Amendment to Schedule 13D Filing for Monte Rosa Therapeutics, Inc.

This filing is an amendment to a Schedule 13D, originally filed on July 12, 2021, by New Enterprise Associates 17, L.P. and related entities and individuals. The amendment reports a decrease of over 1% in the beneficial ownership of Monte Rosa Therapeutics, Inc. common stock by the reporting persons. This decrease is attributed to an increase in the total number of outstanding shares of common stock. The reporting persons, including NEA 17, NEA Partners 17, NEA 17 GP, LLC, and various managers, collectively hold 7,692,298 shares, representing 9.6% of the outstanding stock as of March 19, 2026. Ali Behbahani also holds options to purchase an additional 104,732 shares. The reporting persons state that they may acquire or dispose of additional shares depending on market conditions and their evaluation of the issuer's business. No other present plans that would result in material changes to the issuer's business, structure, or control are disclosed.