Benzinga | Apr 28, 2021 05:36AM EDT

Protalix BioTherapeutics and Chiesi Global Rare Diseases Announced Complete Response Letter for Pegunigalsidase Alfa as Treatment for Fabry Disease from FDA

Protalix BioTherapeutics, Inc. (NYSE:PLX) and Chiesi Global Rare Diseases, a business unit of Chiesi Farmaceutici S.p.A., an international research-focused healthcare Group (Chiesi Group), today announced that they received a Complete Response Letter (CRL) from the U.S. Food and Drug Administration (FDA) regarding the Biologics License Application (BLA) seeking accelerated approval of pegunigalsidase alfa (PRX102) for the proposed treatment of adult patients with Fabry disease.

Protalix and Chiesi are studying the CRL to assess the most expedient regulatory approach to reach an understanding with the FDA on additional actions required to obtain approval of PRX102, and will provide an update soon.

"While disappointing, we remain confident in the strength of our data and in the depth of our program," said Dror Bashan, Protalix's President and Chief Executive Officer. "We remain committed to the program and to working with the FDA and Chiesi toward the approval of PRX102."

"Based on extensive clinical data including results from the PhaseIII BRIDGE clinical trial of PRX-102 for the proposed treatment of Fabry disease, we continue to feel strongly that PRX102 is an important option for the treatment of Fabry disease in adult patients, and we are continuing with our efforts to make this therapy available to patients," said Giacomo Chiesi, Head of Chiesi Global Rare Diseases. "We thank the patients and clinicians participating in our completed and ongoing clinical studies evaluating PRX-102. We are continuing to coordinate closely with the FDA to address and quickly resolve the deficiencies contained in the CRL."

Fabry disease is an X-linked inherited disease caused by deficient activity of the lysosomal GalactosidaseA enzyme, resulting in progressive accumulation of abnormal deposits of a fatty substance called globotriaosylceramide (Gb3) in the blood and blood vessel walls throughout the human body. Symptoms of Gb3 deposition range from episodes of pain, gastrointestinal (GI) symptoms, fatigue, angiokeratoma, and abnormal sweating to serious complications including cardiovascular, renal, and cerebrovascular events.

The PRX-102 BLA was initially submitted under the accelerated approval pathway and was granted Priority Review by the FDA. Priority Review is granted to therapies that the FDA determines have the potential to provide significant improvements in the treatment, diagnosis or prevention of serious conditions. The BLA submission for PRX102 included a comprehensive set of preclinical, clinical, and manufacturing data compiled from the completed PhaseI/II clinical trial of PRX102, including the related extension study succeeding the PhaseI/II clinical trial, interim clinical data from the Phase III BRIDGE switch-over study and safety data from Protalix's on-going clinical studies of PRX102 in patients receiving 1mg/kg every other week.

We remain committed to the Phase III clinical program which is progressing, and patients continue to receive PRX102 treatment in the ongoing BALANCE study sponsored by Protalix and various long-term extension studies