Balance Sheets (USD $)
In Thousands, unless otherwise specified
Sep. 30, 2013
Dec. 31, 2012
Current assets:    
Cash and cash equivalents $ 10,324 $ 22,570
Prepaid expenses and other 957 450
Total current assets 11,281 23,020
Property and equipment, net 2,624 581
Other assets 225 243
Other assets-equipment funding (Note 3(d)) 7,291 6,763
Total assets 21,421 30,607
Current liabilities:    
Current portion of long-term debt 2,993 378
Accounts payable 2,566 800
Accrued expenses 2,852 1,995
Total current liabilities 8,411 3,173
Long-term debt 5,802 8,102
Other long-term liabilities   83
Warrant liability   16,236
Total liabilities 14,213 27,594
Commitments (note 7)      
Stockholders' equity (deficit):    
Preferred stock, $0.001 par value; authorized 10,000,000 shares; issued and outstanding 0 and 8,804 at September 30, 2013 and December 31, 2012, respectively   7,255
Common stock, $0.001 par value. Authorized 90,000,000 shares; issued and outstanding 31,329,179 and 20,023,949 shares at September 30, 2013 and December 31, 2012, respectively 31 20
Treasury stock,42,433 and 0 common shares at September 30, 2013 and December 31, 2012,respectively (112)  
Additional paid-in capital 178,160 136,506
Deficit accumulated during the development stage (170,871) (140,768)
Total stockholders' equity 7,208 3,013
Total liabilities and stockholders' equity $ 21,421 $ 30,607