CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
REVENUES:
Total Revenues	$ 3,573	$ 9,538	$ 12,743
OPERATING EXPENSES:
Research and Development	42,672	66,449	96,171
General and Administrative	15,426	19,269	25,003
Goodwill Impairment		90,976
Intangible Asset Impairment		18,677	13,000
Other Asset Impairment	1,800
Gain on Fair Value Remeasurement of Contingent Consideration	(1,294)	(29,621)	(800)
Amortization of Acquired Intangible Assets		224	896
Total Operating Expenses	58,604	165,974	134,270
Operating Loss	(55,031)	(156,436)	(121,527)
Investment and Other Income, Net	4,153	4,487	4,214
Net Loss Before Income Tax Benefit	(50,878)	(151,949)	(117,313)
Income Tax Benefit		765	24,282
Net Loss	$ (50,878)	$ (151,184)	$ (93,031)
Basic and Diluted Net Loss Per Common Share	$ (3.51)	$ (14.48)	$ (10.86)
Shares Used in Calculating Basic and Diluted Net Loss per Share	14,507	10,442	8,570
COMPREHENSIVE LOSS:
Net Loss	$ (50,878)	$ (151,184)	$ (93,031)
Other Comprehensive Income (Loss):
Unrealized Gain on Marketable Securities	36	19	23
Comprehensive Loss	(50,842)	(151,165)	(93,008)
Product Development and Licensing Agreements
REVENUES:
Total Revenues	473	3,341	3,153
Contracts and Grants
REVENUES:
Total Revenues	$ 3,100	$ 6,197	$ 9,590