FDA Approves New Treatment For Rare Duchenne Muscular Dystrophy Mutation

US FDA approves casimersen injection for the treatment of Duchenne muscular dystrophy (DMD) with a rare mutation.

For the treatment of patients with Duchenne muscular dystrophy (DMD) along with a rare DMD mutation, the US Food and Drug Administration (FDA) has approved the antisense oligonucleotide Casimersen (Amondys 45, Sarepta Therapeutics) injection.

The prevalence of DMD worldwide is about 1 in 3600 boys, girls can also be affected in rare cases. Symptoms of DMD appear around age 3 years but worsen steadily over time. Mutations in the DMD genes lead to decrease in dystrophin, which is a protein that strengthen muscle fibers and protect them from injury as muscles contract and relax.

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‘US FDA approves antisense oligonucleotide- casimersen injection for the treatment of Duchenne muscular dystrophy (DMD) with a rare DMD mutation. This drug increases the level of dystrophin protein.’
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The FDA said in a press release that this mutation of the DMD gene ‘is amenable to exon 45 skipping’ and this is the first approval of a targeted treatment for patients with the mutation. In about 8 percent of patients, DMD gene mutation that is amenable to exon 45 skipping is present.

Eric Bastings, MD, deputy director of the Office of Neuroscience at the FDA's Center for Drug Evaluation and Research said, “Developing drugs designed for patients with specific mutations is a critical part of personalized medicine.”

US FDA approved the drug based on the results from a 43-person randomized controlled trial, which showed that patients who received casimersen had a greater increase in production of the muscle-fiber protein dystrophin as compared to others who received placebo.

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All 43 participants were male between the ages of 7-20 and having exon 45-skipping gene mutation. They were randomly assigned to either receive IV casimersen 30 mg/kg or matching placebo.

Post treatment casimersen group showed a significantly higher increase in levels of dystrophin protein than the placebo group.

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The most common adverse effects experienced by patients in the active-treatment group were upper respiratory infections, fever, joint and throat pain, headache, and cough.

Even though the clinical studies did not show any reports of kidney toxicity, the adverse event was observed in some nonclinical studies. Hence, clinicians should monitor kidney function in any patient receiving this treatment.

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Source-Medindia