Condensed Statements of Convertible Preferred Stock and Stockholders' Equity (Deficit) - USD ($) $ in Thousands	Total	Convertible Preferred Stock	Common Stock	Additional Paid-In Capital	Accumulated Deficit
Balances at Dec. 31, 2019	$ (225,139)		$ 1	$ 2,324	$ (227,464)
Temporary Equity Balance, Shares at Dec. 31, 2019		118,766
Temporary Equity Balance at Dec. 31, 2019		$ 193,959
Common Stock Balance, Shares at Dec. 31, 2019			255
Exercise of stock options	11			11
Exercise of stock options, shares			20
Net loss	(9,705)				(9,705)
Balances at Mar. 31, 2020	(234,833)		$ 1	2,335	(237,169)
Temporary Equity Balance, Shares at Mar. 31, 2020		118,766
Temporary Equity Balance at Mar. 31, 2020		$ 193,959
Common Stock Balance, Shares at Mar. 31, 2020			275
Balances at Dec. 31, 2020	41,166		$ 27	299,953	(258,814)
Common Stock Balance, Shares at Dec. 31, 2020			26,562
Exercise of stock options	$ 475			475
Exercise of stock options, shares	209,000		223
Stock‑based compensation	$ 1,752			1,752
Net loss	(6,961)				(6,961)
Balances at Mar. 31, 2021	$ 36,432		$ 27	$ 302,180	$ (265,775)
Common Stock Balance, Shares at Mar. 31, 2021			26,785