Quarterly Financial Data (Tables)

12 Months Ended

Dec. 31, 2019

Quarterly Financial Information Disclosure [Abstract]

Quarterly Financial Information

	March 31, 2019			June 30, 2019			September 30, 2019			December 31, 2019
Grant revenue	$	3,911		$	2,089		$	4,471		$	2,934
Collaboration revenue		3,807			67			172			696
Operating expenses		13,414			15,808			22,628			29,513
Net loss		(5,072	)		(13,150	)		(17,717	)		(24,986	)
Net loss per share attributable to common shareholders per share, basic and diluted	$	(0.29	)	$	(0.74	)	$	(0.95	)	$	(1.31	)
Weighted average shares outstanding, basic and diluted:		17,221,120			17,667,620			18,659,079			19,052,827

	March 31, 2018			June 30, 2018			September 30, 2018			December 31, 2018
Grant revenue	$	1,153		$	463		$	658		$	1,692
Operating expenses		11,969			10,434			11,593			12,776
Net loss		(10,644	)		(9,956	)		(10,463	)		(10,599	)
Net loss per share attributable to common shareholders per share, basic and diluted	$	(0.74	)	$	(0.69	)	$	(0.60	)	$	(0.60	)
Weighted average shares outstanding, basic and diluted:		14,369,182			14,376,529			17,471,462			17,736,996