DESCRIPTION OF CAPITAL STOCK

General

The descriptions of our capital stock and certain provisions of our amended and restated certificate of incorporation and amended and restated bylaws are summaries and are qualified by reference to the amended and restated certificate of incorporation and amended and restated bylaws that are currently in effect. Copies of these documents have been filed with the SEC and are incorporated by reference herein.

Our amended and restated certificate of incorporation provides for common stock and preferred stock, the rights, preferences and privileges of which may be designated from time to time by our board of directors.

Our authorized capital stock consists of 110,000,000 shares, all with a par value of $0.001 per share, of which 100,000,000 shares are designated as common stock and 10,000,000 shares are designated as preferred stock.

As of August 13, 2018, our common stock was held by approximately 651 stockholders of record. As of August 13, 2018, we had 1,862,875 shares of our common stock available for issuance under our 2018 Plan.

Common Stock

The holders of our common stock are entitled to one vote per share on all matters submitted to a vote of our stockholders. Subject to preferences that may be applicable to any preferred stock outstanding at the time, the holders of outstanding shares of common stock are entitled to receive ratably any dividends declared by our board of directors out of assets legally available therefor. In the event that we liquidate, dissolve or wind up, holders of our common stock are entitled to share ratably in all assets remaining after payment of liabilities and the liquidation preference of any then outstanding shares of preferred stock. Holders of common stock have no preemptive or conversion rights or other subscription rights. There are no redemption or sinking fund provisions applicable to the common stock. All outstanding shares of common stock are fully paid and non-assessable.

Except as otherwise required by Delaware law, all stockholder action, other than the election of directors or certain amendments of our amended and restated certificate of incorporation, is taken by the vote of a majority of the voting power of the shares present in person or represented by proxy at the meeting and entitled to vote on the subject matter, at a meeting in which a quorum, consisting of a majority of the outstanding shares of common stock is present in person or by proxy. The election of directors by our stockholders is determined by a plurality of the voting power of the shares present in person or represented by proxy at the meeting and entitled to vote, at a meeting held for such purposes at which a quorum, consisting of a majority of the outstanding shares of common stock, is present in person or by proxy. Certain amendments to our amended and restated certificate of incorporation require the approval of holders of at least sixty-six and two-third percent (66 2/3%) of the voting power of all then-outstanding shares of our common stock entitled to vote generally in the election of directors, voting together as a single class.

We have never declared or paid any cash dividends on our capital stock. We currently intend to retain all available funds and any future earnings to support our operations and finance the growth and development of our business. We do not intend to pay cash dividends on our common stock for the foreseeable future. Any future determination related to our dividend policy will be made at the discretion of our board of directors and will depend upon, among other factors, our results of operations, financial condition, capital requirements, contractual restrictions, business prospects and other factors our board of directors may deem relevant.

Preferred Stock

Our amended and restated certificate of incorporation provides that our board of directors may, without further action by our stockholders, fix the rights, preferences, privileges and restrictions of up to an aggregate of 10,000,000 shares of preferred stock in one or more series and authorize their issuance. These rights, preferences and privileges could include dividend rights, conversion rights, voting rights, terms of redemption, liquidation preferences, sinking fund terms and the number of shares constituting any series or the designation of such series, any or all of which may be greater than the rights of our common stock. The issuance of our preferred stock could adversely affect the voting power of holders of our common stock and the likelihood that such holders will receive dividend payments and payments upon liquidation. In addition, the issuance of preferred stock could have the effect of delaying, deferring or preventing a change of control or other corporate action. We have no present plan to issue any shares of preferred stock.

Options to Purchase Common Stock

As of August 13, 2018, options to purchase 1,719,771 shares of our common stock issued pursuant to our 2015 Equity Incentive Plan and our 2018 Equity Incentive Plan at a weighted-average exercise price of $1.57 per share were outstanding. As of August 13, 2018, we had 209,579 shares of common stock issuable upon the vesting of restricted stock units outstanding.

Outstanding Warrants to Purchase Common Stock

As of August 13, 2018, we had 11,447,087 shares of common stock issuable upon exercise of outstanding common stock warrants, at a weighted-average exercise price of $1.82 per share.

Common Stock Warrants Issued in June 2018 Private Placement

On June 20, 2018, the Company issued warrants to purchase a total of 1,133,909 shares of Common Stock to an investor in a private placement. Terms used but not otherwise defined herein will have the meaning given them in the warrant, attached as Exhibit 4.1 to our Form 8-K filed on June 20, 2018.

Duration and Exercise Price . The warrants have an exercise price of $1.82 per share and are exercisable after December 20, 2018. The warrants will expire in December 2023.

Adjustment . For so long as the warrants remain outstanding, the exercise price and number of shares of Common Stock issuable upon exercise of the warrant is subject to adjustment as follows: (a) as the Company’s board of directors deems appropriate, or (b) upon subdivision (by stock spilt, stock dividend, recapitalization, or otherwise) or combination (by reverse stock split or otherwise) of shares of Common Stock.

