Subsequent Event	6 Months Ended
Jun. 30, 2022
Subsequent Events [Abstract]
Subsequent Event	10. Subsequent event Restructuring On July 6, 2022 the Company announced Phase 2 topline results for praluzatamab ravtansine in breast cancer and its decision to not advance this program ("praluzatamab ravtansine") alone given the data and financial market conditions. The Company will seek a collaboration partnership to further develop praluzatamab ravtansine in patients with advanced breast cancer. On July 13, 2022, the Company announced a restructuring plan to prioritize its resources on its emerging pre-clinical and early clinical pipeline as well as its existing collaboration partnerships. The restructuring plan will result in a reduction to its workforce by approximately 40%, and is expected to be completed by the fourth quarter of 2022. The Company estimates that it will incur aggregate restructuring charges of approximately $10.0 million, primarily related to one-time severance payments and other employee-related costs, in the third and fourth quarters of 2022.

The entire disclosure for significant events or transactions that occurred after the balance sheet date through the date the financial statements were issued or the date the financial statements were available to be issued. Examples include: the sale of a capital stock issue, purchase of a business, settlement of litigation, catastrophic loss, significant foreign exchange rate changes, loans to insiders or affiliates, and transactions not in the ordinary course of business.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 855
-URI https://asc.fasb.org/topic&trid=2122774

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 855
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=6842918&loc=SL6314017-165662

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