CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (unaudited) - USD ($)	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Operating activities
Net loss	$ (60,815,000)	$ (12,921,000)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation	107,000	101,000
Stock-based compensation expense	682,000	686,000
Loss from change in fair value of contingent consideration	43,000,000	2,700,000
Gain on sale of equipment	0	(5,000)
Changes in operating assets and liabilities:
Prepaid expenses and other assets	(1,487,000)	(426,000)
Accounts payable	809,000	403,000
Accrued expenses and other liabilities	961,000	(517,000)
Net cash used in operating activities	(16,743,000)	(9,979,000)
Investing activities
Purchases (sales) of equipment	(43,000)
Purchases (sales) of equipment		5,000
Net cash (used in) provided by investing activities	(43,000)	5,000
Financing activities
Proceeds from exercise of common stock options	45,000	29,000
Proceeds from issuance of common stock and the issuance and exercise of common stock warrants, net of issuance costs	31,243,000	58,226,000
Proceeds from sale of common stock pursuant to 2014 ESPP	7,000	10,000
Net cash provided by financing activities	31,295,000	58,265,000
Net increase in cash, cash equivalents and restricted cash	14,509,000	48,291,000
Cash, cash equivalents and restricted cash at beginning of period	50,442,000	14,690,000
Cash, cash equivalents and restricted cash at end of period	64,951,000	62,981,000
Supplemental non-cash operating activities
Right-of-use assets obtained in exchange for operating lease liability	236,480,000	0
Cash paid for amounts included in the measurement of lease liabilities	76,071,000	0
Capital Expenditures Incurred but Not yet Paid	$ 119,000	$ 0