Rights upon Distribution of Assets . In the event that the Company declares or makes any dividend or other distribution of its assets to holders of its Common Stock, the warrant holder will be entitled to participate in such distribution to the same extent that such holder would have participated therein if the holder had held the number of shares of Common Stock acquirable upon exercise of the warrant.

Fundamental Transaction . In the event of a Fundamental Transaction, as described in the warrants and generally including the sale, transfer or other disposition of all or substantially all of our properties or assets, our consolidation or merger with or into another person or reorganization, recapitalization or reclassification or the acquisition of our outstanding Common Stock which results in any person or group becoming the beneficial owner of 50% of the voting power represented by our outstanding Common Stock, the holders of the warrants will be entitled to receive upon exercise of the warrants the kind and amount of securities, cash, assets or other property that the holders would have received had they exercised the warrants immediately prior to such Fundamental Transaction. Subject to certain limitations, in the event of a Fundamental Transaction the warrant holder may at its option require the Company or any Successor Entity to purchase the warrant from the holder by paying to the holder an amount of cash equal to the Black Scholes Value of the remaining unexercised portion of the warrant on the date of the consummation of the Fundamental Transaction.

Purchase Right . Any time that the Company grants, issues, or sells any securities pro rata to all of the record holders of the Common Stock (the “Purchase Right”), the holder of the warrant will be entitled to acquire the aggregate Purchase Rights which the holder could have acquired if the holder had held the number of shares of Common Stock acquirable upon exercise of the warrant.

Transferability . Subject to applicable laws and restrictions on transfer, the warrant may be transferred at the option of the holder. The warrants are not listed on any securities exchange or nationally recognized trading system.

Exercisability . After the Initial Exercisability Date, the warrants will be exercisable, at the option of each holder, in whole or in part, by delivering to us a duly executed exercise notice accompanied by payment in full for the number of shares of our Common Stock purchased upon such exercise. If, at the time a holder exercises its warrant, a registration statement registering the issuance of the shares of Common Stock underlying the warrants under the Securities Act is not then effective or available and an exemption from registration under the Securities Act is not available for the issuance of such shares, then in lieu of making the cash payment otherwise contemplated to be made to us upon such exercise in payment of the aggregate exercise price, the holder may elect instead to receive upon such exercise (either in whole or in part) the net number of shares of Common Stock determined according to a formula set forth in the warrant.

Limitations on Exercise . A holder (together with its affiliates) may not exercise any portion of the warrant to the extent that the holder would own more than 4.99% of the outstanding Common Stock after exercise, except that upon at least 61 days’ prior notice from the holder to us, the holder may increase the amount of ownership of outstanding stock after exercising the holder’s warrants up to 9.99% of the number of shares of our Common Stock outstanding immediately after giving effect to the exercise, as such percentage ownership is determined in accordance with the terms of the warrants. No fractional shares of Common Stock will be issued in connection with the exercise of a warrant. In lieu of fractional shares, we will round up to the next whole share.

Right as a Stockholder . Except as otherwise provided in the warrants or by virtue of such holder’s ownership of shares of our Common Stock, the holders of the warrants do not have the rights or privileges of holders of our Common Stock, including any voting rights, unless and until they exercise their warrants.

Waivers and Amendments . Subject to certain exceptions, any term of the warrants may be amended or waived with our written consent and the written consent of the holders.

Failure to Timely Deliver Securities . Upon exercise of the warrant by the holder, if the Company or its transfer agent fails to deliver the securities to holder by the required share delivery date set forth in the warrant, then, generally, the holder may require the Company to pay to the holder an amount in cash to make the investor whole in connection with the Company’s failure to timely deliver securities.

Common Stock Warrants Issued to Participants in November 2017 Offering

On November 21, 2017, in its public offering of common stock, the Company issued warrants to purchase a total of 4,657,500 shares of common stock to investors. Terms used but not otherwise defined herein will have the meaning given them in the warrant, attached as Exhibit 4.2 to our Form 8-K filed on November 17, 2017.

Duration and Exercise Price. The warrants have an initial exercise price of $1.50 per share. The exercise price adjusted to $0.95 per share on the record date of the Rights Offering, which was the lowest weighted average trading price of our common stock during the four trading days immediately following public announcement of the revised subscription price of the Rights Offering. The exercise price for these warrants is subject to further adjustments as described below. The warrants are exercisable immediately and will expire in November 2022, on the fifth anniversary of the original issuance date.

