Condensed Statements of Cash Flows (Unaudited) - USD ($)	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Cash flows from operating activities:
Net loss	$ (20,840,103)	$ (12,170,220)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation expense	1,985,786	1,485,705
Stock-based 401K company common match	40,847	121,620
Depreciation expense	48,542	42,306
Impairment of machinery and equipment	2,672,581	0
Amortization of debt discount	1,039	12,365
Amortization of debt issuance costs	125,355	27,102
Non-cash interest expense	405,278	92,549
Changes in assets and liabilities:
Prepaid expenses and other assets	219,615	255,055
Accounts payable	(1,411,849)	(943,416)
Accrued expenses	3,050,676	303,255
Net cash used in operating activities	(13,702,233)	(10,773,679)
Cash flows from investing activities:
Purchases of property and equipment	0	(89,284)
Net cash used in investing activities	0	(89,284)
Cash flows from financing activities:
Proceeds from exercise of stock options	721,195	50,960
Proceeds from exercise of warrants	0	3,745
Payments for debt issuance costs	(90,000)	0
Net cash provided by (used in) financing activities	631,195	54,705
Net decrease in cash	(13,071,038)	(10,808,258)
Cash and cash equivalents at beginning of period	88,067,647	106,398,919
Cash and cash equivalents at end of period	74,996,609	95,590,661
Cash paid for:
Interest	$ 457,499	$ 343,125