Man with Duchenne muscular dystrophy sitting in a motorized wheelchair using power controller with degenerated hands
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Sarepta is shining, as its Duchenne Muscular Dystrophy (DMD) gene therapy Elevidys has been granted the much wider label the biotech was aiming for—making it available to four-year-olds and older. This news comes just about a week after Pfizer, which was fast on Sarepta’s heels with their own gene therapy for DMD, suffered a key Phase III trial failure.  

Sales of Elevidys were $200.4 million in 2023, significantly exceeding estimates. Helping net the company over $1.145 billion last year: Sarepta also has several phosphorodiamidate morpholino oligomer (PMO) chemistry-based exon-skipping marketed therapies for DMD as well. 

Sarepta almost missed a beat though when it reported, in Oct. 2023, that its pivotal Phase III of Elevidys failed on the primary endpoint—a measure of motor function, called the North Star Ambulatory Assessment.  Despite this setback, the company said the results of the trial were positive and it planned to file for a label expansion to treat “all DMD patients” and to convert the drug’s accelerated approval into a standard approval. That seems to have been a wise choice.

DMD is a genetic muscle wasting disorder caused by mutations of the protein dystrophin. The condition affects an estimated 1-in-3,500 male births worldwide. Elevidys (delandistrogene moxeparvovec-rokl) is a single-dose, adeno-associated virus (AAV)-based gene transfer therapy that delivers a transgene that codes for the targeted production of Elevidys micro-dystrophin in skeletal muscle.

Jerry Mendell, MD, co-inventor of Elevidys and senior advisor, Medical Affairs, Sarepta, said, “The initial approval of Elevidys was a significant milestone, and the expanded indication means clinicians now have a treatment option for the great majority of boys and young men living with Duchenne. This expansion speaks to the success of the science, the evidence and the improvements in the trajectory of the disease we have seen to date across studies

Elevidys was first approved under accelerated approval for ambulatory individuals four through five years of age with DMD with a confirmed mutation in the DMD gene. With this week’s FDA action, the drug received traditional approval in ambulatory individuals 4 years of age and older with DMD with a confirmed mutation in the DMD gene, and accelerated approval in non-ambulatory individuals four years of age and older with DMD with a confirmed mutation in the DMD gene. 

“Representing many years of dedicated research, development, investment and creative energy, the expansion of the ELEVIDYS label to treat Duchenne patients aged four and above, regardless of ambulatory status, is a defining moment for the Duchenne community. Today also stands as a watershed occasion for the promise of gene therapy and a win for science,” said Doug Ingram, president and chief executive officer, Sarepta.

Pfizer meanwhile, said it will continue to closely monitor all participants enrolled in its  late-stage DMD study as it considers appropriate next steps for the program. Last month the company reported that a patient in an earlier stage trial of 2- to 3-year-old boys had died from a cardiac arrest after receiving the therapy. The company is investigating why.

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