Subsequent Events	3 Months Ended
Mar. 31, 2026
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events On May 1, 2026, the Company issued a press release announcing that the FDA has granted approval for VEPPANU™ (vepdegestrant) for the treatment of adults with ER+/ HER2-, ESR1-mutated advanced or metastatic breast cancer, as detected by an FDA-authorized test, with disease progression following at least one line of endocrine-based therapy. VEPPANU is the first-and-only FDA-approved PROteolysis TArgeting Chimera (PROTAC) protein degrader, a type of heterobifunctional protein degrader therapy. FDA approval was received in advance of FDA-assigned PDUFA date of June 5, 2026. The Company and its collaborator, Pfizer, remain on track to announce selection of a third party to commercialize VEPPANU. Pursuant to the Vepdegestrant (ARV-471) Collaboration Agreement, the Company will receive $50.0 million as the Milestone Payment. The Milestone Payment will be offset by certain amounts that the Company will owe to Yale pursuant to the

Subsequent Events

3 Months Ended

Mar. 31, 2026

On May 1, 2026, the Company issued a press release announcing that the FDA has granted approval for VEPPANU™ (vepdegestrant) for the treatment of adults with ER+/ HER2-, ESR1-mutated advanced or metastatic breast cancer, as detected by an FDA-authorized test, with disease progression following at least one line of endocrine-based therapy. VEPPANU is the first-and-only FDA-approved PROteolysis TArgeting Chimera (PROTAC) protein degrader, a type of heterobifunctional protein degrader therapy. FDA approval was received in advance of FDA-assigned PDUFA date of June 5, 2026. The Company and its collaborator, Pfizer, remain on track to announce selection of a third party to commercialize VEPPANU.

Pursuant to the Vepdegestrant (ARV-471) Collaboration Agreement, the Company will receive $50.0 million as the Milestone Payment. The Milestone Payment will be offset by certain amounts that the Company will owe to Yale pursuant to the