Condensed consolidated statements of cash flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Operating activities
Net loss	$ (16,197)	$ (15,937)
Non-cash items and reclassifications:
Financing costs		320
Fees and penalty on bank loan repayment		100
Amortization and extinguishment of remaining discount on preferred stock upon conversion of preferred stock		1,884
Change in fair value of derivative liabilities	70	(958)
Stock-based compensation	1,145	585
Stock-based purchase of patent rights		186
Foreign exchange loss and others	39	218
Changes in operating assets and liabilities:
Accounts and other amounts receivable	46	(48)
Prepayments and deposits	(364)	(125)
Accounts payable and accrued liabilities	(1,515)	2,983
Cash used in operating activities	(16,776)	(10,792)
Investing activities
Purchase of investments		(36,474)
Proceeds from maturity of investments	18,163	6,920
Purchase of property and equipment	(16)	(86)
Sale of property and equipment		16
Cash (used in) provided by investing activities	18,147	(29,624)
Financing activities
Bank loan repayment, fees and penalty		(2,600)
Proceeds from exercise of stock options	1,121
Public offering of common shares	98,038	53,130
Public offering costs	(6,063)	(5,251)
Cash (used in) provided by financing activities	93,096	45,279
Increase (decrease) in cash and cash equivalents during the period	94,467	4,863
Cash and cash equivalents, beginning of period	14,906	11,006
Cash and cash equivalents, end of period	109,373	15,869
Supplemental disclosure of cash flow information:
Interest paid		32
Interest received	36	80
Non-cash financing activities:
Accrued offering costs	$ 169	$ 50