Protalix, Chiesi’s monthly treatment PRX-102 shows benefit in Fabry disease

Protalix Biotherapeutics and Chiesi Global Rare Diseases’s monthly treatment PRX-102 has demonstrated positive top-line results in a phase 3 trial evaluating the therapy in Fabry disease.

Fabry disease is a rare inherited disorder. Patients inherit a deficiency of the α–Galactosidase–A enzyme that results in the breakdown of Gb3.

The abnormal storage of Gb3 increases over time and this leads to an accumulation of the enzyme, mainly in the blood and in the blood vessel walls.

The consequences of this build-up can range from episodes of pain and impaired peripheral sensation to end-organ failure, particularly in the kidneys but also of the heart and the cerebrovascular system.

The phase 3 BRIGHT study of PRX-102 (pegunigalsidase alfa) in Fabry disease evaluated the investigational treatment every four weeks in 30 adult patients previously treated with an enzyme replacement therapy – Takeda’s Replagal (agalsidase alfa) or Sanofi Genzyme’s Fabrazyme (agalsidase beta) – for at least three years and on a stable dose administered every two weeks.

The topline results from this study show that PRX-102, administered every four weeks by intravenous infusion, was well tolerated, with stable clinical presentation maintained in patients.

No new patients developed treatment-induced anti-drug antibodies following the switch from their original treatment to PRX-102.

"Of the 30 patients enrolled, 20 patients remained negative for anti-drug antibodies throughout the course of treatment. Of the ten patients who were initially positive for anti-drug antibodies, four became negative for neutralising antibodies at 12 months, suggesting tolerisation by these patients," said Einat Brill Almon, senior vice president and chief development officer, Protalix.

"We find this immunogenicity data very encouraging and supportive to the positive benefit-risk profile of PRX–102,” he added.

PRX-102 is a chemically modified version of the recombinant α–Galactosidase–A enzyme, the enzyme that is deficient in patients with Fabry disease.

Earlier this month, Protalix and Chiesi announced final results from another phase 3 study of PRX-102 – the BRIDGE trial – where the treatment demonstrated a potential benefit for kidney function in Fabry disease patients.

"On behalf of our team at Chiesi, we are grateful to the patients, families, and investigators for their time and participation in this study," said Giacomo Chiesi, head of Chiesi Global Rare Diseases.

"Their dedication has helped move this phase 3 program forward and this topline data is another important milestone in our collected effort to make PRX–102 available to Fabry patients in need as rapidly as possible,” he added.

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