STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Operating activities
Net loss	$ (66,067)	$ (67,207)	$ (158,165)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization expense	1,292	1,144	2,807
Non-cash lease expense	3,624	3,457	3,085
Stock-based compensation	13,530	10,750	12,039
Non-cash interest expense	4,220	1,962	283
Gain on sale of equipment	0	(1,260)	0
Other, net	(2,930)	685	(678)
Changes in operating assets and liabilities:
Accounts receivable	(14,298)	(7,231)	(502)
Inventory	(21,141)	(28,346)	0
Prepaid commercial manufacturing	(9,593)	(4,161)	(9,406)
Prepaid expenses and other assets	(6,035)	2,299	502
Accounts payable	279	6,582	(1,349)
Accrued compensation and benefits	5,049	2,126	(250)
Operating lease liabilities	(3,928)	(3,491)	(2,853)
Accrued and other liabilities	3,691	4,138	1,386
Deferred revenue	2,590	8,509	550
Net cash used in operating activities	(89,717)	(70,044)	(152,551)
Investing activities
Proceeds from maturities and redemptions of investments	84,321	67,000	125,550
Purchases of investments	(215,225)	(50,328)	(72,735)
Proceeds from sale of property and equipment	0	1,798	0
Purchases of property and equipment	(344)	(55)	(1,867)
Net cash (used in) provided by investing activities	(131,248)	18,415	50,948
Financing activities
Proceeds from issuance of common stock in at the market offering, net of issuance costs	119,236	71,625	101,146
Proceeds from 2022 Loan, net of issuance costs	22,386	26,971	0
Proceeds from the sale of future royalties, net of issuance costs	5,000	9,581	0
Proceeds from issuance of common stock under equity incentive and stock purchase plans	1,173	202	1,403
Payment of the 2018 Exit Fee	(1,500)	0	0
Payments for the 2018 Loan, net of costs	0	(33,038)	(19,444)
Payments for taxes related to net share settlement of equity awards	0	0	(106)
Net cash provided by financing activities	146,295	75,341	82,999
Net (decrease) increase in cash and cash equivalents	(74,670)	23,712	(18,604)
Cash and cash equivalents at beginning of period	96,140	72,428	91,032
Cash and cash equivalents at end of period	21,470	96,140	72,428
Supplementary disclosure of cash flow information:
Cash paid for interest	4,240	2,901	3,469
Cash paid for income taxes	51	6	4
Supplementary disclosure of non-cash activities:
Right-of-use assets obtained in exchange for lease obligations	339	0	1,604
Issuance of common stock for services	337	390	190
Issuance of derivative in connection with issuance of loan payable	$ 0	$ 375	$ 0