RARE Daily

Sarepta Faces Uncertain Delay on Start of DMD Gene Therapy

September 10, 2020

Rare Daily Staff

Sarepta Therapeutics said it has completed a ‘written response only’ meeting with the U.S. Food and Drug Administration’s Office of Tissues and Advanced Therapies to reach agreement on the start of the next clinical trial for its experimental gene therapy SRP-9001 for the rare neuromuscular condition Duchenne muscular dystrophy.

Among other items, the Office of Tissues and Advanced Therapies has requested that Sarepta utilize an additional potency assay for release of SRP-9001 commercial process material prior to dosing in a clinical study. Sarepta has several existing assays and data that it believes could be employed in response to OTAT’s request. However, additional dialogue with the agency is required to determine the acceptability of the potency assay approach.

The ongoing interactions with the agency is expected to delay the start of the trial, which has caused speculation on Wall Street that it may provide Pfizer an edge in getting to market sooner with a competing gene therapy for the condition.

Duchenne muscular dystrophy (DMD) is a rare genetic disorder characterized by progressive muscle deterioration and weakness that primarily affects boys with symptoms beginning as early as three years of age. It is the most common type of muscular dystrophy. DMD is caused by an absence of dystrophin, a protein that helps keep muscle cells intact. Progressive muscle weakness in the lower limbs spreads to the arms, neck and other areas of the body. The condition is universally fatal, and death usually occurs before the age of 30 generally due to respiratory or cardiac failure. DMD occurs in about one out of every 3,600 male infants worldwide.

SRP-9001 is an experimental gene transfer therapy intended to deliver the micro-dystrophin-encoding gene to muscle tissue for the targeted production of the micro-dystrophin protein.

In December 2019, the company entered into a licensing agreement granting Roche the exclusive right to launch and commercialize SRP-9001 outside the United States. Sarepta is responsible for global development and manufacturing for SRP-9001 and plans to commercialize SRP-9001 in the United States.

Under the terms of the agreement, Sarepta will receive an upfront payment of $1.15 billion comprised of $750 million in cash and $400 million in equity. In addition, Sarepta is eligible to receive up to $1.7 billion in regulatory and sales milestones, and royalties on net sales.

“We look forward to working with OTAT to potentially satisfy their requests and to obtain clarity on the timing of the commencement of our commercial supply study. We will provide further updates as we are able,” said Doug Ingram, president and CEO of Sarepta Therapeutics. “Every day, thousands of children degenerate from the irreversible damage caused by Duchenne muscular dystrophy. It is for that reason that we will work relentlessly with the division to satisfy any requests of OTAT and continue the advancement of a potentially transformative therapy for these patients.”  

The U.S. Food and Drug Administration granted Fast Track designation to Sarepta Therapeutics’ SRP-9001.

Photo: Doug Ingram, president and CEO of Sarepta Therapeutics




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