CYTOKINETICS, INCORPORATED

COMMON STOCK PURCHASE AGREEMENT

THIS COMMON STOCK PURCHASE AGREEMENT (the “Agreement”) is made as of
December 22nd, 2014 (the “Execution Date”) by and between Cytokinetics,
Incorporated, a Delaware corporation (the “Company”), and Astellas Pharma Inc.
(the “Investor”). All terms not defined herein shall have the meaning set forth
for such terms in the Amended and Restated License and Collaboration Agreement,
dated as of December 22nd, 2014 by and between the Company and the Investor, as
amended on the date hereof (the “Collaboration Agreement”).

RECITALS

WHEREAS, the Company and the Investor have entered into the Collaboration
Agreement of even date herewith;

WHEREAS, in partial consideration for the additional rights granted to the
Investor under the Collaboration Agreement and pursuant to terms set forth in
this Agreement the Company desires to sell to the Investor, and the Investor
desires to purchase from the Company, shares of the Company’s common stock, par
value $0.001 per share (the “Common Stock”);

NOW, THEREFORE, in consideration of the premises and mutual covenants herein
contained and contained in the Collaboration Agreement, and for other good and
valuable consideration, the receipt and sufficiency of which are hereby
acknowledged, the parties hereto agree as follows:

SECTION 1

Purchase and Sale of Shares

1.1 Sale of Shares. Subject to the terms and conditions hereof and of the
Collaboration Agreement, the Company will issue and sell to the Investor, and
the Investor will purchase from the Company, at the Closing, Ten Million Dollars
($10,000,000) (the “Aggregate Purchase Price”) worth of Common Stock at a price
per share equal to the greater of (a) the closing price of one share of common
stock of the Company on the trading day immediately preceding the public
announcement of the entry into the Collaboration Agreement, and (b) the average
of the closing price of one share of Common Stock for each of the ten
(10) trading days immediately preceding the Execution Date, in either case with
the number of such shares rounded down to the nearest whole share (such number
of shares hereafter referred to as the “Shares”) and in both cases based on the
closing prices as reported by the NASDAQ Capital Market.

1.2 Closing. The purchase and sale of the Shares shall take place at a closing
(the “Closing”) to be held at the offices of Cooley LLP, 3175 Hanover Street,
Palo Alto, California 94304-1130, on the third trading day following the date
hereof, or such other time as agreed by both parties (the “Closing Date”). At
the Closing, the Company will deliver or cause to be delivered to the Investor a
certificate or certificates representing the Shares that the Investor is
purchasing and, concurrently, the Investor shall pay the Aggregate Purchase
Price by (a) check payable to the Company, (b) wire transfer in accordance with
the Company’s instructions, or (c) any combination of the foregoing.

SECTION 2

Representations and Warranties of the Company

Except as set forth on the Schedule of Exceptions attached hereto as Exhibit A,
the Company hereby represents and warrants the following as of the Execution
Date:

2.1 Organization and Good Standing and Qualifications. The Company is a
corporation duly organized, validly existing and in good standing under the laws
of the State of Delaware and has all requisite power and authority to own,
lease, operate and occupy its properties and to carry on its business as now
being conducted. Except as set forth in the Commission Documents (as defined
below), the Company does not own more than 50% of the outstanding capital stock
of or control any other business entity. The Company is duly qualified as a
foreign corporation to do business and is in good standing in every jurisdiction
in which the nature of the business conducted or property owned or leased by it
makes such qualification necessary, other than those in which the failure so to
qualify or be in good standing would not have a Material Adverse Effect. For
purposes of this Agreement, “Material Adverse Effect” shall mean any event or
condition that would reasonably be likely to have a material adverse effect on
the business, operations, properties or financial condition of the Company and
its consolidated subsidiaries, taken as a whole; provided, that none of the
following shall constitute a “Material Adverse Effect”: the effects of
conditions or events that are generally applicable to the capital, financial,
banking or currency markets and the biotechnology industry, and changes in the
market price of the Common Stock.

2.2 Authorization. (i) The Company has the requisite corporate power and
authority to enter into and perform its obligations under this Agreement;
(ii) the execution and delivery of this Agreement by the Company, the
consummation by the Company of the transactions contemplated hereby and thereby
and the issuance, sale and delivery of the Shares have been duly authorized by
all necessary corporate action and no further consent or authorization of the
Company or its Board of Directors or stockholders is required; and (iii)  the
Agreement has been duly executed and delivered and constitutes a valid and
binding obligation of the Company enforceable against the Company in accordance
with its terms, except as such enforceability may be limited by applicable
bankruptcy, securities, insolvency, or similar laws relating to, or affecting
generally the enforcement of, creditors’ rights and remedies, or indemnification
or by other equitable principles of general application.

2.3 Valid Issuance of Shares. The issuance of the Shares has been duly
authorized by all requisite corporate action. When the Shares are issued, sold
and delivered in accordance with the terms of this Agreement for the
consideration expressed herein, the Shares will be duly and validly issued and
outstanding, fully paid, and nonassessable, and will be free of restrictions on
transfer other than restrictions on transfer under this Agreement and under
applicable state and federal securities laws and, except as otherwise set forth
herein or in the Collaboration Agreement, the Investor shall be entitled to all
rights accorded to a holder of shares of Common Stock. The Company has reserved
a sufficient number of shares of Common Stock for issuance to the Investor in
accordance with the Company’s obligations under this Agreement.

