Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Preferred Stock [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Deficit [Member]	Total
Balance at Oct. 31, 2016	$ 10,153	$ 3	$ 123,417	$ (128,176)	$ 5,397
Balance, shares at Oct. 31, 2016	7,374,454	2,782,963
Conversion of Series A preferred stock to common stock	$ (976)	$ 1	975
Conversion of Series A preferred stock to common stock, shares	(3,991,487)	761,798
Conversion of Series B preferred stock to common stock	$ (549)		549
Conversion of Series B preferred stock to common stock, shares	(6,512)	108,543
Conversion of Series C preferred stock to common stock	$ (1,809)	$ 1	1,808
Conversion of Series C preferred stock to common stock, shares	(23,185)	504,184
Conversion of Series D preferred stock to common stock	$ (1,517)		1,517
Conversion of Series D preferred stock to common stock, shares	(129,665)	216,106
Issuance of Series E preferred stock for research and development intellectual property	$ 104,693				104,693
Issuance of Series E preferred stock for research and development intellectual property, shares	7,050
Stock option exercise			1,301		1,301
Stock option exercise, shares		268,847
Warrants exchanged for common stock			78		78
Warrants exchanged for common stock, shares		56,250
Stock-based compensation expense		$ 1	17,744		17,745
Stock-based compensation expense, shares		1,057,500
Common stock issued for cash		$ 1	2,277		2,278
Common stock issued for cash, shares		759,333
Deemed dividend - accretion of discount on Series F preferred stock			(369)		(369)
Cumulative dividends on Series F preferred stock			(124)		124
Series F preferred stock dividends paid in common stock
Net loss				(130,829)	(130,829)
Balance at Oct. 31, 2017	$ 109,995	$ 7	149,173	(259,005)	170
Balance, shares at Oct. 31, 2017	3,230,655	6,515,524
Conversion of Series A preferred stock to common stock	$ (769)	$ 1	768
Conversion of Series A preferred stock to common stock, shares	(3,146,671)	713,036
Conversion of Series B preferred stock to common stock	$ (4,020)	$ 1	4,019
Conversion of Series B preferred stock to common stock, shares	(47,689)	794,820
Conversion of Series C preferred stock to common stock	$ (201)		201
Conversion of Series C preferred stock to common stock, shares	(2,578)	59,950
Conversion of Series D preferred stock to common stock	$ (312)		312
Conversion of Series D preferred stock to common stock, shares	(26,667)	44,445
Conversion of Series E preferred stock to common stock	$ (104,693)	$ 7	104,686
Conversion of Series E preferred stock to common stock, shares	(7,050)	7,050,000
Stock option exercise			687		687
Stock option exercise, shares		161,433
Warrants exchanged for common stock
Stock-based compensation expense			38,821		38,821
Stock-based compensation expense, shares		126,000
Exchange of Series F preferred stock and dividends to common stock		$ 1	13,060		13,061
Exchange of Series F preferred stock and dividends to common stock, shares		1,003,393
Extinguishment of warrant liability			3,045		3,045
Extinguishment of warrant liability, shares		151,871
Proceeds received from issuance of common stock, net of issuance costs of $2,785		$ 4	92,672		92,676
Proceeds received from issuance of common stock, net of issuance costs of $2,785, shares		4,791,819
Deemed dividend - accretion of discount on Series F preferred stock			(1,290)		(1,290)
Cumulative dividends on Series F preferred stock			(373)		373
Series F preferred stock dividends paid in common stock			306		306
Series F preferred stock dividends paid in common stock, shares		11,708
Net loss				(65,441)	(65,441)
Balance at Oct. 31, 2018		$ 21	$ 406,087	$ (324,446)	$ 81,662
Balance, shares at Oct. 31, 2018		21,423,999