Adjustment . For so long as the warrants remain outstanding and notwithstanding any prior adjustments, the exercise price and number of shares of common stock issuable upon exercise of the warrant is subject to adjustment as follows: (a) as the Company’s board of directors deems appropriate, (b) upon subdivision (by stock spilt, stock dividend, recapitalization, or otherwise) or combination (by reverse stock split or otherwise) of shares of common stock, (c) upon the issuance or announcement of contemplated issuance (“Dilutive Issuance”) of shares of common stock, options or convertible securities for consideration per share less than the price equal to the exercise price of the warrants, except for certain Excluded Securities issued in connection with an Approved Equity Plan, (d) at the option of the warrant holder upon the Company’s entering into an agreement to issue securities that are issuable at a price which varies or may vary with the market price of the Company’s common stock (the “Variable Price”), and (e) in certain cases upon granting of stock appreciation rights, phantom stock rights or other rights with equity features, except for those granted pursuant to an Approved Equity Plan. For the adjustments summarized in (c) above, the exercise price of the warrants outstanding generally will adjust upon the record date of such issuance to the New Issuance Price (as defined in the warrant, and which will be based on the net price at which new securities in the Dilutive Issuance are issued, and in some cases such as where warrants are issued with a stock offering, the lower of such price or the lowest weighted average trading price of the common stock during the four trading days immediately following public announcement of the Dilutive Issuance). For the adjustments summarized in (d) above, the holder may, at its option, elect to adjust the exercise price of the warrants to the Variable Price of securities sold by the Company pursuant to the agreement. Any adjustment made upon announcement or pursuant to a Dilutive Issuance will not be readjusted in the event that such Dilutive Issuance does not occur.

Rights upon Distribution of Assets. In the event that the Company declares or makes any dividend or other distribution of its assets to holders of its common stock, the warrant holder will be entitled to participate in such distribution to the same extent that such holder would have participated therein if the holder had held the number of shares of common stock acquirable upon exercise of the warrant.

Fundamental Transaction . In the event of a Fundamental Transaction, as described in the warrants and generally including the sale, transfer or other disposition of all or substantially all of our properties or assets, our consolidation or merger with or into another person or reorganization, recapitalization or reclassification or the acquisition of our outstanding common stock which results in any person or group becoming the beneficial owner of 50% of the voting power represented by our outstanding common stock, the holders of the warrants will be entitled to receive upon exercise of the warrants the kind and amount of securities, cash, assets or other property that the holders would have received had they exercised the warrants immediately prior to such Fundamental Transaction. Subject to certain limitations, in the event of a Fundamental Transaction the warrant holder may at its option require the Company or any Successor Entity to purchase the warrant from the holder by paying to the holder an amount of cash equal to the Black Scholes Value of the remaining unexercised portion of the warrant on the date of the consummation of the Fundamental Transaction.

Purchase Right . Any time that the Company grants, issues, or sells any securities pro rata to all of the record holders of the common stock (the “Purchase Right”), the holder of the warrant will be entitled to acquire the aggregate Purchase Rights which the holder could have acquired if the holder had held the number of shares of common stock acquirable upon exercise of the warrant.

Transferability . Subject to applicable laws and restrictions on transfer, the warrant may be transferred at the option of the holder. The warrants are not listed on any securities exchange or nationally recognized trading system.

Exercisability . The warrants will be exercisable, at the option of each holder, in whole or in part, by delivering to us a duly executed exercise notice accompanied by payment in full for the number of shares of our common stock purchased upon such exercise. If, at the time a holder exercises its warrant, a registration statement registering the issuance of the shares of common stock underlying the warrants under the Securities Act is not then effective or available and an exemption from registration under the Securities Act is not available for the issuance of such shares, then in lieu of making the cash payment otherwise contemplated to be made to us upon such exercise in payment of the aggregate exercise price, the holder may elect instead to receive upon such exercise (either in whole or in part) the net number of shares of common stock determined according to a formula set forth in the warrant.

Limitations on Exercise . A holder (together with its affiliates) may not exercise any portion of the warrant to the extent that the holder would own more than 4.99% of the outstanding common stock after exercise, except that upon at least 61 days’ prior notice from the holder to us, the holder may increase the amount of ownership of outstanding stock after exercising the holder’s warrants up to 9.99% of the number of shares of our common stock outstanding immediately after giving effect to the exercise, as such percentage ownership is determined in accordance with the terms of the warrants. No fractional shares of common stock will be issued in connection with the exercise of a warrant. In lieu of fractional shares, we will round up to the next whole share.

Right as a Stockholder . Except as otherwise provided in the warrants or by virtue of such holder’s ownership of shares of our common stock, the holders of the warrants do not have the rights or privileges of holders of our common stock, including any voting rights, unless and until they exercise their warrants.

Limitation on Variable Rate Transactions. The Company may not effect or enter into any agreement to sell securities in a Variable Rate Transaction.

Waivers and Amendments . Subject to certain exceptions, any term of the warrants may be amended or waived with our written consent and the written consent of the holders.

Failure to Timely Deliver Securities. Upon exercise of the warrant by the holder, if the Company or its transfer agent fails to deliver the securities to holder by the required share delivery date set forth in the warrant, or if the Company did not provide the required notice to holder that a registration statement covering the issuance of the warrant shares subject to the exercise notice is not available and the Company is unable to deliver the securities without any restrictive legend (each, an Exercise Failure), then, generally, the holder may rescind the exercise in whole or in part or may require the Company to pay to the holder an amount in cash to make the investor whole in connection with the Company’s failure to timely deliver securities.

