BALANCE SHEETS (USD $)	Mar. 31, 2013	Dec. 31, 2012
Current assets:
Cash and cash equivalents	$ 21,011,000	$ 36,134,000
Short-term investments	94,115,000	102,868,000
Right to the Horizant business	13,557,000	13,557,000
Prepaids and other current assets	5,113,000	2,529,000
Total current assets	133,796,000	155,088,000
Property and equipment, net	1,383,000	1,528,000
Restricted investments and other assets	2,349,000	2,432,000
Total assets	137,528,000	159,048,000
Current liabilities:
Accounts payable	2,178,000	567,000
Accrued compensation	2,880,000	4,875,000
Accrued restructuring charges	548,000	993,000
Accrued preclinical and clinical costs	4,882,000	4,397,000
Other accrued liabilities	2,426,000	1,424,000
Deferred revenue	1,515,000	1,515,000
Total current liabilities	14,429,000	13,771,000
Deferred revenue	12,374,000	12,753,000
Other noncurrent liability	2,314,000	2,314,000
Commitments and contingencies
Stockholders' equity:
Preferred stock, $0.001 par value; 5,000 shares authorized, no shares issued or outstanding
Common stock, $0.001 par value; 100,000 shares authorized; 47,402 and 47,068 shares issued and outstanding, at March 31, 2013 and December 31, 2012, respectively	47,000	47,000
Additional paid-in capital	583,509,000	581,741,000
Accumulated other comprehensive income	3,000	22,000
Accumulated deficit	(475,148,000)	(451,600,000)
Total stockholders' equity	108,411,000	130,210,000
Total liabilities and stockholders' equity	$ 137,528,000	$ 159,048,000