Chiesi Fabry Data Reveal Monitoring Gaps and New Four-Week Elfabrio Experience

Chiesi Global Rare Diseases presented 13 scientific abstracts spanning Fabry disease and alpha-mannosidosis at the SSIEM 2026 Annual Symposium in Helsinki, with additional topline findings from two Fabry disease studies provided directly to Pharmacally by the company. The findings highlight gaps in disease monitoring among untreated patients and provide early real-world experience with an extended dosing interval for pegunigalsidase alfa (Elfabrio).

Topline Findings from Two Fabry Studies

The following numerical results were provided directly to Pharmacally by Chiesi and were not detailed in the company’s public announcement. The data came from two studies presented at the meeting.

Data from the F60/BRILLIANCE trial evaluated the long-term safety and efficacy of pegunigalsidase alfa in treatment-naïve patients. Separately, real-world experience from a five-patient compassionate-use cohort suggested that an extended four-week (Q4W) dosing interval of 2 mg/kg may be feasible and well tolerated.

After 12 months, patients in the five-patient cohort had no reported infusion-related reactions or serious adverse events while receiving the extended regimen. However, the small cohort and compassionate-use setting limit the conclusions that can be drawn about the safety, feasibility, and broader applicability of the four-week dosing schedule.

Patient-Reported Gaps in Fabry Disease Care

A second study surveyed 238 adults with Fabry disease in the U.S. and Canada, including 49 participants who were not receiving treatment. Topline results shared directly with Pharmacally showed that 40% of treatment-naïve patients reported worsening or new symptoms even though their physicians considered their disease stable.

The survey also found that 76% of untreated patients reported suboptimal disease monitoring. Among treatment-naïve participants who reported inadequate monitoring, 45% identified infrequent physician visits as the primary reason. Only 12% said they were very likely to tell their physician about worsening symptoms, while 68% said they would consider treatment if recommended by their physician.

The findings point to a potential gap between how disease stability is assessed clinically and how patients experience their symptoms. Because the survey was cross-sectional and relied on patient-reported information, it cannot establish whether inadequate monitoring caused delays in treatment or changes in disease outcomes.

Broader SSIEM Research

The 13 abstracts covered Fabry disease and alpha-mannosidosis, with six Chiesi-led presentations and seven independent studies supported through scientific research grants and educational projects. The research addressed disease burden, diagnosis, biomarkers, disease biology and real-world clinical experience.

Fabry disease is caused by mutations in the GLA gene that reduce alpha-galactosidase A activity, leading to accumulation of disease-associated substrates and progressive organ involvement. The condition can affect the kidneys, heart, nervous system and other tissues.

Alpha-mannosidosis results from mutations in MAN2B1, which cause deficient alpha-mannosidase activity and accumulation of oligosaccharides. The disease can involve the skeletal, auditory, immune and nervous systems.

Implications for Rare Disease Management

Chiesi executives emphasized the value of combining long-term clinical data, real-world experience and patient-reported outcomes to better understand disease progression and unmet needs. The company also highlighted Find For Rare, an independently assessed research grant initiative supporting research in lysosomal storage disorders.

The SSIEM findings do not establish a new treatment standard for Fabry disease. However, the company-provided topline results add clinically relevant detail to the public presentation announcement, particularly around patient monitoring and treatment experience. Together, the data underscore the challenges of recognizing disease progression and optimizing long-term management in patients living with rare lysosomal storage disorders.

Reference

Chiesi Global Rare Diseases Demonstrates Its Ongoing Commitment to the Rare Disease Community at the Society of Inborn Errors of Metabolism (SSIEM) 2026 Annual Symposium