Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Current assets:
Cash and cash equivalents	$ 77,336	$ 85,038
Short-term investments	134,925	20,803
Prepaid clinical development costs	888	366
Other prepaid and current assets	1,245	492
Total current assets	214,394	106,699
Property and equipment, net	807	780
Intangible assets	56	56
Long-term investments	80,315	35,741
Total assets	295,572	143,276
Current liabilities:
Accounts payable	707	2,040
Current portion of long-term debt	1,604	638
Accrued clinical development costs	2,191	1,978
Other accrued liabilities	1,123	835
Total current liabilities	5,625	5,491
Long-term debt, net of discount and issuance costs	2,688	4,231
Total liabilities	$ 8,313	$ 9,722
Commitments and contingencies (Note 5)
Stockholders' equity:
Preferred stock, $0.001 par value; 5,000,000 shares authorized as of December 31, 2015 and December 31, 2014; no shares issued or outstanding at December 31, 2015 and December 31, 2014
Common stock, $0.001 par value; 120,000,000 shares authorized as of December 31, 2015 and December 31, 2014; 22,518,907 shares issued and 22,516,508 outstanding at December 31, 2015 and 20,352,876 shares issued and 20,343,325 outstanding at December 31, 2014	$ 23	$ 20
Additional paid-in capital	441,940	238,031
Accumulated other comprehensive income ( loss)	(482)	(59)
Accumulated deficit	(154,222)	(104,438)
Total stockholders' equity	287,259	133,554
Total liabilities and stockholders' equity	$ 295,572	$ 143,276