Common Stock Warrant Issued to Underwriter of November 2017 Offering

In November 2017, the Company issued to Roth Capital Partners, LLC, as underwriter, a warrant to purchase 540,000 shares of common stock, which shares include a warrant (in the form of warrant issued to the public) to purchase an additional 405,000 shares of common stock in connection with our November 2017 offering. Terms used but not otherwise defined herein will have the meaning given them in the warrant.

Duration and Exercise Price . The warrants have an exercise price of $1.50 per share, are exercisable immediately and will expire in November 2022, on the fifth anniversary of the original issuance date. The terms of the warrant are limited by FINRA Rule 5110(f)(2)(G), which provide, among others, that the warrant may not be exercised more than five years from the date that the registration statement registering the warrant was declared effective by the SEC.

Adjustment . The exercise price and number of shares of common stock issuable upon exercise of the warrant is subject to adjustment as follows: (a) as the Company’s board of directors deems appropriate, or (b) upon a stock dividend, stock split, reorganization, subdivision or combination of shares of common stock.

Fundamental Transaction . In the event of a Fundamental Transaction, as described in the warrants and generally including any reorganization, recapitalization or reclassification of our common stock, the sale, transfer or other disposition of all or substantially all of our properties or assets, our consolidation or merger with or into another person, the acquisition of more than 50% of our outstanding common stock, or any person or group becoming the beneficial owner of 50% of the voting power represented by our outstanding common stock, the holders of the warrants will be entitled to receive upon exercise of the warrants the kind and amount of securities, cash or other property that the holders would have received had they exercised the warrants immediately prior to such Fundamental Transaction.

Purchase Right . Any time that the Company grants, issues, or sells any securities pro rata to all of the record holders of the common stock (the “Purchase Right”), the holder of the warrant will be entitled to acquire the aggregate Purchase Rights which the holder could have acquired if the holder had held the number of shares of common stock acquirable upon exercise of the warrant.

Transferability . Subject to applicable laws and restrictions on transfer, the warrant may be transferred at the option of the holder after the expiration of the Lock-Up Period, which is 180 days after the registration statement registering the warrant became effective. The warrants are not listed on any securities exchange or nationally recognized trading system.

Exercisability . The warrants will be exercisable, at the option of each holder, in whole or in part, by delivering to us a duly executed exercise notice accompanied by payment in full for the number of shares of our common stock purchased upon such exercise. If, at the time a holder exercises its warrant, a registration statement registering the issuance of the shares of common stock underlying the warrants under the Securities Act is not then effective or available and an exemption from registration under the Securities Act is not available for the issuance of such shares, then in lieu of making the cash payment otherwise contemplated to be made to us upon such exercise in payment of the aggregate exercise price, the holder may elect instead to receive upon such exercise (either in whole or in part) the net number of shares of common stock determined according to a formula set forth in the warrant.

Limitations on Exercise . A holder (together with its affiliates) may not exercise any portion of the warrant to the extent that the holder would own more than 4.99% of the outstanding common stock after exercise, except that upon at least 61 days’ prior notice from the holder to us, the holder may increase the amount of ownership of outstanding stock after exercising the holder’s warrants up to 9.99% of the number of shares of our common stock outstanding immediately after giving effect to the exercise, as such percentage ownership is determined in accordance with the terms of the warrants. No fractional shares of common stock will be issued in connection with the exercise of a warrant. In lieu of fractional shares, we will round up to the next whole share.

Right as a Stockholder . Except as otherwise provided in the warrants or by virtue of such holder’s ownership of shares of our common stock, the holders of the warrants do not have the rights or privileges of holders of our common stock, including any voting rights, unless and until they exercise their warrants.

Waivers and Amendments . Subject to certain exceptions, any term of the warrants may be amended or waived with our written consent and the written consent of the holder.

Warrants that Expire on or Before the Second Anniversary of the Closing of the Initial Public Offering

Prior to our initial public offering, we issued warrants to purchase 488,119 shares of common stock having a weighted average exercise price of $10.74 per share and are exercisable. Terms used but not otherwise defined herein will have the meaning given them in the warrants.

Duration and Exercise Price . Warrants to purchase 40,000 shares of common stock expire on December 13, 2018. Warrants to purchase 210,526 shares of common stock expire on the earlier of November 15, 2018 and the closing of a liquidation, dissolution or winding up of the Company. Warrants to purchase 137,592 shares of common stock expire on the earlier of December 13, 2018 and the closing of a liquidation, dissolution or winding up of the Company. For purposes of the warrants, the following are deemed to be a liquidation, dissolution or winding up of the Company: (i) a sale, exclusive lease, exclusive license or other disposition of all or substantially all of the assets of the Company; or (ii) any reorganization, consolidation, merger, stock sale, or similar transaction in which the Company is a constituent corporation or is a party if, as a result of such transaction, the voting securities of the Company that are outstanding immediately prior to such transaction do not represent, or are not converted into, securities of the resulting or surviving corporation that together represent a majority of the voting power of the surviving or resulting corporation in such a transaction (a “Change of Control Transaction”).

Adjustment . The exercise price and number of shares of common stock issuable upon exercise of the warrant is subject to adjustment upon a stock dividend, stock split, reorganization, subdivision, combination, reclassification or reorganization of shares of common stock.

