Regeneron's FOP Disease Treatment Reduces New Lesions by 90%

Treatment of FOP disease is almost here.

Treatment of FOP disease is almost here. 

Regeneron is eying potential regulatory approval of its treatment for a rare bone disease after Phase II clinical data showed an almost 90% reduction in the formation of new lesions in patients with fibrodysplasia ossificans progressiva (FOP).

This morning, Regeneron Pharmaceuticals announced the results from the mid-stage LUMINA-I study, which was evaluating garetosmab (REGN2477) in patients with FOP disease, an ultra-rare genetic disorder with no approved treatments that leads to abnormal bone formation resulting in skeletal deformities, progressive loss of mobility and premature death. Following 28 weeks of treatment, data from the Phase II study showed garetosmab decreased total lesion activity, both new and existing lesions, compared to placebo by 25% as measured by PET bone scans. That result was driven by a nearly 90% decrease compared to placebo in the number of new lesions as measured by the same scans, the company said. Additionally, Regeneron said patient-reported flare-ups were cut in half. Investigator-reported adverse events flare-ups were 10% for garetosmab and 42% for placebo, the company added.

Development of FOP Disease Treatment

As a result of the study, Regeneron said it plans to discuss regulatory submission with regulatory authorities and is also planning a pediatric trial in this indication.

George D. Yancopoulos, Regeneron’s president and chief scientific officer, said the work with garetosmab is the culmination of decades of research in FOP disease that began in the 1990s.

“This disease is relentless and devastating, leaving many patients wheelchair-bound or locked in a position unable to move, with a dramatically curtailed lifespan. We believe garetosmab may offer important new hope that can potentially transform the course of FOP and look forward to working closely with the FDA and other regulatory authorities to make garetosmab available,” Yancopoulos said in a statement.

FOP disease is an ultra-rare disease in which muscles, tendons and ligaments are progressively replaced by bone, a process known as heterotopic ossification (HO). There are approximately 800 patients across the globe known to have FOP and a number of other patients who have gone undiagnosed or misdiagnosed, Regeneron said. Most people with FOP are wheelchair bound by 30 years old and the median age of survival is approximately 56 years. Death often results from complications, such as pneumonia, heart failure and aspiration stemming from HO and loss of mobility in the chest, neck and jaw.

Garetosmab is a monoclonal antibody that reduces the formation of heterotopic bone lesions by neutralizing the Activin A protein. Actavin A is a critical protein for the development of HO. In 2017, the U.S. Food and Drug Administration granted Fast Track designation for garetosmab for the prevention of HO in patients with FOP. It has also been granted Orphan Drug designation.

Regeneron’s head of research and development Aris Economides said the data from the LUMINA-I trial proves the hypothesis that Activin A is required for the formation of new heterotopic bone lesions in people with FOP disease. Inhibiting Activin A with garetosmab reduces the occurrence of abnormal bone development and flare-ups, which provides a “true opportunity for a disease-modifying therapy for FOP,” Economides said.

Detailed results from this trial will be used as the basis of regulatory submissions, the company said. The data will also be submitted for presentation at a future medical conference.

Regeneron isn’t the only company working on a treatment for FOP disease. France-based Ipsen is also developing a treatment called palovarotene. However, last month, the FDA placed a partial clinical hold on palovarotene, due to some safety concerns in pediatric patients.

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