Cytokinetics Announces Third Extension of Research Term Under Collaboration With GlaxoSmithKline

SOUTH SAN FRANCISCO, CA, Jun 19 (MARKET WIRE) --
Cytokinetics, Incorporated (NASDAQ: CYTK) announced that it has agreed to
extend the research term under its strategic alliance with
GlaxoSmithKline (GSK) to continue research activities focused towards the
mitotic kinesin centromere-associated protein E (CENP-E). The strategic
alliance, initiated in June 2001, included an initial five-year research
term and has been extended on two prior occasions, in each case with the
objective to conduct joint research directed towards CENP-E. The
companies have agreed again to extend the research program for an
additional year, during which each company, at its own expense, will
continue to perform translational research directed towards CENP-E in
accordance with an agreed plan.

CENP-E is a mitotic kinesin directly involved in coupling the mechanics of
mitosis with the mitotic checkpoint signaling machinery, thereby
regulating cell proliferation. CENP-E is essential for prometaphase
chromosome movements that contribute to proper chromosome alignment. Both
these processes are essential to cell proliferation. Preventing cell
proliferation by disrupting mitosis is a validated approach to treating
patients with cancer. GSK-923295, a CENP-E inhibitor which arose from
joint research between Cytokinetics and GSK under the strategic alliance,
is currently in a Phase I clinical trial under GSK's sponsorship.

"We are pleased to again extend our collaborative research with
GlaxoSmithKline," stated David J. Morgans, Jr., Executive Vice President,
Preclinical Research and Development, Cytokinetics. "Translational
research directed to CENP-E has informed clinical development activities
for GSK-923295. We look forward to continuing these joint activities which
are intended to broaden our knowledge base around CENP-E and lend support
to Phase II clinical development planning activities relating to
GSK-923295."

Background on Cytokinetics and GlaxoSmithKline Strategic Alliance

In June 2001, Cytokinetics and GSK entered into a broad strategic alliance
to discover, develop and commercialize novel small molecule therapeutics
targeting mitotic kinesins for applications in the treatment of cancer and
other diseases. The strategic alliance has generated three drug candidates
in clinical development, ispinesib and SB-743921, which both target
kinesin spindle protein (KSP), and GSK-923295, which targets CENP-E. In
June 2006, June 2007 and June 2008, Cytokinetics announced one-year
extensions of the research term of this strategic alliance, beyond the
original minimum term of five years, to continue activities focused
towards translational research directed to CENP-E. Under a November 2006
amendment to its collaboration and license agreement with GSK,
Cytokinetics assumed responsibility for the costs and activities
associated with the continued development of ispinesib and SB-743921,
subject to GSK's option to resume responsibility for some or all
development and commercialization activities associated with each of
these novel drug candidates, exercisable during a defined period. The
November 2006 amendment superseded a September 2005 amendment to the
collaboration and license agreement, which specifically related to
SB-743921.

Background on Mitotic Kinesin Inhibitors

Since their introduction over 40 years ago, anti-mitotic drugs (taxanes
and vinca alkaloids) have advanced the treatment of cancer and are
commonly used for the treatment of several tumor types. However, these
drugs have demonstrated limited treatment benefit against certain
cancers. In addition, these drugs target tubulin, a cytoskeletal protein
involved not only in mitosis and cell proliferation, but also in other
important cellular functions. Inhibition of these other cellular
functions produces dose-limiting toxicities such as peripheral
neuropathy, an impairment of peripheral nervous system function.
Neuropathies are thought to result when these drugs interfere with the
dynamics of microtubule filaments that are responsible for the
long-distance transport of important cellular components within nerve
cells.

Mitotic kinesins are proteins essential to mitosis, and, unlike tubulin,
appear to have no role in unrelated cellular functions. Cytokinetics
believes that drugs that inhibit KSP, CENP-E and other mitotic kinesins
may represent the next generation of anti-mitotic cancer drugs by
arresting mitosis and cell proliferation without impacting unrelated,
normal cellular functions, thereby avoiding many of the toxicities
commonly experienced by patients treated with existing anti-mitotic drugs.

