Protalix BioTherapeutics receives FDA extension for pegunigalsidase alfa review: What this means for Fabry disease treatment

Protalix BioTherapeutics, a leader in the development of innovative therapies for rare diseases, has announced a significant update regarding its treatment for Fabry disease—pegunigalsidase alfa (PRX–102). The US Food and Drug Administration (FDA) has extended the Prescription Drug User Fee Act (PDUFA) action date for the biologics license application (BLA) submission for PRX–102. Originally scheduled for review on January 27, 2021, the new action date is set for April 27, 2021. This extension offers both challenges and opportunities for Protalix as it continues its efforts to secure approval for a new treatment option for patients with this rare and often debilitating condition.

What is Pegunigalsidase Alfa (PRX–102) and Its Role in Fabry Disease Treatment?

Fabry disease is a rare, inherited genetic disorder caused by mutations in the gene responsible for producing the enzyme alpha-galactosidase A (α-Gal A). This deficiency leads to the accumulation of globotriaosylceramide (GL-3) in various organs, causing a wide range of symptoms, including kidney failure, heart problems, and stroke. Current treatments, such as enzyme replacement therapy, offer some relief but come with limitations, prompting the search for more effective alternatives.

Pegunigalsidase alfa (PRX–102) is a novel enzyme replacement therapy designed to treat Fabry disease. It is a chemically modified, stabilized version of the recombinant α-Galactosidase A enzyme, expressed in plant cell culture. Unlike traditional enzyme replacement therapies, PRX–102 offers a potentially more efficient method of restoring enzyme activity, which may reduce or prevent the harmful buildup of GL-3 in affected tissues.

FDA Extends Review Period for PRX–102: What Does This Mean for Protalix BioTherapeutics?

The FDA’s decision to extend the PDUFA date for PRX–102 by three months is noteworthy for several reasons. First, it provides Protalix BioTherapeutics with more time to address any additional questions or data requests from the FDA. The FDA’s initial decision to grant priority review to PRX–102 under its accelerated approval pathway indicates strong interest in the drug, particularly for patients with limited treatment options.

In its announcement, Protalix stated that the FDA has not indicated plans for an advisory committee meeting to discuss the BLA. This suggests that the FDA may feel confident in the data provided by Protalix, which includes preclinical and clinical trial data from Phase I/II and Phase III studies, as well as ongoing safety data. The Phase I/II trial demonstrated promising results, and the Phase III BRIDGE switch-over study has provided additional insights into the efficacy of PRX–102 at a dose of 1 mg/kg every other week.

What Data Supports the PRX–102 BLA Submission?

The BLA for PRX–102 is supported by a comprehensive data package that includes preclinical, clinical, and manufacturing data. Notably, Protalix has included findings from a completed Phase I/II clinical trial, followed by an extension study that gathered additional clinical data. The Phase III BRIDGE study, which is ongoing, has provided critical safety and efficacy data on the use of PRX–102 in patients previously treated with a different enzyme replacement therapy.

This wealth of data is crucial in establishing the potential benefits of PRX–102 as a viable alternative to existing treatments. By demonstrating sustained efficacy and a favorable safety profile, Protalix aims to secure approval for PRX–102 as a long-term therapeutic option for Fabry disease patients.

Protalix BioTherapeutics Partners with Chiesi Global Rare Diseases

In addition to the regulatory progress with the FDA, Protalix BioTherapeutics has entered into a strategic partnership with Chiesi Global Rare Diseases for the development and commercialization of PRX–102. This collaboration, both in the United States and internationally, will significantly enhance Protalix’s ability to bring this promising therapy to market. With Chiesi’s global expertise in rare diseases and Protalix’s cutting-edge biotechnology, the partnership is well-positioned to accelerate the availability of PRX–102 for patients worldwide.

Expert Insights on the Potential Impact of PRX–102

Experts in the field of rare diseases and biotechnology view the potential approval of PRX–102 as a critical step forward for patients with Fabry disease. If approved, PRX–102 would provide a new treatment option that could improve patient outcomes, particularly those who do not respond well to traditional therapies. The drug’s novel formulation, which includes plant cell culture-expressed enzymes, could represent a more sustainable and effective treatment for a condition that has historically lacked adequate therapeutic options.

The extended review timeline also highlights the FDA’s commitment to thoroughly evaluating new therapies for rare diseases. While the delay in the decision may seem concerning, it is a common part of the regulatory process, especially when dealing with complex biologic treatments like PRX–102.

As the FDA reviews the data provided by Protalix BioTherapeutics, the extension of the PDUFA date underscores the importance of ensuring that therapies for rare diseases undergo rigorous evaluation. Pegunigalsidase alfa (PRX–102) has the potential to revolutionize the treatment of Fabry disease, offering hope to patients in need of more effective solutions. With continued collaboration between Protalix and Chiesi Global Rare Diseases, PRX–102 may soon become a key player in the fight against Fabry disease, benefiting both patients and the broader rare disease community.