Consolidated Balance Sheets (Current Period Unaudited) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Assets
Cash and cash equivalents	$ 75,158	$ 22,104
Restricted cash	2,798	1,546
Investments	23,524	32,546
Receivables from collaborations	9,564	8,768
Inventory	655	500
Prepaid expenses and other current assets	1,721	1,438
Deferred collaboration expense	82	85
Total current assets	113,502	66,987
Investments	3,803	8,926
Property and equipment, net	9,753	9,922
Deferred collaboration expense	184	199
Other assets	2,271	3,813
Total assets	129,513	89,847
Liabilities and Stockholders’ Equity
Accounts payable	5,433	4,269
Accrued expenses	11,335	10,836
Interest payable	10,291	8,990
Deferred revenue	1,869	2,022
Senior credit facility, current	1,276
Non-recourse notes payable	28,353	28,243
Total current liabilities	58,557	54,360
Deferred collaboration revenue	7,888	8,184
Deferred rent	223	244
Lease financing obligation	2,704	2,704
Senior credit facility, noncurrent	21,611	22,777
Stockholders’ equity:
Preferred stock, $0.001 par value; shares authorized — 5,000; no shares issued and outstanding
Common stock, $0.01 par value: shares authorized — 200,000; shares issued and outstanding — 80,381 in 2017 and 73,782 in 2016	804	738
Additional paid-in capital	618,009	566,913
Accumulated other comprehensive loss	(3)	(12)
Accumulated deficit	(580,280)	(566,061)
Total stockholders’ equity	38,530	1,578
Total liabilities and stockholders’ equity	$ 129,513	$ 89,847