2.4 No Conflict. The execution, delivery and performance of this Agreement, and
any other document or instrument contemplated hereby, by the Company and the
consummation by the Company of the transactions contemplated hereby, do not:
(i) violate any provision of the Certificate or Bylaws, (ii) conflict with, or
constitute a default (or an event which with notice or lapse of time or both
would become a default) under, or give to others any rights of termination,
amendment, acceleration or cancellation of, any material agreement, mortgage,
deed of trust, indenture, note, bond, license, lease agreement, instrument or
obligation to which the Company is a party where such default or conflict would
constitute a Material Adverse Effect, (iii) create or impose a lien, charge or
encumbrance on any property of the Company under any agreement or any commitment
to which the Company is a party or by which the Company is bound, which would
constitute a Material Adverse Effect, (iv) result in a violation of any federal,
state, local or foreign statute, rule, regulation, order, writ, judgment or
decree (including federal and state securities laws and regulations) applicable
to the Company or any of its subsidiaries or by which any property or asset of
the Company are bound or affected where such violation would constitute a
Material Adverse Effect, or (v) require any consent of any third-party that has
not been obtained pursuant to any material contract to which the Company is
subject or to which any of its assets, operations or management may be subject
where the failure to obtain any such consent would constitute a Material Adverse
Effect. The Company is not required under federal, state or local law, rule or
regulation to obtain any consent, authorization or order of, or make any filing
or registration with, any court or governmental agency in order for it to
execute, deliver or perform any of its obligations under this Agreement or issue
and sell the Shares in accordance with the terms hereof (other than any filings
that may be required to be made by the Company with the Securities and Exchange
Commission (the “Commission”), the National Association of Securities Dealers,
Inc./Nasdaq or state securities commissions subsequent to the Closing); provided
that, for purposes of the representation made in this sentence, the Company is
assuming and relying upon the accuracy of the relevant representations and
agreements of the Investor herein.

2.5 Compliance. The Company is not, and the execution and delivery of this
Agreement and the consummation of the transactions contemplated herewith will
not cause the Company to be (i) in violation or default of any provision of any
instrument, mortgage, deed of trust, loan, contract, commitment filed with the
Commission Documents, (ii) in violation of any provision of any judgment,
decree, order or obligation to which it is a party or by which it or any of its
properties or assets are bound, or (iii) in violation of any federal, state or,
to its knowledge, local statute, rule or governmental regulation, in the case of
each of clauses (i), (ii) and (iii), which would have a Material Adverse Effect.

2.6 Capitalization. As of October 31, 2014 (the “Reference Date”), a total of
36,608,781 shares of Common Stock were issued and outstanding, increased as set
forth in the next sentence. Other than in the ordinary course of business, the
Company has not issued any capital stock since the Reference Date other than
pursuant to (i) employee benefit plans disclosed in the Commission Documents,
and (ii) outstanding warrants, options or other securities disclosed in the
Commission Documents. The outstanding shares of capital stock of the Company
have been duly and validly issued and are fully paid and nonassessable, were not
issued in violation of any preemptive rights or similar rights to subscribe for
or purchase securities, and, for those shares issued until the Closing, have
been issued in compliance with all federal and state securities laws, in each
case except as would not reasonably be expected to have a Material Adverse
Effect. Except as set forth in the Commission Documents, there are no
outstanding rights (including, without limitation, preemptive rights), warrants
or options to acquire, or instruments convertible into or exchangeable for, any
unissued shares of capital stock or other equity interest in the Company, or any
contract, commitment, agreement, understanding or arrangement of any kind to
which the Company is a party and relating to the issuance or sale of any capital
stock of the Company, any such convertible or exchangeable securities or any
such rights, warrants or options. Without limiting the foregoing, no preemptive
right, co-sale right, right of first refusal, registration right, or other
similar right exists with respect to the Shares or the issuance and sale
thereof. Except as disclosed in the Commission Documents, there are no
shareholder agreements, voting agreements or other similar agreements with
respect to the voting of the Shares to which the Company is a party or, to the
knowledge of the Company, between or among any of the Company’s shareholders.

