in this Current Report on Form 8-K (including Exhibit 99.1) shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that section, nor shall it be deemed incorporated by reference in any filing under the Securities Act of 1933, as amended, or the Exchange Act, except as expressly set forth by specific reference in such a filing.

in this Current Report on Form 8-K (including Exhibit 99.1) shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that section, nor shall it be deemed incorporated by reference in any filing under the Securities Act of 1933, as amended, or the Exchange Act, except as expressly set forth by specific reference in such a filing.

in this Current Report on Form 8-K (including Exhibit 99.1) shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that section, nor shall it be deemed incorporated by reference in any filing under the Securities Act of 1933, as amended, or the Exchange Act, except as expressly set forth by specific reference in such a filing.

SVP, Corporate Controller and Principal Accounting Officer — Edmund Dunn: Edmund Dunn is retiring from his role, but a successor has been named.

Entry into a Material Definitive Agreement. On January 8, 2026, Monte Rosa Therapeutics, Inc. (the “Company”) entered into an Underwriting Agreement (the “Underwriting Agreement”) with Jefferies LLC, TD Securities (USA) LLC and Piper Sandler & Co., as representatives of the several underwriters listed on Schedule 1 thereto (collectively, the “Underwriters”), related to an underwritten public offering (the “Offering”) of 11,125,000 shares (the “Underwritten Shares”) of the Company’s common sto…

Other Events Effective January 7, 2026, Monte Rosa Therapeutics, Inc. (the “Company”) terminated the sales agreement prospectus (the “ATM Prospectus”) filed with the Company’s registration statement on Form S-3 (File No. 333-285942) (the “Registration Statement”) and related to the shares of the Company’s common stock, par value $0.0001 per share (“Common Stock”), issuable pursuant to the Open Market Sale Agreement, dated July 1, 2022, by and among the Company and Jefferies LLC, as amended by…

Other Events On January 7, 2026, the Company announced positive interim data from an ongoing Phase 1 clinical study evaluating MRT-8102, a NEK7-directed MGD being developed for the treatment of inflammatory conditions driven by the NLRP3 inflammasome, IL-1, and IL-6. Summary of Key Interim Study Results • Single ascending dose (“SAD”) cohorts enrolled 48 subjects and multiple ascending dose (“MAD”) cohorts enrolled 40 subjects. In the Part 3 cohort, 24 subjects have completed 4 weeks of dosin…

Other Events On December 16, 2025, the Company announced positive interim data from its ongoing Phase 1/2 clinical study evaluating MRT-2359 in combination with enzalutamide in heavily pretreated patients with metastatic CRPC. The Phase 1/2 study evaluated 0.5 mg and 0.75 mg of MRT-2359 administered orally on a 21-days-on, 7-days-off drug schedule in combination with enzalutamide, an AR inhibitor. The study population as of the data cutoff date of December 3, 2025, included 20 individuals wit…

in this Current Report on Form 8-K (including Exhibit 99.1) shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that section, nor shall it be deemed incorporated by reference in any filing under the Securities Act of 1933, as amended, or the Exchange Act, except as expressly set forth by specific reference in such a filing.

Entry into a Material Definitive Agreement On September 13, 2025, Monte Rosa Therapeutics AG (“Monte Rosa AG,” hereinafter the “Company”), a wholly‑owned subsidiary of Monte Rosa Therapeutics, Inc., and Novartis Pharma AG (“Novartis”) entered into a Collaboration, Option, and License Agreement (the “Agreement”) to discover and develop degraders to treat immune-mediated diseases using the Company’s QuEEN TM product engine. Pursuant to the Agreement, the Company has granted Novartis an exclusiv…

of this Form 8-K (including Exhibit 99.1) shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that section, nor shall it be deemed incorporated by reference in any filing under the Securities Act of 1933, as amended, or the Exchange Act, except as expressly set forth by specific reference in such a filing. Forward-Looking Statements This Current Report on Form 8-K contains “f…

in this Current Report on Form 8-K (including Exhibit 99.1) shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that section, nor shall it be deemed incorporated by reference in any filing under the Securities Act of 1933, as amended, or the Exchange Act, except as expressly set forth by specific reference in such a filing.

