CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Operating activities
Net (loss) income	$ (52,764)	$ 43,750
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation expense	4,611	5,191
Gain on sale of priority review voucher		(100,000)
Deferred tax provision		22,006
Depreciation and amortization	350	201
Non-cash rent expense	(65)	(61)
Changes in operating assets and liabilities:
Prepaid expenses and other current assets	950	1,651
Other long-term assets	(6,661)
Accounts payable, accrued expenses and other current liabilities	(53)	(6,269)
Net cash used in operating activities	(53,632)	(33,531)
Investing activities
Purchases of short-term investments	(39,479)	(297,542)
Maturities of short-term investments	112,128	51,842
Proceeds from sale of priority review voucher		100,000
Purchases of property and equipment	(127)	(12)
Net cash provided by (used in) investing activities	72,522	(145,712)
Financing activities
Net proceeds from issuance of common stock		161,731
Proceeds from the exercise of stock options		3,466
Proceeds from issuance of common stock from ESPP	399	388
Net cash provided by financing activities	399	165,585
Net increase (decrease) in cash, cash equivalents and restricted cash	19,289	(13,658)
Cash, cash equivalents and restricted cash at beginning of period	59,576	101,257
Cash, cash equivalents and restricted cash at end of period	$ 78,865	$ 87,599