Subsequent Event	6 Months Ended
Jun. 30, 2021
Subsequent Events [Abstract]
Subsequent Event	13. Subsequent Event In July 2021, the Company entered into a Collaboration Agreement with Pfizer, or the ARV-471 Collaboration Agreement, pursuant to which the Company granted Pfizer worldwide co-exclusive rights to develop and commercialize products containing the Company’s proprietary compound ARV-471 (“Licensed Product”). Under the ARV-471 Collaboration Agreement, Pfizer made an upfront payment of $650 million. In addition, the Company will be eligible to receive up to an additional $1.4 billion in contingent payments based on specific regulatory and sales-based milestones for the Licensed Product. Of the total contingent payments, $400 million in regulatory milestones are related to marketing approvals. The parties will share equally all development costs, including costs for conducting clinical trials, for the Licensed Product, subject to certain exceptions. Except for certain regions described below, the parties will also share equally all profits and losses in commercialization and medical affairs activities for the Licensed Product in all other countries, subject to certain exceptions. The Company will be the marketing authorization holder in the United States and, subject to marketing approval, book sales in the United States, while Pfizer will hold marketing authorizations outside the United States. The parties will determine which, if any, regions within the world will be solely commercialized by one party, and in such region the parties will adjust their share of all profits and losses for the Licensed Product based on the role each party will be performing In addition, in connection with the execution of the ARV-471 Collaboration Agreement, in July 2021, the Company and Pfizer entered into a Stock Purchase Agreement (“Pfizer Equity Transaction”), for the sale and issuance of 3,457,815 shares of the Company’s common stock (the “Shares”) to Pfizer at a price of $101.22 per share, for an aggregate purchase price of approximately $350 million. The consummation of the Pfizer Equity Transaction is subject to certain conditions, including clearance under the Hart-Scott Rodino Antitrust Improvements Act of 1976, as amended. Pursuant to terms of the Stock Purchase Agreement, Pfizer has agreed not to sell or transfer the Shares without prior written approval of the Company for a specified time period, subject to specified exceptions.

Subsequent Event

6 Months Ended

Jun. 30, 2021

13. Subsequent Event

In July 2021, the Company entered into a Collaboration Agreement with Pfizer, or the ARV-471 Collaboration Agreement, pursuant to which the Company granted Pfizer worldwide co-exclusive rights to develop and commercialize products containing the Company’s proprietary compound ARV-471 (“Licensed Product”). Under the ARV-471 Collaboration Agreement, Pfizer made an upfront payment of $650 million. In addition, the Company will be eligible to receive up to an additional $1.4 billion in contingent payments based on specific regulatory and sales-based milestones for the Licensed Product. Of the total contingent payments, $400 million in regulatory milestones are related to marketing approvals.

The parties will share equally all development costs, including costs for conducting clinical trials, for the Licensed Product, subject to certain exceptions. Except for certain regions described below, the parties will also share equally all profits and losses in commercialization and medical affairs activities for the Licensed Product in all other countries, subject to certain exceptions.

The Company will be the marketing authorization holder in the United States and, subject to marketing approval, book sales in the United States, while Pfizer will hold marketing authorizations outside the United States. The parties will determine which, if any, regions within the world will be solely commercialized by one party, and in such region the parties will adjust their share of all profits and losses for the Licensed Product based on the role each party will be performing

In addition, in connection with the execution of the ARV-471 Collaboration Agreement, in July 2021, the Company and Pfizer entered into a Stock Purchase Agreement (“Pfizer Equity Transaction”), for the sale and issuance of 3,457,815 shares of the Company’s common stock (the “Shares”) to Pfizer at a price of $101.22 per share, for an aggregate purchase price of approximately $350 million. The consummation of the Pfizer Equity Transaction is subject to certain conditions, including clearance under the Hart-Scott Rodino Antitrust Improvements Act of 1976, as amended. Pursuant to terms of the Stock Purchase Agreement, Pfizer has agreed not to sell or transfer the Shares without prior written approval of the Company for a specified time period, subject to specified exceptions.