FDA Approves Pegunigalsidase Alfa for Adults with Fabry Disease

The US Food and Drug Administration (FDA) has approved pegunigalsidase alfa-iwxi (ELFABRIO) for the treatment of adults with Fabry disease.

The approval, granted to Chiesi Global Rare Diseases and Protalix BioTherapeutics, introduces an alternative treatment with a unique mechanism of action to an in-need rare disease patient population.

Pegunigalsidase alfa is PEGylated enzyme replacement therapy (ERT) comprised of recombinant human α‑Galactosidase‑A enzyme, expressed in plant-cell culture designed for elongated half-life—an estimated initial 78.9 ±10.3 hours.

The new agent’s approval was supported by findings from a clinical development program assessing the efficacy, safety and tolerability of pegunigalsidase alfa in >140 patients for ≤7.5 years in follow-up. Key assessments included a non-inferiority head-to-head treat showing comparable efficacy to agalsidase beta in controlled estimated glomerular filtration rate (eGFR) decline.

Pegunigalsidase alfa was also reportedly well-tolerated by treated patients; a majority of adverse events observed in clinical assessment were mild to moderate in severity. At least 15% of treated patients reported infusion-associated reactions, nasopharyngitis, headaches, diarrhea, fatigue, nausea, back pain, pain in extremity, and sinusitis.

Investigators additionally confirmed the benefit of pegunigalsidase alfa in patients both naïve and experienced with ERT regimens.

The FDA approval includes a label warning for hypersensitivity reactions including anaphylaxis risk among treated patients; investigators reported 20 (14%) treated patients in clinical trials reported hypersensitive reactions. Clinicians are advised to consider pretreatment with antihistamines, antipyretics, and/or corticosteroids prior to initiating pegunigalsidase alfa for patients with Fabry disease.

The inherited, rare Fabry disease is characterized by deficient lysosomal α‑Galactosidase‑A enzyme activity that results in continued accumulation of abnormal fatty substance deposits throughout the body. Approximately 1 in 40,000 – 60,000 patients are impacyed by the condition, with outcomes including wide ranges of pain episodes, impaired peripheral sensations, and end-organ failure.

In a statement accompanying the approval, Giacomo Chiesi, head of Chiesi Global Rare Diseases, stressed the continued need for Fabry disease treatments despite recent advances of drug classes including ERT.

“We established Chiesi Global Rare Diseases to deliver innovative therapies and solutions for people affected by rare diseases,” Chiesi said. “With the FDA approval of ELFABRIO, we can now offer people living with Fabry disease an alternative treatment option.”

Dror Bashan, Protalix president and chief executive officer, added in the statement their excitement for the FDA approval.

“The totality of clinical data suggests that ELFABRIO has the potential to be a long-lasting therapy,” Bashan said. “Together with Chiesi, we are grateful to all of the patients and investigators and their staff members who participated in our clinical trial programs and remain committed to bringing ELFABRIO to patients with Fabry disease.”