Exhibit 4.3

DESCRIPTION OF CAPITAL STOCK

General

MediciNova, Inc. (“we,” “us,” and “our”) has one class of securities registered under Section 12 of the Securities Exchange Act of 1934, as amended - our common stock, $0.001 par value per share.

The following information describes our capital stock, as well as certain provisions of our restated certificate of incorporation, as amended, and amended and restated bylaws. The summary does not purport to be complete and is qualified in its entirety by reference to our restated certificate of incorporation and amended and restated bylaws, copies of which have been filed as exhibits to our public filings with the Securities and Exchange Commission (the “SEC”).

General

Our authorized capital stock consists of 100,000,000 shares of common stock, with a $0.001 par value per share, and 10,000,000 shares of preferred stock, with a $0.01 par value per share, all of which shares of preferred stock are undesignated. Our board of directors may establish the rights and preferences of the preferred stock from time to time. As of February 16, 2021, there were 48,680,867 shares of common stock issued and outstanding, held of record by 15 stockholders, although we believe that there may be a significantly larger number of beneficial owners of our common stock. We derived the number of stockholders by reviewing the listing of outstanding common stock recorded by our transfer agent as of February 16, 2021.

Common Stock

The holders of common stock are entitled to one vote per share on all matters to be voted upon by the stockholders. The holders of common stock are entitled to receive ratably such dividends, if any, as may be declared from time to time by the board of directors out of funds legally available, subject to preferences that may be applicable to preferred stock, if any, then outstanding. In the event of a liquidation, dissolution or winding up of our company, the holders of common stock are entitled to share ratably in all assets remaining after payment of liabilities, subject to prior distribution rights of preferred stock, if any, then outstanding. The common stock has 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.

The rights, preferences and privileges of the holders of our common stock are subject to, and may be adversely affected by, the rights of the holders of shares of any series of preferred stock that we may designate and issue in the future.

Our common stock is listed on the Nasdaq Capital Market under the symbol “MNOV.” The transfer agent and registrar for our common stock is American Stock Transfer & Trust Company, LLC. Its address is 6201 15th Avenue, Brooklyn, New York 11219, and its telephone number is (718) 921-8200.

Preferred Stock

Under the terms of our restated certificate of incorporation, our board of directors is authorized to issue shares of preferred stock in one or more series without stockholder approval. Our board of directors has the discretion to determine the rights, preferences, privileges and restrictions, including voting rights, dividend rights, conversion rights, redemption privileges and liquidation preferences, of each series of preferred stock. There are no restrictions presently on the repurchase or redemption of any shares of our preferred stock.

The issuance of preferred stock will affect, and may adversely affect, the rights of holders of common stock. It is not possible to state the actual effect of the issuance of any shares of preferred stock on the rights of holders of common stock until the board of directors determines the specific rights attached to that preferred stock. The effects of issuing preferred stock could include one or more of the following:

We have no present plans to issue any shares of preferred stock nor are any shares of our preferred stock presently outstanding. Preferred stock will be fully paid and nonassessable upon issuance.

Effect of Certain Provisions of our Restated Certificate of Incorporation and Bylaws

Provisions of our restated certificate of incorporation and our amended and restated bylaws could have the effect of delaying, deferring or discouraging another party from acquiring control of us. These provisions, which are summarized below, may have the effect of discouraging takeover bids. These provisions are also designed, in part, to encourage persons seeking to acquire control of us to first negotiate with our board of directors. We believe that the benefits of increased protection of our potential ability to negotiate with an unfriendly or unsolicited acquirer outweigh the disadvantages of discouraging a proposal to acquire us because negotiation of these proposals could result in an improvement of their terms.

Undesignated Preferred Stock. The authority of our board of directors to issue preferred stock could potentially be used to discourage attempts by third parties to obtain control of our company through a merger, tender offer, proxy contest, or otherwise by making it more difficult or more costly to obtain control of our company. Our board of directors may issue preferred stock with voting rights or conversion rights that, if exercised, could adversely affect the voting power of the holders of common stock.

Limits on Ability of Stockholders to Call a Special Meeting. Our restated certificate of incorporation, as amended and our amended and restated bylaws generally provide that special meetings of our stockholders may be called only by the Chairman of the board of directors, our Chief Executive Officer or by resolution of the board of directors. Stockholders are not permitted to call a special meeting or require our board of directors to call a special meeting.

Limits on Stockholder Action by Written Consent. Any action required or permitted to be taken by the stockholders must be taken at a duly called annual or special meeting and not by written consent.

Classified Board of Directors. Our board of directors is divided into three classes, one class of which is elected each year by our stockholders. The directors in each class serve for a three-year term. A third party may be discouraged from making a tender offer or otherwise attempting to obtain control of us as it is more difficult and time consuming for stockholders to replace a majority of the directors on a classified board of directors.

Requirements for Advance Notification of Stockholder Nominations and Proposals. Our amended and restated bylaws establish advance notice procedures with respect to stockholder proposals and the nomination of candidates for election as directors, other than nominations made by or at the direction of our board of directors or a committee of our board of directors. However, our amended and restated bylaws may have the effect of precluding the conduct of certain business at a meeting if the proper procedures are not followed. These provisions may also discourage or deter a potential acquirer from conducting a solicitation of proxies to elect the acquirer's own slate of directors or otherwise attempting to obtain control of our company.

No Cumulative Voting. The Delaware General Corporation Law (“DGCL”) provides that stockholders are not entitled to the right to cumulate votes in the election of directors unless our restated certificate of incorporation provides otherwise. Our restated certificate of incorporation and amended and restated bylaws do not expressly provide for cumulative voting.

