European Regulators Grant Orphan Drug Status to Protalix’s PRX-102 for Fabry Disease

The European Commission has granted Protalix BioTherapeutics’ experimental treatment PRX-102 (pegunigalsidase alfa) Orphan Drug Designation for the treatment of Fabry disease, the company recently announced.

The decision follows a European Medicines Agency (EMA) recommendation in November 2017, which stated the therapy may be of “significant benefit” to Fabry disease patients.

The designation is reserved for treatments of rare life-threatening or chronically debilitating diseases which lack satisfactory treatments. If such treatments do exist, the proposed therapy needs to “be of significant benefit” to qualify for the designation — as was the case with PRX-102.

Protalix will now be entitled to receive expert scientific advice on the design of clinical studies and may receive fee reductions. The designation also ensures PRX-102 will receive 10 years of marketing exclusivity in the E.U., if the treatment is approved.

“The action from the EMA on this decision mirrors our own strategy for developing PRX-102 as a potential better therapeutic alternative for people living with Fabry disease, a patient population in need of new treatment options,” Moshe Manor, Protalix’s president and CEO, said in a press release at the time of the EMA endorsement.

PRX-102 is similar to current enzyme replacement therapies for Fabry disease, made up of lab-made versions of the enzyme alpha-galactosidase-A.

Fabry disease is caused by mutations in the gene producing this enzyme — causing the buildup of a fatty substance called globotriaosylceramide in blood vessel walls throughout the body.

Compared to the available versions of the enzyme, PRX-102 is chemically modified in a way that makes it more stable and active, Protalix says.

This may reduce the need of infusions by half, from once every two weeks to one time per month. It might also be more effective, studies indicate.

The treatment is currently being evaluated in three clinical trials in Fabry disease patients. The Phase 3 BRIGHT study (NCT03180840) explores the safety, effectiveness and general properties of PRX-102, given every four weeks over a year to patients who were previously treated with approved enzyme replacement therapies.

The Phase 3 BALANCE trial (NCT02795676) recruits Fabry patients with impaired kidney function, and will also treat patients for about a year.

A final Phase 3 study (NCT03018730) is studying PRX-102 in Fabry patients who switch from Replagal (agalsidase alfa).

All three trials are currently recruiting participants. For more information, including locations and contact details, follow the links to the trials’ registration websites, provided above.