STATEMENTS OF CHANGES IN STOCKHOLDERS’ EQUITY (DEFICIT) - USD ($) $ in Thousands	Common stock IPO	Common stock	Additional Paid in Capital IPO	Additional Paid in Capital	Accumulated Deficit	IPO	Total
Beginning Balance at Dec. 31, 2017		$ 10		$ 3,458	$ (4,450)		$ (982)
Beginning Balance (in shares) at Dec. 31, 2017		9,907,548
Issuance of common stock	$ 5	$ 1	$ 54,097	1,949		$ 54,102	1,950
Issuance of common stock (in shares)	5,454,545	283,452
Stock-based compensation				3,082			3,082
Exercise of stock options				7			7
Exercise of stock options (in shares)		17,676
Net loss					(19,270)		(19,270)
Ending Balance at Dec. 31, 2018		$ 16		62,593	(23,720)		$ 38,889
Ending Balance (in shares) at Dec. 31, 2018		15,663,221					15,663,221
Issuance of common stock		$ 2		17,808			$ 17,810
Issuance of common stock (in shares)		2,369,223
Stock-based compensation				3,142			3,142
Exercise of stock options				22			22
Exercise of stock options (in shares)		54,938
Net loss					(32,968)		(32,968)
Ending Balance at Dec. 31, 2019		$ 18		$ 83,565	$ (56,688)		$ 26,895
Ending Balance (in shares) at Dec. 31, 2019		18,087,382					18,087,382