Size of Board and Vacancies. Our restated certificate provides that the number of directors on our board of directors is fixed exclusively by our board of directors. Newly created directorships resulting from any increase in our authorized number of directors or any vacancies in the board of directors resulting from death, resignation or other cause (including removal from office by a vote of the stockholders) may be filled only by a majority vote of the directors based on the total number of designated directors, though less than a quorum, or by the sole remaining director. The directors so chosen shall hold office for a term expiring at the next annual meeting of stockholders, and until their respective successors are elected, except in the case of the death, incapacity, resignation or removal of any director.

Amendments of Governance Documents. Our restated certificate of incorporation provides that the affirmative vote of the holders of at least sixty-six and two-thirds (66 ²⁄₃%) of our voting stock then outstanding is required to amend certain provisions relating to the number, term, election and removal of our directors, the filling of our board vacancies, the calling of special meetings of stockholders, and the indemnification of directors.     

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Limitations on Liability, Indemnification of Officers and Directors and Insurance.  

The DGCL authorizes corporations to limit or eliminate the personal liability of directors to corporations and their stockholders for monetary damages for breaches of directors’ fiduciary duties as directors, subject to certain exceptions, by provision of the corporation’s certificate of incorporation. Our restated certificate of incorporation contains a provision eliminating the personal liability of our directors to the fullest extent permitted by the DGCL. In addition, our restated certificate of incorporation includes provisions that require us to indemnify, to the fullest extent allowable under the DGCL, our directors and officers for monetary damages for actions taken as our director or officer, or for serving at our request as a director or officer or another position at another corporation or enterprise, as the case may be. Our restated certificate of incorporation also provides that we must advance reasonable expenses to our directors and officers, subject to our receipt of an undertaking from the indemnified party as may be required under the DGCL.

We are also expressly authorized by the DGCL to carry directors’ and officers’ insurance to protect us, our directors, officers and certain employees for some liabilities. The limitation of liability and indemnification and advancements provisions in our restated certificate of incorporation and amended and restated bylaws, respectively, may discourage stockholders from bringing a lawsuit against directors for breach of their fiduciary duties. These provisions may also have the effect of reducing the likelihood of derivative litigation against directors and officers, even though such an action, if successful, might otherwise benefit us and our stockholders. However, the provision in our restated certificate of incorporation eliminating the personal liability of our directors to the fullest extent permitted by the DGCL does not limit or eliminate our rights, or those of any stockholder, to seek non-monetary relief such as injunction or rescission in the event of a breach of a director’s fiduciary duties, including the duty of care. The indemnification provisions will not alter the liability of directors under the federal securities laws. In addition, your investment may be adversely affected to the extent that, in a derivative or direct suit, we pay the litigation costs of our directors and officers and the costs of settlement and damage awards against directors and officers pursuant to these indemnification and advancements provisions.

We expect to maintain standard policies of insurance that provide coverage (i) to our directors and officers against loss arising from claims made by reason of breach of duty or other wrongful act and (ii) to us with respect to indemnification and advancements payments that we may make to such directors and officers.

We have entered into an indemnification agreement with each of our officers and directors. These agreements require us to indemnify these individuals to the fullest extent permitted under Delaware law against liabilities that may arise by reason of their service to us, and to advance expenses incurred as a result of any proceeding against them as to which they could be indemnified. We believe that the limitation of liability provision in our restated certificate of incorporation and the indemnification agreements will facilitate our ability to continue to attract and retain qualified individuals to serve as directors and officers.

Insofar as the above described indemnification provisions permit indemnification of directors, officers or persons controlling us for liability arising under the Securities Act of 1933, as amended (the “Securities Act”), we understand that in the opinion of the SEC, this indemnification is against public policy as expressed in the Securities Act and is therefore unenforceable.

Delaware Anti-Takeover Statute

We are subject to the provisions of Section 203 of the DGCL 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 on which the person became an interested stockholder unless:

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

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

 The provisions of the DGCL, our restated certificate of incorporation and our amended and restated 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 may make it more difficult to accomplish transactions that stockholders may otherwise deem to be in their best interests.

Registration Rights

Certain holders of shares of our common stock are entitled to contractual rights to require us to register such shares under the Securities Act. These rights are provided under the terms of our amended and restated registration rights agreement. We will pay all expenses relating to any such registration, other than underwriting discounts and selling commissions. The registration rights terminate with respect to any holder if all of the following conditions are met: (a) as reflected on our books and records, such holder (together with its affiliates) holds less than 1% of our outstanding common stock (on an as-if-converted to common stock basis), (b) our securities trade on a national securities exchange or list on a national automatic quotation system, in each case, located in the United States, and (c) all shares of common stock issued or issuable upon conversion of the registrable securities held by such holder (and its affiliates) either (i) may be sold pursuant to Rule 144 promulgated under the Securities Act during any ninety (90) day period or (ii) have ceased to be outstanding.

Piggyback Registration Rights. If we propose to register any of our securities under the Securities Act either for our own account or for the account of other stockholders, the holders of shares having registration rights will, subject to certain exceptions, be entitled to include their shares in our registration statement. These piggyback registration rights are subject to specified conditions and limitations, including the right of the underwriters to limit the number of shares included in any such registration statement under certain circumstances, but not below 25% of the total number of shares covered by the registration statement without the consent of more than 50% of the holders of registrable securities.

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