2.7 Commission Documents, Financial Statements. The Company’s Common Stock is
registered pursuant to Section 12(b) or 12(g) of the Securities Exchange Act of
1934, as amended (the “Exchange Act”), and during the past twelve (12) months
the Company has timely filed all reports, schedules, forms, statements and other
documents required to be filed by it with the Commission pursuant to the
reporting requirements of the Exchange Act, including material filed pursuant to
Section 13(a) or 15(d) of the Exchange Act (all of the foregoing, including
filings incorporated by reference therein, being referred to herein as the
“Commission Documents”). The Company’s Common Stock is currently listed or
quoted on the NASDAQ Capital Market. The Company is not in violation of the
listing requirements of the NASDAQ Capital Market and has no knowledge of any
facts that would reasonably lead to delisting or suspension of its common stock
from NASDAQ in the foreseeable future. As of its date, each Commission Document
filed within the past twelve (12) months for the year ended December 31, 2013
complied in all material respects with the requirements of the Exchange Act and
the rules and regulations of the Commission promulgated thereunder applicable to
such document, and, as of its date, after giving effect to the information
disclosed and incorporated by reference therein, no such Commission Document
within the past twelve (12) months contained any untrue statement of a material
fact or omit to state a material fact required to be stated therein or necessary
in order to make the statements therein, in light of the circumstances under
which they were made, not misleading. As of their respective dates, the
financial statements of the Company included in the Commission Documents filed
with the Commission during the past twelve months complied as to form and
substance in all material respects with applicable accounting requirements and
the published rules and regulations of the Commission or other applicable rules
and regulations with respect thereto. Such financial statements have been
prepared in accordance with generally accepted accounting principles (“GAAP”)
applied on a consistent basis during the periods involved (except (i) as may be
otherwise indicated in such financial statements or the notes thereto or (ii) in
the case of unaudited interim statements, to the extent they may not include
footnotes or may be condensed or summary statements), and fairly present in all
material respects the financial position of the Company as of the dates thereof
and the results of operations and cash flows for the periods then ended
(subject, in the case of unaudited statements, to normal year-end audit
adjustments).

2.8 Internal Controls and Procedures. The Company maintains disclosure controls
and procedures as such terms are defined in, and required by, Rule 13a-15 and
Rule 15d-15 under the Exchange Act. Such disclosure controls and procedures are
effective as of the latest date of management’s evaluation of such disclosure
controls and procedures as set forth in the Commission Documents to ensure that
all material information required to be disclosed by the Company in the reports
that it files or furnishes under the Exchange Act is recorded, processed,
summarized and reported within the time periods specified in the rules and forms
of the Commission. The Company maintains a system of internal controls over
financial reporting sufficient to provide reasonable assurance that (i)
transactions are executed in accordance with management’s general or specific
authorizations; and (ii) transactions are recorded as necessary to permit
preparation of financial statements in conformity with GAAP.

2.9 Material Adverse Change. Except as disclosed in the Commission Documents,
since September 30, 2014, no event or series of events has or have occurred that
would, individually or in the aggregate, have a Material Adverse Effect on the
Company.

2.10 No Undisclosed Liabilities. To the Company’s knowledge, neither the Company
nor any of its subsidiaries has any liabilities, obligations, claims or losses
(whether liquidated or unliquidated, secured or unsecured, absolute, accrued,
contingent or otherwise) that would be required to be disclosed on a balance
sheet of the Company or any of its subsidiaries (including the notes thereto) in
conformity with GAAP and are not disclosed in the Commission Documents, other
than those incurred in the ordinary course of the Company’s or its subsidiaries’
respective businesses since September 30, 2014 or which, individually or in the
aggregate, do not or would not have a Material Adverse Effect on the Company.

2.11 No Undisclosed Events or Circumstances. Except for the transactions
contemplated by this Agreement and the Collaboration Agreement, no event or
circumstance has occurred or exists with respect to the Company, its
subsidiaries, or their respective businesses, properties, operations or
financial condition, which, under applicable law, rule or regulation, requires
public disclosure or announcement by the Company but which has not been so
publicly announced or disclosed and which, individually or in the aggregate,
would have a Material Adverse Effect on the Company.

2.12 Actions Pending. There is no action, suit, claim, investigation or
proceeding pending or, to the knowledge of the Company, threatened against the
Company or any subsidiary which questions the validity of this Agreement or the
transactions contemplated hereby or any action taken or to be taken pursuant
hereto. Except as set forth in the Commission Documents or as previously
disclosed in writing to the Investor, there is no action, suit, claim,
investigation or proceeding pending or, to the knowledge of the Company,
threatened, against or involving the Company, any subsidiary, or any of their
respective properties or assets that could be reasonably expected to have a
Material Adverse Effect on the Company. Except as set forth in the Commission
Documents or as previously disclosed to the Investor in writing, no judgment,
order, writ, injunction or decree or award has been issued by or, to the
knowledge of the Company, requested of any court, arbitrator or governmental
agency which could be reasonably expected to result in a Material Adverse
Effect.

2.13 Compliance with Law. The businesses of the Company and its subsidiaries
have been and are presently being conducted in accordance with all applicable
federal, state and local governmental laws, rules, regulations and ordinances,
except as set forth in the Commission Documents or such that would not
reasonably be expected to cause a Material Adverse Effect. Except as set forth
in the Commission Documents, the Company and each of its subsidiaries have all
franchises, permits, licenses, consents and other governmental or regulatory
authorizations and approvals necessary for the conduct of its business as now
being conducted by it, except for such franchises, permits, licenses, consents
and other governmental or regulatory authorizations and approvals, the failure
to possess which, individually or in the aggregate, could not reasonably be
expected to have a Material Adverse Effect.

2.14 Exemption from Registration, Valid Issuance. Subject to, and in reliance
on, the representations, warranties and covenants made herein by the Investor,
the issuance and sale of the Shares in accordance with the terms and on the
bases of the representations and warranties set forth in this Agreement, may and
shall be properly issued pursuant to Section 4(a)(2) of the Securities Act of
1933, as amended (the “Securities Act”), Regulation D promulgated pursuant to
the Act (“Regulation D”) and/or any other applicable federal and state
securities laws. The sale and issuance of the Shares pursuant to, and the
Company’s performance of its obligations under, this Agreement will not
(i) result in the creation or imposition of any liens, charges, claims or other
encumbrances upon the Shares or any of the assets of the Company, or (ii) except
as previously disclosed to the Investor in writing, entitle the holders of any
outstanding shares of capital stock of the Company to preemptive or other rights
to subscribe to or acquire the Shares or other securities of the Company.

