Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 75,253	$ 86,769
Short-term investments	225	110
Other receivables	6,820	5,402
Contract asset	1,500
Prepaid expenses	1,150	1,558
Total current assets	84,948	93,839
Property, plant and equipment, net	1,285	1,327
Intangible assets, net	127	172
Long-term receivables	428	425
Total assets	86,788	95,763
Current liabilities:
Accounts payable	2,928	5,136
Accrued expense and other current liabilities	8,364	8,124
Total current liabilities	11,292	13,260
Non-current liabilities
Long-term debt	592	232
Other non-current liabilities	236	203
Total non-current liabilities	828	435
Total liabilities	12,120	13,695
Commitments and contingencies (Note 10)
Stockholders' Equity:
Ordinary shares, nominal value $0.01, 1,000,000,000 ordinary shares authorized at June 30, 2018; 36,707,685 and 40,959,452 issued and outstanding at December 31, 2017 and June 30, 2018, respectively	410	367
Preferred shares, par value $0.01, 100,000,000 shares authorized at June 30, 2018; None issued and outstanding
Additional paid in capital	384,557	360,872
Accumulated other comprehensive income	27	27
Accumulated deficit	(310,326)	(279,198)
Total stockholders' equity	74,668	82,068
Total liabilities and stockholders' equity	$ 86,788	$ 95,763