Annual report pursuant to Section 13 and 15(d)

CONSOLIDATED STATEMENTS OF CONVERTIBLE PREFERRED STOCK AND STOCKHOLDERS’ (DEFICIT) EQUITY

CONSOLIDATED STATEMENTS OF CONVERTIBLE PREFERRED STOCK AND STOCKHOLDERS’ (DEFICIT) EQUITY - USD ($) $ in Thousands	Common Stock Series A convertible preferred stock	Common Stock Series B convertible preferred stock	Common Stock	Additional Paid‑In Capital Series A convertible preferred stock	Additional Paid‑In Capital Series B convertible preferred stock	Additional Paid‑In Capital	Accumulated Other Comprehensive Loss	Accumulated Deficit	Series A convertible preferred stock	Series B convertible preferred stock	Total
Balance at Dec. 31, 2013			$ 1			$ 970		$ (10,264)			$ (9,293)
Balance (in shares) at Dec. 31, 2013			1,379,669
Increase (Decrease) in Stockholders' Equity
Exercise of stock options and vesting of restricted stock awards						15					15
Exercise of stock options and vesting of restricted stock awards (in shares)			260,340
Stock-based compensation expense						937					937
Net loss								(13,431)			(13,431)
Balance at Dec. 31, 2014			$ 1			1,922		(23,695)			(21,772)
Balance (in shares) at Dec. 31, 2014			1,640,009
Balance at Dec. 31, 2013									$ 13,266
Balance (in shares) at Dec. 31, 2013									14,600,000
Increase (Decrease) in Temporary Equity
Issuance of convertible preferred stock, net of issuance costs									$ 15,749	$ 52,998
Issuance of convertible preferred stock, net of issuance costs (in shares)									15,750,000	16,893,931
Balance at Dec. 31, 2014									$ 29,015	$ 52,998
Balance (in shares) at Dec. 31, 2014									30,350,000	16,893,931
Increase (Decrease) in Stockholders' Equity
Exercise of stock options and vesting of restricted stock awards			$ 1			392					393
Exercise of stock options and vesting of restricted stock awards (in shares)			723,009
Stock-based compensation expense						3,233					3,233
Net loss								(29,818)			(29,818)
Balance at Dec. 31, 2015			$ 2			5,547		(53,513)			$ (47,964)
Balance (in shares) at Dec. 31, 2015			2,363,018								2,363,018
Balance at Dec. 31, 2015									$ 29,015	$ 52,998
Balance (in shares) at Dec. 31, 2015									30,350,000	16,893,931
Increase (Decrease) in Stockholders' Equity
Conversion of convertible preferred stock into common stock	$ 8	$ 8		$ 29,007	$ 92,784				$ 29,015	$ 92,792
Conversion of convertible preferred stock into common stock (in shares)	8,093,326	7,895,474
Issuance of common stock under IPO, net of IPO costs of $7.6 million			$ 5			49,877					$ 49,882
Issuance of common stock under IPO, net of IPO costs of $7.6 million (in shares)			4,600,000
Exercise of stock options and vesting of restricted stock awards						395					395
Exercise of stock options and vesting of restricted stock awards (in shares)			429,070
Stock-based compensation expense						4,234					4,234
Other comprehensive loss							$ (9)				(9)
Net loss								(47,743)			(47,743)
Balance at Dec. 31, 2016			$ 23			$ 181,844	$ (9)	$ (101,256)			$ 80,602
Balance (in shares) at Dec. 31, 2016			23,380,888								23,380,888
Increase (Decrease) in Temporary Equity
Issuance of convertible preferred stock, net of issuance costs										$ 39,794
Issuance of convertible preferred stock, net of issuance costs (in shares)										12,714,150
Conversion of convertible preferred stock into common stock									$ (29,015)	$ (92,792)
Conversion of convertible preferred stock into common stock (in shares)									(30,350,000)	(29,608,081)
Balance (in shares) at Dec. 31, 2016									0	0