2.15 Transfer Taxes. All stock transfer or other taxes (other than income taxes)
which are required to be paid in connection with the sale and transfer of the
Shares to be sold to Investor hereunder will be, or will have been, fully paid
or provided for by the Company and all laws imposing such taxes will be or will
have been fully complied with.

2.16 Investment Company. The Company is not and, after giving effect to the
offering and sale of the Shares, will not be an “investment company” as defined
in the Investment Company Act of 1940, as amended.

2.17 Brokers. Except as expressly set forth in this Agreement or the
Collaboration Agreement, no brokers, finders or financial advisory fees or
commissions will be payable by the Company or any of its subsidiaries in respect
of the transactions contemplated by this Agreement or the Collaboration
Agreement.

SECTION 3

Representations and Warranties of the Investor

The Investor hereby represents and warrants the following as of the date hereof
and as of the Closing Date:

3.1 Experience. The Investor is experienced in evaluating companies such as the
Company, has such knowledge and experience in financial and business matters
that the Investor is capable of evaluating the merits and risks of the
Investor’s prospective investment in the Company, and has the ability to bear
the economic risks of the investment.

3.2 Investment. The Investor is acquiring the Shares for investment for the
Investor’s own account and not with the view to, or for resale in connection
with, any distribution thereof. The Investor understands that the Shares have
not been and will not be registered under the Securities Act by reason of a
specific exemption from the registration provisions of the Securities Act which
depends upon, among other things, the bona fide nature of the investment intent
as expressed herein. The Investor acknowledges and agrees that the Shares
purchased by the Investor, until disposition of such Shares in accordance with
the provisions of this Agreement, shall remain at all times within the
Investor’s control. The Investor further represents that it does not have any
contract, undertaking, agreement or arrangement with any person to sell,
transfer or grant participation to any third person with respect to any of the
Shares.

3.3 Rule 144. The Investor acknowledges that the Shares must be held
indefinitely unless subsequently registered under the Securities Act or an
exemption from such registration is available. The Investor is aware of the
provisions of Rule 144 promulgated under the Securities Act which permit limited
resale of shares purchased in a private placement subject to the satisfaction of
certain conditions. In connection therewith, the Investor acknowledges that the
Company will make a notation on its stock books regarding the restrictions on
transfers set forth in this Section 3 and will transfer the Shares on the books
of the Company only to the extent not inconsistent therewith.

3.4 Access to Information. The Investor has received and reviewed information
about the Company and has had an opportunity to discuss the Company’s business,
management and financial affairs with its management and to review the Company’s
facilities. The Investor has had a full opportunity to ask questions of and
receive answers from the Company, or any person or persons acting on behalf of
the Company, concerning the terms and conditions of an investment in the Shares.
The Investor is not relying upon, and has not relied upon, any statement,
representation or warranty made by any person, except for the statements,
representations and warranties contained in this Agreement and the Collaboration
Agreement.

3.5 Authorization. This Agreement when executed and delivered by the Investor
will constitute a valid and legally binding obligation of the Investor,
enforceable in accordance with its terms, subject to: (i) judicial principles
respecting election of remedies or limiting the availability of specific
performance, injunctive relief, and other equitable remedies; and
(ii) bankruptcy, insolvency, reorganization, moratorium or other similar laws
now or hereafter in effect generally relating to or affecting creditors’ rights.

3.6 Investor Status. The Investor acknowledges that it is either (i) an
institutional “accredited investor” as defined in Rule 501(a) of Regulation D of
the Securities Act (an “Institutional Accredited Investor”) or (ii) a “qualified
institutional buyer” as defined in Rule 144A of the Securities Act, as indicated
on Schedule A hereto, and the Investor shall submit to the Company such further
assurances of such status as may be reasonably requested by the Company.

3.7 No Inducement. The Investor was not induced to participate in the offer and
sale of the Shares by the filing of any registration statement in connection
with any public offering of the Company’s securities, and the Investor’s
decision to purchase the Shares hereunder was not influenced by the information
contained in any such registration statement.

SECTION 4

Conditions to Investor’s Obligations at Closing

The obligations of the Investor under this Agreement are subject to the
fulfillment on or before the Closing of each of the following conditions, any of
which may be waived in writing by the Investor (except to the extent not
permitted by law):

4.1 No Injunction, etc. No preliminary or permanent injunction or other binding
order, decree or ruling issued by a court or governmental agency shall be in
effect which shall have the effect of preventing the consummation of the
transactions contemplated by this Agreement. No action or claim shall be pending
before any court or quasi-judicial or administrative agency of any federal,
state, local or foreign jurisdiction or before any arbitrator wherein an
unfavorable injunction, judgment, order, decree, ruling or charge would be
reasonably likely to (i) prevent consummation of any of the transactions
contemplated by this Agreement, (ii) cause any of the transactions contemplated
by this Agreement to be rescinded following consummation or (iii) have the
effect of making illegal the purchase of, or payment for, any of the Shares by
the Investor.

