Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Cash flow from operating activities:
Net loss	$ (59,699)	$ (28,060)	$ (11,388)
Income (loss) from discontinued operations		2,274	(1,715)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	757	631	462
Share-based compensation	1,573	1,974	177
Non-cash interest income			(58)
Non-cash interest expense			700
Increase in fair value of warrant liability			641
Loss (gain) on disposal of property and equipment	(36)	8
Changes in operating assets and liabilities:
Contracts and grants receivable			519
Prepaid expenses and other current assets	(22)	(604)	(278)
Accounts payable	1,372	825	338
Accrued compensation	1,258	769	61
Accrued outside research and development services	4,649	837	251
Accrued legal and professional fees	179	200	3
Accrued expenses	1,083	411	(92)
Other	(25)	(30)	(22)
Net cash used in continuing operating activities	(48,911)	(20,765)	(10,401)
Net cash provided by (used in) discontinued operating activities	(257)	(1,427)	1,798
Net cash used in operating activities	(49,168)	(22,192)	(8,603)
Cash flow from investing activities:
Purchases of property and equipment	(6,143)	(1,212)	(772)
Purchase of intangible asset	(75)
Cash restricted to secure letter of credit		(539)
Net cash used in continuing investing activities	(6,218)	(1,751)	(772)
Net cash used in discontinued investing activities		(139)	(6)
Net cash used in investing activities	(6,218)	(1,890)	(778)
Cash flow from financing activities:
Proceeds from issuance of preferred stock		67,099	11,959
Proceeds from issuance of convertible notes			3,502
Proceeds from initial public offering, net of underwriting fees and commissions	47,785
Payments related to public offering costs	(3,190)
Proceeds from exercise of stock options	35	458	57
Proceeds from the exercise of preferred stock warrants			550
Purchase of treasury stock	(155)
Dividend Distribution		(5,200)
Payments on capital lease obligation	(7)	(6)	(5)
Payments on facility financing obligation	(159)
Net cash provided by financing activities	44,309	62,351	16,063
Net increase (decrease) in cash and cash equivalents	(11,077)	38,269	6,682
Cash and cash equivalents as of beginning of period	45,688	7,419	737
Cash and cash equivalents as of end of period	34,611	45,688	7,419
Supplemental disclosure of cash flow information:
Cash paid for interest, including capitalized interest	410	1	2
Supplemental disclosure of non-cash investing and financing activities:
Purchases of equipment with accounts payable and accrued expenses	420	92	240
Conversion of notes payable and unpaid interest into preferred stock			3,782
Exercise of preferred stock warrants			$ 853
Distribution of KNOW Bio, LLC equipment		125
Equipment acquired through capital lease	39
Non-cash addition to construction in progress related to build-to-suit lease and facility financing obligation	8,157
Non-cash addition to deferred offering costs		$ 309
Conversion of convertible preferred stock and non-voting common stock to voting common stock	104,798
Deferred offering costs reclassified to additional paid-in capital	$ 3,190