Cytokinetics, Inc. : Cytokinetics Announces Presentation of Phase IIA Clinical Trial Data of Tirasemtiv in Patients with

Cytokinetics, Inc. : Cytokinetics Announces Presentation of Phase IIA Clinical
         Trial Data of Tirasemtiv in Patients with Myasthenia Gravis

Positive Results from Evidence of Effect Trial Inform Translation of Novel
Mechanism of Action

South San Francisco, CA, March 21, 2013 - Cytokinetics, Incorporated  (Nasdaq: 
CYTK) announced the presentation yesterday  of positive data from a  completed 
Phase IIa "Evidence of Effect" clinical  trial of tirasemtiv in patients  with 
generalized myasthenia gravis (MG) during the Emerging Science Program at  the 
65^th Annual Meeting of  the American Academy  of Neurology. Tirasemtiv,  the 
lead drug candidate from the company's skeletal muscle contractility  program, 
selectively activates the fast skeletal muscle troponin complex by  increasing 
its sensitivity  to  calcium,  thereby increasing  skeletal  muscle  force  in 
response to neuronal input and delaying  the onset and reducing the degree  of 
muscle fatigue. Tirasemtiv  is being  evaluated as a  potential treatment  for 
amyotrophic lateral  sclerosis (ALS)  in  BENEFIT-ALS (Blinded  Evaluation  of 
Neuromuscular Effects and Functional Improvement  with Tirasemtiv in ALS),  an 
international Phase IIb clinical trial that is now enrolling patients. 

Emerging Science  Presentation at  the 65^th  Annual Meeting  of the  American 
Academy of Neurology

A presentation titled "A Study  to Evaluate Efficacy, Safety and  Tolerability 
of Single Doses of Tirasemtiv in Patients with Myasthenia Gravis" was made  by 
Donald B. Sanders, MD, FAAN, Professor,  Division of Neurology and Founder  of 
the Duke Myasthenia Gravis Clinic and Chair. The presentation summarized  the 
results   of    a    double-blind,   randomized,    three-period    crossover, 
placebo-controlled, pharmacokinetic and pharmacodynamic study of tirasemtiv in
patients with generalized MG. In this trial, also known as CY 4023,  patients 
received single, oral, double-blind  doses of placebo,  250 mg of  tirasemtiv, 
and 500 mg of tirasemtiv in random order and approximately one week apart. The
main objectives of  this trial  were to assess  the effects  of tirasemtiv  on 
various measures of skeletal muscle strength and fatigue including measures of
pulmonary function.  Since  CY 4023  was  a hypothesis-generating  trial,  no 
single primary efficacy endpoint was pre-specified. 

At six hours after  dosing in CY 4023,  improvements (i.e., decreases) in  the 
Quantitative MG score (QMG) were related to the dose of tirasemtiv. Decreases
in the QMG score were  dose related (-0.49 QMG points  per 250 mg; p =  0.02). 
At six hours after the 500 mg dose of tirasemtiv, the QMG score decreased  by 
0.99 points (p = 0.02). In a responder analysis, twice as many patients (n  = 
12) improved  by 3  points or  more  six hours  after dosing  with 500  mg  of 
tirasemtiv than six hours after placebo (p  = 0.098). The QMG is a  validated 
index of disease  severity that  is often employed  as a  primary endpoint  in 
clinical trials  of patients  with  MG. In  addition, the  percent  predicted 
forced vital capacity (FVC) increased relative  to placebo at six hours  after 
both the 250 mg and 500 mg doses of tirasemtiv (7.0 ± 2.1%, p = 0.0012 and 4.5
± 2.1%, p  = 0.034, respectively).  Increases in percent  predicted FVC  were 
also dose-related (2.2% per 250mg, p = 0.043).

The authors concluded that  both the 250  mg and 500 mg  single oral doses  of 
tirasemtiv studied in this Phase IIa clinical trial were well-tolerated by the
32 patients enrolled. No premature terminations and no serious adverse events
were reported in this trial. The most commonly reported adverse event in this
trial was dizziness, which was mild in all but one case that was classified as

Cytokinetics  has  been   awarded  $3.5  million   in  grants  (Award   Number 
RC3NS070670) from the National Institute of Neurological Disorders and  Stroke 
(NINDS) to fund research and development of tirasemtiv in MG. Through December
31, 2012, Cytokinetics has incurred  $4.6 million in research and  development 
expenses associated with its MG program, and has received $3.2 million or  70% 
of the program's  funding from  NINDS. The content  of this  press release  is 
solely the responsibility of Cytokinetics  and does not necessarily  represent 
the official views of the NINDS or the National Institutes of Health.