Notice . The warrant holder is entitled to notice of certain transactions, including when: (i) the Company takes a record of holders of its common stock for the purpose of entitling or enabling them to receive any dividend or other distribution, or to receive any right to subscribe for or purchase any shares of stock or any class or other securities, (ii) the Company makes any changes to its certificate of incorporation, (iii) the Company undertakes any capital reorganization of the Company, reclassification of the Company stock, any Change of Control Transaction, or a transfer of all or substantially all of the assets of the Company, (iv) the Company undergoes a voluntary or involuntary dissolution, liquidation or winding up of the Company.

Transferability . Subject to applicable laws and restrictions on transfer, the warrant may be transferred at the option of the holder.

Exercisability . The warrants will be exercisable, at the option of each holder, in whole or in part, by delivering to us a duly executed exercise notice accompanied by payment in full for the number of shares of our common stock purchased upon such exercise. At the election of the holder, in lieu of making the cash payment otherwise contemplated to be made to us upon such exercise in payment of the aggregate exercise price, the holder may elect instead to receive upon such exercise (either in whole or in part) the net number of shares of common stock determined according to a formula set forth in the warrant. The warrant will be deemed to be exercised automatically in full pursuant to net issue exercise immediately prior to the time it would otherwise expire or terminate pursuant to its terms.

Right as a Stockholder . Except as otherwise provided in the warrants or by virtue of such holder’s ownership of shares of our common stock, the holders of the warrants do not have the rights or privileges of holders of our common stock, including any voting rights, unless and until they exercise their warrants.

Waivers and Amendments . Subject to certain exceptions, any term of the warrants may be amended or waived with our written consent and the written consent of the holder.

Warrants that Expire on or Before the Third Anniversary of the Closing of the Initial Public Offering

Prior to our initial public offering, we issued warrants to purchase 138,666 shares of common stock having a weighted-average exercise price of $7.50 per share and are exercisable. Terms used but not otherwise defined herein will have the meaning given them in the warrants.

Duration and Exercise Price . The warrants expire on the earlier of November 15, 2019 and the closing of a liquidation, dissolution or winding up of the Company. For purposes of the warrants, the following are deemed to be a liquidation, dissolution or winding up of the Company: (i) a sale, exclusive lease, exclusive license or other disposition of all or substantially all of the assets of the Company; or (ii) any reorganization, consolidation, merger, stock sale, or similar transaction in which the Company is a constituent corporation or is a party if, as a result of such transaction, the voting securities of the Company that are outstanding immediately prior to such transaction do not represent, or are not converted into, securities of the resulting or surviving corporation that together represent a majority of the voting power of the surviving or resulting corporation in such a transaction (a “Change of Control Transaction”).

Adjustment . The exercise price and number of shares of common stock issuable upon exercise of the warrant is subject to adjustment upon a stock dividend, stock split, reorganization, subdivision, combination, reclassification or reorganization of shares of common stock.

Notice . The warrant holder is entitled to notice of certain transactions, including when: (i) the Company takes a record of holders of its common stock for the purpose of entitling or enabling them to receive any dividend or other distribution, or to receive any right to subscribe for or purchase any shares of stock or any class or other securities, (ii) the Company makes any changes to its certificate of incorporation, (iii) the Company undertakes any capital reorganization of the Company, reclassification of the Company stock, any Change of Control Transaction, or a transfer of all or substantially all of the assets of the Company, (iv) the Company undergoes a voluntary or involuntary dissolution, liquidation or winding up of the Company.

Transferability . Subject to applicable laws and restrictions on transfer, the warrant may be transferred at the option of the holder.

Exercisability . The warrants will be exercisable, at the option of each holder, in whole or in part, by delivering to us a duly executed exercise notice accompanied by payment in full for the number of shares of our common stock purchased upon such exercise. At the election of the holder, in lieu of making the cash payment otherwise contemplated to be made to us upon such exercise in payment of the aggregate exercise price, the holder may elect instead to receive upon such exercise (either in whole or in part) the net number of shares of common stock determined according to a formula set forth in the warrant. The warrant will be deemed to be exercised automatically in full pursuant to net issue exercise immediately prior to the time it would otherwise expire or terminate pursuant to its terms.

Right as a Stockholder . Except as otherwise provided in the warrants or by virtue of such holder’s ownership of shares of our common stock, the holders of the warrants do not have the rights or privileges of holders of our common stock, including any voting rights, unless and until they exercise their warrants.

Waivers and Amendments . Subject to certain exceptions, any term of the warrants may be amended or waived with our written consent and the written consent of the holder.

Other Warrants

Prior to our initial public offering and in connection with entering into a license agreement, we issued warrants to purchase 15,000 shares of common stock to the University of Arizona. Terms used but not otherwise defined herein will have the meaning given them in the warrant.

Duration and Exercise Price . The warrants expire in June 2020 and have an exercise price of $7.50 per share.

Adjustment . The exercise price and number of shares of common stock issuable upon exercise of the warrant is subject to adjustment upon a stock dividend, stock split, reorganization, subdivision, combination, reclassification or reorganization of shares of common stock.