4.2 Representations and Warranties. The representations and warranties of the
Company contained in Section 2 shall have been true and correct in all material
respects (except for such representations and warranties that are qualified by
materiality which shall be true and correct in all respects) on and as of the
Execution Date with the same effect as though such representations and
warranties had been made on and as of such date.

4.3 Performance. The Company shall have performed and complied with all
covenants, agreements, obligations and conditions contained in this Agreement
that are required to be performed or complied with by it on or before the
Execution Date.

4.4 Compliance Certificate. A duly authorized officer of the Company shall
deliver to the Investor at the Closing a certificate stating that the conditions
specified in Sections 4.2 and 4.3 have been fulfilled and certifying and
attaching the Company’s Certificate of Incorporation, Bylaws and authorizing
Board of Directors resolutions with respect to this Agreement, the Collaboration
Agreement and the transactions contemplated hereby and thereby.

4.5 Securities Laws. The offer and sale of the Shares to the Investor pursuant
to this Agreement shall be exempt from the registration requirements of the
Securities Act and the registration and/or qualification requirements of all
applicable state securities laws.

4.6 Authorizations. All authorizations, approvals or permits, if any, of any
governmental authority or regulatory body that are required in connection with
the lawful issuance and sale of the Shares pursuant to this Agreement shall have
been duly obtained and shall be effective on and as of the Closing.

4.7 Legal Opinion. The Investor shall have received a legal opinion from
Cooley LLP containing the substance set forth on Exhibit B attached hereto.

SECTION 5

Conditions to the Company’s Obligations at Closing

The obligations of the Company to the Investor under this Agreement are subject
to the fulfillment on or before the Closing of each of the following conditions
by the Investor:

5.1 Representations and Warranties. The representations and warranties of the
Investor contained in Section 3 shall be true and correct in all material
respects (except for such representations and warranties that are qualified by
materiality which shall be true and correct in all respects) on and as of the
Closing with the same effect as though such representations and warranties had
been made on and as of the Closing.

5.2 Securities Law Compliance. The offer and sale of the Shares to the Investor
pursuant to this Agreement shall be exempt from the registration requirements of
the Securities Act and the registration and/or qualification requirements of all
applicable state securities laws.

5.3 Authorization. All authorizations, approvals or permits, if any, of any
governmental authority or regulatory body that are required in connection with
the lawful issuance and sale of the Shares pursuant to this Agreement shall have
been duly obtained and shall be effective on and as of the Closing.

SECTION 6

Investor Covenants

6.1 Trading Restrictions.

(a) Definitions.

(i) “Affiliate” shall have the meaning set forth in Rule 12b-2 of the
regulations promulgated under the Securities Exchange Act of 1934, as amended.

(ii) “Restriction Period” shall mean the period commencing on the Closing Date
and continuing until the date that is two (2) years from such date.

(iii) “Significant Event” shall mean any of the following not involving a
violation of this Section 6: (A) the public announcement of a proposal or
intention to acquire, or the acquisition, by any person or 13D Group of
beneficial ownership of Voting Securities representing 15% or more of the then
outstanding Voting Securities; (B) the public announcement of a proposal or
intention to commence, or the commencement, by any person or 13D Group of a
tender or exchange offer to acquire Voting Securities which, if successful,
would result in such person or 13D Group owning, when combined with any other
Voting Securities owned by such person or 13D Group, 15% or more of the then
outstanding Voting Securities; or (C) the entry into by the Company, or the
public announcement by the Company of an intention or determination to enter
into, any merger, sale or other business combination transaction, or an
agreement therefor, pursuant to which the outstanding shares of capital stock of
the Company would be converted into cash, other consideration or securities of
another person or 13D Group or 50% or more of the then outstanding shares of
capital stock of the Company would be owned by persons other than the then
current holders of shares of capital stock of the Company, or which would result
in all or a substantial portion of the Company’s assets being sold to any person
or 13D Group.

(iv) “Voting Securities” shall mean at any time shares of any class of capital
stock of the Company which are then entitled to vote generally in the election
of directors.

(v) “13D Group” shall mean, with respect to the Voting Securities of the
Company, any group of persons formed for the purpose of acquiring, holding,
voting or disposing of such Voting Securities which would be required under
Section 13(d) of the Exchange Act and the rules and regulations thereunder to
file a statement on Schedule 13D with the Commission as a “person” within the
meaning of Section 13(d)(3) of the Exchange Act if such group beneficially owned
Voting Securities representing more than 5% of the total combined voting power
of all such Voting Securities then outstanding.

(b) Restriction Period No Sell. The Investor agrees that during the Restriction
Period, neither the Investor nor any of its Affiliates shall offer, sell,
contract to sell, pledge, grant any option to purchase, make any short sale or
otherwise dispose of in any manner, either directly or indirectly (“Sale” or
“Sell”), any Shares, or any securities of the Company issued as a dividend or
distribution on, or involving a recapitalization or reorganization with respect
to, such Shares (collectively, “Covenant Shares”), other than transfers of
securities between and among the Company and any one or more of its Affiliates.
The Company shall use commercially reasonable efforts to permit the Shares to be
eligible for clearance and settlement through the facilities of The Depository
Trust Company immediately following the termination of the Restriction Period.

