Monte Rosa Therapeutics : Corporate Presentation - January 2023

From Serendipity to Rational Design

Taking Molecular Glue Degraders to New Heights | January 2023

Forward-Looking Statements

These materials include express and implied "forward-looking statements," including forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. Forward looking statements include all statements that are not historical facts, and in some cases, can be identified by terms such as "may," "might," "will," "could," "would," "should," "expect," "intend," "plan," "objective," "anticipate," "believe," "estimate," "predict," "potential," "continue," "ongoing," or the negative of these terms, or other comparable terminology intended to identify statements about the future. Forward-looking statements contained in herein include, but are not limited to, statements about our product development activities, including our expectations around MRT-2359, such as for our ongoing clinical trial for MRT-2359 and the timing thereof and our expectations regarding the potential significance of obtaining Fast Track Designation from the FDA, the ongoing development of our QuEEN™ platform, the advancement, and timing thereof, of our pipeline and the various products therein, our ability to initiate and the timing of initiation of additional lead optimization programs, and our expectations regarding our ability to nominate and the timing of our nominations of additional development candidates, as well as our expectations of success for our programs and the strength of our financial position, among others. By their nature, these statements are subject to numerous risks and uncertainties, including the impact that the ongoing COVID-19 pandemic will have on our development activities and operations, as well as those risks and uncertainties set forth in our Annual Report on Form 10-K for the fourth quarter and full year ended December 31, 2021 filed, with the US Securities and Exchange Commission on March 29, 2022, and any subsequent filings, including our most recently filed Quarterly Report on Form 10-Q, that could cause actual results, performance or achievement to differ materially and adversely from those anticipated or implied in the statements. You should not rely upon forward looking statements as predictions of future events. Although our management believes that the expectations reflected in our statements are reasonable, we cannot guarantee that the future results, performance or events and circumstances described in the forward-looking statements will be achieved or occur. Recipients are cautioned not to place undue reliance on these forward-looking statements, which speak only as of the date such statements are made and should not be construed as statements of fact. We undertake no obligation to publicly update any forward-looking statements, whether as a result of new information, any future presentations or otherwise, except as required by applicable law. Certain information contained in these materials and any statements made orally during any presentation of these materials that relate to the materials or are based on studies, publications, surveys and other data obtained from third-party sources and our own internal estimates and research. While we believe these third-party studies, publications, surveys and other data to be reliable as of the date of these materials, we have not independently verified, and make no representations as to the adequacy, fairness, accuracy or completeness of, any information obtained from third-party sources. In addition, no independent source has evaluated the reasonableness or accuracy of our internal estimates or research and no reliance should be made on any information or statements made in these materials relating to or based on such internal estimates and research.

2 These materials remain the proprietary intellectual property of Monte Rosa Therapeutics and should not be distributed or reproduced in whole or in part without the prior written consent of Monte Rosa Therapeutics.

Monte Rosa Therapeutics Highlights

Taking molecular glue degraders (MGDs) to new heights

Developing breakthrough drugs that selectively degrade therapeutically- relevant proteins previously considered undruggable

AI-based degron prediction & rational design of highly selective MGDs enable a next-generationmolecular glue-basedtargeted protein degradation platform

Five disclosed programs targeting high unmet medical needs in oncology, autoimmune disease, inflammation and other indications

PhI/II initiated for MRT-2359 with clinical development in MYC-driven tumors

Strong financial position with $274M cash as of December 31, 2022, providing runway into 2025

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World-Class Leadership

Deep expertise in molecular glue discovery, drug development and precision medicine

Markus Warmuth, M.D.

Chief Executive Officer

Ajim Tamboli, CFA

Chief Financial Officer

Owen Wallace, Ph.D.

Chief Scientific Officer

Sharon Townson, Ph.D.

Chief Technology Officer

John Castle, Ph.D.

Chief Data Scientist

Filip Janku, M.D., Ph.D.

Chief Medical Officer

Jullian Jones, Ph.D., J.D., MBA

Chief Business Officer

Silvia Buonamici, Ph.D.

SVP, Drug Discovery Biology

Phil Nickson, Ph.D., J.D.

General Counsel

Jennifer Champoux,

SVP, Operations

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Molecular Glue Degraders (MGDs) - Drugging The Undruggable

Expanding target space, fostering a new generation of drugs

INHIBITOR

PROTAC

MGDs

E3 Ligase

E3 Ligase

DRUGGABLE TARGETS

UNDRUGGABLE TARGETS

DRUGGABLE TARGETS

• Favorable drug-like properties
• Broad tissue distribution

• No hook effect

Drugging	Redrugging	Drugging
the Druggable	the Druggable	the Undruggable

Expanding the Degradable Proteome

Target Space

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