SCHEDULE 13G/A 0000902664-23-003397 0001910456 XXXXXXXX LIVE 2 Voting Common Stock, par value $0.0001 per share 06/30/2025 0001783328 TScan Therapeutics, Inc. 89854M101 830 WINTER STREET WALTHAM MA 02451 Rule 13d-1(c) Lynx1 Capital Management LP DE 0.00 7857347.00 0.00 7857347.00 7857347.00 N 15.0 PN Weston Nichols X1 0.00 7857347.00 0.00 7857347.00 7857347.00 N 15.0 IN TScan Therapeutics, Inc. 830 Winter Street, Waltham, Massachusetts 02451 This statement is filed by: (i) Lynx1 Capital Management LP (the "Investment Manager"), a Delaware limited partnership, and the investment manager to Lynx1 Master Fund LP (the "Lynx1 Fund"), with respect to the shares of voting common stock, par value $0.0001 per share ("Voting Common Stock") of TScan Therapeutics, Inc., a Delaware corporation (the "Company") directly held by the Lynx1 Fund; and (ii) Mr. Weston Nichols ("Mr. Nichols"), the sole member of Lynx1 Capital Management GP LLC, the general partner of the Investment Manager, with respect to the shares of Voting Common Stock directly held by the Lynx1 Fund. The foregoing persons are hereinafter sometimes collectively referred to as the "Reporting Persons." The filing of this statement should not be construed as an admission that any of the foregoing persons or any Reporting Person is, for the purposes of Section 13 of the Act, the beneficial owner of the securities reported herein. Lynx1 Capital Management LP D81 Calle C Suite 301, PMB 1202 Dorado, PR, 00646-2051 Weston Nichols c/o Lynx1 Capital Management LP D81 Calle C Suite 301, PMB 1202 Dorado, PR, 00646-2051 Investment Manager - Delaware Mr. Nichols - United States of America Y The information required by Item 4(a) is set forth in Row 9 of the cover page for each of the Reporting Persons and is incorporated herein by reference. The percentage set forth in this Schedule 13G is calculated based upon an aggregate of 52,314,039 shares of Voting Common Stock outstanding as of May 7, 2025, as reported in the Company's Definitive Proxy Statement on Schedule 14A filed with the Securities and Exchange Commission on May 14, 2025. 15.0% The information required by Item 4(c)(i) is set forth in Row 5 of the cover page for each of the Reporting Persons and is incorporated herein by reference. The information required by Item 4(c)(ii) is set forth in Row 6 of the cover page for each of the Reporting Persons and is incorporated herein by reference. The information required by Item 4(c)(iii) is set forth in Row 7 of the cover page for each of the Reporting Persons and is incorporated herein by reference. The information required by Item 4(c)(iv) is set forth in Row 8 of the cover page for each of the Reporting Persons and is incorporated herein by reference. Y N The Lynx1 Fund has the right to receive or the power to direct the receipt of dividends from, or the proceeds from the sale of, the shares of Voting Common Stock reported herein. Y Y Y N By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect, other than activities solely in connection with a nomination under ?? 240.14a-11. Lynx1 Capital Management LP /s/ Weston Nichols 08/14/2025 Weston Nichols /s/ Weston Nichols 08/14/2025