STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Operating activities
Net loss	$ (67,207)	$ (158,165)	$ (94,313)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization expense	1,144	2,807	2,541
Non-cash lease expense	3,457	3,085	2,147
Stock-based compensation	10,750	12,039	10,583
Change in derivative liabilities	583	(678)	407
Debt refinancing costs	102	0	0
Gain on sale of equipment	(1,260)	0	0
Non-cash interest expense	1,962	283	413
Changes in operating assets and liabilities:
Unbilled revenue	0	0	750
Accounts receivable	(7,231)	(502)	0
Inventory	(28,346)	0	0
Prepaid commercial manufacturing	(4,161)	(9,406)	0
Prepaid expenses and other assets	2,299	502	(4,653)
Accounts payable	6,582	(1,349)	3,439
Accrued compensation and benefits	2,126	(250)	1,219
Operating lease liabilities	(3,491)	(2,853)	(2,604)
Accrued and other liabilities	4,138	1,386	(1,000)
Deferred revenue	8,509	550	(364)
Net cash used in operating activities	(70,044)	(152,551)	(81,435)
Investing activities
Proceeds from maturities and redemptions of investments	67,000	125,550	119,734
Purchases of investments	(50,328)	(72,735)	(150,852)
Proceeds from sale of property and equipment	1,798	0	0
Purchases of property and equipment	(55)	(1,867)	(324)
Net cash provided by (used in) investing activities	18,415	50,948	(31,442)
Financing activities
Proceeds from 2022 Loan, net of issuance costs	26,971	0	0
Payments for 2018 Loan, net of costs	(33,038)	(19,444)	(125)
Proceeds from the sale of future royalties, net of issuance costs	9,581	0	0
Proceeds from issuance of common stock in at the market offering, net of issuance costs	71,625	101,146	21,047
Proceeds from issuance of common stock under equity incentive and stock purchase plans	202	1,403	1,854
Payments for taxes related to net share settlement of equity awards	0	(106)	0
Net cash provided by financing activities	75,341	82,999	22,776
Net increase (decrease) in cash and cash equivalents	23,712	(18,604)	(90,101)
Cash and cash equivalents at beginning of period	72,428	91,032	181,133
Cash and cash equivalents at end of period	96,140	72,428	91,032
Supplementary disclosure of cash flow information:
Cash paid for interest	2,901	3,469	4,200
Cash paid for income taxes	6	4	1
Supplementary disclosure of non-cash activities:
Right-of-use assets obtained in exchange for lease obligations	0	1,604	450
Issuance of common stock for services	390	190	310
Issuance of derivative in connection with issuance of loan payable	$ 375	$ 0	$ 0