15. Selected Quarterly Financial Data (Unaudited)

Prior to its IPO on October 18, 2016, the Company had outstanding participating Preferred Shares. During the fourth quarter of the year ended December 31, 2016, the Company had net income, although for the full year the Company had a net loss. Accordingly, the Company used the two-class method to calculate net income per share for the fourth quarter of 2016. For purposes of calculating basic net income per share for the fourth quarter of 2016, the Company excluded from the numerator $3.1 million of net income attributable to participating securities. The Company calculated diluted net income per share under both the if-converted method and the two-class method and concluded that the two-class method was more dilutive than the if-converted method. Accordingly, the two-class income allocations were reapplied after taking into account the dilutive effect of non-participating securities. This resulted in net income of $3.1 million being allocated to the participating securities and excluded from the numerator of the Common Stock dilutive net income per share calculation.

	2016
	First Quarter			Second Quarter			Third Quarter			Fourth Quarter (1)
Collaboration revenue	$	476		$	795		$	1,549		$	2,344
Total operating expenses		12,128			17,353			16,159			27,654
Loss from operations		(11,652	)		(16,558	)		(14,610	)		(25,310	)
Net (loss) income		(8,442	)		(17,164	)		(14,694	)		17,098
Net (loss) income attributable to common shareholders		(8,439	)		(17,157	)		(14,680	)		17,099
Net (loss) income per share attributable to common shareholders:
Basic	$	(1.53	)	$	(3.15	)	$	(2.77	)	$	0.43
Diluted	$	(1.53	)	$	(3.15	)	$	(2.77	)	$	0.40
Weighted-average common shares outstanding used in net (loss) income per share attributable to common shareholders:
Basic		5,528,079			5,448,855			5,292,348			32,987,335
Diluted		5,528,079			5,448,855			5,292,348			34,989,218

	2015
	First Quarter			Second Quarter			Third Quarter			Fourth Quarter
Collaboration revenue	$	—		$	—		$	—		$	247
Total operating expenses		3,736			3,625			6,202			12,413
Loss from operations		(3,736	)		(3,625	)		(6,202	)		(12,166	)
Net loss		(3,522	)		(3,666	)		(6,354	)		(12,286	)
Net loss attributable to common shareholders	$	(3,237	)	$	(3,643	)	$	(6,353	)	$	(12,270	)
Net loss per share applicable to common shareholders- basic and diluted	$	(0.91	)	$	(0.80	)	$	(1.15	)	$	(2.22	)
Weighted-average common shares outstanding used in net loss per share attributable to common shareholders - basic and diluted		3,560,000			4,538,595			5,528,079			5,528,079

(1)	During the fourth quarter the Company recorded an immaterial correction of an error of $1.2 million for rent expense related to the three months ended September 30, 2016. The Company determined that these errors are not material to the respective interim financial statements.