FDA Will Give Potential Treatment PRX-102 Another Look
Agency agrees to review resubmitted biologics license application
Note: This story was updated Dec. 12, 2022, to correct the date by which the FDA must announce its decision about whether to approve PRX-102 is May 9, 2023.
The U.S. Food and Drug Administration (FDA) has accepted for review a second biologics license application (BLA) requesting the approval of PRX-102 (pegunigalsidase alfa) to treat adults with Fabry disease.
The announcement comes less than a month after the therapy’s developers, Protalix BioTherapeutics and Chiesi Global Rare Diseases, resubmitted the BLA.
Last year, the FDA rejected the companies’ request for accelerated approval of PRX-102 citing issues with the manufacturing process and facility inspections. No concerns in terms of the therapy’s safety or effectiveness were cited by the agency.
The new prescription drug user fee act (PDUFA) action date — the date by which the FDA must announce its decision about whether to approve the PRX-102 — is set for May 9, 2023, according to a joint press release from the companies.
A similar application also is being reviewed by health authorities in Europe.
Fabry disease is caused by a deficiency in alpha-galactosidase A (Gal A), an enzyme responsible for breaking down certain fatty molecules, due to mutations in the GLA gene. Gal A deficiency leads to the toxic accumulation of such fatty molecules in cells throughout the body, causing damage to the kidneys, as well as other organs.
PRX-102, an enzyme replacement therapy (ERT), delivers a modified version of Gal A directly into patients’ bloodstream. Created with Protalix’s plant-based ProCellEx platform, the enzyme has been modified chemically to last longer in the body. That means it requires less-frequent infusions than existing ERTs.
The resubmitted BLA included a comprehensive set of manufacturing information and clinical results from studies that evaluated the therapy’s safety and effectiveness in more than 140 adults with Fabry with up to five years of follow-up.
In the Phase 3 BALANCE clinical trial (NCT02795676), two years of treatment with PRX-102 was found to be as safe and effective at preventing kidney function decline in Fabry patients as Sanofi Genzyme’s approved ERT Fabrazyme.
Findings from other completed studies included two Phase 3 trials — BRIDGE (NCT03018730) and BRIGHT (NCT03180840) — as well as a Phase 1/2 trial (NCT01678898) and its extension study (NCT01981720).
Safety data compiled from the ongoing extension studies associated with these trials (NCT03566017 and NCT03614234) also were included.
If PRX-102 earns FDA approval, Protalix will be eligible to receive a milestone payment from Chiesi, according to the press release.