Selected Quarterly Financial Data (Unaudited)

12 Months Ended

Dec. 31, 2019

Quarterly Financial Data [Abstract]

Selected Quarterly Financial Data (Unaudited)

16. Selected Quarterly Financial Data (Unaudited)

The following table contains quarterly financial information for 2019 and 2018. The Company believes that the following information reflects all normal recurring adjustments necessary for a fair statement of the information for the periods presented. The operating results for any quarter are not necessarily indicative of results for any future period.

	2019
	First Quarter			Second Quarter			Third Quarter			Fourth Quarter			Total
Collaboration revenue - related party	$	6,615		$	10,454		$	4,840		$	5,279		$	27,188
Grant revenue		446			260			85			311			1,102
Collaboration revenue		260			1,817			2,106			2,032			6,215
Total operating expenses		31,874			23,479			24,214			26,814			106,381
Loss from operations		(24,553	)		(10,948	)		(17,183	)		(19,192	)		(71,876	)
Net loss		(24,333	)		(10,759	)		(16,409	)		(18,778	)		(70,279	)
Net loss per share applicable to common    stockholders - basic and diluted	$	(0.59	)	$	(0.24	)	$	(0.23	)	$	(0.27	)	$	(1.24	)

	2018
	First Quarter			Second Quarter			Third Quarter			Fourth Quarter			Total
Collaboration revenue - related party	$	3,766		$	4,271		$	8,684		$	10,196		$	26,917
Grant revenue		205			341			371			433			1,350
Total operating expenses		32,237			32,748			31,266			32,300			128,551
Loss from operations		(28,266	)		(28,136	)		(22,211	)		(21,671	)		(100,284	)
Net loss		(27,919	)		(27,787	)		(21,949	)		(21,287	)		(98,942	)
Net loss per share applicable to common    stockholders - basic and diluted	$	(0.69	)	$	(0.68	)	$	(0.54	)	$	(0.52	)	$	(2.43	)