Summary of Significant Accounting Policies | Use of Estimates The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the financial statements, and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. Significant estimates include those relating to share-based compensation, and assumptions that have been used historically to value warrants and warrant modifications. With the exception of the BlueRock Agreement pursuant to which we recorded sublicense revenue in the third quarter of our fiscal year ended March 31, 2017, we do not currently have, nor have we had during the periods covered by this Report, any arrangements requiring the recognition of revenue. Research and Development Expenses Research and development expenses are composed of both internal and external costs. Internal costs include salaries and employment-related expenses, including stock-based compensation expense, of scientific personnel and direct project costs. External research and development expenses consist primarily of costs associated with clinical and non-clinical development of AV-101, stem cell research and development costs, and costs related to the application and prosecution of patents related to AV-101 and, to a lesser extent, our stem cell technology platform. All such costs are charged to expense as incurred. We also record accruals for estimated ongoing clinical trial costs. Clinical trial costs represent costs incurred by contract research organizations ( CRO Subsequent Events Stock-Based Compensation We recognize compensation cost for all stock-based awards to employees and non-employee consultants based on the grant date fair value of the award. We record non-cash, stock-based compensation expense over the period during which the employee is required to perform services in exchange for the award, which generally represents the scheduled vesting period. We have not granted restricted stock awards to employees nor do we have any awards with market or performance conditions. For option grants to non-employees, we re-measure the fair value of the awards as they vest and the resulting value is recognized as an expense during the period over which the services are performed. Compensatory grants of stock to non-employees are generally treated as fully-earned at the time of the grant and the non-cash expense recognized is based on the quoted market price of the stock on the date of grant. The table below summarizes stock-based compensation expense included in the accompanying Condensed Consolidated Statements of Operations and Comprehensive Loss for the three and six months ended September 30, 2018 and 2017. Three Months Ended September 30, Six Months Ended September 30, 2018 2017 2018 2017 Research and development expense: Stock option grants $ 450,600 $ 136,900 $ 680,700 $ 328,300 450,600 136,900 680,700 328,300 General and administrative expense: Stock option grants 721,800 193,700 1,104,300 369,300 721,800 193,700 1,104,300 369,300 Total stock-based compensation expense $ 1,172,400 $ 330,600 $ 1,785,000 $ 697,600 In August 2018, our Board approved the grant of options from our 2016 Amended and Restated Stock Incentive Plan (the 2016 Plan Assumption: August 2018 Market price per share at grant date $ 1.27 Exercise price per share $ 1.27 Risk-free interest rate 2.84 % Estimated term in years 5.50 Volatility 99.29 % Dividend rate 0.0 % Shares 860,000 Fair Value per share $ 0.98 In August 2018, our Board also approved the modification of outstanding options having exercise prices over $1.56 per share and held by independent members of our Board, our officers and our employees to reduce the exercise prices thereof to $1.50 per share. We calculated the fair value of the options immediately before and after the modification using the Black-Scholes Option Pricing Model and the weighted average assumptions indicated in the table below. We immediately recognized the additional fair value attributable to vested options, $258,100, as stock compensation expense, which is included in the figures reported above. The additional fair value resulting from the modification is being expensed over the remaining vesting period of the modified options. Assumption: Pre-modification Post-modification Market price per share $ 1.49 $ 1.49 Exercise price per share $ 3.57 $ 1.50 Risk-free interest rate 2.77 % 2.77 % Remaining expected term in years 5.08 5.08 Volatility 94.9 % 94.9 % Dividend rate 0.0 % 0.0 % Number of warrant shares 2,419,503 2,419,503 Weighted average fair value per share $ 0.91 $ 1.08 At September 30, 2018, there were stock options outstanding to purchase 6,160,338 shares of our common stock at a weighted average exercise price of $1.46 per share. See Note 10, Subsequent Events Comprehensive Loss We have no components of other comprehensive loss other than net loss, and accordingly our comprehensive loss is equivalent to our net loss for the periods presented. Loss per Common Share Basic net loss attributable to common stockholders per share of common stock excludes the effect of dilution and is computed by dividing net loss increased by the accrual of dividends on outstanding shares of our Series B 10% Convertible Preferred Stock ( Series B Preferred As a result of our net loss for all periods presented, potentially dilutive securities were excluded from the computation of diluted loss per share, as their effect would be antidilutive. Potentially dilutive securities excluded in determining diluted net loss attributable to common stockholders per common share are as follows: As of September 30, 2018 2017 Series A Preferred stock issued and outstanding (1) 750,000 750,000 Series B Preferred stock issued and outstanding (2) 1,160,240 1,160,240 Series C Preferred stock issued and outstanding (3) 2,318,012 2,318,012 Outstanding options under the Amended and Restated 2016 (formerly 2008) and 1999 Stock Incentive Plans (1999 Plan in 2017 only) 6,160,338 3,279,871 Outstanding warrants to purchase common stock 20,709,516 6,965,151 Total 31,098,106 14,473,274 ____________ (1) Assumes exchange under the terms of the October 11, 2012 Note Exchange and Purchase Agreement, as amended (2) Assumes exchange under the terms of the Certificate of Designation of the Relative Rights and Preferences of the Series B 10% Convertible Preferred Stock, effective May 5, 2015 (3) Assumes exchange under the terms of the Certificate of Designation of the Relative Rights and Preferences of the Series C Convertible Preferred Stock, effective January 25, 2016 Fair Value Measurements We do not use derivative instruments for hedging of market risks or for trading or speculative purposes. We carried no assets or liabilities at fair value at September 30, 2018 or March 31, 2018. Recent Accounting Pronouncements Except as described below, there have been no recent accounting pronouncements or changes in accounting pronouncements during the six months ended September 30, 2018, as compared to the recent accounting pronouncements described in our Form 10-K for our fiscal year ended March 31, 2018, that are of significance or potential significance to us. In June 2018, the Financial Accounting Standards Board ( FASB ASU Compensation-Stock Compensation (Topic 718), Improvements to Nonemployee Share-Based Payment Accounting ASU 2018-07 Revenue from Contracts with Customers Topic 606 In February 2016, the FASB issued ASU 2016-02, Leases ASC 842 Leases |