SCHEDULE 13G/A 0000902664-22-001524 0001633313 XXXXXXXX LIVE 5 Common Stock, par value $0.0001 per share 09/30/2025 0001826457 Monte Rosa Therapeutics, Inc. 61225M102 321 HARRISON AVENUE SUITE 900 BOSTON MA 02118 Rule 13d-1(b) Avoro Capital Advisors LLC b DE 0.00 0.00 0.00 0.00 0.00 N 0 IA OO Behzad Aghazadeh b X1 0.00 0.00 0.00 0.00 0.00 N 0 HC IN Monte Rosa Therapeutics, Inc. 321 Harrison Avenue, Suite 900, Boston, MA 02118 This statement is filed by: (i) Avoro Capital Advisors LLC, a Delaware limited liability company ("Avoro"), which provides investment advisory and management services and has acquired the shares of common stock, par value $0.0001 per share ("Common Stock") of Monte Rosa Therapeutics, a Delaware corporation (the "Company"), solely for investment purposes on behalf of Avoro Life Sciences Fund LLC, a Delaware limited liability company, and (ii) Behzad Aghazadeh ("Dr. Aghazadeh," and together with Avoro, the "Reporting Persons"), who serves as the portfolio manager and controlling person of Avoro. The filing of this statement should not be construed as an admission that any Reporting Person is, for purposes of Section 13 of the Act, the beneficial owner of the securities reported herein. The address of the business office of each of the Reporting Persons is 110 Greene Street, Suite 800, New York, NY 10012. Avoro is a Delaware limited liability company. Dr. Aghazadeh is a United States citizen. N IA HC 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. 0.00% 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. N Y Y Y Y Y N By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were acquired and are held in the ordinary course of business and 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. Avoro Capital Advisors LLC /s/ Scott Epstein 11/14/2025 Behzad Aghazadeh /s/ Behzad Aghazadeh 11/14/2025