(c) Post-Restriction Period Selling Restrictions. After the Restriction Period,
neither the Investor nor its Affiliates shall Sell a number of Covenant Shares
in any three-month period that collectively exceeds 25% of the aggregate
Covenant Shares held by the Investor and its Affiliates as of the end of the
Restriction Period (such number of Covenant Shares, the “Post-Restriction
Allowance”), provided, however, that (i) if in any such three-month period the
Investor and its Affiliates Sell a number of Covenant Shares that is less than
the Post-Restriction Allowance (such shortfall, the “Carry-Forward Allowance”),
the Investor and its Affiliates may Sell any Carry-Forward Allowance in any
subsequent three-month period, along with the Post-Restriction Allowance for
such subsequent three-month period, and (ii) the Investor and its Affiliates may
continue to Sell any portion of any Carry-Forward Allowance in any three-month
period until the Investor and its Affiliates have Sold all of such Carry-Forward
Allowance. Notwithstanding the foregoing, (x) the Investor and its Affiliates
may not sell a number of Covenant Shares in any three-month period following the
Restriction Period that collectively exceeds 37.5% of the aggregate Covenant
Shares held by the Investor and its Affiliates as of the end of the Restriction
Period, and (y) the limitations set forth in this Section 6.1(c) shall not apply
to transfers of securities between and among the Company and any one or more of
its Affiliates. For any proposed Sale of 100,000 or more shares of Common Stock
of the Company by the Investor or any of its Affiliates in any single
transaction or series of related transactions (“Proposed Sale Shares”), the
Investor shall give the Company at least 30 days prior written notice of such
sale. During such 30 day period, the Company may seek to find a buyer for the
Proposed Sale Shares.

(d) Termination of Collaboration Agreement. The restrictions contained in
Sections 6.1(b) and (c) shall expire as follows:

(i) The restrictions contained in Section 6.1(b) shall expire on the earlier of
(A) the date of the expiration of the Restriction Period or (B) the date that is
six (6) months following the expiration or termination of the Collaboration
Agreement in accordance with the terms thereof;

(ii) The restrictions contained in Section 6.1(c) shall expire on the date that
is six (6) months following the expiration or termination of the Collaboration
Agreement in accordance with the terms thereof.

(e) Occurrence of Significant Event. The restrictions contained in
Sections 6.1(b) and (c) shall be suspended and shall not apply to or otherwise
restrict the Investor’s actions in respect of the Company’s securities for so
long as a Significant Event has occurred and is continuing.

6.2 Invalid Transfers. Any sale, assignment or other transfer of Covenant Shares
by the Investor or any of its Affiliates, as applicable, contrary to the
provisions of this Section 6 shall be null and void, and the transferee shall
not be recognized by the Company as the holder or owner of the Covenant Shares
sold, assigned, or transferred for any purpose (including, without limitation,
voting or dividend rights), unless and until the Investor or such Affiliate, as
applicable, has satisfied the requirements of this Section 6 with respect to
such sale. The Investor shall provide the Company with written evidence that
such requirements have been met or waived, prior to it or its Affiliates
consummating any sale, assignment or other transfer of securities, and no
Covenant Shares shall be transferred on the books of the Company until such
written evidence has been received by the Company from the Investor. The
Company, or, at the instruction of the Company, the transfer agent of the
Company, may place a legend on any certificate representing Covenant Shares
stating that such shares are subject to the restrictions contained in this
Agreement. Upon delivery by the Investor of the written evidence required above,
the Company agrees to facilitate the timely preparation and delivery (but in no
event longer than seven (7) business days) of certificates representing the
Covenant Shares to be sold by the Investor or any Affiliate free of any
restrictive legends and in such denominations and registered in such names as
the Investor or such Affiliate may request in connection with such sale.

6.3 Performance by Affiliates. The Investor shall remain responsible for and
guarantee its Affiliates’ performance in connection with this Agreement, and
shall cause each such Affiliate to comply fully with the provisions of this
Agreement in connection with such performance. The Investor hereby expressly
waives any requirement that the Company exhaust any right, power or remedy, or
proceed directly against such an Affiliate, for any obligation or performance
hereunder, prior to proceeding directly against the Investor.

SECTION 7

Registration Rights

7.1 Rule 144 Reporting. With a view to making available to the Investor the
benefits of certain rules and regulations of the Commission which may permit the
sale of the Shares to the public without registration, the Company agrees to use
commercially reasonable efforts to:

(a) Make and keep public information available, as those terms are understood
and defined in Rule 144 promulgated under the Securities Act;

(b) File with the Commission in a timely manner all reports and other documents
required of the Company under the Exchange Act; and

(c) Furnish the Investor forthwith upon request (i) a written statement by the
Company as to its compliance with the public information requirements of said
Rule 144, (ii) a copy of the most recent annual or quarterly report of the
Company, and (iii) such other reports and documents as may be reasonably
requested in availing the Investor of any rule or regulation of the Commission
permitting the sale of any such securities without registration.

