Description of Securities

EXHIBIT 4.8

DESCRIPTION OF THE REGISTRANT’S SECURITIES REGISTERED PURSUANT TO SECTION 12 OF THE SECURITIES EXCHANGE ACT OF 1934

Cytokinetics, Incorporated (“we,” “our,” or “us,”) has one class of securities registered under Section 12 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”): our common stock, $0.001 par value per share (the “Common Stock”).

The following summary sets forth certain material terms and provisions of our Common Stock. The following summary does not purport to be complete and is subject to, and is qualified in its entirety by reference to, the applicable provisions of our Amended and Restated Certificate of Incorporation, as amended, (the “Certificate of Incorporation”) and our Amended and Restated Bylaws (the “Bylaws”), each of which is filed as an exhibit to our Annual Report on Form 10-K, of which this Exhibit 4.8 is a part. We encourage you to read our Certificate of Incorporation, our Bylaws, and the applicable provisions of the Delaware General Corporation Law for more information.

General

Under the Certificate of Incorporation, we are authorized to issue 173,000,000 shares. Those shares consist of 163,000,000 shares designated as Common Stock, and 10,000,000 shares designated as preferred stock, $0.001 par value per share (the “Preferred Stock”).

Voting Rights

Holders of Common Stock are entitled to one vote for each share held of record on all matters submitted to a vote of stockholders. Upon any liquidation, dissolution or winding up of our business, the holders of Common Stock are entitled to share equally in all assets available for distribution after payment of all liabilities and provision for liquidation preference of shares of Preferred Stock then outstanding. Holders of Common Stock have no preemptive rights or rights to convert their Common Stock into any other securities. There are no redemption or sinking fund provisions applicable to the Common Stock. Holders of Common Stock are entitled to receive dividends declared by the board of directors, out of funds legally available for the payment of dividends, subject to the rights of holders of Preferred Stock. Currently, we are not paying dividends.

All outstanding shares of Common Stock are fully paid and non-assessable.

Preferred Stock

Pursuant to our Certificate of Incorporation, our board of directors has the authority, without further approval by our stockholders, to designate and issue up to 10,000,000 shares of Preferred Stock in one or more series. Our board of directors previously designated 8,070 of the authorized shares of Preferred Stock as Series A convertible preferred stock, and 23,026 of the authorized shares of Preferred Stock as Series B convertible preferred stock, none of which are currently outstanding. Our board of directors may designate the powers, preferences and rights, and the qualifications, limitations or restrictions of each series of Preferred Stock, including dividend rights, dividend rate, conversion rights, voting rights, rights and terms of redemption (including sinking fund provisions), redemption price or prices, and liquidation preferences, any or all of which may be greater than the rights of the Common Stock. Thus, without stockholder approval, our board of directors could authorize the issuance of Preferred Stock with voting, conversion and other rights that could dilute the voting power and other rights of holders of our Common Stock, and may have the effect of decreasing the market price of the Common Stock.

Anti-Takeover Effects of Some Provisions of Delaware Law

Provisions of Delaware law and our Certificate of Incorporation and our Bylaws could make the acquisition of our company through a tender offer, a proxy contest or other means more difficult and could make the removal of incumbent officers and directors more difficult. We expect these provisions to discourage coercive takeover practices and inadequate takeover bids and to encourage persons seeking to acquire control of our company to first negotiate with our board of directors. We believe that the benefits provided by our ability to negotiate with the proponent of an

unfriendly or unsolicited proposal outweigh the disadvantages of discouraging these proposals. We believe the negotiation of an unfriendly or unsolicited proposal could result in an improvement of its terms.

We are subject to Section 203 of the Delaware General Corporation Law, an anti-takeover law. 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:

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, did own 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 also discourage attempts that might result in a premium over the market price for the shares of Common Stock held by stockholders.

Anti-Takeover Effects of Provisions of Our Charter Documents

Our Certificate of Incorporation provides for our board of directors to be divided into three classes serving staggered terms. Approximately one-third of the board of directors will be elected each year. The provision for a classified board could prevent a party who acquires control of a majority of the outstanding voting stock from obtaining control of the board of directors until the second annual stockholders meeting following the date the acquirer obtains the controlling stock interest. The classified board provision could discourage a potential acquirer from making a tender offer or otherwise attempting to obtain control of our company and could increase the likelihood that incumbent directors will retain their positions. Our Certificate of Incorporation provides that directors may be removed with cause by the affirmative vote of the holders of the outstanding shares of Common Stock.

Our Bylaws establish an advance notice procedure for stockholder proposals to be brought before an annual meeting of our stockholders, including proposed nominations of persons for election to the board of directors. At an annual meeting, stockholders may only consider proposals or nominations specified in the notice of meeting or brought before the meeting by or at the direction of the board of directors. Stockholders may also consider a proposal or nomination by a person who was a stockholder of record on the record date for the meeting, who is entitled to vote at the meeting and who has given to our Secretary timely written notice, in proper form, of his or her intention to bring that business before the meeting. The Bylaws do not give the board of directors the power to approve or disapprove stockholder nominations of candidates or proposals regarding other business to be conducted at a special or annual meeting of the stockholders. However, our Bylaws may have the effect of precluding the conduct of 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.

Under Delaware law, a special meeting of stockholders may be called by the board of directors or by any other person authorized to do so in the Certificate of Incorporation or the Bylaws. Our Bylaws authorize a majority of the authorized directors on our board of directors, the chairperson of the board, the chief executive officer, the president or the secretary to call a special meeting of stockholders.

Because our stockholders do not have the right to call a special meeting, a stockholder could not force stockholder consideration of a proposal over the opposition of the board of directors by calling a special meeting of stockholders prior to such time as a majority of the board of directors believed or the chief executive officer believed the matter should be considered or until the next annual meeting provided that the requestor met the notice requirements. The restriction on the ability of stockholders to call a special meeting means that a proposal to replace the board also could be delayed until the next annual meeting.

Delaware law provides that stockholders may execute an action by written consent in lieu of a stockholder meeting. However, Delaware law also allows us to eliminate stockholder actions by written consent. Elimination of written consents of stockholders may lengthen the amount of time required to take stockholder actions since actions by written consent are not subject to the minimum notice requirement of a stockholder’s meeting. However, we believe that the elimination of stockholders’ written consents may deter hostile takeover attempts. Without the availability of stockholder’s actions by written consent, a holder controlling a majority of our capital stock would not be able to amend our Bylaws or remove directors without holding a stockholders’ meeting. The holder would have to obtain the consent of a majority of the board of directors, the chairman of the board or the chief executive officer to call a stockholders’ meeting and satisfy the notice periods determined by the board of directors. Our Certificate of Incorporation provides for the elimination of actions by written consent of stockholders.

Listing

Our Common Stock is listed on The Nasdaq Global Select Market under the trading symbol “CYTK.”

Transfer Agent and Registrar

The transfer agent and registrar for our Common Stock is Computershare Trust Company, N.A. The transfer agent and registrar’s address is 250 Royall Street, Canton, Massachusetts 02021.