About Cytokinetics

Cytokinetics is a biopharmaceutical company focused on the discovery,
development and commercialization of novel small molecule drugs that may
address areas of significant unmet clinical needs. Cytokinetics'
development activities are primarily directed to advancing multiple drug
candidates through clinical trials with the objective of determining the
intended pharmacodynamic effect or effects in two principal diseases:
heart failure and cancer. Cytokinetics' cardiovascular disease program is
focused to cardiac myosin, a motor protein essential to cardiac muscle
contraction. Cytokinetics' lead compound from this program, CK-1827452, a
novel small molecule cardiac myosin activator, entered Phase II clinical
trials for the treatment of heart failure in 2007. Under a strategic
alliance established in 2006, Cytokinetics and Amgen Inc. are performing
joint research focused on identifying and characterizing activators of
cardiac myosin as back-up and follow-on potential drug candidates to
CK-1827452. Amgen has obtained an option for an exclusive license to
develop and commercialize CK-1827452, subject to Cytokinetics'
development and commercial participation rights. Cytokinetics' cancer
program is focused on mitotic kinesins, a family of motor proteins
essential to cell division. Under a strategic alliance established in
2001, Cytokinetics and GlaxoSmithKline (GSK) are conducting research and
development activities focused on the potential treatment of cancer.
Cytokinetics is developing two novel drug candidates that have arisen
from this program, ispinesib and SB-743921, each a novel inhibitor of
kinesin spindle protein (KSP), a mitotic kinesin. Cytokinetics believes
clinical activity for ispinesib has been observed in Phase II monotherapy
clinical trials in breast cancer, ovarian cancer and non-small cell lung
cancer and recently initiated an additional Phase I/II clinical trial of
ispinesib as monotherapy as a first-line treatment in chemotherapy-naive
patients with locally advanced or metastatic breast cancer on a more
dose-dense schedule than previously studied. Cytokinetics is also
conducting a Phase I/II trial of SB-743921 on a similar more dose-dense
schedule in non-Hodgkin and Hodgkin lymphomas. GSK has obtained an option
for the joint development and commercialization of ispinesib and
SB-743921. Cytokinetics and GSK are conducting collaborative research
activities directed to the mitotic kinesin centromere-associated protein
E (CENP-E). GSK-923295, a CENP-E inhibitor, is being developed under the
strategic alliance by GSK, subject to Cytokinetics' option to co-fund
certain later-stage development activities and to co-promote any
resulting approved drug in North America. GSK began a Phase I clinical
trial with GSK-923295 in 2007. In April 2008, Cytokinetics announced the
selection of a potential drug candidate directed towards skeletal muscle
contractility which may be developed as a potential treatment for
skeletal muscle weakness associated with neuromuscular diseases or other
conditions. All of these drug candidates and potential drug candidates
have arisen from Cytokinetics' research activities and are directed
towards the cytoskeleton. The cytoskeleton is a complex biological
infrastructure that plays a fundamental role within every human cell.
Cytokinetics' focus on the cytoskeleton enables it to develop novel and
potentially safer and more effective classes of drugs directed at
treatments for cancer and cardiovascular and other diseases. Additional
information about Cytokinetics can be obtained at www.cytokinetics.com.

This press release contains forward-looking statements for purposes of the
Private Securities Litigation Reform Act of 1995 (the "Act"). Cytokinetics
disclaims any intent or obligation to update these forward-looking
statements, and claims the protection of the Safe Harbor for
forward-looking statements contained in the Act. Examples of such
statements include, but are not limited to, statements relating to
Cytokinetics' and its partners' research and development programs, the
potential benefits of Cytokinetics' drug candidates and potential drug
candidates and the enabling capabilities of Cytokinetics' cytoskeletal
focus. Such statements are based on management's current expectations, but
actual results may differ materially due to various risks and
uncertainties, including, but not limited to, potential difficulties or
delays in the development, testing, regulatory approval or production of
Cytokinetics' drug candidates that could slow or prevent clinical
development, product approval, including risks that current and past
results of clinical trials or preclinical studies may not be indicative of
future clinical trials results, patient enrollment for clinical trials may
be difficult or delayed, Cytokinetics' drug candidates may have adverse
side effects or inadequate therapeutic efficacy, the U.S. Food and Drug
Administration or foreign regulatory agencies may delay or limit
Cytokinetics' or its partners' ability to conduct clinical trials, and
Cytokinetics may be unable to obtain or maintain patent or trade secret
protection for its intellectual property; GSK may decide to postpone or
discontinue development activities for GSK-923295, Cytokinetics may incur
unanticipated research and development and other costs or be unable to
obtain additional financing necessary to conduct development of its
products, standards of care may change, others may introduce products or
alternative therapies for the treatment of indications Cytokinetics' drug
candidates and potential drug candidates may target, and risks and
uncertainties relating to the timing and receipt of payments from our
partners, including milestones and royalties on future potential product
sales under Cytokinetics' collaboration agreements with such partners. For
further information regarding these and other risks related to
Cytokinetics' business, investors should consult Cytokinetics' filings
with the Securities and Exchange Commission.

Contacts:
Scott R. Jordan
Media
Director, Corporate Development
(650) 624-3000

Christopher S. Keenan
Investors
Director, Investor Relations
(650) 624-3000

Copyright 2008, Market Wire, All rights reserved.

-0-