Release Details

SOUTH PLAINFIELD, NJ – September 25, 2013 – PTC Therapeutics, Inc. (NASDAQ: PTCT) announced that four posters will be presented at the 18th International World Muscle Society Congress (WMS) in Asilomar, California, on October 1-5. The following posters will be presented on October 3 from 14:30 - 16:00 during Dystrophinopathy pharmco and pharmaco-gene therapy Session.

• Phase 2b, dose-ranging study of ataluren (PTC124®) in nonsense mutation Duchenne muscular dystrophy - results of a post-hoc analysis of change in %-predicted 6-minute walk distance;
• Design of a confirmatory phase 3, multicenter, randomized, double-blind, placebo-controlled study of ataluren in patients with nonsense mutation Duchenne muscular dystrophy

In addition, Craig McDonald, M.D., one of the world's leading experts in muscular dystrophy clinical endpoints and DMD natural history studies, will present two posters on data obtained from ataluren's Phase 2b study in patients with nonsense mutation Duchenne muscular dystrophy.

• The 6-minute walk test and other clinical endpoints in Duchenne muscular dystrophy: reliability, concurrent validity, and minimal clinically important differences from a multicenter study;
• The 6-minute walk test and other endpoints in Duchenne muscular dystrophy: longitudinal natural history observations over 48 weeks from a multicenter study

ABOUT PTC THERAPEUTICS, INC.
PTC is biopharmaceutical company focused on the discovery and development of orally-administered, proprietary small molecule drugs that target post-transcriptional control processes. While PTC's discovery programs are directed at targets in multiple therapeutic areas, PTC is focusing particularly on the development and commercialization of treatments for orphan and ultra-orphan disorders. Post-transcriptional control processes regulate the rate and timing of protein production and are essential to proper cellular function. PTC's internally-discovered pipeline addresses multiple therapeutic areas, including neuromuscular disorders, oncology and infectious diseases. For more information on the company, please visit our website www.ptcbio.com.

FOR MORE INFORMATION PLEASE CONTACT
Jane Baj
+1 (908) 912-9167
jbaj@ptcbio.com

FORWARD LOOKING STATEMENTS:
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