – – Plan to Dose Additional Participants in Cohort 3 per Clinical Trial Protocol – Cambridge, MA – December 20, 2022 – Magenta Therapeutics (Nasdaq: MGTA) today announces that, per the clinical trial pr

December 20, 2022 8-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): December 20, 2022 MAGENTA THERAPE

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): December 20, 2022 MAGENTA THERAPEUTICS, INC. (Exact name of registrant as specified in its charter) Delaware 001-38541 81-0724163 (State or other jurisdiction of incorporation) (Commi

December 13, 2022 8-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): December 9, 2022 MAGENTA THERAPEU

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): December 9, 2022 MAGENTA THERAPEUTICS, INC. (Exact name of registrant as specified in its charter) Delaware 001-38541 81-0724163 (State or other jurisdiction of incorporation) (Commis

December 13, 2022 EX-99.1

Magenta Therapeutics Presents Positive MGTA-117 Clinical Data at the American Society of Hematology (ASH) Annual Meeting and Provides Program Updates – MGTA-117 preliminary clinical results from 15 patients across three dose-escalation cohorts of the

EX-99.1 Exhibit 99.1 Magenta Therapeutics Presents Positive MGTA-117 Clinical Data at the American Society of Hematology (ASH) Annual Meeting and Provides Program Updates – MGTA-117 preliminary clinical results from 15 patients across three dose-escalation cohorts of the ongoing Phase 1/2 clinical trial shows single-agent activity with no dose-limiting toxicities; transition to patients with trans

December 13, 2022 EX-3.1

Second Amended and Restated By-laws of Magenta Therapeutics, Inc. (Incorporated by reference to Exhibit 3.1 to Magenta Therapeutics, Inc.’s Current Report on Form 8-K filed with the Securities and Exchange Commission on December 13, 2022).

EX-3.1 Exhibit 3.1 SECOND AMENDED AND RESTATED BY-LAWS OF MAGENTA THERAPEUTICS, INC. (the “Corporation”) ARTICLE I Stockholders SECTION 1. Annual Meeting. The annual meeting of stockholders (any such meeting being referred to in these By-laws as an “Annual Meeting”) shall be held at the hour, date and place within or without the United States which is fixed by the Board of Directors, which time, d

December 13, 2022 EX-99.2

Agenda & Introductions Introduction Review of

EX-99.2 Exhibit 99.2 Exhibit 99.2 MGTA-117 Clinical Data Update ASH Annual Meeting December 13, 2022 (NASDAQ: MGTA) Agenda & Introductions Introduction Review of MGTA-117 Phase 1/2 Clinical Results – Cohorts 1-3 Next Steps Q&A Session Jason Gardner, D.Phil. CEO, President and Co-founder Lisa Olson, Ph.D. Chief Scientific Officer Shawn Rose, M.D., Ph.D. Senior Vice President, Clinical Development S

November 3, 2022 EX-99.1

Magenta Therapeutics Reports Third Quarter Financial Results and Recent Program Highlights – New clinical results from ongoing MGTA-117 Phase 1/2 clinical trial support earlier observations of target binding, target cell depletion, rapid drug clearan

Exhibit 99.1 Magenta Therapeutics Reports Third Quarter Financial Results and Recent Program Highlights ? New clinical results from ongoing MGTA-117 Phase 1/2 clinical trial support earlier observations of target binding, target cell depletion, rapid drug clearance and a favorable tolerability profile; clinical trial has progressed into the third dose escalation cohort; oral presentation of clinic

November 3, 2022 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q ? QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended September 30, 2022 OR ? TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001-3854

November 3, 2022 8-K

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): November 3, 2022 MAGENTA THERAPEUTICS, INC. (Exact name of registrant as specified in its charter) Delaware 001-38541 81-0724163 (State or other jurisdiction of incorporation) (Commis

November 3, 2022 EX-10.1

Amendment No. 3, effective as of August 1, 2022, to the Exclusive Research, Development Option and License Agreement by and between the Registrant and Heidelberg Pharma Research GmbH, dated as of March 1, 2018.

