Condensed Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Cash flows from operating activities:
Net loss	$ (10,563)	$ (9,150)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	247	80
Accretion of premium (discount) on marketable investment securities	539	286
Non-cash interest expense	5,296	4,007
Non-cash royalties	(22,341)	(3,833)
Compensation expense on share based awards	1,880	951
(Increase) decrease in operating assets:
Accounts receivable	84	(689)
Prepaid expenses, other current assets and other assets	871	(2,166)
(Decrease) increase in operating liabilities:
Accounts payable and accrued expenses	152	(5,402)
Other liabilities	(29)	(26)
Net cash used in operating activities	(23,864)	(15,942)
Cash flows from investing activities:
Sales of marketable investment securities	0	240
Maturities of marketable investment securities	27,196	14,277
Purchases of marketable investment securities	(36,545)	(24,290)
Acquisitions of equipment	(532)	(325)
Net cash used in investing activities	(9,881)	(10,098)
Cash flows from financing activities:
Principal payments on debt and capital lease obligation	0	(55,752)
Net proceeds from the sale of common stock and exercise of stock options	324	884
Decrease in restricted cash and cash equivalents	0	50,780
Net cash provided by (used in) financing activities	324	(4,088)
Effect of exchange rate changes on cash	(7)	(3)
Net increase in cash and cash equivalents	(33,428)	(30,131)
Cash and cash equivalents at beginning of period	82,401	77,170
Cash and cash equivalents at end of period	48,973	47,039
Supplemental Disclosures of Cash Flow Information
Cash paid for interest	237	14,363
Cash paid for income taxes	0	0
Supplemental Disclosure of Non-cash Investing and Financing Activities
Unrealized gains on marketable investment securities	100	36
Accrued acquisition of property and equipment	228	326
Noncash reduction of debt	19,584	0
Conversion of 5.75% convertible notes	$ 0	$ 2,861