NATURE OF OPERATIONS AND BASIS OF PRESENTATION (Detail Textuals) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2016	Mar. 31, 2015
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Net use of cash	$ (6,432)	$ (7,554)
License agreement \| Daiichi Sankyo Co. Ltd
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Milestone payment received	100,000
Milestone payments related to first patient enrolled in METIV-HCC trial	15,000
License agreement \| Kyowa Hakko Kirin Co. Ltd.
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Milestone payment received	$ 48,000

Amount of cash inflow (outflow) from operating activities, excluding discontinued operations. Operating activity cash flows include transactions, adjustments, and changes in value not defined as investing or financing activities.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 24
-URI http://asc.fasb.org/extlink&oid=56944662&loc=d3e3521-108585

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-URI http://asc.fasb.org/extlink&oid=56944662&loc=d3e3602-108585

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 25
-URI http://asc.fasb.org/extlink&oid=56944662&loc=d3e3536-108585

Name:	us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperations
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	duration