SCHEDULE 13G/A

Day One Biopharmaceuticals Inc

Common Stock, par value $0.0001 per share · CUSIP: 23954D109

Event date: 2024-12-31

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

• RA Capital Management, L.P.

  Shares: 5,755,577.00 · Class: 5.7%

• Peter Kolchinsky

  Shares: 5,755,577.00 · Class: 5.7%

• Rajeev Shah

  Shares: 5,755,577.00 · Class: 5.7%

• RA Capital Healthcare Fund, L.P.

  Shares: 5,307,848.00 · Class: 5.3%

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