Stockholders' Equity | 5. Stockholders’ Equity Stock-based compensation expense and valuation information Stock-based compensation expense for all stock awards consists of the following (in thousands): Year Ended March 31, 2018 Year Ended March 31, 2017 Year Ended March 31, 2016 (1) Research and development $ 1,174 $ 1,646 $ 1,248 General and administrative $ 5,729 $ 5,746 $ 7,308 Total $ 6,903 $ 7,392 $ 8,556 (1) Included in total stock-based compensation for the year ended March 31, 2016 is additional expense resulting from acceleration of the vesting schedule to fully vest options held by a terminated executive as pursuant to the 2012 Equity Incentive Plan. Additionally, as part of the severance agreement, a modification was made to extend the exercise period of the fully vested options, resulting in an incremental expense. The total unrecognized compensation cost related to unvested stock option grants as of March 31, 2018 was approximately $5,650,000 and the weighted average period over which these grants are expected to vest is 2.42 years. The total unrecognized stock-based compensation cost related to unvested restricted stock units (not including performance-based restricted stock units) as of March 31, 2018 was approximately $4,281,000, which will be recognized over a weighted average period of 2.76 years. The total unrecognized stock-based compensation cost related to unvested performance-based restricted stock units as of March 31, 2018 was approximately $308,000, which will be recognized over a weighted average period of 2.00 years. The total unrecognized stock-based compensation cost related to unvested employee stock purchase plan (“ESPP”) shares as of March 31, 2018 was approximately $19,000, which will be recognized over a period of 5 months. The Company calculates the grant date fair value of all stock-based awards in determining the stock-based compensation expense. Stock-based awards include (i) stock options, (ii) restricted stock units, (iii) performance-based restricted stock units, and (iv) rights to purchase stock granted under the 2016 Employee Stock Purchase Plan (“ESPP”). The Company uses the Black-Scholes valuation model to calculate the fair value of stock options. Stock-based compensation expense is recognized over the vesting period using the straight-line method. The fair value of stock options was estimated at the grant date using the following assumptions: Year Ended March 31, 2018 Year Ended March 31, 2017 Year Ended March 31, 2016 Dividend yield — — — Volatility 76.86 % 72.17 % 73.96 % Risk-free interest rate 1.81 % 1.16 % 1.57 % Expected life of options 6.00 years 6.00 years 6.00 years Weighted average grant date fair value $ 1.73 $ 2.41 $ 2.52 The assumed dividend yield was based on the Company’s expectation of not paying dividends in the foreseeable future. Due to the Company’s limited historical data, the estimated volatility incorporates the historical and implied volatility of comparable companies whose share prices are publicly available, in addition to our own. The risk-free interest rate assumption was based on the U.S. Treasury rates. The weighted average expected life of options was estimated using the average of the contractual term and the weighted average vesting term of the options. Certain options granted to consultants are subject to variable accounting treatment and are required to be revalued until vested. The fair value of each restricted stock unit is recognized as stock-based compensation expense over the vesting term of the award. The fair value is based on the closing stock price on the date of the grant. The Company uses the Black-Scholes valuation model to calculate the fair value of shares issued pursuant to the Company’s ESPP. Stock-based compensation expense is recognized over the purchase period using the straight-line method. The fair value of ESPP shares was estimated at the purchase period commencement date using the following weighted average assumptions: Year Ended March 31, 2018 Year Ended March 31, 2017 Dividend yield — — Volatility 43.0% - 74.7% 72.9% - 74.7% Risk-free interest rate 0.79% - 1.85% 0.47% - 0.79% Expected term 6 months 6 months Grant date fair value $ 0.30 - $1.04 $ 1.04 - $1.22 The assumed dividend yield was based on the Company’s expectation of not paying dividends in the foreseeable future. For the first full year