Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($)	6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021
Cash flows from operating activities:
Net loss	$ (54,531,000)	$ (32,123,000)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	2,352,000	1,989,000
Accretion of premium on investments	70,000	24,000
Stock-based compensation	6,551,000	3,855,000
Non-cash interest expense related to sale of future royalties	663,000	800,000
Non-cash revenue related to sale of future royalties	(152,000)	(802,000)
Change in operating assets and liabilities:
Accounts receivable	71,000	227,000
Prepaid expenses and other assets	(10,243,000)	(3,473,000)
Accounts payable	1,147,000	1,348,000
Other accrued liabilities	3,060,000	(1,596,000)
Net cash used in operating activities	(51,012,000)	(29,751,000)
Cash flows from investing activities:
Purchase of property and equipment	(3,672,000)	(2,818,000)
Purchases of investments	(17,471,000)	(34,890,000)
Proceeds from maturities of investments	16,000,000	1,200,000
Net cash used in investing activities	(5,143,000)	(36,508,000)
Cash flows from financing activities:
Net proceeds from issuance of common stock through ATM facilities	3,797,000	101,914,000
Proceeds from issuance of common stock upon exercise of warrants	2,000	1,849,000
Proceeds from issuance of common stock upon exercise of stock options	79,000	892,000
Net cash provided by financing activities	3,878,000	104,655,000
Net (decrease) increase in cash and cash equivalents	(52,277,000)	38,396,000
Cash and cash equivalents at beginning of the period	143,745,000	126,870,000
Cash and cash equivalents at end of the period	91,468,000	165,266,000
Supplemental disclosure of non-cash investing and financing activity:
Operating lease liabilities arising from obtaining right-of-use assets	125,000	56,000
Lease-related assets and liabilities derecognized on early termination and modification of leases	0	158,000
Acquisition of property and equipment included in accounts payable and accrued expenses	$ 333,000	$ 314,000