What We Do News Pfizer provides update on Myostatin trial November 2016 Read the update from Pfizer: As part of our on-going efforts to keep engaged with you and the DMD community, Pfizer is pleased to provide you with the following updates pertaining to the on-going multicenter Phase II clinical trial of the investigational compound, domagrozumab (PF-06252616) in boys with Duchenne muscular dystrophy (DMD). As a reminder, domagrozumab is an experimental, infused, anti-myostatin monoclonal antibody. Myostatin is a naturally occurring protein in muscles that helps control muscle growth; it is hypothesized that blocking the activity of myostatin may have potential therapeutic application in treating muscle wasting diseases such as DMD. The phase II clinical study is designed to evaluate the safety & tolerability, efficacy, pharmacokinetics (what the body does to a drug) and pharmacodynamics (what a drug does to a body) of domagrozumab, in 6 to <16 year old boys diagnosed with Duchenne Muscular Dystrophy (DMD) who are able to walk. More about the study can be found at www.clinicaltrials.gov (NCT02310763) and www.dmdmyostatintrial.com and by contacting the Call Center at 877-763-0415 or [email protected]. Kindly take note that the age range for this clinical study has been expanded from 6 to <10 years of age to 6 to <16 years of age. This amendment to the original protocol is based on our assessment of evolving natural history data over the course of the clinical study, which enabled us to refine our original thinking. We are continually learning from our research and others’ about the trajectory of this devastating disease. In addition, the first two sites have received IRB approval to begin recruiting within this expanded age range. We have also listened to the community and expanded the number of sites participating in the study. Sites for the study continue to be in the US, Canada, Japan, the United Kingdom, and Italy. Additional sites have been added in the US, United Kingdom, Poland, Bulgaria and Australia. The currently open sites are posted on ClinicalTrials.gov. Transfer between study sites continues to not be permitted. Enrollment of the phase 2 study of domagrozumab has met the two-thirds milestone, with the investigational drug being well tolerated with no serious adverse events to date. The first participant completed the phase 2 study and entered the extension study in October, 2016. Domagrozumab was granted Orphan Drug designation in July 2012 and Fast Track Designation in November 2012 by the U.S. Food and Drug Administration (FDA). The European Medicines Agency (EMA) granted the investigational candidate Orphan Medical Product designation in February 2013. In addition to this letter, please find enclosed an updated FAQ sheet intended to provide additional information to you about the trial. Complete information about the trial is available at ClinicalTrials.gov and www.myostatintrial.com. Should you have further questions, please feel free to contact the Call Center at 877-763-0415 or [email protected].