The European Medicines Agency’s Committee for Medicinal Product for Human Use has issued a positive opinion recommending approval of a 2 mg/kg every four weeks dosing regimen of pegunigalsidase alfa for adult patients with Fabry disease who are stable on enzyme replacement therapy.

If approved by the European Commission, the extended dosing schedule would reduce the treatment burden for eligible adult patients, their families and healthcare systems, compared with the current requirement for infusions every two weeks delivered either at infusion centres or at home.

Pegunigalsidase alfa is jointly developed by Chiesi Global Rare Diseases and Protalix BioTherapeutics. The CHMP opinion follows a re-examination of the application for the additional dosing regimen and represents a regulatory step towards offering greater flexibility in long-term Fabry disease management.

Giacomo Chiesi, executive vice president at Chiesi Global Rare Diseases, said: “It is our privilege to provide the adult Fabry community with an alternative dosing option, and we are pleased that the CHMP positive opinion supporting a 2 mg/kg body weight every four weeks dosing regimen for pegunigalsidase alfa brings us one step forward to reducing the treatment burden in this condition.”

He added that the company’s focus is on aligning treatment approaches with real-world needs, noting: “By extending the time between infusions, our aim is that people living with this condition can focus on what truly matters, living their lives.”

Protalix highlighted the regulatory opinion as an important milestone for its Fabry disease programme and manufacturing platform. Dror Bashan, president and chief executive officer of Protalix, said: “The CHMP’s positive opinion is another testament to Protalix’s commitment to advancing treatments for people living with Fabry disease.”

He added: “The CHMP’s positive opinion is a significant validation of Protalix’s proprietary manufacturing platform, built on years of rigorous research and clinical progress.”

Patient groups also welcomed the recommendation, pointing to the potential impact of fewer infusions on daily life. Mary Pavlou, president of the Fabry International Network, said: “The CHMP positive opinion on the every four weeks regimen recognises the importance of reducing treatment burden for people living with Fabry and their families.”

She added: “Extending infusion intervals allows therapy to better fit into everyday life, supporting work, study, and family commitments.”

The CHMP opinion is informed by data from the open-label switch-over study Bright, previously known as PB-102-F50. The trial evaluated safety, efficacy and pharmacokinetics of pegunigalsidase alfa administered at 2 mg/kg every four weeks over 52 weeks. Additional supporting data were generated from an ongoing open-label extension study, CLI-06657AA1-03, formerly PB-102-F51.

Fabry disease is a rare inherited lysosomal storage disorder caused by mutations in the GLA gene, resulting in deficient activity of the enzyme alpha-galactosidase A. This leads to the accumulation of globotriaosylceramide in cells throughout the body, affecting organs including the heart, kidneys and nervous system. Symptoms can include chronic pain, fatigue, gastrointestinal problems, renal impairment, cardiac complications and increased risk of stroke.

The condition affects both males and females and may present at any age, often with delayed or missed diagnosis. Enzyme replacement therapy remains a key treatment option to slow disease progression and manage symptoms.

Under the terms of the agreement between the two companies, Protalix will be eligible to receive a $25 million regulatory milestone payment from Chiesi if the every four weeks dosing regimen is approved by the European Commission.