Chiesi and Protalix Launch Expanded Access Program for Experimental Fabry Disease Therapy

Rare Daily Staff

Chiesi Global Rare Diseases and Protalix BioTherapeutics announced the launch of an expanded access program in the United States for pegunigalsidase alfa for its experimental treatment of Fabry disease.

A biologics license application for pegunigalsidase alfa is currently under review by the U.S. Food and Drug Administration. The expanded access program will run concurrently with Protalix’s ongoing phase 3 clinical program.

“The launch of this expanded access program for pegunigalsidase alfa is another example of Chiesi’s and Protalix’s shared commitment to support patients whose condition cannot be adequately treated by currently available FDA-approved therapies for Fabry disease,” said Marcel van Kuijck, global head of medical affairs at Chiesi Global Rare Diseases.

Fabry disease is a rare X-linked inherited disease that results from deficient activity of the lysosomal α–Galactosidase–A enzyme resulting in progressive accumulation of abnormal deposits of the fatty substance globotriaosylceramide (Gb3) in blood vessel walls throughout the body. Fabry patients inherit a deficiency of the α–Galactosidase–A enzyme, which is normally responsible for the breakdown of Gb3. The ultimate consequences of Gb3 deposition range from episodes of pain and impaired peripheral sensation to end-organ failure–particularly of the kidneys, but also of the heart and the cerebrovascular system.

Pegunigalsidase alfa is an experimental, plant cell culture-expressed, and chemically modified stabilized version of the recombinant α-Galactosidase-A enzyme. Protein sub-units are covalently bound via chemical cross-linking using short PEG moieties. It is being developed through a collaboration between Chiesi Global Rare Diseases, a unit of Chiesi Group, and Protalix BioTherapeutics.

The expanded access program is open to patients with a clinical diagnosis of Fabry disease who, in the opinion of the treating physician, have no comparable or satisfactory alternative treatment options with currently available FDA-approved therapies for Fabry disease. Other eligibility criteria apply. Patients participating in the expanded access program will receive infusions of pegunigalsidase alfa every two weeks at 1mg/kg body weight. Information related to adverse events and other limited data will be collected from participants.

“As the number of people diagnosed with Fabry disease continues to exceed predictions, access to treatment through expanded access program can play an important role in helping as many eligible patients as possible access the treatment they need,” said Jerry Walter, founder and president of the National Fabry Disease Foundation.

In August 2020, the FDA accepted the pegunigalsidase alfa BLA and granted it Priority Review for the proposed treatment of adult patients with Fabry disease. Concurrently with the EAP, pegunigalsidase alfa is being evaluated by Protalix BioTherapeutics in patients with Fabry disease under an open Investigational New Drug application in the Phase III BALANCE, BRIGHT and BRIDGE clinical trials and other related open label studies.

The companies note that when seeking expanded access, treating physicians should consider all possible risks of treatment with pegunigalsidase alfa. Access must be compliant with all applicable federal and state laws and regulations. Investigators should not seek reimbursement for product provided to patients who participate in a government-funded insurance program.

Photo: Marcel van Kuijck, global head of medical affairs at Chiesi Global Rare Diseases