Results of Operations and Financial Condition On May 8, 2025, Monte Rosa Therapeutics, Inc. (the "Company") announced its financial results for the quarter ended March 31, 2025. The full text of the press release issued in connection with the announcement is furnished as Exhibit 99.1 to this Current Report on Form 8-K.

Results of Operations and Financial Condition On March 20, 2025, Monte Rosa Therapeutics, Inc. (the "Company") announced its financial results for the quarter and year ended December 31, 2024. The full text of the press release issued in connection with the announcement is furnished as Exhibit 99.1 to this Current Report on Form 8-K.

Results of Operations and Financial Condition On January 10, 2025, Monte Rosa Therapeutics, Inc. (the “Company”) released the following preliminary information about its cash, cash equivalents, restricted cash, and marketable securities as of December 31, 2024. The Company’s preliminary estimated cash, cash equivalents, restricted cash, and marketable securities are expected to be $377.0 million as of December 31, 2024, including the previously announced $150 million upfront payment from Nova…

Director — Eric A. Hughes, M.D., Ph.D.: Dr. Eric A. Hughes was appointed to the Board of Directors and will serve as a Class III director.

Other Events On December 5, 2024, the Company reported an update from its ongoing Phase 1/2 open-label, multicenter study of MRT-2359 in patients with MYC-driven solid tumors. Summary of Interim Data on Enrollment, Safety & Pharmacodynamics Enrollment Highlights • Patients have been dosed with MRT-2359 in 6 dose levels across two dosing schedules, namely a 5 days on, 9 days off drug (5/9) dosing schedule and a 21 days on, 7 days off drug (21/7) dosing schedule. • The study has enrolled patien…

in this Current Report on Form 8-K (including Exhibit 99.1) shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that section, nor shall it be deemed incorporated by reference in any filing under the Securities Act of 1933, as amended, or the Exchange Act, except as expressly set forth by specific reference in such a filing.

of this Form 8-K (including Exhibit 99.1) shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that section, nor shall it be deemed incorporated by reference in any filing under the Securities Act of 1933, as amended, or the Exchange Act, except as expressly set forth by specific reference in such a filing. Forward-Looking Statements This Current Report on Form 8-K contains “f…

Entry into a Material Definitive Agreement On October 25, 2024, Monte Rosa Therapeutics AG (“Monte Rosa AG,” hereinafter the “Company”), a wholly‑owned subsidiary of Monte Rosa Therapeutics, Inc. and Novartis Pharma AG (“Novartis”) entered into a License Agreement (the “Agreement”). Pursuant to the Agreement, the Company will grant to Novartis an exclusive, royalty-bearing, sublicensable and transferable license to develop, manufacture, and commercialize VAV1 molecular glue degraders (“MGDs”)…

in this Current Report on Form 8-K (including Exhibit 99.1) shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that section, nor shall it be deemed incorporated by reference in any filing under the Securities Act of 1933, as amended, or the Exchange Act, except as expressly set forth by specific reference in such a filing.

Chief Operating Officer — Jennifer Champoux: Jennifer Champoux was promoted to Chief Operating Officer.

Entry into a Material Definitive Agreement. On May 15, 2024, Monte Rosa Therapeutics, Inc. (the “Company”) entered into an Underwriting Agreement (the “Underwriting Agreement”) with TD Securities (USA) LLC, as representative of the several underwriters listed on Schedule 1 thereto (collectively, the “Underwriters”), related to an underwritten public offering (the “Offering”) of 10,638,476 shares (the “Shares”) of the Company’s common stock, par value $0.0001 per share (“Common Stock”), at a p…

Results of Operations and Financial Condition On May 9, 2024, Monte Rosa Therapeutics, Inc. (the "Company") announced its financial results for the quarter ended March 31, 2024. The full text of the press release issued in connection with the announcement is furnished as Exhibit 99.1 to this Current Report on Form 8-K.

Chief Scientific Officer — Owen Wallace: Dr. Owen Wallace resigned from his role as Chief Scientific Officer.