Consolidated Statements of Cash Flows (USD $)	12 Months Ended			84 Months Ended
	Aug. 31, 2012	Aug. 31, 2011	Aug. 31, 2010	Aug. 31, 2012
Cash flows from operating activities:
Net loss	$ (38,644,000)	$ (37,195,000)	$ (18,928,000)	$ (116,646,000)
Adjustments to reconcile net loss to net cash used in operating activities:
Employee stock-based compensation expense	4,487,000	1,920,000	217,000	7,838,000
Consultant stock-based compensation expense	72,000	197,000	78,000	755,000
Fair value adjustment of common stock warrants	3,173,000	16,301,000	5,895,000	25,369,000
Amortization of intangible assets	146,000	153,000	152,000	697,000
Depreciation of fixed assets	65,000	78,000	72,000	566,000
Write-off of intangible assets and other intellectual property	900,000	108,000	0	1,249,000
Amortization of capitalized finder's fee			0	102,000
Capitalized acquisition costs previously expensed			0	38,000
Changes in assets and liabilities:
Prepaid expenses and other	(2,695,000)	(130,000)	(79,000)	(3,011,000)
Intangible assets			0	(150,000)
Deposits	0	(2,000)	(3,000)	(105,000)
Accounts payable	754,000	210,000	24,000	1,601,000
Accrued liabilities	403,000	1,119,000	(2,000)	1,972,000
Deferred rent	(10,000)	22,000	3,000	14,000
Net cash used in operating activities	(31,349,000)	(17,219,000)	(12,571,000)	(79,711,000)
Cash flows from investing activities:
Purchase of fixed assets	(378,000)	(50,000)	(20,000)	(925,000)
Purchase of short-term investments	(45,307,000)	0	0	(45,307,000)
Sale of short-term investments	30,000,000	0	0	30,000,000
Cash acquired in 2009 Merger			581,000	581,000
Investment in restricted cash	(54,000)	(114,000)	0	(169,000)
Net cash provided by (used in) investing activities	(15,739,000)	(164,000)	561,000	(15,820,000)
Cash flows from financing activities:
Proceeds from the sale of common stock	46,000,000	0	22,555,000	85,941,000
Proceeds from the sale of common stock under an equity line	0	6,740,000	4,900,000	11,640,000
Proceeds from the sale of common stock under an ATM agreement	7,684,000	0	0	7,684,000
Proceeds from the exercise of common stock warrants	5,013,000	8,912,980	475,019	20,911,000
Proceeds from the exercise of common stock options	366,000	96,000	64,000	535,000
Fundraising costs	(3,528,000)	0	(2,720,000)	(7,855,000)
Deferred offering costs	18,000	(152,000)	0	18,000
Proceeds from the sale of common stock to initial investors		0	0	310,000
Proceeds from bridge loan			0	200,000
Repayment of bridge loan			0	(200,000)
Principal payments on capital lease	(5,000)	(5,000)	(4,000)	(23,000)
Net cash provided by financing activities	55,548,000	15,592,000	25,270,000	119,161,000
Foreign currency translation adjustment	(52,000)	10,000	(8,000)	(50,000)
Net increase (decrease) in cash and cash equivalents	8,408,000	(1,781,000)	13,252,000	23,580,000
Cash and cash equivalents, beginning of period	15,172,000	16,953,524	3,702,000	0
Cash and cash equivalents, end of period	23,580,000	15,172,000	16,953,524	23,580,000
Supplemental cash flow information:
Interest Paid	3,000	2,000	4,000	17,000
Supplemental disclosure of non-cash financing activities:
Warrants issued in connection with financings			9,677,000	16,310,000
Initial fair value of warrants issued to placement agents in connection with financings			209,000	209,000
Common stock and warrants issued in connection with reverse merger			4,417,000	4,417,000
Common stock issued as fee for equity line	0	519,000	309,000	828,000
Acquisition of equipment in exchange for capital lease	13,000	14,000	0	48,000
Fair value of warrant liability reclassified to equity upon exercise	9,482,000	8,506,000	0	17,988,000
Notes receivable issued in exchange for common stock			0	110,000
Common stock issued for a finder's fee			0	102,000
Common stock issued in asset purchase			$ 0	$ 2,899,000