Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
Cash flows from operating activities
Net loss	$ (71,395)	$ (41,242)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	256	129
Stock-based compensation	8,055	1,391
Amortization of debt discount	698	544
Change in fair value of warrant liabilities	0	(95)
Other	540	0
Changes in operating assets and liabilities:
Prepaid expenses and other current assets (includes the change in related party amounts of $82, and $0, respectively)	2,203	10,428
Accounts payable and accrued expenses (includes the change in related party amounts of $722 and $(181), respectively)	(12,860)	8,129
Accrued clinical trial expenses	(5,759)
Accrued interest	(10)	146
Operating right-of-use asset and lease liabilities	50	9
Other long-term assets	93	(200)
Net cash used in operating activities	(78,129)	(20,761)
Cash flows from investing activities
Cash paid for property, plant and equipment	(214)	(733)
Net cash used in investing activities	(214)	(733)
Cash flows from financing activities
Proceeds from issuance of common stock from exercise of stock options	516
Net proceeds from issuance of long-term debt		25,000
Net cash provided by financing activities	516	25,000
Net (decrease) increase in cash and cash equivalents	(77,827)	3,506
Cash and cash equivalents – beginning of period	287,496	243,765
Cash and cash equivalents – end of period	209,669	247,271
Supplemental disclosure of cash flow information
Interest paid	1,833	1,309
Supplemental disclosure of noncash investing and financing activities
Property and equipment purchases included in accounts payable and accrued liabilities	3	20
Final interest payment fee		2,063
Settlement of ESPP liability in common stock	358
Settlement of 401(k) liability in common stock	$ 323
Operating lease liabilities arising from obtaining right-of-use assets		1,423
Conversion of Lender Warrants into equity		$ 318