Protalix, Chiesi Request U.S. Approval of PRX-102 to Treat Fabry in Adults

Protalix BioTherapeutics and its partner Chiesi Global Rare Diseases, have submitted an application to the U.S. Food and Drug Administration (FDA) requesting the approval of PRX-102 (pegunigalsidase alfa), an investigational enzyme replacement therapy (ERT), to treat adults with Fabry disease

The request was submitted in the form of a biologics license application (BLA) through the FDA’s accelerated approval program, which allows medications that address an unmet need in a serious medical condition to rapidly obtain a conditional approval, provided they have shown benefits on surrogate or interim measures in a clinical trial.

“We are grateful for the assistance the FDA provided leading up to the submission of this BLA via the Accelerated Approval pathway, and we look forward, together with Chiesi, to working with the FDA as we seek marketing approval for PRX‑102,” Dror Bashan, president and CEO of Protalix, said in a press release.

“Together with Chiesi, we thank the investigators and study participants who have made reaching this milestone possible and have supported Protalix in our commitment to bringing this new treatment option to the Fabry patient community,” Bashan added.

PRX-102 is a recombinant (man-made) version of the enzyme alpha-galactosidase A based on Protalix’s proprietary ProCellEx technology platform that uses plant cells to produce recombinant enzymes.

Like other ERTs for Fabry, PRX-102 works by replenishing the levels of alpha-galactosidase A — the enzyme that patients with Fabry are missing — to help their cells break down a fatty molecule called globotriaosylceramide (Gb3), and prevent its accumulation in different tissues and organs.

The therapy previously received the designation of orphan drug from the European Commission (EC), and fast track from the FDA.

The BLA submission was based on a set of preclinical and clinical data, including findings from a completed Phase 1/2 trial (NCT01678898) and its extension study (NCT01769001). That study showed that when given every two weeks PRX-102 remained active in the patients’ blood, lowering the levels of disease biomarkers, improving kidney function, and slowing disease progression.

The BLA also was supported by interim findings from the Phase 3 BRIDGE trial (NCT03018730), which is currently evaluating the safety and effectiveness of PRX-102 in adults with Fabry previously treated with Replagal (agalsidase alpha).

Interim findings from BRIDGE, which included data from the first 16 patients who completed the study, showed PRX-102 was well-tolerated and effective at slowing the progression of kidney disease in these patients.

Safety data from other ongoing trials of PRX-102, including a second open-label extension study (NCT01981720) enrolling patients who completed the original Phase 1/2 trial and the first extension study, also were included in the BLA submission.

“The submission of this BLA to the FDA represents a significant milestone for our Global Rare Diseases division that was established earlier this year to strengthen Chiesi’s focus on making a difference for patients living with rare diseases around the world,” said Giacomo Chiesi, head of Chiesi Global Rare Diseases.

“Our partnership and active collaboration with Protalix are a great example showing how we can leverage Chiesi’s global reach and decades of experience in drug development to support patients and their families living with Fabry disease and many other devastating rare diseases,” he added.