Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014
Cash flows from operating activities:
Net loss	$ (19,767)	$ (13,523)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	67	35
Gain on bargain purchase		(486)
Share-based compensation expense	1,578	824
Changes in assets and liabilities, net of effect of acquisitions:
(Increase)/decrease in prepaid expenses and other assets	(124)	89
Increase/(decrease) in accounts payable and accrued liabilities	2,364	(201)
Net cash used in operating activities	(15,882)	(13,262)
Cash flows from investing activities:
Purchases of certificates of deposit	(7,986)	(7,981)
Proceeds from maturities of certificates of deposit	7,337	6,626
Purchases of property and equipment	(91)	(109)
Cash obtained through acquisition		3,534
Net cash (used in)/provided by investing activities	(740)	2,070
Cash flows from financing activities:
Proceeds from sale of common stock	2,140	12,474
Payments for capital lease	(3)
Payments for offering costs	(109)	(595)
Net cash provided by financing activities	2,028	11,879
Net (decrease)/increase in cash and cash equivalents	(14,594)	687
Cash and cash equivalents at beginning of period	35,808	25,681
Cash and cash equivalents at end of period	$ 21,214	$ 26,368