Sarepta says FDA may limit gene therapy nod to smaller population, shares fall

[May 25, 2023]  By Leroy Leo and Aditya Samal

(Reuters) -Sarepta Therapeutics Inc said the U.S. drug regulator could initially approve its gene therapy for a muscle wasting disorder for a smaller patient group after the agency deferred an accelerated approval decision, sending its shares down 7%.

The U.S. Food and Drug Administration (FDA) has deferred the highly anticipated approval decision for the company's gene therapy for Duchenne muscular dystrophy (DMD) to June 22 from May 29 as it needs more time to complete the review. Sarepta said on Wednesday the FDA has indicated it could initially grant an accelerated approval for the therapy, called SRP-9001, for use in DMD patients aged 4 and 5. The drug was tested in DMD patients who could walk, with the mean age of about 7 years.

The smaller-than-expected patient group is a net negative for the company in the near term, Credit Suisse analyst Judah Frommer said.

Sarepta is hoping to gain accelerated approval based on limited current data that the drug helped patients make a mini version of the dystrophin protein needed to keep muscle cells intact, but FDA staff earlier this month said the studies did not provide "unambigious evidence" of benefit.

Signage is seen outside of the Food and Drug Administration (FDA) headquarters in White Oak, Maryland, U.S., August 29, 2020. REUTERS/Andrew Kelly/File Photo

On the other hand, Peter Marks, who heads the FDA's biological division, said in March the FDA was moving to encourage use of disease-related biomarkers for approval of gene therapies for diseases with small patient populations.

Sarepta is conducting a late-stage trial to confirm the therapy's actual benefit to patients. Initial data from the trial is expected by December.

The company's announcement on Wednesday followed a meeting of FDA's external advisers less than two weeks ago, where the panel narrowly backed an accelerated approval for the gene therapy with 8-6 votes.

DMD is a muscle-wasting disorder that is estimated to affect one in 3,500 male births worldwide, according to the National Organization for Rare Disorders.

(Reporting by Aditya Samal and Leroy Leo in Bengaluru; Editing by Shinjini Ganguli and Shounak Dasgupta)

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