SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Tables)

9 Months Ended

Sep. 30, 2013

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

Schedule of available-for-sale securities

	September 30, 2013
(In thousands)	Amortized Cost		Gains in Accumulated Other Comprehensive Income		Losses in Accumulated Other Comprehensive Income		Estimated Fair Value
U.S. government agency securities	$	44,477	$	56	$	—	$	44,533
Corporate bonds	80,973		52		—		81,025
Certificates of deposit	7,565		9		—		7,574
Commercial paper	4,998		1		—		4,999
Total available-for-sale securities	$	138,013	$	118	$	—	$	138,131

Available-for-sale securities at December 31, 2012 consisted of the following:

	December 31, 2012
(In thousands)	Amortized Cost		Gains in Accumulated Other Comprehensive Income		Losses in Accumulated Other Comprehensive Income		Estimated Fair Value
U.S. government agency securities	$	44,270	$	38	$	—	$	44,308
Corporate bonds	43,303		27		—		43,330
Certificates of deposit	5,926		13		—		5,939
Commercial paper	1,199		—		—		1,199
Total available-for-sale securities	$	94,698	$	78	$	—	$	94,776

Schedule of estimated useful lives of fixed assets

	Estimated
Asset Classification	Useful Life
Laboratory equipment	3 - 5 years
Office and computer equipment	3 years
Leasehold improvements	Lesser of the remaining lease term or useful life
Furniture and fixtures	3 years

Schedule of potentially issuable common shares not included in the computation of diluted net loss per share because they would have an anti-dilutive effect

	September 30,
(In thousands)	2013	2012
Shares issuable upon exercise of stock options	6,108	6,282
Shares issuable upon exercise of outstanding warrants (1)	155	325
Shares issuable upon the release of restricted stock awards	1,264	945
Shares issuable upon the vesting of restricted stock awards related to a licensing agreement	49	73
	7,576	7,625

(1)  At September 30, 2013, represents warrants to purchase 80,000 shares of common stock issued under a license agreement and warrants to purchase 75,000 shares of common stock issued under a consulting agreement.  At September 30, 2012, represents warrants to purchase 250,000 shares of common stock issued under a license agreement and warrants to purchase 75,000 shares of common stock issued under a consulting agreement.