7.2 Registration.

(a) If, at the end of the Restriction Period, the Shares cannot be sold without
restriction pursuant to Rule 144 promulgated under the Securities Act, then upon
Investor’s written request, received by the Company on or before the 30th day
after the end of the Restriction Period, the Company will use commercially
reasonable efforts to register the Shares for resale under the Securities Act on
a Registration Statement on Form S-3 (the “Registration Statement”), filed
within 60 days of such written request, and will use commercially reasonable
efforts to have such Registration Statement promptly declared effective by the
Commission.

(b) The Company will use commercially reasonable efforts to keep the
Registration Statement continuously effective under the Securities Act until the
earlier of (i) the date all of the Shares covered by such Registration Statement
have been sold or can be sold publicly without restriction or limitation under
Rule 144 or (ii) the date that is two years following the Closing Date.

(c) The Investor shall furnish to the Company such information regarding the
Investor, and the distribution proposed by the Investor, as the Company may
reasonably request in writing and as shall be required in connection with the
Registration Statement.

(d) The Company shall pay all fees and expenses incident to the performance of
or compliance with this Section 7 by the Company.

7.3 Restrictive Legend. The certificates representing the Shares, when issued,
will bear a restrictive legend in substantially the following form:

“THE SECURITIES EVIDENCED OR CONSTITUTED HEREBY HAVE BEEN ISSUED WITHOUT
REGISTRATION UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE “ACT”) AND MAY
NOT BE SOLD, OFFERED FOR SALE, TRANSFERRED, PLEDGED OR HYPOTHECATED WITHOUT
REGISTRATION UNDER THE ACT UNLESS EITHER (i) THE COMPANY HAS RECEIVED AN OPINION
OF COUNSEL, IN FORM AND SUBSTANCE REASONABLY SATISFACTORY TO THE COMPANY, TO THE
EFFECT THAT REGISTRATION IS NOT REQUIRED IN CONNECTION WITH SUCH DISPOSITION OR
(ii) THE SALE OF SUCH SECURITIES IS MADE PURSUANT TO SECURITIES AND EXCHANGE
COMMISSION RULE 144.”

SECTION 8

Indemnification

Each party (an “Indemnifying Party”) hereby indemnifies and holds harmless the
other party, such other party’s respective officers, directors, employees,
consultants, representatives and advisers, and any and all Affiliates (as
defined in Section 6.1(a)) of the foregoing (each of the foregoing, an
“Indemnified Party”) from and against all losses, liabilities, costs, damages
and expense (including reasonable legal fees and expenses) (collectively,
“Losses”) suffered or incurred by any such Indemnified Party to the extent
arising from, connected with or related to (i) breach of any representation or
warranty of such Indemnifying Party in this Agreement; and (ii) breach of any
covenant or undertaking of any Indemnifying Party in this Agreement. If an event
or omission (including, without limitation, any claim asserted or action or
proceeding commenced by a third party) occurs which an Indemnified Party asserts
to be an indemnifiable event pursuant to this Section 8, the Indemnified Party
will provide written notice to the Indemnifying Party, setting forth the nature
of the claim and the basis for indemnification under this Agreement. The
Indemnified Party will give such written notice to the Indemnifying Party
immediately after it becomes aware of the existence of any such event or
occurrence. Such notice will be a condition precedent to any obligation of the
Indemnifying Party to act under this Agreement but will not relieve it of its
obligations under the indemnity except to the extent that the failure to provide
prompt notice as provided in this Agreement prejudices the Indemnifying Party
with respect to the transactions contemplated by this Agreement and to the
defense of the liability. In case any such action is brought by a third party
against any Indemnified Party and it notifies the Indemnifying Party of the
commencement thereof, the Indemnifying Party will be entitled to participate
therein and, to the extent that it wishes, to assume the defense and settlement
thereof with counsel reasonably selected by it and, after notice from the
Indemnifying Party to the Indemnified Party of such election so to assume the
defense and settlement thereof, the Indemnifying Party will not be liable to the
Indemnified Party for any legal expenses of other counsel or any other expenses
subsequently incurred by such Indemnified Party in connection with the defense
thereof, provided, however, that an Indemnified Party shall have the right to
employ separate counsel at the expense of the Indemnifying Party if (i) the
employment thereof has been specifically authorized in writing by the
Indemnifying Party; or (ii) representation of both parties by the same counsel
would be inappropriate due to actual or potential conflicts of interests between
such parties (which such judgment shall be made in good faith after consultation
with counsel). The Indemnified Party agrees to cooperate fully with (and to
provide all relevant documents and records and make all relevant personnel
available to) the Indemnifying Party and its counsel, as reasonably requested,
in the defense of any such asserted claim at no additional cost to the
Indemnifying Party. No Indemnifying Party will consent to the entry of any
judgment or enter into any settlement with respect to any such asserted claim
without the prior written consent of the Indemnified Party, not to be
unreasonably withheld or delayed, (a) if such judgment or settlement does not
include as an unconditional term thereof the giving by each claimant or
plaintiff to each Indemnified Party of a release from all liability in respect
to such claim or (b) if, as a result of such consent or settlement, injunctive
or other equitable relief would be imposed against the Indemnified Party or such
judgment or settlement could materially and adversely affect the business,
operations or assets of the Indemnified Party. No Indemnified Party will consent
to the entry of any judgment or enter into any settlement with respect to any
such asserted claim without the prior written consent of the Indemnifying Party,
not to be unreasonably withheld or delayed. If an Indemnifying Party makes a
payment with respect to any claim under the representations or warranties set
forth herein and the Indemnified Party subsequently receives from a third party
or under the terms of any insurance policy a sum in respect of the same claim,
the receiving party will repay to the other party such amount that is equal to
the sum subsequently received.

