Contingencies and commitments - Alpine Collaboration Agreement (Details) - Research and development - Collaboration agreement - Alpine Immune Sciences Inc. - USD ($)	1 Months Ended
Jun. 30, 2019	Jun. 30, 2022
Contingencies and commitments
Milestone payment accrued but not yet paid		$ 1,000,000
Upfront license fees	$ 2,000,000
Maximum
Contingencies and commitments
Potential milestone payments	$ 288,000,000

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