The BALANCE trial (NCT02795676) estimated enrolling 78 Fabry disease patients with impaired renal function who had been previously treated with Sanofi Genzyme’s Fabrazyme for about one year and were on a stable therapy dose for at least six months before entering the trial, which is taking place across 49 clinical sites worldwide.
BALANCE is designed to evaluate PRX-102’s safety and tolerability as well as its potential to prevent renal function decline, compared with Fabrazyme in Fabry patients from 18 to 60 years old.
Researchers will also assess changes in cardiac function, pain, and quality of life, among other clinical and biochemical parameters.
“We are excited to complete enrollment in our third Phase III study of PRX‑102 for the treatment of Fabry disease. This achievement marks a major milestone in our development of PRX‑102,” Dror Bashan, president and CEO of Protalix BioTherapeutics (which is developing the therapy along with Chiesi Farmaceutici), said in a news release.
“We are most grateful to the BALANCE study participants and to our investigators for their support and dedication, and we remain committed to bringing the Fabry community a potentially better treatment option,” he added.
PRX-102 is an investigational enzyme replacement therapy (ERT) that is being developed to compensate for the lack of alpha-galactosidase A (αGAL-A) enzyme in Fabry patients. The ERT was developed from Protalix’s plant-based ProCellEx platform that uses plant cells to produce therapeutic proteins, rather than the commonly used mammalian cells which can pose safety issues.
BALANCE is one of three Phase 3 studies that are currently exploring the safety and efficacy of PRX-102. The ongoing Phase 3 BRIDGE (NCT03018730) and BRIGHT (NCT03180840) studies are also fully enrolled.
The companies announced in June 2019 that they were preparing to submit a biologics license application for PRX-102 to the U.S. Food and Drug Administration.
The application — which is expected to be submitted in the first quarter of 2020 — will be based on available data from Phase 1/2 clinical trials of PRX-102 and from the BRIDGE study.
“We believe our three, now fully enrolled, studies represent a robust clinical program for Fabry disease, and we look forward to reporting on the results upon completion of the studies,” Bashan said.
Data from the BRIGHT trial have also demonstrated that the investigational therapy was able to achieve a sevenfold increase in blood concentrations within 28 days after administration compared with Fabrazyme.
“The progressive loss of kidney function seen in Fabry patients may be the result of insufficient enzyme coverage combined with the presence of neutralizing antibodies,” said David G. Warnock, MD, professor of medicine at the University of Alabama at Birmingham.
“Given the favorable half-life of PRX-102 and its low level of inhibition by pre-existing neutralizing antibodies, there is potential for PRX-102 to attenuate and/or stabilize renal function in patients who continue to lose renal function while on currently-available enzyme replacement therapy,” he said.