SECTION 9

Miscellaneous

9.1 Governing Law. This Agreement shall be governed in all respects by the laws
of the State of New York as applied to agreements entered into and performed
entirely in the State of New York by residents thereof.

9.2 Survival. The representations, warranties, covenants and agreements made
herein shall survive any investigation made by the Investor and the Closing.

9.3 Successors, Assigns. Except as otherwise provided herein, the provisions
hereof shall inure to the benefit of, and be binding upon, the successors,
assigns, heirs, executors and administrators of the parties hereto. This
Agreement may not be assigned by either party without the prior written consent
of the other; except that either party may assign this Agreement to an Affiliate
(as defined in Section 6.1(a)) of such party or to any third party that acquires
all or substantially all of such party’s business, whether by merger, sale of
assets or otherwise.

9.4 Notices. All notices and other communications required or permitted
hereunder shall be in writing and shall be sent by facsimile (receipt confirmed)
or mailed by registered or certified mail, postage prepaid, return receipt
requested, or otherwise delivered by hand or by messenger, addressed

if to the Investor, at the following address:

         
Astellas Pharma Inc.
        2-5-1, Nihonbashi-Honcho
Chuo-ku, Tokyo 103-8411

Japan
        Attn:Vice President, Legal & Compliance

Facsimile:
    81-3-3244-5811  

if to the Company, at the following address:

Cytokinetics, Incorporated

280 E Grand Ave

South San Francisco, CA 94080

Attention: General Counsel

Facsimile: (650) 624-3010

or at such other address as one party shall have furnished to the other party in
writing. If notice is provided by facsimile, it shall be deemed to be given one
(1) business day after transmission (with receipt of appropriate confirmation).
If notice is provided by U.S. mail, notice shall be deemed to be given ten
(10) business days after proper deposit in a U.S. mailbox, postage prepaid, and
properly addressed. If notice is provided by nationally-recognized overnight
courier, it shall be deemed effective five (5) business day after dispatch.

9.5 Expenses. Each of the Company and the Investor shall bear its own expenses
and legal fees incurred on its behalf with respect to this Agreement and the
transactions contemplated hereby.

9.6 Finder’s Fees. Each of the Company and the Investor shall indemnify and hold
the other harmless from any liability for any commission or compensation in the
nature of a finder’s fee, placement fee or underwriter’s discount (including the
costs, expenses and legal fees of defending against such liability) for which
the Company or the Investor, or any of its respective partners, employees, or
representatives, as the case may be, is responsible.

9.7 Counterparts. This Agreement may be executed in counterparts, each of which
shall be enforceable against the party actually executing the counterpart, and
all of which together shall constitute one instrument.

9.8 Severability. In the event that any provision of this Agreement becomes or
is declared by a court of competent jurisdiction to be illegal, unenforceable or
void, this Agreement shall continue in full force and effect without said
provision; provided that no such severability shall be effective if it
materially changes the economic benefit of this Agreement to any party.

9.9 Entire Agreement. This Agreement and the Collaboration Agreement, including
the exhibits and schedule attached hereto and thereto, constitute the full and
entire understanding and agreement among the parties with regard to the subjects
hereof and thereof. No party shall be liable or bound to any other party in any
manner with regard to the subjects hereof or thereof by any warranties,
representations or covenants except as specifically set forth herein or therein.

9.10 Waiver. The failure of either party to assert a right hereunder or to
insist upon compliance with any term or condition of this Agreement shall not
constitute a waiver of that right or excuse a similar subsequent failure to
perform any such term or condition by the other party. None of the terms,
covenants and conditions of this Agreement can be waived except by the written
consent of the party waiving compliance.

IN WITNESS WHEREOF, the parties have executed this Common Stock Purchase
Agreement as of the date first set forth above.

     
CYTOKINETICS, INCORPORATED
By: s/Robert I. Blum
Name: Robert I. Blum
  ASTELLAS PHARMA INC.
By: s/Yoshihiko Hatanaka
Name: Yoshihiko Hatanaka
 
   
Title: President and CEO
  Title: President and CEO
 
   

Schedule A

The Investor is an institutional “accredited investor” as defined in Rule 501(a)
of Regulation D of
the Securities Act.EXHIBIT A

Schedule of Exceptions

None

EXHIBIT B

Form of Legal Opinion

1. The Company has been duly incorporated and is a validly existing corporation
in good standing under the laws of the State of Delaware.

2. The Shares have been duly authorized, and upon issuance and delivery against
payment therefor in accordance with the terms of the Agreement, the Shares will
be validly issued, outstanding, fully paid and nonassessable.

3. The offer and sale of the Shares are exempt from the registration
requirements of the Securities Act of 1933, as amended, subject to the timely
filing of a Form D pursuant to Securities and Exchange Commission Regulation D.