Condensed Consolidated Statement of Changes in Redeemable Convertible Preferred Stock and Stockholders' Equity - USD ($) $ in Thousands	Total	Preferred Stock Series A	Preferred Stock Series B	Common Stock	Additional Paid-in Capital	Accumulated Deficit
Balance at beginning of period (in shares) at Dec. 31, 2018		978,849	1,989,616	1,345,402
Balance at beginning of period at Dec. 31, 2018	$ (46,919)	$ 20,903	$ 39,592	$ 12	$ 1	$ (46,932)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share-based compensation	48				48
Accretion of preferred stock to current redemption value (pre-merger)	(750)	$ 247	$ 503			(750)
Net income (loss)	(2,105)					(2,105)
Balance at end of period (in shares) at Mar. 31, 2019		978,849	1,989,616	1,345,402
Balance at end of period at Mar. 31, 2019	(49,726)	$ 21,150	$ 40,095	$ 12	49	(49,787)
Balance at beginning of period (in shares) at Dec. 31, 2019		978,849	1,989,616	1,177,933
Balance at beginning of period at Dec. 31, 2019	(59,463)	$ 21,904	$ 41,631	$ 12	202	(59,677)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Accretion of preferred stock to current redemption value (pre-merger)	(651)	$ 216	$ 435			(651)
Issuance of common stock to former stockholders of NewLink upon merger (in shares)				4,146,405
Issuance of common stock to former stockholders of NewLink upon merger	116,949			$ 41	116,908
Conversion of preferred stock into common stock upon merger (in shares)		(978,849)	(1,989,616)	2,968,465
Conversion of preferred stock into common stock upon merger	64,186	$ (22,120)	$ (42,066)	$ 30	64,156
Share-based compensation	177				177
Net income (loss)	340					340
Balance at end of period (in shares) at Mar. 31, 2020		0	0	8,292,803
Balance at end of period at Mar. 31, 2020	$ 121,538	$ 0	$ 0	$ 83	$ 181,443	$ (59,988)