se — particularly in men, further supporting the therapy’s potential to lessen disease burden.
The most common moderate adverse events reported with PRX-102 included common cold, headache, and shortness of breath. Four patients (20%) developed persistent antibodies against the delivered Gal A enzyme, which were found to suppress its activity in two of these individuals, rendering the treatment less effective.
The ongoing BALANCE trial is assessing whether PRX-102 works better than Fabrazyme at preventing kidney function decline in 78 adults who were previously treated with Fabrazyme for a year. Fabrazyme was the first ERT approved for Fabry in several countries, including the U.S. and some European nations.
Participants were randomly assigned to either continue on the approved therapy or to switch to PXR-102 (1 mg/kg), both administered twice a month for up to two years.
Interim data showed that PRX-102 was at least as effective as Fabrazyme at slowing kidney disease progression among participants who had completed a minimum of one year of treatment. BALANCE is set to end in May 2022, and final data are expected by June 2022.
In the completed switch-over BRIGHT study (NCT03180840), 30 adults who had been stable on Fabrazyme or Replagal for at least three years were switched to 2 mg/kg of PRX-102, given every four weeks, for up to one year.
Top-line data showed that PRX-102’s once-a-month regimen was well-tolerated and effectively maintained lyso-Gb3 levels, kidney function, and quality of life throughout the study. In addition, 75% of patients reported a reduction or stabilization in pain severity.
Notably, 10 patients (33.3%) were positive for anti-Gal A antibodies at the study’s start, and four of them became negative for such antibodies after switching to PRX-102. No other participant developed antibodies against delivered Gal A after one year of PRX-102 treatment, further supporting the therapy’s favorable safety profile.
Protalix also is sponsoring two open-label extension studies to assess the long-term safety and effectiveness of PRX-102 given with the every-other-week regimen (NCT03566017) and the once-a-month regimen (NCT03614234) in patients who complete PRX-102 trials.
A total of 18 BRIDGE participants and 29 BRIGHT patients entered those extension studies. Patients completing the BALANCE trial also are expected to join. Participants will be followed for up to three or four years or until the therapy becomes commercially available, whichever occurs first. |
