DEFERRED REVENUE, REFUND LIABILITY AND LIABILITY RELATED TO SALE OF FUTURE ROYALTIES - Narrative (Details) $ / shares in Units, $ in Thousands			1 Months Ended		3 Months Ended
	Feb. 18, 2022 USD ($)	Feb. 25, 2021 USD ($)	Feb. 28, 2022 USD ($) $ / shares shares	May 31, 2017 USD ($) $ / shares shares	Mar. 31, 2024 USD ($) performance_obligation shares	Mar. 31, 2023 USD ($)	Dec. 31, 2023 USD ($) shares	Mar. 18, 2022 USD ($)
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Deferred revenue					$ 43,991
Common stock, issued (in shares) | shares					209,454,149		194,582,539
Deferred revenue, net of current portion					$ 43,296		$ 43,296
Refund liability to customer, amortization of discount					700	$ 800
Refund liability to customer, amortization of deferred gain					900	$ 1,000
Refund liability to customer					39,927		40,093
Maximum annual royalty payout capacity		$ 13,000
Percentage of royalty payment to be received once maximum annual royalty payout has been paid		85.00%
Maximum aggregate royalty payout capacity		$ 150,000
Long-term portion		$ 44,800			$ 53,498		$ 54,013
Annual effective interest rate					0.00%
Vifor (International) Ltd.
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Contract termination, prior written notice period	30 months
Private Placement
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Sale of stock, price per share (in dollars per share) | $ / shares			$ 5.00
Number of shares sold in offering (in shares) | shares			4,000,000
Aggregate net proceeds from offering			$ 20,000
Vifor (International) Ltd.
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Deferred revenue					$ 43,296
Contract termination, prior written notice period	6 months
Deferred revenue, net of current portion					43,296
Refund liability to customer, gross								$ 40,000
Refund liability to customer					39,900
Vifor (International) Ltd. | License Agreement
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Common stock, issued (in shares) | shares				3,571,429
Sale of stock, price per share (in dollars per share) | $ / shares				$ 14.00
Proceeds from common stock sold				$ 50,000
Vifor (International) Ltd. | License
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Revenue, remaining performance obligation, profit share percentage	66.00%
Deferred revenue	$ 25,000
Deferred revenue, net of current portion			$ 13,600	$ 4,700	$ 43,300
Number of performance obligations | performance_obligation					1
Transaction price	$ 43,300
Refund liability, percentage								50.00%
Refund liability to customer, interest rate								15.00%
Vifor (International) Ltd. | License | Private Placement
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Deferred revenue, net of current portion					$ 18,300
Vifor International Limited, First Investment | License
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Deferred revenue, net of current portion					4,700
Vifor International Limited, Second Investment | License
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Deferred revenue, net of current portion					$ 13,600