Description of Capital Stock

The following is a summary of all material characteristics of our capital stock as set forth in our certificate of incorporation and bylaws, and our outstanding warrants. The summary does not purport to be complete and is qualified in its entirety by reference to our certificate of incorporation and bylaws, which are incorporated by reference as exhibits to the Annual Report on Form 10-K to which this description is an exhibit.

Our authorized capital stock consists of 500,000,000 shares of common stock, par value $0.001 per share and 20,000,000 shares of preferred stock, par value $0.01 per share.

Common Stock    

The holders of our common stock are entitled to one vote per share in the election of directors and on all other matters on which stockholders are entitled or permitted to vote. The holders of our common stock are not entitled to cumulative voting rights. Therefore, holders of a majority of the shares voting for the election of directors can elect all of the directors. Subject to the terms of any outstanding series of preferred stock, the holders of our common stock are entitled to dividends in the amounts and at times as may be declared by the Board of Directors out of funds legally available. Upon liquidation or dissolution, holders of our common stock are entitled to share ratably in all net assets available for distribution to stockholders after payment of any liquidation preferences to holders of our preferred stock. The holders of our common stock have no redemption, conversion or preemptive rights.

As of March 5, 2020, we had 59,505,261 shares of common stock issued and outstanding, exclusive of existing convertible preferred stock, options and warrants.

Our Board of Directors has the authority to issue up to 20,000,000 shares of preferred stock with such designations, rights, and preferences as may be determined from time to time by our Board of Directors. Accordingly, our Board of Directors is empowered, without stockholder approval, to issue preferred stock with dividend, liquidation, conversion, voting, or other rights that could adversely affect the voting power or other rights of the holders of our common stock. The issuance of preferred stock could have the effect of restricting dividends on our common stock, diluting the voting power of our common stock, impairing the liquidation rights of our common stock, or delaying or preventing a change in control of our company, all without further action by our stockholders.

As of March 5, 2020, there were 10,000 shares of our Series B Convertible Redeemable Preferred Stock, $0.01 par value per share (“Series B Preferred Stock”), issued and outstanding.

The Series B Preferred Stock ranks pari passu with our common stock with respect to the payment of dividends and to the distribution of assets upon liquidation, dissolution or winding up.

So long as any shares of the Series B Preferred Stock are outstanding, no dividend shall be declared or paid or set aside for payment or other distribution declared or made upon our common stock or upon any other stock ranking junior to, or on a parity with, the Series B Preferred Stock as to dividends or upon liquidation, dissolution or winding up, unless, in the case of our preferred stock, the same dividend is declared, paid or set aside for payment on all outstanding shares of the Series B Preferred Stock or in the case of our common stock, ten times such dividend per share is declared, paid or set aside for payment on each outstanding share of the Series B Preferred Stock.

Except as otherwise provided by law, each share of the Series B Preferred Stock has the same voting rights as ten shares of our common stock and the holders of the Series B Preferred Stock and the common stock shall vote together as one class on all matters.

The holder of any share of Series B Preferred Stock has the right, at such holder’s option, to convert such share into one one-hundredth of a fully paid and non-assessable share of our common stock, subject to adjustment.

In the event of any voluntary or involuntary dissolution, liquidation or winding up of our Company, after any distribution of assets is made to the holders of any other class or series of stock that ranks prior to the Series B Preferred Stock in respect of distributions upon the liquidation of the Company, the holder of each share of Series B Preferred Stock then outstanding shall be entitled to be paid out of our assets available for distribution to our stockholders, an amount on a pari passu basis equal to ten times the amount per share distributed to the holders of our common stock. After payment of the full amount of the distribution

to which they are entitled, the holders of shares of the Series B Preferred Stock will not be entitled to any further participation in any distribution of assets by the Company.

Shares of Series B Preferred Stock issued and reacquired by us shall have the status of authorized and unissued shares of preferred stock, undesignated as to series, subject to later issuance.

