Stock-Based Compensation | Stock-Based Compensation The Company’s stock option activity and related information for the three months ended March 31, 2016 was as follows (in thousands, except share and per share data): Weighted-avg. Shares Weighted-avg. Remaining Aggregate Available Stock Options Exercise Price Contractual Intrinsic for Grant Outstanding Per Share Life (in Years) Value Balance at December 31, 2015 1,299,301 2,429,511 $ 7.00 8.01 $ 287 Stock options granted (1,406,000 ) 1,406,000 $ 3.00 Stock options canceled 106,968 (106,968 ) $ 4.81 Stock options exercised — (11,969 ) $ 0.92 Balance at March 31, 2016 269 3,716,574 $ 5.57 8.41 $ 237 At March 31, 2016: Vested and expected to vest 3,562,789 $ 5.64 8.37 $ 237 Exercisable 1,186,221 $ 8.22 6.61 $ 237 The aggregate intrinsic value of options exercised under all option plans was $25,000 and $0 for the three months ended March 31, 2016 and 2015, respectively, determined as of the date of option exercise. The Company recognized stock-based compensation expense within the condensed consolidated statements of operations and comprehensive loss as follows (in thousands): Three Months Ended March 31, 2016 2015 Research and development $ 207 $ 209 General and administrative 899 756 Total $ 1,106 $ 965 The above table includes $10 ,000 of stock compensation expense for the three months ended March 31, 2016 related to stock option grants to consultants. At March 31, 2016 there were 136,000 unvested options outstanding with performance conditions related to the achievement of certain clinical milestones. During the three months ended March 31, 2016 , no expense has been recorded for the performance based options as it was not yet probable that such milestones would be met. In March 2016, the Company amended its non-employee director compensation policy to increase the annual cash compensation for each non-employee member of its board of directors from $30,000 to $35,000 , the annual cash compensation of the audit committee chairperson from $15,000 to $17,500 and the annual stock option grant from 10,000 to 12,500 shares. As of March 31, 2016 , there was unrecognized stock compensation expense of $8.8 million related to stock options and the Company expects to recognize those costs over a weighted average period of 2.47 years. Stock-based compensation expense for stock options is estimated at the grant date based on the fair-value using the Black-Scholes option pricing model. The fair value of employee stock options is being amortized on a straight-line basis over the requisite service period of the awards. The fair value of all stock options granted was estimated using the following weighted-average assumptions: Three Months Ended 2016 2015 Expected dividend yield — — Risk-free interest rates 1.33% - 1.97% 1.52% Expected term in years 4.66 - 8.04 6.08 Expected volatility 75% - 92% 91% On January 6, 2016 the Company granted certain of its executive officers non-qualified stock options to purchase 206,625 shares of the Company’s common stock that vest on a monthly basis in equal installments over 48 months following the grant date if the Company's stock price equals or exceeds $6.00 for 20 consecutive trading days on or before June 30, 2017 . The options expire ten years from the date of the grant. The weighted-average fair values of these options was determined using a Monte Carlo simulation model incorporating the following assumptions: Three Months Ended 2016 2015 Expected dividend yield — — Risk-free interest rates 1.82% - 2.05% —% Expected term in years 6.02 - 8.00 — Expected volatility 77% - 89% —% Weighted-average fair value per share 1.33 - 1.42 — The estimated expense for these awards is being recognized on an accelerated basis over the estimated requisite service period, with no adjustments in the future periods based upon the Company's actual common stock price. During the three months ended March 31, 2016, the Company recorded $62,000 of share-based compensation expense in connection with the market condition stock option awards described above. |