PTC Therapeutics Reports Positive Results in Mid-Stage Trial of DMD Drug

Rare Daily Staff

PTC Therapeutics said a study of its drug Translarna in children ages 2 to 5 with nonsense mutation Duchenne muscular dystrophy was consistent with results seen in older children and showed that treatment resulted in improvements in function after one year.

Duchenne muscular dystrophy is a rare, progressive, and fatal genetic disorder that results in muscle weakness from early childhood and leads to premature death in the mid-twenties due to heart and respiratory failure. Patients with Duchenne can lose the ability to walk as early as age 10, followed by loss of the use of their arms.

Translarna is a protein-restoration therapy designed to enable the formation of a functioning protein in patients with genetic disorders caused by a nonsense mutation and the only approved treatment to address the underlying cause of nonsense mutation DMD. It is currently approved in Europe for ambulatory patients aged five years and older.

The data at 28 weeks formed the basis of the recent positive opinion from the Committee for Medicinal Products for Human Use of the European Medicines Agency to expand the current indication of Translarna to include nonsense mutation DMD ambulatory children from 2 to 5 years of age.  The data was presented at the International Congress on Neuromuscular Diseases in Vienna.

An interim analysis of the study showed that at week 28, the safety and pharmacokinetic profile for Translarna in children aged 2 to 5 years is consistent with that for older children. Clinical benefits were also observed at 28 weeks with Translarna, with decreases versus baseline in the time to run/walk 10 meters, climb four stairs, and stand from lying face up. The most common adverse events included fever, ear infection, and colds.

The study evaluated changes in timed function tests and the three-part, eight-part and full 16-items North Star Ambulatory Assessment scales, adopted for children under five years of age. It showed as much as a 25 percent improvement over baseline in mean changes at 52 weeks.

“We are excited to demonstrate that Translarna showed an improvement over one year of treatment in patients with nonsense mutation Duchenne as young as 2 years of age,” said Stuart Peltz, CEO of PTC Therapeutics. “Irreversible muscle damage starts before the age of five. Early intervention is critical to maintain muscle function and delay disease progression.”

July 9, 2018
Photo: Stuart Peltz, CEO of PTC Therapeutics