CONDENSED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Cash Flows from Operating Activities:
Net income	$ 115,738	$ 8,817
Adjustments to reconcile net income to net cash used in operating activities:
Stock-based compensation	1,111	750
Warrant liability revaluation gain	(6,983)	(1,101)
Future tranche right liability revaluation gain	(118,803)	(20,711)
Issuance of common stock for services rendered	67	26
Accretion of discounts on short-term investments	(1)	(18)
Depreciation and amortization expense	6	24
Changes in operating assets and liabilities:
Prepaid expenses and other assets	1,150	1,313
Accounts payable, accrued expenses, and other liabilities	(1,879)	148
Other	3	4
Net cash used in operating activities	(9,591)	(10,748)
Cash Flows from Investing Activities:
Purchases of available-for-sale securities		(5,535)
Proceeds from maturity of available-for-sale securities	4,500	2,749
Purchases of property and equipment		(7)
Net cash provided by (used in) investing activities	4,500	(2,793)
Cash Flows from Financing Activities:
Proceeds from common stock financings, net	16,322	1,406
Proceeds from employee stock purchases	28	25
Proceeds from exercise of common stock options and warrants	271
Payments on seller-financed purchases	(218)
Net cash provided by financing activities	16,403	1,431
Net increase (decrease) in cash and cash equivalents	11,312	(12,110)
Cash and cash equivalent, beginning of period	33,229	40,019
Cash and cash equivalents, end of period	44,541	27,909
Supplemental disclosure of cash flow information:
Cash paid for interest	3
Supplemental disclosure of non-cash financing and investing activities:
Offering costs in accounts payable and accrued expenses	$ 61	$ 260