3 Months Ended
Jan. 31, 2018
Jan. 31, 2017
Reconciliation of net loss to net cash used in operating activities:    
Net loss $ (1,865,474) $ (1,589,260)
Stock option compensation to employees and directors 214,427 259,737
Stock option compensation to consultants 52,546
Common stock issued to consultants 15,002 17,811
Depreciation of property and equipment 4,391 10,505
Amortization of patents 81,324 81,324
Accretion of interest on patent acquisition obligations to interest expense 141,299
Issuance of noncontrolling interest in Certainty Therapeutics, Inc. expensed as a license fee 64,656
Change in operating assets and liabilities:    
Prepaid expenses and other current assets (103,930) 93,480
Accounts payable (63,399) 167,453
Accrued expenses 260,464 87,738
Net cash used in operating activities (1,339,993) (729,913)
Cash flows from investing activities:    
Disbursements to acquire short-term investments in certificates of deposit (1,250,000)
Proceeds from maturities of short-term investments in certificates of deposit 2,100,000 150,000
Purchase of property and equipment (2,518) (14,121)
Net cash provided by investing activities 847,482 135,879
Cash flows from financing activities:    
Redemption of convertible preferred stock (500,000)
Proceeds from exercise of employee stock options 5,665
Net cash used in by financing activities (494,335)
Net decrease in cash and cash equivalents (492,511) (1,088,369)
Cash and cash equivalents at beginning of period 3,339,374 2,488,323
Cash and cash equivalents at end of period 2,846,863 1,399,954
Supplemental disclosure of non-cash financing activities:    
Redemption of Series A convertible preferred stock into secured debenture (Note 6) $ (3,000,000)