Holders of shares of Series B Preferred Stock are not entitled to any preemptive or subscription rights in respect of any securities of the corporation.

As of March 5, 2020, we had outstanding options to purchase an aggregate of 1,280,193, shares of our common stock with exercise prices ranging from $3.01 to $174.00 per share, with an approximate weighted average exercise price of $15.54 per share. The shares of our common stock underlying all such options are registered with the SEC.

As of March 5, 2020, we had 313,442 restricted stock units issued and outstanding.

As of March 5, 2020, we had outstanding warrants to purchase an aggregate of 30,000 shares of our common stock with an exercise price of $5.89. On March 11, 2016, we entered into a Consent and Third Amendment to Loan and Security Agreement (the “Amendment”) with Oxford Finance, LLC (the “Lender”). In connection with the Amendment, we issued to the Lender warrants to purchase an aggregate of 30,000 shares of common stock (the “Lender Warrants”), which are exercisable for a period of 7 years from the issuance date at an exercise price of $5.89 per share. The shares of common stock underlying such warrants have been registered for resale.

Our Amended and Restated Certificate of Incorporation and bylaws contain some provisions that could make our acquisition by means of a tender or exchange offer, a proxy contest or otherwise more difficult. These provisions are summarized below.

Special Meetings. Our bylaws provide that special meetings of our stockholders may, unless otherwise prescribed by law, be called by our Chairman of the Board (if any), our Board of Directors or our Chief Executive Officer and shall be held at such place, on such date and at such time as shall be fixed by our Board of Directors or the person calling the meeting. Business transacted at any special meeting shall be limited to matters relating to the purpose or purposes stated in the notice of the meeting.

Undesignated Preferred Stock. The ability to authorize 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 acquire us. The ability to issue preferred stock may have the effect of deferring hostile takeovers or delaying changes in control or management of our company.

Delaware Anti-Takeover Statute. We are subject to the provisions of Section 203 of the Delaware General Corporation Law regulating corporate takeovers. In general, Section 203 prohibits a publicly held Delaware corporation from engaging in a business combination with an interested stockholder for a period of three years following the date the person became an interested stockholder unless:

•prior to the date of the transaction, the board of directors of the corporation approved either the business

        combination or the transaction which resulted in the stockholder becoming an interested stockholder;

•upon completion of the transaction that resulted in the stockholder becoming an interested stockholder, the

stockholder owned at least 85% of the voting stock of the corporation outstanding at the time the transaction

commenced, excluding for purposes of determining the number of shares outstanding (1) shares owned by

persons who are directors and also officers and (2) shares owned by employee stock plans in which employee

participants do not have the right to determine confidentially whether shares held subject to the plan will be

tendered in a tender or exchange offer; and

•on or subsequent to the date of the transaction, the business combination is approved by the board and authorized

at an annual or special meeting of stockholders, and not by written consent, by the affirmative vote of at least 66

2/3% of the outstanding voting stock which is not owned by the interested stockholder.

Generally, a business combination includes a merger, asset or stock sale, or other transaction resulting in a financial benefit to the interested stockholder. An interested stockholder is a person who, together with affiliates and associates, owns or, within three years prior to the determination of interested stockholder status, owned 15% or more of a corporation’s outstanding voting securities. We expect the existence of this provision to have an anti-takeover effect with respect to transactions our Board of Directors does not approve in advance. We also anticipate that Section 203 may discourage attempted acquisitions that might result in a premium over the market price for the shares of our common stock held by stockholders.

The provisions of Delaware law, our Amended and Restated Certificate of Incorporation and our bylaws could have the effect of discouraging others from attempting hostile takeovers and, as a consequence, they may also inhibit temporary fluctuations in the market price of our common stock that often result from actual or rumored hostile takeover attempts. These provisions may also have the effect of preventing changes in our management. It is possible that these provisions could make it more difficult to accomplish transactions that stockholders may otherwise deem to be in their best interests.