LICENSE AGREEMENTS - Narrative (Details) € in Thousands				1 Months Ended					3 Months Ended							12 Months Ended
	Aug. 05, 2021 USD ($)	Nov. 30, 2020 USD ($)	Jul. 30, 2020 USD ($)	Jan. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)	Sep. 30, 2016 USD ($)	Aug. 31, 2016 USD ($)	Jun. 30, 2016 USD ($) period	Dec. 31, 2021 USD ($)	Jun. 30, 2021 USD ($)	Mar. 31, 2021 USD ($)	Mar. 31, 2021 EUR (€)	Dec. 31, 2020 USD ($)	Dec. 31, 2020 EUR (€)	Sep. 30, 2020 USD ($)	Dec. 31, 2021 USD ($)	Dec. 31, 2021 EUR (€)	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)
Organization And Basis Of Presentation [Line Items]
License and related revenue																$ 26,544,000		$ 11,236,000	$ 0
License agreement, royalty rate					2.00%				2.00%							2.00%
Transaction price													$ 11,200,000		$ 11,200,000			11,200,000
Qilu Pharmaceutical Co., Ltd. | Licensing Agreements
Organization And Basis Of Presentation [Line Items]
Potential milestone payments											$ 23,000,000
License and related revenue										$ 900,000	2,800,000				$ 11,200,000
Upfront payment			$ 12,000,000															12,000,000
Total milestone payments			$ 23,000,000
Royalty payment, percentage			12.00%
Business combination, milestone payments											3,000,000
University of Zurich
Organization And Basis Of Presentation [Line Items]
Royalty payment obligation, percent																4.00%	4.00%
Third party maximum ownership, percent																10.00%	10.00%
Third party minimum ownership, percent																2.00%	2.00%
Expenses related to achievement of development milestone																$ 500,000		300,000
University of Zurich | Collaborative Arrangement, Revenue Based on Clinical Development Milestone
Organization And Basis Of Presentation [Line Items]
License agreement, amount payable upon achievement of specified milestone																$ 500,000
Micromet AG
Organization And Basis Of Presentation [Line Items]
Royalty payment obligation, percent																3.50%	3.50%
Expenses related to achievement of development milestone											600,000	€ 500	900,000	€ 700
Potential milestone payments																$ 2,700,000	€ 2,400
License agreement, royalty payment, reduction, conditions not met																1.50%	1.50%
License maintenance fees																$ 56,625	€ 50
XOMA Ireland Limited
Organization And Basis Of Presentation [Line Items]
License agreement, amount payable upon achievement of specified milestone																$ 250,000
Royalty payment obligation, percent																2.50%	2.50%
Third party maximum ownership, percent																50.00%	50.00%
Third party minimum ownership, percent																1.75%	1.75%
Roche
Organization And Basis Of Presentation [Line Items]
License agreement, up-front fee							$ 7,500,000
License agreement, additional up-front fee							262,500,000
Milestone achieved					$ 20,000,000				$ 20,000,000							$ 20,000,000
Payment terms					30 days
License agreement, option periods | period								2
License agreement, buyout amount under first option period								$ 135,000,000
License agreement, period to pay buyout option once exercised								30 days
License agreement, buyout amount under second option period								$ 265,000,000
Buyout amount under second option period								$ 220,000,000
Roche | Subsequent Event
Organization And Basis Of Presentation [Line Items]
Proceeds from milestone achieved				$ 20,000,000
Roche | EBI-031
Organization And Basis Of Presentation [Line Items]
Milestone achieved					$ 20,000,000				20,000,000							$ 20,000,000
Payment terms																30 days	30 days
License and related revenue									$ 20,000,000
Roche | EBI-031 | Minimum
Organization And Basis Of Presentation [Line Items]
License agreement, royalty rate					7.50%				7.50%							7.50%
Roche | EBI-031 | Maximum
Organization And Basis Of Presentation [Line Items]
License agreement, royalty rate					15.00%				15.00%							15.00%
Roche | EBI-031 | Subsequent Event
Organization And Basis Of Presentation [Line Items]
Proceeds from milestone achieved				$ 20,000,000
Roche | IL-6
Organization And Basis Of Presentation [Line Items]
License agreement, royalty rate					50.00%				50.00%							50.00%
Roche | First Indication
Organization And Basis Of Presentation [Line Items]
License agreement, amount payable upon achievement of specified milestone							197,500,000
Roche | Collaborative arrangement, revenue based on development milestone
Organization And Basis Of Presentation [Line Items]
License agreement, amount payable upon achievement of specified milestone							72,500,000
Roche | Collaborative arrangement, revenue based on development milestone | EBI-031
Organization And Basis Of Presentation [Line Items]
License agreement, amount payable upon achievement of specified milestone						$ 22,500,000
Roche | Collaborative Arrangement, Revenue Based on Development Milestone, Phase II
Organization And Basis Of Presentation [Line Items]
License agreement, amount payable upon achievement of specified milestone							30,000,000
Roche | Collaborative arrangement, revenue based on regulatory milestone
Organization And Basis Of Presentation [Line Items]
License agreement, amount payable upon achievement of specified milestone							50,000,000
Roche | Collaborative arrangement, revenue based on commercialization milestone
Organization And Basis Of Presentation [Line Items]
License agreement, amount payable upon achievement of specified milestone							$ 75,000,000
Roche | Second Indication
Organization And Basis Of Presentation [Line Items]
License agreement, amount payable upon achievement of specified milestone																$ 65,000,000
MENA License Agreement | Licensing Agreements
Organization And Basis Of Presentation [Line Items]
License and related revenue											$ 1,500,000
Upfront payment		$ 3,000,000
Transaction price					$ 1,500,000				$ 1,500,000				$ 1,500,000			$ 1,500,000		$ 1,500,000
Royalty revenue, percentage													0.50					0.50
Eczacibasi Pharmaceuticals Marketing Agreement
Organization And Basis Of Presentation [Line Items]
Potential milestone payments	$ 2,000,000
Transaction price	$ 1,500,000
Eczacibasi Pharmaceuticals Marketing Agreement | TURKEY
Organization And Basis Of Presentation [Line Items]
Royalty revenue, percentage	0.30