of ESPP offering periods, beginning September 1, 2016, due to the Company’s limited historical data as an early-stage commercial business, the estimated volatility incorporates the historical and implied volatility of comparable companies whose share prices are publicly available. As of September 1, 2017 and the beginning of the second year of ESPP offering periods, the Company is using our Company-specific volatility rate. The risk-free interest rate assumption was based on U.S. Treasury rates. The expected life is the 6-month purchase period. Preferred stock The Company is authorized to issue 25,000,000 shares of preferred stock. There are no shares of preferred stock currently outstanding, and the Company has no present plans to issue shares of preferred stock. Common stock In May of 2008, the Board of Directors of the Company approved the 2008 Equity Incentive Plan (the “2008 Plan”). The 2008 Plan authorized the issuance of up to 1,521,584 common shares for awards of incentive stock options, non-statutory stock options, restricted stock awards, restricted stock award units, and stock appreciation rights. The 2008 Plan terminates on July 1, 2018. No shares have been issued under the 2008 Plan since 2011, and the Company does not intend to issue any additional shares from the 2008 Plan in the future. In January 2012, the Board of Directors of the Company approved the 2012 Equity Incentive Plan (the “2012 Plan”). The 2012 Plan authorized the issuance of up to 6,553,986 shares of common stock for awards of incentive stock options, non-statutory stock options, stock appreciation rights, restricted stock, restricted stock units, performance units, performance shares, and other stock or cash awards. The Board of Directors and stockholders of the Company approved an amendment to the 2012 Plan in August 2013 to increase the number of shares of common stock that may be issued under the 2012 Plan by 5,000,000 shares. In addition, the Board of Directors and stockholders of the Company approved an amendment to the 2012 Plan in August 2015 to further increase the number of shares of common stock that may be issued under the 2012 Plan by 6,000,000 shares, bringing the aggregate shares issuable under the 2012 Plan to 17,553,986. The 2012 Plan as amended and restated became effective on August 20, 2015 and terminates ten years after such date. As of March 31, 2018, 4,595,021 shares remain available for issuance under the 2012 plan. On April 24, 2017 the Company filed a Registration Statement on Form S-8 with the SEC authorizing the issuance of 2,297,034 shares of the Company’s Common Stock, pursuant to the terms of an Inducement Award Stock Option Agreement and an Inducement Award Performance-Based Restricted Stock Unit Agreement (collectively, the “Inducement Award Agreements”). The Company filed a shelf registration statement on Form S-3 (File No. 333-189995), or the 2013 Shelf, with the SEC on July 17, 2013 authorizing the offer and sale in one or more offerings of up to $100,000,000 in aggregate of common stock, preferred stock, debt securities, or warrants to purchase common stock, preferred stock or debt securities, or any combination of the foregoing, either individually or as units comprised of one or more of the other securities. This 2013 Shelf was declared effective by the SEC on July 26, 2013. A shelf registration statement on Form S-3 (File No. 333-202382), or the 2015 shelf, was filed with the SEC on February 27, 2015 authorizing the offer and sale in one or more offerings of up to $190,000,000 in aggregate of common stock, preferred stock, debt securities, warrants to purchase common stock, preferred stock or debt securities, or any combination of the foregoing, either individually or as units comprised of one or more of the other securities. The 2015 shelf was declared effective by the SEC on March 17, 2015. In December 2014, the Company entered into an equity offering sales agreement (“2014 Sales Agreement”) with an investment banking firm. Under the terms of the sales agreement, the Company was eligible to offer and sell shares of its common stock, from time to time, through the investment bank in at-the-market offerings, as defined by the SEC, and pursuant to the Company’s 2013 Shelf. During the years ended March 31, 2018, 2017, and 2016, the Company issued 5,307,105, 997,181, and 0 shares of common