First UK patient joins Pfizer's phase 3 DMD gene therapy trial

The first UK patient has enrolled on Pfizer’s phase 3 trial for its Duchenne muscular dystrophy (DMD) gene therapy.

Pfizer’s CIFFREO study began in the US in January this year and has now begun enrolling eligible patients in the UK.

The first patient was recruited 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 trial is expected to enrol 99 ambulatory male patients, aged four to seven.

The primary endpoint of the study is the change from baseline in a 17-item test that measures motor function in boys with DMD.

Known as the North Star Ambulatory Assessment (NSAA), results of the test will be assessed after a year.

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 in the CIFFREO study for five years after treatment with the investigational gene therapy.

Pfizer added the gene therapy to its pipeline in 2016, when it acquired Bamboo Therapeutics in a deal worth up to $645 million.

There are already several drugs on the market to treat Duchenne, notably from Sarepta Therapeutics which has three FDA-approved drugs that use "exon skipping" technology.

These allow the body to produce a correct version of the misfolded dystrophin protein that is the root cause of DMD.

But gene therapies go one step further by inserting the dystrophin gene into the patient’s muscle tissue, in order to produce a working version of the protein that is essential for building muscles.

Pfizer’s gene therapy uses a modified adeno-associated virus to carry a shortened version of the human dystrophin gene to the target muscle tissue.

Sarepta is also developing a DMD gene therapy, although it’s a step behind Pfizer in mid-stage clinical development.

The 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.