Capital Return Program	12 Months Ended
Dec. 31, 2022
Capital Return Program
Capital Return Program	15. Capital Return Program In September 2022, the Company’s board of directors authorized a $250.0 million capital return program consisting of three elements as described below. GSK Share Repurchase On September 20, 2022, the Company repurchased 9,644,807 ordinary shares, par value $0.00001 per share, of the Company from GSK Finance (No.3) plc (“GSK Finance”), representing all of the ordinary shares of the Company owned by GSK Finance or its affiliates. The purchase price under the Share Repurchase Agreement was $9.75 per share, resulting in a total consideration of $94.0 million. The repurchased shares were accounted for as authorized shares that are no longer issued and outstanding upon the settlement date of the repurchase transaction. Modified Dutch Auction Tender Offer On September 28, 2022, the Company announced a “modified Dutch auction” tender offer (the “Offer”) to purchase up to $95.0 million of its ordinary shares. Upon the terms and subject to the conditions set forth in the Company's Offer to Purchase, dated September 28, 2022 (the "Offer to Purchase"), and the related Letter of Transmittal, the Company offered to purchase up to $95.0 million of its ordinary shares, at a purchase price not greater than $10.50 nor less than $9.75 per share, in cash, less any applicable withholding taxes and without interest. The Offer expired at midnight, New York City time, at the end of the day on November 17, 2022. A "modified Dutch auction" tender offer allows shareholders to indicate how many shares and at what price or within the range described above they wish to tender their shares. Based on the number of shares tendered and the prices specified by the tendering shareholders, the Company determined the lowest per-share price that enabled it to purchase up to $95.0 million of all shares that were validly tendered and not validly withdrawn. All shares accepted in the Offer were purchased at the same price even if tendered at a lower price. On November 22, 2022, the Company completed the Offer and purchased a total of 115,967 ordinary shares at a price of $10.50 per share, for an aggregate cost of $1.2 million, excluding fees and expenses relating to the Offer. The total of 115,967 shares that were accepted for purchase represented approximately 0.2% of the total number of shares outstanding as of November 21, 2022. The purchased shares were cancelled and ceased to be outstanding. The Company intends to use the unused portion of the Offer to enlarge our previously announced, planned open market share repurchase plan which is described below. Open Market Share Repurchase Plan On December 13, 2022, the Company initiated its open market repurchase plan to repurchase ordinary shares. As of December 31, 2022, the Company repurchased 2,978,341 shares on the open market at an average cost of $11.06 per share for an aggregate cost of $32.9 million, excluding fees and expenses. From January 1, 2023 through February 27, 2023, the Company repurchased an additional 2,461,000 shares on the open market at an average cost of $10.99 per share for an aggregate cost of $27.1 million, excluding fees and expenses.

Capital Return Program

12 Months Ended

Dec. 31, 2022

15. Capital Return Program

In September 2022, the Company’s board of directors authorized a $250.0 million capital return program consisting of three elements as described below.

GSK Share Repurchase

On September 20, 2022, the Company repurchased 9,644,807 ordinary shares, par value $0.00001 per share, of the Company from GSK Finance (No.3) plc (“GSK Finance”), representing all of the ordinary shares of the Company owned by GSK Finance or its affiliates. The purchase price under the Share Repurchase Agreement was $9.75 per share, resulting in a total consideration of $94.0 million. The repurchased shares were accounted for as authorized shares that are no longer issued and outstanding upon the settlement date of the repurchase transaction.

Modified Dutch Auction Tender Offer

On September 28, 2022, the Company announced a “modified Dutch auction” tender offer (the “Offer”) to purchase up to $95.0 million of its ordinary shares. Upon the terms and subject to the conditions set forth in the Company's Offer to Purchase, dated September 28, 2022 (the "Offer to Purchase"), and the related Letter of Transmittal, the Company offered to purchase up to $95.0 million of its ordinary shares, at a purchase price not greater than $10.50 nor less than $9.75 per share, in cash, less any applicable withholding taxes and without interest. The Offer expired at midnight, New York City time, at the end of the day on November 17, 2022.

A "modified Dutch auction" tender offer allows shareholders to indicate how many shares and at what price or within the range described above they wish to tender their shares. Based on the number of shares tendered and the prices specified by the tendering shareholders, the Company determined the lowest per-share price that enabled it to purchase up to $95.0 million of all shares that were validly tendered and not validly withdrawn. All shares accepted in the Offer were purchased at the same price even if tendered at a lower price.

On November 22, 2022, the Company completed the Offer and purchased a total of 115,967 ordinary shares at a price of $10.50 per share, for an aggregate cost of $1.2 million, excluding fees and expenses relating to the Offer. The total of 115,967 shares that were accepted for purchase represented approximately 0.2% of the total number of shares outstanding as of November 21, 2022. The purchased shares were cancelled and ceased to be outstanding. The Company intends to use the unused portion of the Offer to enlarge our previously announced, planned open market share repurchase plan which is described below.

Open Market Share Repurchase Plan

On December 13, 2022, the Company initiated its open market repurchase plan to repurchase ordinary shares. As of December 31, 2022, the Company repurchased 2,978,341 shares on the open market at an average cost of $11.06 per share for an aggregate cost of $32.9 million, excluding fees and expenses. From January 1, 2023 through February 27, 2023, the Company repurchased an additional 2,461,000 shares on the open market at an average cost of $10.99 per share for an aggregate cost of $27.1 million, excluding fees and expenses.