Phase III BRIDGE trial of PRX 102 met main objectives for safety and efficacy in Fabry disease.- Protalix BioTherapeutics

Protalix BioTherapeutics announced positive topline results from its Phase III BRIDGE clinical trial of PRX 102 (pegunigalsidase alfa), the Company’s plant cell-expressed recombinant, PEGylated, cross-linked alpha-galactosidase-A product candidate under development for the treatment of Fabry disease. The BRIDGE study was a Phase III 12 month open-label, single arm switch-over study evaluating the safety and efficacy of pegunigalsidase alfa, 1 mg/kg infused every two weeks, in up to 22 Fabry patients previously treated with agalsidase alfa, marketed by Takeda Pharmaceutical Company Limited (Shire Plc) as Replagal, for at least two years and on a stable dose for at least six months.

Topline results of the data generated in the study showed substantial improvement in renal function as measured by mean annualized estimated Glomerular Filtration Rate (eGFR slope) in both male and female patients who were switched from agalsidase alfa to PRX-102. Consistent with previously announced interim data, PRX-102 was found to be well tolerated, with all adverse events being transient in nature without sequelae.

Twenty-two patients were enrolled in the study; two of those patients withdrew early from the study due to hypersensitivity reaction, and 20 of the patients successfully completed the 12-month treatment duration. Eighteen of the patients who completed the study opted to roll over to a long-term extension study and continue to be treated with PRX-102. In the study, the mean annualized eGFR slope of the study participants improved from -5.90 mL/min/1.73m2/year while on agalsidase alfa to -1.19 mL/min/1.73m2/year on PRX-102 in all patients. Male patients improved from -6.36 mL/min/1.73m2/year to -1.73 mL/min/1.73m2/year and female patients improved from -5.03 mL/min/1.73m2/year to -0.21 mL/min/1.73m2/year. Baseline characteristics of the patients, ranging from ages 24 to 60 years, were as follows: mean eGFR 75.87 mL/min/1.73m2 in males and 86.14 mL/min/1.73m2 in females and plasma lyso-Gb3 mean levels were 51.81 nM and 13.81 nM in males and females, respectively. While lyso-Gb3 levels remain slightly high, particularly within the male cohort, continuous reduction in lyso-Gb3 levels was observed of 19.55nM (32.35%) in males and 4.57nM (29.81%) in females.