Disclosure of Compensation Related Costs, Share-based Payments [Text Block] | 5. STOCK-BASED COMPENSATION Accounting for Stock-Based Compensation Three Months Ended Six Months Ended June 30, June 30, 2015 2014 2015 2014 Employee and director stock option grants: Research and development $ 40,296 $ 47,274 $ 83,653 $ 110,701 General and administrative 29,101 176,581 174,436 360,965 Restructuring 47,853 47,853 69,397 271,708 258,089 519,519 Non-employee consultant stock option grants: Research and development 2,358 1,982 5,456 16,697 Total stock-based compensation $ 71,755 $ 273,690 $ 263,545 $ 536,216 Assumptions Used In Determining Fair Value Valuation and amortization method . The fair value of each stock award is estimated on the grant date using the Black-Scholes option-pricing model. The estimated fair value of employee stock options is amortized to expense using the straight-line method over the vesting period. The estimated fair value of the non-employee options is amortized to expense over the period during which a non-employee is required to provide services for the award (usually the vesting period). Volatility. The Company estimates volatility based on an average of (1) the Company’s historical volatility since its common stock has been publicly traded and (2) review of volatility estimates of publicly held drug development companies with similar market capitalizations. Risk-free interest rate . The risk-free interest rate is based on the U.S. Treasury yield curve in effect at the time of grant commensurate with the expected term assumption. Expected term . The expected term of stock options granted is based on an estimate of when options will be exercised in the future. The Company applied the simplified method of estimating the expected term of the options, as described in the SEC’s Staff Accounting Bulletins 107 and 110, as the historical experience is not indicative of the expected behavior in the future. The expected term, calculated under the simplified method, is applied to groups of stock options that have similar contractual terms. Using this method, the expected term is determined using the average of the vesting period and the contractual life of the stock options granted. The Company applied the simplified method to non-employees who have a truncation of term based on termination of service and utilizes the contractual life of the stock options granted for those non-employee grants which do not have a truncation of service. Forfeitures. The Company records stock-based compensation expense only for those awards that are expected to vest. A forfeiture rate is estimated at the time of grant and revised, if necessary, in subsequent periods if actual forfeitures differ from initial estimates. An annual forfeiture rate of 2 0 Six Months Six Months Ended Ended June 30, 2015 June 30, 2014 Volatility 105-107 % 108 % Risk-free interest rate 1.70-1.95 % 1.76 % Expected life (years) 6.0 6.0 Dividend 0 % 0 % Weighted-average exercise price $ 2.65-2.69 $ 7.40 Weighted-average grant-date fair value $ 2.17-2.20 $ 6.20 Exercise prices for all grants made during the six months ended June 30, 2015 were equal to the market value of the Company’s common stock on the date of grant. Stock Option Activity Weighted Number of Average Shares Issuable Remaining Upon Exercise Weighted Contracted Aggregate of Outstanding Average Term in Intrinsic Options Exercise Price Years Value Outstanding at December 31, 2014 719,466 $ 15.59 Granted 510,200 $ 2.65 Canceled 105,072 $ 27.22 Forfeited 229,475 $ 9.29 Outstanding at June 30, 2015 895,119 $ 8.47 Vested, June 30, 2015 315,203 $ 18.14 5.33 $ 7,969 Unvested, June 30, 2015 579,916 $ 3.21 9.73 $ 110,269 Exercisable at June 30, 2015 315,203 $ 18.14 5.33 $ 7,969 The aggregate intrinsic value of options outstanding is calculated based on the positive difference between the estimated per-share fair value of common stock at the end of the respective period and the exercise price of the underlying options. There have been no option exercises to date. Shares of common stock issued upon the exercise of options are from authorized but unissued shares. As of June 30, 2015, there was approximately $ 1,421,000 335,000 459,000 331,000 206,000 90,000 579,916 50,000 |