Condensed Consolidated Statements of Cash Flows - USD ($)	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015
Cash flows from operating activities:
Net loss	$ (10,962,916)	$ (4,579,576)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation	40,963	13,285
Change in fair value of warrant liability	(926,671)	(1,989,162)
Financing expense	31,231	88,939
Stock-based compensation	480,947	429,964
Accrued interest on CIRM award	546,823	0
Changes in assets and liabilities:
Other assets	595,679	(403,344)
Supplies for clinical trials	(293,100)	0
Accounts payable	(531,531)	130,199
Accrued compensation and benefits	(459,562)	(43,787)
Accrued liabilities	284,005	(554,045)
Net cash used in operating activities	(11,194,132)	(6,907,527)
Cash flows from investing activities:
Purchase of property and equipment	(4,015)	(6,443)
Net cash used in investing activities	(4,015)	(6,443)
Cash flows from financing activities:
Proceeds from the issuance of common stock	691,187	0
Deferred financing costs	(148,663)	0
Proceeds from issuance of common stock and warrants net of offering costs	0	14,599,627
Net cash provided by financing activities	542,524	14,599,627
(Decrease) increase in cash and cash equivalents	(10,655,623)	7,685,657
Cash and cash equivalents, beginning of period	22,604,481	23,222,296
Cash and cash equivalents, end of period	11,948,858	30,907,953
Supplemental cash flows disclosures:
Interest expense paid	0	0
Income taxes paid	0	0
Supplemental non-cash financing disclosures:
Deferred offering costs included in accounts payable	$ 79,440	$ 0