Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Operating activities
Net loss	$ (143,099)	$ (165,291)	$ (124,088)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation expense	21,709	35,399	29,783
Depreciation and amortization	530	621	789
Amortization of debt issuance costs	814	812	780
Net amortization of premiums and discounts on investments	(4,098)	(825)	1,560
Acquired in-process research and development	0	0	7,355
Other	6	(281)	(106)
Changes in operating assets and liabilities:
Accounts receivable, net	20,124	(5,084)	(9,616)
Inventory	1,181	(118)	(1,462)
Prepaid expenses and other assets	6,674	(5,782)	(24,759)
Operating lease right-of-use assets	1,962	1,677	1,449
Accounts payable	350	1,170	(2,847)
Accrued expenses and other liabilities	3,996	(9,536)	15,963
Operating lease liabilities	(2,872)	(2,316)	(1,917)
Net cash used in operating activities	(92,723)	(149,554)	(107,116)
Investing activities
Proceeds from sales and maturities of investments	167,091	121,878	192,780
Purchases of investments	(159,151)	(226,016)	(45,228)
Purchases of property and equipment	0	(118)	(212)
Acquired in-process research and development	0	0	(5,500)
Net cash provided by (used in) investing activities	7,940	(104,256)	141,840
Financing activities
Proceeds from issuance of common stock, net of issuance costs	0	189,761	9,903
Proceeds from the exercise of stock options and shares issued under the employee stock purchase plan	1,124	3,977	3,745
Proceeds from Amended Revenue Interest Agreement	0	0	60,000
Net cash provided by financing activities	1,124	193,738	73,648
Effect of exchange rate on cash, cash equivalents and restricted cash	(34)	(488)	(48)
Net (decrease) increase in cash, cash equivalents and restricted cash	(83,693)	(60,560)	108,324
Cash, cash equivalents and restricted cash at beginning of period	136,885	197,445	89,121
Cash, cash equivalents and restricted cash at end of period	53,192	136,885	197,445
Reconciliation of cash, cash equivalents and restricted cash reported within the consolidated balance sheets
Cash and cash equivalents	52,231	135,188	190,459
Short-term restricted cash	660	1,064	6,349
Long-term restricted cash	301	633	637
Total cash, cash equivalents and restricted cash	53,192	136,885	197,445
Supplemental disclosures:
Cash paid for interest on convertible debt	5,175	5,175	5,175
Cash paid for amounts included in the measurement of operating lease liabilities	3,718	3,447	3,277
Cash paid for interest on deferred royalty obligation	$ 16,053	$ 29,273	$ 10,361