CERTAIN CONFIDENTIAL INFORMATION CONTAINED IN THIS DOCUMENT, MARKED BY [**], HAS BEEN OMITTED BECAUSE IT IS BOTH NOT MATERIAL AND IS THE TYPE THAT MAGENTA THERAPEUTICS, INC.

September 27, 2022 SC 13G/A

MGTA / Magenta Therapeutics Inc / RA CAPITAL MANAGEMENT, L.P. - SC 13G/A Passive Investment

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 SCHEDULE 13G/A Under the Securities Exchange Act of 1934 (Amendment No. 1)*1 MAGENTA THERAPEUTICS, INC. (Name of Issuer) Common Stock, $0.001 par value per share (Title of Class of Securities) 55910K108 (CUSIP Number) September 15, 2022 (Date of Event Which Requires Filing of this Statement) Check the appropriate box to design

September 26, 2022 SC 13G

COGT / Cogent Biosciences Inc / RA CAPITAL MANAGEMENT, L.P. - SC 13G Passive Investment

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. )* MAGENTA THERAPEUTICS, INC. (Name of Issuer) Common Stock, $0.001 par value per share (Title of Class of Securities) 19240Q201 (CUSIP Number) September 15, 2022 (Date of Event Which Requires Filing of this Statement) Check the appropriate box to designate

August 18, 2022 424B5

Up to $50,000,000 Common Stock

Table of Contents Filed pursuant to Rule 424(b)(5) Registration No. 333-266511 PROSPECTUS Up to $50,000,000 Common Stock We have entered into a sales agreement, as amended, or Sales Agreement, with Cowen and Company, LLC, or Cowen, relating to shares of our common stock, par value $0.001 per share, offered by this prospectus. In accordance with the terms of the Sales Agreement we may offer and sel

August 17, 2022 EX-99.1

Magenta Therapeutics Appoints Michael Vasconcelles, M.D. to the Board of Directors

Exhibit 99.1 Magenta Therapeutics Appoints Michael Vasconcelles, M.D. to the Board of Directors Cambridge, MA ? August 17, 2022 ? Magenta Therapeutics (Nasdaq: MGTA), a clinical-stage biotechnology company developing novel medicines designed to bring the curative power of stem cell transplant to more patients, today announced that it has appointed Michael Vasconcelles, M.D. to its board of directo

August 17, 2022 8-K

Regulation FD Disclosure, Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Financial Statements and Exhibits, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): August 15, 2022 MAGENTA THERAPEUTICS, INC. (Exact name of registrant as specified in its charter) Delaware 001-38541 81-0724163 (State or other jurisdiction of incorporation) (Commiss

August 10, 2022 CORRESP

Magenta Therapeutics, Inc. 100 Technology Square Cambridge, MA 02139

Magenta Therapeutics, Inc. 100 Technology Square Cambridge, MA 02139 August 10, 2022 Via EDGAR Transmission United States Securities and Exchange Commission Division of Corporation Finance Office of Life Sciences 100 F Street, N.E. Washington, D.C. 20549 Attention: Tyler Howes Re: Magenta Therapeutics, Inc.: Registration Statement on Form S-3 filed August 4, 2022 (File No. 333-266511) Ladies and G

August 4, 2022 EX-1.3

First Amendment to Sales Agreement by and between the Registrant and Cowen and Company, LLC, dated August 4, 2022.

EX-1.3 3 d378261dex13.htm EX-1.3 Exhibit 1.3 AMENDMENT NO. 1 TO SALES AGREEMENT August 4, 2022 Magenta Therapeutics, Inc. 100 Technology Square Cambridge, Massachusetts 02139 Ladies and Gentlemen: Magenta Therapeutics, Inc., a Delaware corporation (the “Company”), together with Cowen and Company, LLC (the “Agent”), are parties to that certain Sales Agreement dated August 8, 2019 (the “Original Agr

August 4, 2022 S-3

As filed with the Securities and Exchange Commission on August 4, 2022.

