Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Cash flows from operating activities
Net Loss	$ (89,945)	$ (76,849)	$ (36,980)
Adjustments to reconcile net loss to net cash used in operating activities:
Non-cash rent expense	199	367	367
Stock based compensation	29,853	14,470	2,056
Depreciation and amortization	344	332	188
Amortization of premium / (discount) on available for sale investments	878	635	(812)
Changes in operating assets and liabilities:
Prepaid expenses and other current assets	(829)	2,184	(5,324)
Other assets	(155)	178	(207)
Accounts payable	1,356	480	2,580
Accrued expenses and other current liabilities	(4,633)	7,385	4,855
Net cash used in operating activities	(62,932)	(50,818)	(33,277)
Cash flow from investing activities:
Purchase of investments	(38,789)	(187,141)	(135,415)
Proceeds from maturities of investments	97,921	134,762	117,723
Purchase of property and equipment	(180)	(52)	(55)
Net cash provided by (used in) investing activities	58,952	(52,431)	(17,747)
Cash flows from financing activities:
Payments of finance leases	0	(34)	(559)
Proceeds from issuance of commons stock upon exercise of stock options	6,808	1,282	97
Proceeds from stock warrant exercise	0	0	1
Proceeds from initial public offering, net of stock offering costs	0	0	77,827
Proceeds from private placement offering, net of issuance costs	0	117,628	0
Net cash provided by financing activities	6,808	118,876	77,366
Effect of exchange rate changes on cash	55	0	0
Net increase in cash and cash equivalents	2,883	15,627	26,342
Cash and cash equivalents at beginning of period	66,841	51,214	24,872
Cash and cash equivalents at end of period	69,724	66,841	51,214
Supplemental disclosures of non-cash information:
Right-of-use assets obtained in exchange for new operating lease liabilities	1,254	620	878
Series A Redeemable Convertible Preferred Stock
Supplemental disclosures of non-cash information:
Conversion of redeemable convertible preferred stock to common stock on initial public offering	0	0	17,178
Series B Redeemable Convertible Preferred Stock
Supplemental disclosures of non-cash information:
Conversion of redeemable convertible preferred stock to common stock on initial public offering	0	0	87,816
Acceleration of vesting of redeemable convertible preferred stock on initial public offering	$ 0	$ 0	$ 856