Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($)	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Cash flows from operating activities:
Net loss	$ (12,707,551)	$ (10,050,005)
Non-cash items included in net loss:
Depreciation and amortization	174,342	341,058
Change in fair value of earn-out milestone liability	547,324	575,979
Deferred revenue	(250,000)	(250,000)
Stock-based compensation costs	3,371,301	804,592
Restricted shares issued	29,841
Amortization of deferred finance charges and debt discount associated with notes payable	4,237	35,370
Change in deferred rent liability	(2,955)	24,488
Net changes in:
Accrued interest on investment securities	(2,392)	4,008
Advances, deposits and other current assets	(12,000)	94,461
Accounts payable and accrued liabilities	35,776	1,093,740
Net cash (used in) operating activities:	(8,812,077)	(7,326,309)
Cash flows from investing activities:
Purchases of investment securities	(5,712,170)
Proceeds from sale and maturity of investment securities	5,000,000	1,680,000
Refund (deposit) on corporate office lease	(50,000)	100,000
Purchases of property and equipment	(77,698)	(21,126)
Net cash (used in) provided by investing activities	(839,868)	1,758,874
Cash flows from financing activities:
Proceeds from sale of common stock equity, net of issuance costs	1,236,584	4,252,948
Proceeds from notes payable, net of issuance costs	9,725,000
Proceeds from exercise of common stock warrants		4,915,286
Principal payments on notes payable		(2,595,923)
Net cash provided by financing activities	10,961,584	6,572,311
Increase in cash and cash equivalents	1,309,639	1,004,876
Cash and cash equivalents at beginning of period	11,444,055	2,624,162
Cash and cash equivalents at end of period	12,753,694	3,629,038
Supplemental disclosures of cash flow information:
Interest paid	10,794	56,386
Non-cash investing and financing activities:
Fair value of warrants issued in connection with the notes payable	$ 507,116