CONDENSED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021
Operating activities
Net loss	$ (27,806)	$ (56,037)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	1,204	1,057
Stock-based compensation	1,312	1,398
(Gain)/loss from remeasurement of development derivative liability	(15,952)	7,203
Non-cash interest expense	77	173
Non-cash research and development expense	7,395	23,705
Changes in operating assets and liabilities:
Receivable from sublicense	0	(18,400)
Prepaid expenses and other assets	3,504	8,855
Accounts payable	(6,439)	(585)
Accrued expenses and other current liabilities	3,735	1,679
Deferred sublicense revenue	(325)	9,662
Net cash used in operating activities	(33,295)	(21,290)
Investing activities
Purchases of property and equipment	(107)	(385)
Net cash used in investing activities	(107)	(385)
Financing activities
Proceeds from issuance of common stock in public offering, net	1,920	60,351
Payments of deferred stock offering costs	0	(40)
Proceeds from exercise of stock options	0	223
Issuance of common stock under employee stock purchase plan	213	202
Repayments of long-term debt	(2,727)	(2,727)
Net cash (used in)/provided by financing activities	(594)	58,009
Net (decrease)/increase in cash and cash equivalents	(33,996)	36,334
Cash and cash equivalents at the beginning of the period	41,800	28,122
Cash and cash equivalents at the end of the period	7,804	64,456
Supplemental disclosure for cash flow
Cash paid for interest	187	366
Supplemental disclosure of non-cash investing and financing activities
Purchases of property and equipment by incurring development derivative liability	0	4,160
Purchases of property and equipment included in accounts payable and accrued expenses	$ 205	$ 44