Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021
Cash flows from operating activities:
Net loss	$ (128,248)	$ (114,197)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation expense	15,421	14,275
Depreciation and amortization expense	217	202
Amortization of debt issuance costs and discount	178	0
Changes in operating assets and liabilities:
Prepaid expenses and other current assets	(1,442)	(1,208)
Accounts payable	(10,086)	50
Accrued expense	16,788	10,018
Accrued interest, net of interest received on maturity of investments	(101)	550
Net cash used in operating activities	(107,273)	(90,310)
Cash flows from investing activities:
Purchases of marketable securities	(116,496)	(224,071)
Sales and maturities of marketable securities	191,813	163,328
Purchases of property and equipment, net of disposals	(155)	(46)
Net cash provided by (used in) investing activities	75,162	(60,789)
Cash flows from financing activities:
Proceeds from issuances of stock, excluding related parties, net of transaction costs	0	130,157
Proceeds from the exercise of common stock options	0	478
Proceeds from issuance of loan payable	50,000	0
Payment of debt issuance costs	(886)	0
Net cash provided by financing activities	49,114	130,635
Net increase (decrease) in cash and cash equivalents	17,003	(20,464)
Cash and cash equivalents at beginning of period	36,269	54,004
Cash and cash equivalents at end of period	53,272	33,540
Supplemental disclosure of cash flow information:
Obtaining a right-of-use asset in exchange for a lease liability	$ 583	$ 376