stock in at-the-market offerings under the sales agreement with net proceeds of $9.2 million, $4.6, and $0 million, respectively. As of March 31, 2018, the Company had sold an aggregate of 7,304,286 shares of common stock in at-the-market offerings under the 2014 Sales Agreement, with net proceeds of approximately $19.9 million. On July 20, 2016, the Company filed a prospectus supplement to move the remaining shares of common stock that previously could have been sold pursuant to the 2014 Sales Agreement under the 2013 Shelf to the 2015 Shelf. On the same date, the Company filed a post-effective amendment to the 2013 Shelf de-registering all remaining securities that could have been offered by the Company pursuant to the 2013 Shelf. On June 18, 2015, the Company entered into an Underwriting Agreement with Jefferies LLC and Piper Jaffray & Co., acting as representatives of the underwriters named in the 2015 Underwriting Agreement and as joint book-running managers, relating to the issuance and sale of 9,425,000 shares of the Company’s common stock, par value $0.001 per share (the “2015 Offering”). The price to the public in the 2015 Offering was $4.25 per share, and the Underwriters agreed to purchase the shares from the Company pursuant to the 2015 Underwriting Agreement at a price of $3.995 per share. Under the terms of the 2015 Underwriting Agreement, the Company granted the Underwriters an option, exercisable for 30 days, to purchase up to an additional 1,413,750 shares. The Company issued 10,838,750 shares of common stock pursuant to the 2015 Underwriting Agreement, including shares issuable upon the exercise of the over-allotment option, with net proceeds of approximately $43.1 million, after deducting underwriting discounts and commissions and expenses payable by the Company. The shares were issued pursuant to the 2015 Shelf. On October 25, 2016, the Company closed the issuance and sale of 10,065,000 shares (the “2016 Offering”) of its common stock. The 2016 Offering was effected pursuant to an Underwriting Agreement (the “2016 Underwriting Agreement”) with Jefferies LLC (the “Representative”), acting as representative of the underwriters named in the 2016 Underwriting Agreement. The price to the public in the 2016 Offering was $2.75 per share, and the underwriters purchased the shares from the Company pursuant to the 2016 Underwriting Agreement at a price of $2.585 per share. The net proceeds to the Company from the 2016 Offering were approximately $25.7 million after deducting underwriting discounts and commissions and expenses payable by the Company. The 2016 Offering was made pursuant to the Company’s 2015 Shelf. The Company has an effective shelf registration statement on Form S-3 (File No. 333-222929) and the related prospectus previously declared effective by the Securities and Exchange Commission (the “SEC”) on February 22, 2018, as supplemented by a prospectus supplement, dated March 16, 2018 (the “2018 Shelf”), that expires on February 22, 2021. This replaces the 2015 Shelf which expired on March 17, 2018. On March 16, 2018, the Company entered into a Sales Agreement (“2018 Sales Agreement”) with H.C. Wainwright & Co., LLC and Jones Trading Institutional Services LLC (each an “Agent” and together, the “Agents”), pursuant to which the Company may offer and sell, from time to time through the Agents, shares of its common stock in “at the market” sales transactions having an aggregate offering price of up to $50,000,000 (the “Shares”). Any shares offered and sold will be issued pursuant to the Company’s 2018 Shelf. As of March 31, 2018, the Company cannot raise more than an aggregate of $100.0 million in future offerings under the 2018 Shelf including $50.0 million remaining for future issuance through its at-the-market program under the 2018 Sales Agreement . The Company intends to use the net proceeds raised through any at-the-market sales for general corporate purposes, general administrative expenses, and working capital and capital expenditures. In addition, during the years ended March 31, 2018, 2017, and 2016, the Company issued 0, 700,379, and 32,914 shares of common stock upon exercise of 0, 822,903, and 43,796 warrants, respectively. During the years ended March 31, 2018, 2017, and 2016, the Company issued 500,000, 245,271, and 116,001 shares of common stock upon exercise of 