CONDENSED CONSOLIDATED STATEMENTS OF REDEEMABLE CONVERTIBLE PREFERRED STOCK AND STOCKHOLDERS' (EQUITY) - USD ($) $ in Thousands	Total	Initial Public Offering	Series A Redeemable Convertible Preferred Stock	Series B Redeemable Convertible Preferred Stock	Series C Redeemable Convertible Preferred Stock	Common Stock	Common Stock Initial Public Offering	Additional Paid-in Capital	Additional Paid-in Capital Initial Public Offering	Accumulated Other Comprehensive (Loss) Income	Accumulated Deficit
Beginning balance at Dec. 31, 2019	$ (192,833)							$ 2		$ 43	$ (192,878)
Temporary equity, Beginning balance, shares at Dec. 31, 2019			33,200,000	20,520,828	20,204,079
Temporary equity, Beginning balance at Dec. 31, 2019			$ 44,169	$ 81,108	$ 89,507
Beginning balance, shares at Dec. 31, 2019						2,997,040
Issuance of Series B redeemable convertible preferred stock in conjunction with sponsored research agreement, shares				62,500
Exercise of options to purchase common stock	18							18
Exercise of options to purchase common stock, shares						5,340
Accretion of preferred stock to redemption value	(3,372)							(1,768)			1,604
Temporary equity, Accretion of preferred stock to redemption value			$ 662	$ 1,184	$ 1,526
Stock-based compensation	1,750							1,750
Unrealized loss on investments	(41)									(41)
Net loss	(22,502)										(22,502)
Ending balance at Mar. 31, 2020	(216,980)							2		$ 2	(216,984)
Temporary equity, Ending balance, shares at Mar. 31, 2020			33,200,000	20,583,328	20,204,079
Temporary equity, Ending balance at Mar. 31, 2020			$ 44,831	$ 82,292	$ 91,033
Ending balance, shares at Mar. 31, 2020						3,002,380
Beginning balance at Dec. 31, 2020	14,567					$ 2		302,655			(288,090)
Beginning balance, shares at Dec. 31, 2020						18,787,579
Exercise of options to purchase common stock	$ 316							316
Exercise of options to purchase common stock, shares	46,807					46,807
Stock-based compensation	$ 2,273							2,273
Issuance of common stock, net of issuance costs		$ 61,868							$ 61,868
Issuance of common stock, net of issuance costs, shares							3,162,500
Net loss	(10,308)										(10,308)
Ending balance at Mar. 31, 2021	$ 68,716					$ 2		$ 367,112			$ (298,398)
Ending balance, shares at Mar. 31, 2021						21,996,886