Monte Rosa Therapeutics, Inc.

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, DC 20549

FORM 10-Q

(Mark One)

For the quarterly period ended September 30,2026

OR

For the transition period from ____________ to ____________

Commission File Number:001-40522

(Exact name of registrant as specified in its charter)

Registrant’s telephone number, including area code: (617)949-2643

Securities registered pursuant to Section 12(b) of the Act:

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days. Yes ☒ No☐

Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit such files). Yes ☒ No☐

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, smaller reporting company, or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company,” and “emerging growth company” in Rule 12b-2 of the Exchange Act.

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act.☐

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act). Yes☐ No☒

As of October 30, 2026, the registrant had 85,450,119 shares of common stock, $0.0001 per share, outstanding.

Special note regarding forward-looking statements

This Quarterly Report on Form 10-Q, or Quarterly Report, contains forward-looking statements which are made pursuant to the safe harbor provisions of Section 27A of the Securities Act of 1933, as amended, or the Securities Act, and Section 21E of the Securities Exchange Act of 1934, as amended, or the Exchange Act. All statements other than statements of historical facts contained in this Quarterly Report are forward-looking statements. In some cases, you can identify forward-looking statements by terminology such as “may”, “will”, “should”, “expects”, “intends”, “plans”, “anticipates”, “believes”, “estimates”, “predicts”, “potential”, “continue” or the negative of these terms or other comparable terminology. These statements are not guarantees of future results or performance and involve substantial risks and uncertainties. Forward-looking statements in this Quarterly Report include, but are not limited to, statements about:

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the initiation, timing, progress, results, costs, and any expectations and/or predictions of success of our current and future research and development programs and preclinical studies, including our expectations for our molecular glue degraders, or MGDs, molecules, including our GSPT1-directed MGD MRT-2359, our out-licensed VAV1-directed MGD MRT-6160, our NEK7-directed MGDs, including MRT-8102, and our CDK2 and CCNE1 MGDs;

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the initiation, timing, progress, results, costs, and any expectations and/or predictions of success of our current and any future clinical trials, including our clinical trials for our GSPT1-directed MGD MRT-2359, our NEK7 directed MGD MRT-8102, and for our out-licensed VAV1 directed MGD MRT-6160, including statements regarding the nature of or the timing for when any results of any clinical trials will become available;

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our ability to continue to develop our proprietary discovery engine, called QuEENTM, and to expand our proteomics and translational medicine capabilities;

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the potential advantages of our discovery engine technology and product candidates;

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the extent to which our scientific approach and discovery engine technology may target proteins that have been considered undruggable or inadequately drugged;

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our plans to submit Investigational New Drug, or IND applications to the U.S. Food and Drug Administration, or the FDA for current and future product candidates;

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the potential benefits of strategic collaborations and our ability to enter into strategic collaborations with third parties who have the expertise to enable us to further develop our biological targets, product candidates and discovery engine technologies, including our agreements with Novartis AG, or Novartis, for MRT-6160 and other discovery programs and our agreement with F. Hoffmann-La Roche Ltd., or Roche Basel, and Hoffmann-La Roche Inc., or Roche US, and together with Roche Basel, collectively referred to herein as Roche;

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our ability to obtain and maintain regulatory approval of our product candidates;

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our ability to maintain and expand, including through third-party vendors, our library of MGDs;

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our ability to manufacture, including through third-party manufacturers, our product candidates for preclinical use, future clinical trials and commercial use, if approved;

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our ability to commercialize our product candidates, including our ability to establish sales, marketing and distribution capabilities for our product candidates;

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the rate and degree of market acceptance of our product candidates;

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the size and growth potential of the markets for our product candidates, and our ability to serve those markets;

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our ability to establish and maintain intellectual property rights covering our current and future product candidates and technologies;

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the implementation of our business model and strategic plans for our business, product candidates, and technology;

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estimates of our future expenses, revenues, capital requirements, and our needs for additional capital;

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our expected use of proceeds from sales of our common stock in "at-the-market" offerings and other offerings, and the period over which such proceeds, together with existing cash, will be sufficient to meet our operating needs;

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our ability to obtain funding for our operations necessary to complete further development and commercialization of our product candidates;

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our financial performance;

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developments in laws and regulations in the United States, or the U.S., and foreign countries;

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the success of competing therapies that are or may become available;

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our ability to attract and retain key scientific or management personnel;

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the effect of global economic uncertainty and financial market volatility caused by economic effects of rising inflation and interest rates, global health crises, geopolitical events, elections, changes in international trade relationships and military conflicts on any of the foregoing or other aspects of our business or operations;

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the effect of any geopolitical conflicts or new or increased international tariffs, including mitigation efforts and economic effects, on any of the foregoing or other aspects of our business operations, including but not limited to our preclinical studies, ongoing clinical trials and future clinical trials; and

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other risks and uncertainties, including those listed under the section entitled “Risk factors" and those included in "Part I, Item 1A, Risk Factors" in our Annual Report on Form 10-K for the year ended December 31, 2025, or our 2025 Annual Report, filed with the Securities and Exchange Commission, or the SEC, on March 17, 2026.

Any forward-looking statements in this Quarterly Report reflect our current views with respect to future events and with respect to our future financial performance, and involve known and unknown risks, uncertainties and other factors that may cause our actual results, performance or achievements to be materially different from any future results, performance or achievements expressed or implied by these forward-looking statements. Factors that may cause actual results to differ materially from current expectations include, among other things, those described under Part II, Item 1A, “Risk Factors” and elsewhere in this Quarterly Report. Given these uncertainties, you should not place undue reliance on these forward-looking statements.

All of our forward-looking statements are as of the date of this Quarterly Report only. In each case, actual results may differ materially from such forward-looking information. We can give no assurance that such expectations or forward-looking statements will prove to be correct. An occurrence of or any material adverse change in one or more of the risk factors or risks and uncertainties referred to in this Quarterly Report or included in our other public disclosures or our other periodic reports or other documents or filings filed with or furnished to the SEC could materially and adversely affect our business, prospects, financial condition and results of operations. Except as required by law, we do not undertake or plan to update or revise any such forward-looking statements to reflect actual results, changes in plans, assumptions, estimates or projections or other circumstances affecting such forward-looking statements occurring after the date of this Quarterly Report, even if such results, changes or circumstances make it clear that any forward-looking information will not be realized. Any public statements or disclosures by us following this Quarterly Report that modify or impact any of the forward-looking statements contained in this Quarterly Report will be deemed to modify or supersede such statements in this Quarterly Report.

We may from time to time provide estimates, projections and other information concerning our industry, the general business environment, and the markets for certain diseases, including estimates regarding the potential size of those markets and the estimated incidence and prevalence of certain medical conditions. Information that is based on estimates, forecasts, projections, market research or similar methodologies is inherently subject to uncertainties, and actual events, circumstances or numbers, including actual disease prevalence rates and market size, may differ materially from the information reflected in this Quarterly Report. Unless otherwise expressly stated, we obtained this industry, business information, market data, prevalence information and other data from reports, research surveys, studies and similar data prepared by market research firms and other third parties, industry, medical and general publications, government data, and similar sources, in some cases applying our own assumptions and analysis that may, in the future, prove not to have been accurate.

TRADEMARKS

Solely for convenience, our trademarks and trade names in this report are sometimes referred to without the ® and ™ symbols, but such references should not be construed as any indicator that we will not assert, to the fullest extent under applicable law, our rights thereto.

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