Table of Contents As filed with the Securities and Exchange Commission on August 4, 2022.

August 4, 2022 EX-1.2

Sales Agreement by and between the Registrant and Cowen and Company, LLC, dated August 8, 2019.

Exhibit 1.2 MAGENTA THERAPEUTICS, INC. $100,000,000 COMMON STOCK SALES AGREEMENT August 8, 2019 Cowen and Company, LLC 599 Lexington Avenue New York, NY 10022 Ladies and Gentlemen: Magenta Therapeutics, Inc. (the “Company”), confirms its agreement (this “Agreement”) with Cowen and Company, LLC (“Cowen”), as follows: 1. Issuance and Sale of Shares. The Company agrees that, from time to time during

August 4, 2022 EX-4.5

Form of Senior Indenture between the Registrant and one or more trustees to be named (including Form of Senior Note).

Exhibit 4.5 MAGENTA THERAPEUTICS, INC., Issuer AND [TRUSTEE], Trustee INDENTURE Dated as of [?], [?] Senior Debt Securities TABLE OF CONTENTS1 ARTICLE 1 DEFINITIONS 1 Section 1.01 Definitions of Terms 1 ARTICLE 2 ISSUE, DESCRIPTION, TERMS, EXECUTION, REGISTRATION AND EXCHANGE OF SECURITIES 5 Section 2.01 Designation and Terms of Securities 5 Section 2.02 Form of Securities and Trustee?s Certificat

August 4, 2022 EX-99.1

Magenta Therapeutics Reports Second Quarter Financial Results and Recent Program Highlights – MGTA-117 Phase 1/2 clinical trial progress continues and remains consistent with earlier observations of target binding, target cell reductions, rapid drug

Exhibit 99.1 Magenta Therapeutics Reports Second Quarter Financial Results and Recent Program Highlights ? MGTA-117 Phase 1/2 clinical trial progress continues and remains consistent with earlier observations of target binding, target cell reductions, rapid drug clearance and a favorable tolerability profile; interim clinical data disclosure anticipated in Q4 2022 ? ? IND-enabling preclinical stud

August 4, 2022 EX-4.6

Form of Subordinated Indenture between the Registrant and one or more trustees to be named (including Form of Subordinated Note).

Exhibit 4.6 MAGENTA THERAPEUTICS, INC., Issuer AND [TRUSTEE], Trustee INDENTURE Dated as of [?], [?] Subordinated Debt Securities TABLE OF CONTENTS1 ARTICLE 1 DEFINITIONS 1 Section 1.01 Definitions of Terms. 1 ARTICLE 2 ISSUE, DESCRIPTION, TERMS, EXECUTION, REGISTRATION AND EXCHANGE OF SECURITIES 5 Section 2.01 Designation and Terms of Securities. 5 Section 2.02 Form of Securities and Trustee?s Ce

August 4, 2022 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2022 OR ☐ TRANSITION REPORT PURSUANT T

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q ? QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2022 OR ? TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001-38541 Mag

August 4, 2022 EX-FILING FEES

Filing Fee Table.

Exhibit 107 Calculation of Filing Fee Tables Form S-3 (Form Type) Magenta Therapeutics, Inc.

August 4, 2022 8-K

Entry into a Material Definitive Agreement, Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): August 1, 2022 MAGENTA THERAPEUTICS, INC. (Exact name of registrant as specified in its charter) Delaware 001-38541 81-0724163 (State or other jurisdiction of incorporation) (Commissi

June 30, 2022 8-K

Submission of Matters to a Vote of Security Holders

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): June 28, 2022 MAGENTA THERAPEUTICS, INC. (Exact name of registrant as specified in its charter) Delaware 001-38541 81-0724163 (State or other jurisdiction of incorporation) (Commissio

May 16, 2022 8-K

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 16, 2022 MAGENTA THERAPEUTICS, INC. (Exact name of registrant as specified in its charter) Delaware 001-38541 81-0724163 (State or other jurisdiction of incorporation) (Commission

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