Amicus' muscle disorder therapy gets US FDA nod but restricted label drags shares

[September 29, 2023]  By Sriparna Roy

(Reuters) -Amicus Therapeutics' treatment for a rare muscle disorder called Pompe disease was approved by the U.S. health regulator, the drugmaker said on Thursday, ending its years-long efforts to launch the therapy.

The concerns over the limited use of the drug, however, dragged the shares down to settle 8% lower.

The U.S. Food and Drug Administration's (FDA) nod allowed the use of the therapy only in adults, weighing 40 kg and above, who had to switch from their current enzyme replacement therapy due to no signs of improvement.

That makes the label narrower than that in Europe, which allows use in all adults with late-onset Pompe disease.

At least one analyst said the drug's label, which restricts its use only to switch patients, weighed on the drugmaker's shares. The late-stage trial also tested patients who had received no prior treatment.

The approval marks Amicus' entry into the market, which is much dominated by French rival Sanofi, whose enzyme replacement therapies have been the standard of care of the disease.

While Amicus' therapy is better than the existing standard of care, it "will have a pretty significant uphill battle of taking significant market share from Sanofi", said Needham and Co analyst Gil Blum.

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

The FDA's decision comes after the health regulator last October extended for the second time a review of the therapy, citing delays in inspections caused by pandemic-related travel restrictions.

Amicus said it would launch the therapy immediately in the U.S. with a list price of around $650,000 for a patient weighing about 70 kilograms.

Its treatment consists of two components - Pombiliti, a lab-made protein alpha-glucosidase and the company's oral drug migalastat under the brand name Opfolda, which work together to help break down glycogen.

Pompe disease is a rare genetic condition in which the body is unable to break down the complex sugar glycogen, leading to a buildup that causes muscular impairment. The condition may also lead to heart failure in young patients.

(Reporting by Sriparna Roy in Bengaluru; Editing by Shinjini Ganguli, Sriraj Kalluvila and Shweta Agarwal)

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