STATEMENTS OF CASH FLOWS - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Cash flows from operating activities:
Net loss	$ (34,986,432)	$ (50,771,221)	$ (58,587,190)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	629,312	536,631	317,649
Loss on retirement of equipment and furnishings	424,049	12,276	2,614
Gain on warrant liabilities	(1,367,777)	(3,827,617)	(4,437,628)
Amortization of loan cost and discount	1,923,816	587,837	0
Stock-based compensation expense	3,344,520	6,735,576	7,384,656
Non-cash litigation settlement due in common stock	0	0	4,500,000
Changes in assets and liabilities:
Receivable	(7,344,941)	4,412,097	(2,574,182)
Interest receivable	0	28,130	76,497
Prepaid expenses and other current assets	1,534,738	(28,569)	1,118,931
Accounts payable	(2,286,416)	(1,672,631)	916,919
Deferred revenue	6,924,353	0	0
Accrued expenses and other current liabilities	4,007,210	(5,862,861)	3,699,287
Net cash used in operating activities	(27,197,568)	(49,850,352)	(47,582,447)
Cash flows from investing activities:
Proceeds from matured short-term investments	0	35,035,420	76,544,319
Purchase of short-term investments	0	0	(65,958,146)
Purchases of equipment and furnishings	(134,598)	(1,020,441)	(331,328)
Net cash provided by (used in) investing activities	(134,598)	34,014,979	10,254,845
Cash flows from financing activities:
Proceeds from common stock issued in public offering, net of fees	13,951,218	25,777,257	26,780,068
Proceeds from term loan, net	0	24,012,078	0
Proceeds from sale of common shares and warrants related to NantCell	6,075,647	0	0
Loan amendment fee payment	(200,000)	0	0
Term loan principal repayment	(15,013,638)	0	0
Net proceeds from exercise of stock options and warrants	3,202,858	744,151	590,001
Net cash provided by financing activities	8,016,085	50,533,486	27,370,069
Net increase (decrease) in cash and cash equivalents	(19,316,081)	34,698,113	(9,957,533)
Cash and cash equivalents at beginning of year	56,959,485	22,261,372	32,218,905
Cash and cash equivalents at end of year	37,643,404	56,959,485	22,261,372
Supplemental disclosures of non-cash financing/investing activities:
Warrant liability exercises	1,894,589	0	3
Warrants repriced in connection with the sale of licenses	76,549	0	0
Receivable from issuance of restricted stock	388	2,325	0
Equipment and furnishings purchased but not paid	1,988	20,452	485,743
Retirement of treasury stock	0	0	2,612,861
Warrants issued in connection with the term loan	0	633,749	0
1 - 6 reverse stock split	12	4,500,000	0
Series B Preferred stock beneficial conversion feature and deemed dividend	0	314,286	0
Warrants issued/amended in connection with the public offering	0	6,923,551	0
Series B Preferred stock conversion	1,233	457	0
Supplemental disclosure of Cash Flow Information:
Cash paid during the year for income taxes	800	800	800
Cash paid during the year for interest	$ 2,025,468	$ 1,959,375	$ 0