Terminating Change. In the event of a Terminating Change, defined to include any consolidation, merger, sale of all or substantially all of the assets of the Company, or capital reorganization or certain reclassifications of the Company’s stock, the Company will pay to the holder the fair market value of the warrant shares immediately prior to the Terminating Change.

Notice . The warrant holder is entitled to notice of certain transactions, including when: (i) the Company takes a record of holders of its common stock for the purpose of entitling or enabling them to receive any dividend or other distribution, or to receive any right to subscribe for or purchase any shares of stock or any class or other securities, (ii) the Company offers to sell certain Company securities, (iii) the Company’s common stock is reorganized or reclassified, (iv) any consolidation or merger of the Company or any conveyance of all or substantially all of the assets of the Company, (v) the Company undergoes a voluntary or involuntary dissolution, liquidation or winding up of the Company.

Transferability . Subject to applicable laws and restrictions on transfer, the warrant may be transferred at the option of the holder.

Exercisability . The warrants will be exercisable, at the option of each holder, in whole or in part, by delivering to us a duly executed exercise notice accompanied by payment in full for the number of shares of our common stock purchased upon such exercise. At the election of the holder, in lieu of making the cash payment otherwise contemplated to be made to us upon such exercise in payment of the aggregate exercise price, the holder may elect instead to receive upon such exercise (either in whole or in part) the net number of shares of common stock determined according to a formula set forth in the warrant.

Right as a Stockholder . Except as otherwise provided in the warrants or by virtue of such holder’s ownership of shares of our common stock, the holders of the warrants do not have the rights or privileges of holders of our common stock, including any voting rights, unless and until they exercise their warrants.

Waivers and Amendments . Subject to certain exceptions, any term of the warrants may be amended or waived with our written consent and the written consent of the holder.

IPO Underwriter Warrant

In connection with our initial public offering in December 2016, we issued warrants to purchase 187,500 shares of our common stock to Roth Capital Partners LLC.

Duration and Exercise Price . The warrants have an exercise price of $9.60 per share. The warrant was fully vested and exercisable on the date of grant and will expire in December 2021, on the fifth anniversary of the original issuance date.

Adjustment . The exercise price and number of shares of common stock issuable upon exercise of the warrant is subject to adjustment as follows: (a) as the Company’s board of directors deems appropriate, or (b) upon a stock dividend, stock split, reorganization, subdivision or combination of shares of common stock.

Rights upon Distribution of Assets. In the event that the Company declares or makes any dividend or other distribution of its assets to holders of its common stock, the warrant holder will be entitled to participate in such distribution to the same extent that such holder would have participated therein if the holder had held the number of shares of common stock acquirable upon exercise of the warrant.

Fundamental Transaction . In the event of a Fundamental Transaction, as described in the warrants and generally including any reorganization, recapitalization or reclassification of our common stock, the sale, transfer or other disposition of all or substantially all of our properties or assets, our consolidation or merger with or into another person, the acquisition of more than 50% of our outstanding common stock, or any person or group becoming the beneficial owner of 50% of the voting power represented by our outstanding common stock, the holders of the warrants will be entitled to receive upon exercise of the warrants the kind and amount of securities, cash or other property that the holders would have received had they exercised the warrants immediately prior to such Fundamental Transaction. The Company may not enter into a Fundamental Transaction unless the successor entity assumes all obligations of the Company under the warrant pursuant to an agreement in form and substance reasonably satisfactory to the holder.

Purchase Right . Any time that the Company grants, issues, or sells any securities pro rata to all of the record holders of the common stock (the “Purchase Right”), the holder of the warrant will be entitled to acquire the aggregate Purchase Rights which the holder could have acquired if the holder had held the number of shares of common stock acquirable upon exercise of the warrant.

Transferability . Subject to applicable laws and restrictions on transfer, the warrant may be transferred at the option of the holder. The warrants are not listed on any securities exchange or nationally recognized trading system.

Exercisability . The warrants will be exercisable, at the option of each holder, in whole or in part, by delivering to us a duly executed exercise notice accompanied by payment in full for the number of shares of our common stock purchased upon such exercise. If, at the time a holder exercises its warrant, a registration statement registering the issuance of the shares of common stock underlying the warrants under the Securities Act is not then effective or available and an exemption from registration under the Securities Act is not available for the issuance of such shares, then in lieu of making the cash payment otherwise contemplated to be made to us upon such exercise in payment of the aggregate exercise price, the holder may elect instead to receive upon such exercise (either in whole or in part) the net number of shares of common stock determined according to a formula set forth in the warrant.

Limitations on Exercise . A holder (together with its affiliates) may not exercise any portion of the warrant to the extent that the holder would own more than 4.99% of the outstanding common stock after exercise, except that upon at least 61 days’ prior notice from the holder to us, the holder may increase the amount of ownership of outstanding stock after exercising the holder’s warrants up to 9.99% of the number of shares of our common stock outstanding immediately after giving effect to the exercise, as such percentage ownership is determined in accordance with the terms of the warrants. No fractional shares of common stock will be issued in connection with the exercise of a warrant. In lieu of fractional shares, we will round up to the next whole share.