500,000, 245,271, and 116,001 stock options, respectively. Restricted stock units During the year ended March 31, 2018, the Company issued restricted stock units for an aggregate of 1,996,478 shares of common stock to its employees and directors. These shares of common stock will be issued upon vesting of the restricted stock units. A summary of the Company’s restricted stock unit activity for the year ended March 31, 2018 is as follows: Number of Shares Weighted Average Price Unvested at March 31, 2017 1,178,114 $ 3.57 Granted 1,996,478 $ 2.59 Vested (578,605 ) $ 3.22 Canceled / forfeited (560,642 ) $ 2.91 Unvested at March 31, 2018 2,035,345 $ 2.89 Performance-based restricted stock units On April 24, 2017, the Company issued a Performance-Based Restricted Stock Unit Award for 208,822 shares of common stock (the “PBRSU”) to its newly hired Chief Executive Officer. The PBRSU was issued outside of the 2012 Plan, in the Inducement Award Agreement, as an “inducement award” within the meaning of NASDAQ Marketplace Rule 5635(c)(4). While outside the Company’s 2012 Plan, the terms and conditions of this award are consistent with awards granted to the Company’s executive officers pursuant to the 2012 Plan. On August 23, 2017, the Board of Directors formally approved the vesting criteria for the PBRSU. The vesting of the PBRSU is divided into five separate tranches each with independent vesting criteria. The first four tranches have performance criteria related to annual revenue goals with measurement at the end of fiscal year 2018 (20 percent), fiscal year 2019 (20 percent), fiscal year 2020 (20 percent), and fiscal year 2021 (20 percent). The fifth tranche has a performance metric related to a path to profitability goal measured as Negative Adjusted Earnings Before Interest, Taxes, Depreciation and Amortization (“EBITDA”) achievable at any point between the grant date and the end of fiscal year 2020 (20 percent). The number of units that ultimately vest for each tranche will range from 0 percent to 120 percent of the target amount, not to exceed 208,822 in aggregate. As of March 31, 2018, no tranches had vested, but 120% of the Negative Adjusted EBITDA tranche is expected to vest in a future year. The grant date fair value of the PBRSU was $393,000 of which one-fifth is being recognized over each tranches’ service period. The Company began recording stock-based compensation expense for these tranches after the August 23, 2017 grant date when the financial performance goals were established and approved. As of March 31, 2018, the Negative Adjusted EBITDA tranche is expected to vest in the amount of 41,766 shares. A summary of the Company’s performance-based restricted stock unit activity from March 31, 2017 through March 31, 2018 is as follows: Number of Shares Maximum Number of Shares Eligible to be Issued Weighted Average Price Unvested at March 31, 2017 — — $ — Awarded at target 208,822 208,822 $ 1.88 Vested — — $ — Canceled / forfeited (41,764 ) (8,352 ) $ 1.88 Unvested at March 31, 2018 167,058 200,470 $ 1.88 Stock options During the year ended March 31, 2018 under the 2012 Equity Incentive Plan, 281,956 stock options were issued at various exercise prices. In addition, on April 24, 2017, the Company granted a stock option for 2,088,212 shares of common stock to its newly hired Chief Executive Officer. This stock option award was issued outside of the 2012 Plan, in the Inducement Award Agreement, as an “inducement award” within the meaning of NASDAQ Marketplace Rule 5635(c)(4). While granted outside the Company’s 2012 Plan, the terms and conditions of this stock option award are consistent with awards granted to the Company’s executive officers pursuant to the 2012 Plan. The following table summarizes stock option activity for the year ended March 31, 2018: Options Outstanding Weighted- Average Exercise Price Aggregate Intrinsic Value Outstanding at March 31, 2017 10,956,201 $ 4.63 $ 4,876,437 Options granted 2,370,168 $ 2.64 $ — Options canceled (2,694,057 ) $ 5.78 $ — Options exercised (500,000 ) $ 1.65 $ 235,000 Outstanding at March 31, 2018 10,132,312 $ 4.01 $ 591,082 Vested and Exercisable at March 31, 2018 6,211,427 $ 4.54 $ 591,082 The weighted-average remaining contractual term of stock options exercisable and outstanding at March 31, 2018 was approximately 5.91 years. Employee Stock Purchase Plan In