Development Status of Tirasemtiv

Tirasemtiv (formerly CK-2017357) is currently being evaluated in  BENEFIT-ALS, 
an international,  double-blind,  randomized,  placebo-controlled,  Phase  IIb 
clinical trial designed  to evaluate  the safety,  tolerability and  potential 
efficacy of this novel  drug candidate in patients  with ALS. BENEFIT-ALS  is 
designed to enroll approximately 400 patients who will first complete one week
of treatment  with open-label  tirasemtiv  at 125  mg twice  daily.  Following 
completion of the open-label period, patients will be randomized to receive 12
weeks of  double-blind  treatment with  twice-daily  oral ascending  doses  of 
tirasemtiv beginning at 125 mg twice daily and increasing weekly up to 250  mg 
twice daily or a dummy dose titration with placebo. Clinical assessments  will 
take place  monthly  during  the  course  of  treatment;  patients  will  also 
participate in  follow-up evaluations  one and  four weeks  after their  final 
dose. The  primary efficacy  analysis  of BENEFIT-ALS  will compare  the  mean 
change from baseline in  the ALS Functional Rating  Scale in its revised  form 
(ALSFRS-R) on  tirasemtiv versus  placebo.  Secondary endpoints  will  include 
Maximum Voluntary  Ventilation (MVV)  and other  measures of  respiratory  and 
skeletal muscle function. Patients taking  riluzole at the time of  enrollment 
and who  are randomized  to  receive tirasemtiv  will  receive riluzole  at  a 
reduced dose of 50 mg daily. Cytokinetics plans to conduct this trial at  over 
70 sites across the United States, Canada, and several European countries.

Data from prior Phase IIa clinical  trials of tirasemtiv in patients with  ALS 
were presented at the  2012 American Academy of  Neurology Annual Meeting  and 
the 2010 International Symposium on ALS and Motor Neurone Diseases.  

About Cytokinetics

Cytokinetics is  a clinical-stage  biopharmaceutical  company focused  on  the 
discovery and development of novel  small molecule therapeutics that  modulate 
muscle function for the  potential treatment of  serious diseases and  medical 
conditions.  Cytokinetics'  lead  drug  candidate  from  its  cardiac   muscle 
contractility program, omecamtiv mecarbil, is in Phase II clinical development
for the potential treatment  of heart failure. Amgen  Inc. holds an  exclusive 
license worldwide  (excluding Japan)  to develop  and commercialize  omecamtiv 
mecarbil and related compounds, subject to Cytokinetics' specified development
and commercialization  participation  rights.  Cytokinetics  is  independently 
developing tirasemtiv, a skeletal muscle  activator, as a potential  treatment 
for  diseases  and  conditions  associated  with  aging,  muscle  wasting   or 
neuromuscular dysfunction. Tirasemtiv is currently  the subject of a Phase  II 
clinical trials program and has been granted orphan drug designation and  fast 
track status by  the U.S. Food  and Drug Administration  and orphan  medicinal 
product designation  by  the  European  Medicines  Agency  for  the  potential 
treatment  of  amyotrophic  lateral  sclerosis,  a  debilitating  disease   of 
neuromuscular  impairment  in   which  treatment   with  tirasemtiv   produced 
potentially clinically relevant  pharmacodynamic effects in  Phase II  trials. 
All of these drug  candidates have arisen  from Cytokinetics' muscle  biology 
focused research activities  and are  directed towards  the cytoskeleton.  The 
cytoskeleton is a complex biological  infrastructure that plays a  fundamental 
role within every human cell. Additional information about Cytokinetics can be
obtained at

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 Act's  Safe  Harbor  for  forward-looking 
statements. Examples  of such  statements  include, but  are not  limited  to, 
statements  relating  to   Cytokinetics'  and  its   partners'  research   and 
development activities, including the conduct, design and results of  clinical 
trials, the  significance  and utility  of  clinical trial  results,  and  the 
properties and potential benefits of  tirasemtiv and Cytokinetics' other  drug 
candidates. 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, Cytokinetics anticipates that it
will be required to conduct at least one confirmatory Phase III clinical trial
of tirasemtiv  in  ALS  patients which  will  require  significant  additional 
funding, and it may be unable to obtain such additional funding on  acceptable 
terms, if  at  all;  potential  difficulties or  delays  in  the  development, 
testing, regulatory approvals for  trial commencement, progression or  product 
sale or manufacturing,  or production  of Cytokinetics'  drug candidates  that 
could slow  or prevent  clinical development  or 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 or conduct of 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;  Amgen's  decisions  with 
respect to  the  design,  initiation,  conduct,  timing  and  continuation  of 
development  activities  for  omecamtiv   mecarbil;  Cytokinetics  may   incur 
unanticipated research and development and other costs or be unable to  obtain 
additional  financing  necessary  to  conduct  development  of  its  products; 
Cytokinetics may be unable to  enter into future collaboration agreements  for 
its drug candidates and programs on acceptable terms, if at all; standards  of 
care may change, rendering Cytokinetics' drug candidates obsolete; competitive
products or alternative therapies may be developed by others 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  its  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.

Joanna (Jodi) L. Goldstein
Manager, Corporate Communications & Marketing
(650) 624-3000


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Source: Cytokinetics, Inc. via Thomson Reuters ONE
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