Right as a Stockholder . Except as otherwise provided in the warrants or by virtue of such holder’s ownership of shares of our common stock, the holders of the warrants do not have the rights or privileges of holders of our common stock, including any voting rights, unless and until they exercise their warrants.

Waivers and Amendments . Subject to certain exceptions, any term of the warrants may be amended or waived with our written consent and the written consent of the holder.

For additional information about outstanding warrants, please read “Item 1. Financial Statements — Notes to Condensed Financial Statements — Note 10. Common Stock Warrants and Common Stock Warrant Liability” in our Quarterly Report on Form 10-Q filed with the SEC on August 14, 2018.

Anti-Takeover Provisions

Certificate of Incorporation and Bylaws

Because our stockholders do not have cumulative voting rights, our stockholders holding a majority of the outstanding shares of common stock outstanding will be able to satisfy the quorum requirement and be able to elect all of our directors by a plurality of the voting power of the shares present in person or by proxy. Our amended and restated certificate of incorporation and amended and restated bylaws provide that all stockholder actions must be effected at a duly called meeting of stockholders and not by written consent. A special meeting of stockholders may be called by a resolution adopted by a majority of our board, our chair of the board, our chief executive officer or the president in absence of the chief executive officer. Any power of the stockholders to call a special meeting is specifically denied by the terms of our amended and restated certificate of incorporation.

Our board of directors is divided into three classes with staggered three-year terms. These provisions make it more difficult for our existing stockholders to replace our board of directors as well as for another party to obtain control of us by replacing our board of directors. Since our board of directors has the power to retain and discharge our officers, these provisions could also make it more difficult for existing stockholders or another party to effect a change in management. In addition, the authorization of undesignated preferred stock makes it possible for our board of directors to issue preferred stock with voting or other rights or preferences that could impede the success of any attempt to obtain control of us.

These provisions are intended to enhance the likelihood of continued stability in the composition of our board of directors and its policies and to discourage certain types of transactions that may involve an actual or threatened acquisition of us. These provisions are also designed to reduce our vulnerability to an unsolicited acquisition proposal and to discourage certain tactics that may be used in proxy fights. However, such provisions could have the effect of discouraging others from making tender offers for our shares and may have the effect of deterring hostile takeovers or delaying changes in our control or management. As a consequence, these provisions also may inhibit fluctuations in the market price of our stock that could result from actual or rumored takeover attempts.

Section 203 of the Delaware General Corporation Law

We are subject to Section 203 of the Delaware General Corporation Law, which prohibits a Delaware corporation from engaging in any business combination with any interested stockholder for a period of three years after the date that such stockholder became an interested stockholder, with the following exceptions:

In general, Section 203 defines business combination to include the following:

In general, Section 203 defines an “interested stockholder” as an entity or person who, together with the person’s affiliates and associates, beneficially owns, or within three years prior to the time of determination of interested stockholder status did own, 15% or more of the outstanding voting stock of the corporation.

Choice of Forum

Our amended and restated certificate of incorporation provides that the Court of Chancery of the State of Delaware is the exclusive forum for any derivative action or proceeding brought on our behalf; any action asserting a claim of a breach of fiduciary duty owed by any director, officer or other employee to the Company or the Company’s stockholders; any action asserting a claim against us or any of our directors, officers or other employees arising pursuant to the Delaware General Corporation Law, our amended and restated certificate of incorporation or our amended and restated bylaws; or any action or proceeding asserting a claim against us or any of our directors, officers or other employees that is governed by the internal affairs doctrine.

Listing of our Common Stock

Our common stock is listed on the Nasdaq Capital Market under the symbol “SNES.”

DESCRIPTION OF WARRANTS

We may issue warrants for the purchase of debt securities, preferred stock or common stock. Each series of warrants will be issued under a separate warrant agreement to be entered into between us and a bank or trust company, as warrant agent, or between us and the holder. If we elect to use a warrant agent, the warrant agent will act solely as our agent in connection with the warrants and will not assume any obligation or relationship of agency or trust for or with any registered holders of warrants or beneficial holders of warrants.

We will distribute a prospectus supplement with regard to each issue of warrants under this prospectus. Each prospectus supplement will describe:

Except for certain participation rights as set forth in the warrants, prior to the exercise of any warrants to purchase debt securities, preferred stock or common stock, holders of the warrants will not have any of the rights of holders of the debt securities, preferred stock or common stock purchasable upon exercise, including:

DESCRIPTION OF DEBT SECURITIES

As used in this prospectus, debt securities means the debentures, notes, bonds and other evidences of indebtedness that we may issue from time to time. The debt securities will either be senior debt securities or subordinated debt securities and may be secured or unsecured obligations. We may also issue convertible debt securities. Senior debt securities will be issued under a “Senior Indenture” and subordinated debt securities will be issued under a “Subordinated Indenture,” each entered into between us and a trustee to be named in the Indenture. This prospectus sometimes refers to the Senior Indenture and the Subordinated Indenture collectively as the “Indentures.”

