PRX-102 Given to 1st Patient in US Under Expanded Access Program

Patricia Inácio, PhD avatar

by Patricia Inácio, PhD |

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A first patient has been treated with PRX-102 (pegunigalsidase alfa), an investigational enzyme replacement therapy for Fabry disease that is under review for approval, through an expanded access program (EAP) in the United States.

“The initiation of treatment in the first patient enrolled in our EAP is an important milestone for the Fabry disease community and another reflection of our commitment to supporting patients, caregivers and their healthcare providers as they make important decisions about their health and disease management,” Giacomo Chiesi, head of Chiesi Global Rare Diseases, which holds a license for the treatment, said in a press release.

The EAP (NCT04552691), launched in October 2020 , is open to patients who, in the opinion of their physician, have no satisfactory alternatives among therapies currently approved by the U.S. Food and Drug Administration (FDA), and/or cannot participate in other ongoing trials of potential Fabry treatments.

“Through this EAP, many patients can have access to treatment with pegunigalsidase alfa as we continue to work diligently to advance this therapy through the final stages of the regulatory review process in the months ahead. We would like to thank the Fabry patient and medical community for the support they have provided to us in the setup of this program,” Chiesi added.

Patients participating in the EAP are given PRX-102 infusions every two weeks at a dose of 1 mg/kg of body weight. Data related to adverse events (side effects) and efficacy are collected from all participants.

Additional information on Chiesi’s expanded access policy is available here. To be considered for the EAP, a patient’s physician must submit requests on their behalf through the company’s portal

Treatment began for the EAP patient at a center in Fairfax, Virgina, on Dec. 21.

PRX-102, developed by Protalix BioTherapeutics and later licensed to Chiesi Global Rare Diseases for all markets outside the U.S., is man-made version of the enzyme alpha-galactosidase A. 

Like other enzyme replacement therapies (ERTs), it replenishes the levels of alpha-galactosidase A, which is missing in patients with Fabry. This helps cells break down the fatty molecule globotriaosylceramide (Gb3), and preventing it from building in different tissues, including those of the kidneys, heart, and blood vessels in the brain.

The investigational ERT is being, or was, evaluated in three Phase 3 trials — BALANCE (NCT02795676), BRIGHT (NCT03180840), and BRIDGE  (NCT03018730) — and other related open-label studies.

BALANCE is assessing the effectiveness of PRX-102 at preventing kidney function decline in patients with Fabry who had been previously treated with Sanofi Genzyme’s approved ERT Fabrazyme (agalsidase beta).

The open-label BRIGHT trial, which was expected to conclude in December, is assessing both the safety and effectiveness of PRX-102 in patients previously treated with Fabrazyme or Replagal (agalsidase alfa), another approved ERT, developed by Shire (now owned by Takeda).

BRIDGE, an open-label switch-over study that finished in 2019, tested the safety and effectiveness of PRX-102 in adults with Fabry disease previously treated with Replagal for at least two years, and who remained on a stable dose of the medication for a minimum of six months.

The FDA is currently reviewing an application, under its accelerated approval program and priority review, seeking the approval of PRX-102 for Fabry disease. The agency has set April 27 as a deadline to announce its decision.