Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 91,042	$ 102,003
Short-term investments	225	225
Other receivables	7,238	3,871
Contract asset	1,000	1,500
Prepaid expenses	973	1,154
Total current assets	100,478	108,753
Property, plant and equipment, net	2,972	1,139
Intangible assets, net	99	98
Long-term receivables	438	428
Total assets	103,987	110,418
Current liabilities:
Accounts payable	7,562	3,304
Accrued expense and other current liabilities	10,533	14,502
Total current liabilities	18,095	17,806
Non-current liabilities
Long-term debt	23,945	23,718
Other non-current liabilities	1,840	264
Total non-current liabilities	25,785	23,982
Total liabilities	43,880	41,788
Commitments and contingencies (Note 13)
Stockholders' Equity:
Ordinary shares, nominal value $0.01, 1,000,000,000 ordinary shares authorized at March 31, 2019; 67,019,094 and 71,335,980 issued and outstanding at December 31, 2018 and March 31, 2019, respectively	713	670
Preferred shares, par value $0.01, 100,000,000 shares authorized at March 31, 2019; None issued and outstanding
Additional paid in capital	473,562	461,911
Accumulated other comprehensive income	27	27
Accumulated deficit	(414,195)	(393,978)
Total stockholders' equity	60,107	68,630
Total liabilities and stockholders' equity	$ 103,987	$ 110,418