The Indentures or forms of Indentures will be filed as exhibits to the registration statement of which this prospectus is a part. The statements and descriptions in this prospectus or in any prospectus supplement regarding provisions of the Indentures and debt securities are summaries thereof, do not purport to be complete and are subject to, and are qualified in their entirety by reference to, all of the provisions of the Indentures (and any amendments or supplements we may enter into from time to time that are permitted under each Indenture) and the debt securities, including the definitions in the applicable Indenture of various terms.

Unless otherwise specified in a prospectus supplement, the debt securities will be direct unsecured obligations of SenesTech. The senior debt securities will rank equally with any of our other unsecured senior and unsubordinated debt. The subordinated debt securities will be subordinate and junior in right of payment to any senior indebtedness.

The Indentures do not limit the aggregate principal amount of debt securities that we may issue and provide that we may issue debt securities from time to time in one or more series, in each case with the same or various maturities, at par or at a discount. Unless indicated in a prospectus supplement, we may issue additional debt securities of a particular series without the consent of the holders of the debt securities of the series outstanding at the time of the issuance. Any of the additional debt securities, together with all other outstanding debt securities of that series, will constitute a single series of debt securities under the applicable Indenture and will be equal in ranking.

The senior indebtedness issued pursuant to the Senior Indenture will effectively be subordinate to any of our secured indebtedness. In the event of a bankruptcy or other liquidation event involving a distribution of assets to satisfy our outstanding indebtedness, or an event of default under a loan agreement relating to secured indebtedness, the holders of our secured indebtedness would be entitled to receive payment of principal and interest prior to payments on the senior indebtedness issued under the Senior Indenture.

Additionally, the senior indebtedness issued pursuant to the Senior Indenture will effectively be subordinate to any indebtedness of any subsidiaries. In the event of a bankruptcy, receivership, state-ordered rehabilitation, liquidation or similar event involving a subsidiary, the assets of that subsidiary would be used to satisfy claims of creditors of the subsidiary rather than our creditors. As a result of the application of the subsidiary’s assets to satisfy claims of creditors, the value of the stock of the subsidiary would be diminished and perhaps rendered worthless. Any diminution in the value of the shares of any subsidiaries would adversely affect our financial condition and possibly impair our ability to meet our obligations on the debt securities. In addition, any liquidation of the assets of any subsidiaries to satisfy claims of the subsidiary’s creditors might make it impossible for the subsidiary to pay dividends to us. This inability to pay dividends would further impair our ability to satisfy our obligations under the debt securities.

Prospectus Supplement

Each prospectus supplement will describe the terms relating to the specific series of debt securities being offered. These terms will include some or all of the following:

Unless otherwise specified in the applicable prospectus supplement, the debt securities will not be listed on any securities exchange and will be issued in fully-registered form without coupons.

Holders of the debt securities may present their securities for exchange and may present registered debt securities for transfer in the manner described in the applicable prospectus supplement. Except as limited by the applicable Indenture, we will provide these services without charge, other than any tax or other governmental charge payable in connection with the exchange or transfer.

Debt securities may bear interest at a fixed rate or a variable rate as specified in the prospectus supplement. In addition, if specified in the prospectus supplement, we may sell debt securities bearing no interest or interest at a rate that at the time of issuance is below the prevailing market rate, or at a discount below their stated principal amount. We will describe in the applicable prospectus supplement any special federal income tax considerations applicable to these discounted debt securities.

We may issue debt securities with the principal amount payable on any principal payment date, or the amount of interest payable on any interest payment date, to be determined by referring to one or more currency exchange rates, commodity prices, equity indices or other factors. Holders of these debt securities may receive a principal amount on any principal payment date, or interest payments on any interest payment date, that are greater or less than the amount of principal or interest otherwise payable on those dates, depending upon the value on those dates of applicable currency, commodity, equity index or other factors. The applicable prospectus supplement will contain information as to how we will determine the amount of principal or interest payable on any date, as well as the currencies, commodities, equity indices or other factors to which the amount payable on that date relates and various additional tax considerations.

DESCRIPTION OF UNITS

We may issue units comprised of two or more of debt securities, common shares, preferred shares, warrants or other securities in any combination. Each unit will be issued so that the holder of the unit is also the holder of each security included in the unit. As a result, the holder of a unit will have the rights and obligations of a holder of each included security. Each unit will be issued under a separate unit agreement to be entered into between us and, at our discretion, a bank or trust company, as unit agent, all as will be set forth in the prospectus supplement relating to the particular issue of units. The unit agent, if any, will act solely as our agent in connection with the units and will not assume any obligation or relationship of agency or trust for or with any holders of units or beneficial owners of units. The summary of the terms of the units contained in this prospectus is not complete and is subject to, and is qualified in its entirety by, all provisions of the applicable unit agreement. Reference is made to the prospectus supplement relating to the particular issue of units offered pursuant to such prospectus supplement for the terms of and information relating to such units, including, where applicable: