SCHEDULE 13G/A

Monte Rosa Therapeutics Inc

Common Stock, $0.0001 par value per share · CUSIP: 61225M102

Event date: 2025-12-31

Reporting persons may disclose overlapping interests. Their amounts are shown individually and are not added into a filing total.

Filing-level shares

Unavailable

Percent of class

Unavailable

• BIOTECHNOLOGY VALUE FUND L P

  Shares: 2,050,405.00 · Class: 3.1%

• BVF I GP LLC

  Shares: 2,050,405.00 · Class: 3.1%

• BIOTECHNOLOGY VALUE FUND II LP

  Shares: 1,496,859.00 · Class: 2.3%

• BVF II GP LLC

  Shares: 1,496,859.00 · Class: 2.3%

• Biotechnology Value Trading Fund OS LP

  Shares: 232,097.00 · Class: 0.4%

• BVF Partners OS Ltd.

  Shares: 232,097.00 · Class: 0.4%

• BVF GP HOLDINGS LLC

  Shares: 3,547,264.00 · Class: 5.4%

• BVF PARTNERS L P/IL

  Shares: 3,835,886.00 · Class: 5.9%

• BVF INC/IL

  Shares: 3,835,886.00 · Class: 5.9%

• LAMPERT MARK N

  Shares: 3,835,886.00 · Class: 5.9%

Amounts are as disclosed in this filing. Schedule type alone does not establish investment intent.