they have enrolled the first patient in a Phase 2 clinical trial in which boys with Duchenne muscular dystrophy (DMD) are given the anti-myostatin monoclonal antibody PF-06252616. Myostatin is a protein in muscles that helps control muscle growth. By blocking the activity of this protein with an antibody, it may attenuate or block the muscle wasting seen in DMD.
The phase 2 clinical trial will evaluate the safety, tolerability and efficacy of PF-06252616 in boys aged 6 to <10 years old diagnosed with DMD regardless of genotype. Based on the proposed mechanism of action of PF-06252616, Pfizer is exploring whether there is the potential to increase muscle mass and function in boys with DMD who are weak and have lost muscle.
Dr. Sharon Hesterlee, vice president of Research for Parent Project Muscular Dystrophy (PPMD) said:
“We are enthusiastic about the potential for myostatin inhibitors to stimulate increases in muscle mass and strength for people living with Duchenne muscular dystrophy. This approach could potentially add an important angle in our fight against this disease and we are pleased to see the time and great care that Pfizer has expended on its development.”
PF-06252616 was granted Orphan Drug designation in July, 2012 and Fast Track Designation in November, 2012 by the U.S. Food and Drug Administration (FDA). The European Medicines Agency (EMA) granted the investigational candidate Orphan Medical Product designation in February 2013.
Duchenne Muscular Dystrophy
Duchenne muscular dystrophy is the most common of the muscular dystrophies and the most lethal genetic disorder of childhood. It is caused by a genetic mutation that renders boys unable to make functional dystrophin, a protein critical for normal muscle function. As boys age, muscle strength continues to decline until they are wheelchair bound, on a respirator, and eventually die by the time they reach their late teens/early twenties.
There are an estimated 35,000 patients with Duchenne in the United States and Europe but the population has many subsets based on mutations of the dystrophin gene.
At present, there is no approved treatment for DMD but numerous companies are developing drugs for the condition, including Sarepta’s eteplirsen
, Prosensa’s drisapersen
, PTC Therapeutics’ ataluren
, Eli Lilly’s tadalafil
, and others.