Condensed Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021
Cash flows from operating activities
Net loss	$ (46,925)	$ (35,621)
Adjustments to reconcile net loss to net cash used in operating activities
Depreciation	334	292
Amortization of operating lease right-of-use asset	127
Non-cash interest expense, and amortization of debt discount and issuance costs	3	41
Amortization of premiums / (accretion of discounts), net on marketable securities	278	377
Stock-based compensation	4,180	4,176
Changes in assets and liabilities
Prepaid expenses and other assets	3,592	1,850
Accounts payable	495	(1,167)
Accrued and other current liabilities	(1,397)	666
Operating lease liabilities, net	(109)
Other non-current liabilities		(9)
Net cash used in operating activities	(39,422)	(29,395)
Cash flows from investing activities
Purchases of marketable securities	(25,292)	(69,226)
Proceeds from maturities of marketable securities	81,048	32,830
Purchases of property and equipment	(335)	(2,000)
Net cash provided by (used in) investing activities	55,421	(38,396)
Cash flows from financing activities
Repayment of debt	(1,083)	(1,500)
Proceeds from private placement financing, net of issuance costs		75,215
Proceeds from At-the-Market offering, net	9,700
Proceeds from issuance of common stock under employee plans	105	8
Net cash provided by financing activities	8,722	73,723
Net increase in cash and cash equivalents	24,721	5,932
Cash and cash equivalents
Cash and cash equivalents, at beginning of period	15,835	36,326
Cash and cash equivalents, at end of period	40,556	42,258
Supplemental disclosure of cash flow information:
Cash paid for income taxes		5
Cash paid for interest	14	107
Supplemental non-cash investing and financing activities:
Operating lease right-of-use asset recorded on the adoption of ASC 842	80
Operating lease right-of-use assets obtained in exchange for new lease liabilities	$ 201
Purchases of property and equipment in accounts payable and accrued and other current liabilities		$ 218