Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Cash flows from operating activities:
Net loss	$ (18,735)	$ (13,424)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation expense	1,077	1,048
Depreciation and amortization	557	286
Non-cash interest expense	71	63
Other	11
Change in fair value of contingent consideration liability	900	800
Changes in assets and liabilities:
Accounts receivable	(1,136)	491
Other current assets	(447)	(204)
Other assets	146
Accounts payable	124	(1,757)
Accrued expenses	(991)	(1,632)
Other current liabilities	18
Other liabilities	(114)	73
Net cash used in operating activities	(18,519)	(14,256)
Cash flows from investing activities:
Acquisition of AZEDRA manufacturing assets	(8,000)
Purchases of property and equipment	(491)	(16)
Net cash used in investing activities	(8,491)	(16)
Cash flows from financing activities:
Net proceeds from issuance of common stock in connection with at-the-market offering		9,524
Repayment of debt	(1,037)
Net cash (used in) provided by financing activities	(1,037)	9,524
Effect of currency rate changes on cash, cash equivalents and restricted cash	(46)	(17)
Net decrease in cash, cash equivalents, and restricted cash	(28,093)	(4,765)
Cash, cash equivalents, and restricted cash at beginning of period	139,220	92,164
Cash, cash equivalents, and restricted cash at end of period	111,127	87,399
Supplemental disclosure of cash flow information
Cash paid for interest	1,077	1,205
Noncash financing activity
Subscription receivable		(1,359)
Cash, cash equivalents and restricted cash information
Cash and cash equivalents at beginning of period	137,686	90,642
Restricted cash included in long-term assets at the beginning of period	1,534	1,522
Cash, cash equivalents, and restricted cash at beginning of period	139,220	92,164
Cash and cash equivalents at end of period	109,587	83,431
Restricted cash included in current assets at the end of period		2,444
Restricted cash included in long-term assets at the end of period	1,540	1,524
Cash, cash equivalents, and restricted cash at end of period	$ 111,127	$ 87,399