Condensed consolidated balance sheets - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Current assets
Cash and cash equivalents (Note 3)	$ 72,700	$ 76,928
Receivables, prepayments and deposits	509	237
Total current assets	73,209	77,165
Property and equipment, net	318	400
Operating lease right-of-use asset (Note 2(i))	186
Long-term prepayments and deposits	30	53
Total assets	73,743	77,618
Current liabilities
Accounts payable and other liabilities	958	4,627
Operating lease liability (Note 5)	201
Total current liabilities	1,159	4,627
Other liabilities (Note 4)	2	319
Non-current operating lease liability (Note 5)	253
Total liabilities	1,414	4,946
Share capital: (Note 6)
Common stock
Additional paid-in capital	304,625	302,759
Accumulated deficit	(232,296)	(230,087)
Total stockholders' equity	72,329	72,672
Total liabilities and stockholders' equity	$ 73,743	$ 77,618