CONSOLIDATED BALANCE SHEETS (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Current assets:
Cash and cash equivalents	$ 1,441	$ 354
Short-term investments	68,621	6,532
Receivables	538	392
Inventory	566	568
Prepaid expense	1,784	1,191
Other current assets	116	120
Total current assets	73,066	9,157
Property and equipment, net	727	782
Restricted cash	679	679
Other assets	439	472
Total assets	74,911	11,090
Current liabilities:
Accounts payable	4,611	4,915
Accrued expenses	6,438	7,070
Current portion of notes payable, net of discount	9,019	6,446
Total current liabilities	20,068	18,431
Notes payable, net of current portion and discount	23,906	26,263
Deferred rent	9,091	9,050
Commitments and contingencies (Note 8)
Shareholders’ equity:
Preferred stock, par value $0.01 per share: Authorized shares - 20,000,000 at March 31, 2015 (unaudited) and December 31, 2014; Issued and outstanding shares—none	0	0
Common stock, par value $0.01 per share: Authorized shares - 150,000,000 at March 31, 2015 (unaudited) and December 31, 2014; Issued and outstanding shares—37,185,464 and 34,185,464 at March 31, 2015 (unaudited) and December 31, 2014, respectively	378	342
Additional paid-in capital	368,183	285,050
Accumulated deficit	(346,715)	(328,046)
Total shareholders’ equity (deficit)	21,846	(42,654)
Total liabilities and shareholders’ equity (deficit)	$ 74,911	$ 11,090