Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021
CASH FLOWS FROM OPERATING ACTIVITIES
Net loss	$ (64,993)	$ (45,355)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	1,182	1,165
Stock-based compensation	5,684	5,944
Purchase net premium on marketable securities	351	(374)
Non-cash operating lease expense	292	334
Net amortization of premium (accretion of discount) on marketable securities	(175)	490
Other	0	2
Changes in operating assets and liabilities:
Accounts payable	859	(390)
License and development receivables	146	0
Prepaid expenses and other assets	(2,863)	(1,555)
Accrued and other liabilities	(1,293)	(828)
Deferred revenue	(897)	6,405
Operating lease liabilities	(297)	(286)
Net cash used in operating activities	(62,004)	(34,448)
CASH FLOWS FROM INVESTING ACTIVITIES
Purchases of property and equipment	(38)	(573)
Purchases of marketable securities	(35,000)	(119,829)
Proceeds from maturities and sales of marketable securities	78,046	88,120
Net cash provided by (used in) investing activities	43,008	(32,282)
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from issuance of common stock and pre-funded warrants in registered direct offering, net of offering costs	42,874	0
Proceeds from employee stock plan purchases and stock option exercises	222	1,654
Principal payments on finance lease obligation	(410)	(341)
Net cash provided by financing activities	42,686	1,313
Effect of exchange rate on cash, cash equivalents, and restricted cash	(152)	(18)
NET INCREASE (DECREASE) IN CASH, CASH EQUIVALENTS, AND RESTRICTED CASH	23,538	(65,435)
CASH, CASH EQUIVALENTS, AND RESTRICTED CASH
Beginning of period	16,980	91,937
End of period	40,518	26,502
Supplemental Disclosure of Non-Cash Investing and Financing Information:
Leased assets obtained in exchange for lease obligations	$ 0	$ 872