First UK patient enrolled in Duchenne muscular dystrophy gene therapy trial

The Phase III trial will evaluate the safety and efficacy of Pfizer’s PF-06939926 gene therapy in 99 paediatric Duchenne muscular dystrophy patients across 15 countries.

DNA inside a red and white capsule - gene therapy concept

The first UK patient has been enrolled in the Phase III CIFFREO study, evaluating the efficacy and safety of Pfizer’s investigational gene therapy, PF-06939926, in boys with Duchenne muscular dystrophy (DMD).

The first patient was enrolled in The Newcastle upon Tyne Hospitals NHS Foundation Trust, one of three UK sites for the clinical trial and part of 55 globally, across 15 countries. The CIFFREO trial is expected to enrol 99 ambulatory male patients, aged four to seven years.

Dr Michela Guglieri, Consultant Neurologist at Newcastle Hospitals NHS Foundation Trust and UK Chief Investigator, commented: “The enrolment of the first UK patient in this Phase III gene therapy programme is a great achievement for the UK Duchenne community and we are very pleased to contribute to innovative research in the pursuit of future therapies. There are currently no approved disease-modifying treatment options available for all genetic forms of the disease in the UK. I am very proud to be leading the UK arm of this global study.”

CIFFREO is a Phase III global, multi-centre, randomised, double-blind, placebo-controlled study. The primary endpoint of the study is the change from baseline in the North Star Ambulatory Assessment (NSAA) at one year. The NSAA is a 17-item test that measures gross motor function in boys with DMD. Regardless of cohort, eligible participants are scheduled to receive the investigational gene therapy, either at the start of the study or after one year following treatment with placebo. Participants will be followed for five years after treatment with the investigational gene therapy.

Jack Brownrigg, Rare Disease Medical Director, Pfizer UK said: “This is the first Phase III DMD gene therapy programme to begin enrolling eligible participants in the UK. We believe our gene therapy candidate, if successful in Phase III and approved, has the potential to significantly improve the trajectory of DMD disease progression.

“As well as a positive milestone for the DMD community, this is also an important step for the UK life science sector. This exciting development comes shortly after the UK Government launched a new Rare Disease framework which places an emphasis on improving access to speciality care, treatment and medicines. With the era of gene therapy increasingly becoming a reality, it is now more important than ever that we work together to do all we can to ensure rare disease patients have access to these treatments once deemed well tolerated and efficacious.”

DMD is an X chromosome-linked disease caused by mutations in the gene encoding dystrophin, which is needed for muscle membrane stability. Due to the lack of dystrophin, boys present with muscle degeneration that progressively worsens with age. This dystrophy becomes so severe that boys typically require wheelchair assistance when they are in their early teens and usually succumb to their disease by the time they are in their late twenties. It is estimated that there are approximately 140,000 boys affected with DMD worldwide.

PF-06939926 received Fast Track designation from the US Food and Drug Administration (FDA) in October 2020, as well as Orphan Drug and Rare Paediatric Disease designations in the US in May 2017.