June 2016, our Board of Directors adopted, and in August 2016 stockholders subsequently approved, the 2016 Employee Stock Purchase Plan (“ESPP”). We reserved 1,500,000 shares of common stock for issuance thereunder. The ESPP permits employees after five months of service to purchase common stock through payroll deductions, limited to 15 percent of each employee’s compensation up to $25,000 per employee per year or 10,000 shares per employee per purchase period. Shares under the ESPP are purchased at 85 percent of the fair market value at the lower of (i) the closing price on the first trading day of the six-month purchase period or (ii) the closing price on the last trading day of the six-month purchase period. The initial offering period commenced in September 2016. During the year ended March 31, 2018, 162,340 shares were issued under the ESPP. At March 31, 2018, there were 1,285,103 shares remaining available for the purchase under the ESPP. Warrants During the years ended December 31, 2012 and 2011, the Company issued warrants to investors to purchase 21,347,182 and 2,909,750 shares, respectively, of its common stock. During the years ended March 31, 2018, 2017 and 2016, 0, 353,093 and 0 of these warrants were exercised for cash proceeds of approximately $0, $336,000 and $0, respectively, and 0, 469,000 and 43,796 of these warrants were exercised through a cashless exercise for issuance of 0, 347,286 and 32,914 shares of common stock, respectively. In 2012, the Company issued a total of 650,000 warrants to purchase common stock, in connection with consulting agreements, at prices ranging from $1.70 to $3.24, with lives ranging from two to five years, to be earned over service periods of up to six months. During the years ended March 31, 2018, 2017, and 2016, no warrants held by consultants were exercised. As of March 31, 2018, 220,000 of these warrants are outstanding. Additionally, during September 2014, the Company issued 50,000 warrants to a consultant in recognition of services previously provided. These warrants were classified as equity instruments because they do not contain any anti-dilution provisions. As of December 31, 2014, the full amount of the warrants related to these services, approximately $237,000 had been recognized. In November 2014, in connection with a consulting agreement, the Company issued 145,000 warrants to purchase common stock, at a price of $6.84, with a life of five years, to be earned over a seventeen month service period ended on March 31, 2016. The final number of vested warrant shares was 95,000, based on management’s judgment of the satisfaction of specific performance metrics. The fair value of the warrants was estimated to be approximately $74,000, which was revalued and amortized over the term of the consulting agreement. These warrants were classified as equity instruments because they do not contain any anti-dilution provisions. The Black-Scholes model, using a volatility rate of 73.4% and a risk-free interest rate factor of 1.21%, was used to determine the value as of March 31, 2016. The Company recognized approximately $6,000 during the year ended March 31, 2016 related to these services. As of March 31, 2016, these warrants were fully expensed. The following table summarizes warrant activity for the year ended March 31, 2018: Warrants Weighted-Average Exercise Price Balance at March 31, 2017 221,370 $ 7.16 Granted — — Expired / Canceled (1,370 ) $ 2.28 Exercised — — Balance at March 31, 2018 220,000 $ 7.19 The warrants outstanding at March 31, 2018 are immediately exercisable at prices between $6.84 and $7.62 per share, and have a weighted average remaining term of approximately 1.21 years. Common stock reserved for future issuance Common stock reserved for future issuance consisted of the following at March 31, 2018: Common stock warrants outstanding 220,000 Common stock options outstanding under the 2008 Plan 622,192 Common stock options outstanding under the 2012 Plan 7,421,908 Common stock reserved under the 2012 Plan 4,595,021 Common stock reserved under the 2016 Employee Stock Purchase Plan 1,285,103 Restricted stock units outstanding under the 2012 Plan 2,035,345 Common stock options outstanding and reserved under the Incentive Award Agreement 2,088,212 Restricted stock units outstanding under the Incentive Award Agreement 200,470 Total 18,468,251 |