On February 3 2009, PTC Therapeutics announced that they have completed the patient enrollment for participation in phase IIb of their clinical trial of PTC124™, two months ahead of schedule.
The investigational drug PTC124™ has now been given the generic name of ‘ataluren’. In the trial ataluren will be given to boys with Duchenne and Becker muscular dystrophy caused by a specific type of mutation called a nonsense mutation. This phase of the trial is estimated to last for 48 weeks and should be completed by early 2010. It is hoped that the trial will generate the information required for approval of the investigational drug by the U.S FDA (Food and Drug Administration), the EMEA (European Medicines Authority) and other regulatory authorities.
- What is ataluren (formerly referred to as PTC124™)?
- What will the latest stage of this trial involve?
- How can ataluren help people with Becker and Duchenne muscular dystrophies?
- What has been found in previous phases of this clinical trial?
- Further information
Ataluren is an orally administered investigational drug that targets a specific type of mutation in the genetic code, called a nonsense mutation. The mutation creates a premature stop signal within a gene and therefore production of a complete functional protein is interrupted.
Phase IIb of this clinical trial is a multi-centre, randomised, double-blind, placebo-controlled study. All participants in this study will have had a blood test to determine that a nonsense mutation is responsible for their Duchenne or Becker muscular dystrophy. This test is known as genotyping or full-length gene-sequencing.
This long-term trial is aimed at understanding whether ataluren can improve walking, activity, muscle function, and strength in boys with Duchenne and Becker muscular dystrophies and whether the drug can safely be given for a long period of time.
The trial is being conducted on approximately 165 patients at 37 sites across the world including three centres in the UK. These are:
- Imperial College London, Hammersmith Hospital, London
- Robert Jones and Agnes Hunt Orthopaedic NHS Trust, Shropshire
- University of Newcastle, Institute of Human Genetics, Newcastle.
PTC Therapeutics works in collaboration with the pharmaceutical company Genzyme. The two corporations have an exclusive collaboration to commercialise PTC124 under the generic name of ataluren. The Genzyme Corporation will be responsible for the commercialisation of this drug in the UK.
Duchenne and Becker muscular dystrophies are characterised by the absence of dystrophin, an essential muscle protein responsible for the integrity of the muscle cells. In approximately 10-15% of all boys the condition is caused by a nonsense mutation. In those boys ataluren has the potential to treat the underlying cause by reading through the nonsense mutation and thus restoring production of the dystrophin protein.
PTC Therapeutics has recently completed Phase 2a of this clinical study which demonstrated proof of principle of ataluren. This smaller scale trial indicated that this investigational drug was able to partially restore full-length dystrophin production and reduce muscle fragility. Previous studies have also indicated that this drug has an excellent safety profile and that any adverse affects appeared to be mild and associated with background symptoms.
Download PTC Therapeutics’ Ataluren brochure Jan 2009.