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Related Party Transactions - Additional Information (Details) - USD ($)		12 Months Ended
	Jan. 30, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Follow-on-offering
Related Party Transaction [Line Items]
Public offerings	9,602,500
Share price	$ 25.00
Follow-on-offering | Director
Related Party Transaction [Line Items]
Public offerings	20,000
Share price	$ 25.00
Adimab
Related Party Transaction [Line Items]
Related party transaction expenses		$ 0	$ 2,800,000	$ 2,300,000
Accrued liabilities due to related parties		0	$ 0
Two Thousand Fourteen Adimab Agreement | Maximum
Related Party Transaction [Line Items]
Future milestone payments owed		$ 3,500,000

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+ References

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Carrying amount as of the balance sheet date of obligations due all related parties. For classified balance sheets, represents the current portion of such liabilities (due within one year or within the normal operating cycle if longer).

+ References

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