CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) - USD ($) $ in Thousands		Mar. 31, 2016	Dec. 31, 2015
Current assets:
Cash and cash equivalents		$ 23,858	$ 26,886	[1]
Marketable securities		16,158	19,544	[1]
Prepaids and other current assets		701	558	[1]
Total current assets		40,717	46,988	[1]
Property and equipment, net		11	14	[1]
Total assets		40,728	47,002	[1]
Current liabilities:
Accounts payable		2,581	2,453	[1]
Accrued clinical expense		2,185	1,954	[1]
Accrued compensation		929	1,606	[1]
Other accrued liabilities		1,639	2,711	[1]
Current portion of deferred revenue		2,441	2,441	[1]
Current portion of notes payable	[1]		7,834
Total current liabilities		9,775	18,999	[1]
Non-current portion of deferred revenue	[1]		$ 610
Non-current portion of notes payable		$ 11,685
Commitments				[1]
Stockholders’ equity:
Convertible Preferred stock		$ 16,459	$ 16,459	[1]
Common stock		9	9	[1]
Additional paid-in capital		572,257	570,309	[1]
Accumulated other comprehensive income (loss)		2	(11)	[1]
Accumulated deficit		(569,459)	(559,373)	[1]
Total stockholders’ equity		19,268	27,393	[1]
Total liabilities and stockholders’ equity		$ 40,728	$ 47,002	[1]

[1] The condensed consolidated balance sheet as of December 31, 2015 has been derived from the audited financial statements as of that date included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2015.