Protalix’s Pegunigalsidase Alfa Granted FDA Fast Track Status for Fabry Disease

The U.S. Food and Drug Administration (FDA) has granted fast track designation to pegunigalsidase alfa, or PRX-102, Protalix BioTherapeutics’ therapy candidate under development for Fabry disease.

FDA’s fast track status is designed to facilitate the development and speed up FDA review of investigational drugs and vaccines for serious conditions that fill an unmet medical need, so that patients can have access to the treatments sooner.

Pegunigalsidase alfa is a genetically engineered version of  human alpha-GAL-A protein,  an enzyme that facilitates the breakage of the link between globotriaosylceramide (Gb3), a kind of fat called a glycolipid, and several substances in the body.

The absence or reduced levels of this enzyme leads to the progressive accumulation of glycolipids, especially Gb3, that normally keeps cell membranes (the outer layer of cells) stable. When there’s too much Gb3 present, it affects the function of many types of cells in the body, including cells lining the walls of small blood vessels, glomerular endothelial cells (which line the walls of the glomeruli, the parts of the kidneys responsible for producing urine), heart muscle cells, fibroblasts, and nerve cells.

Pegunigalsidase alfa is artificially produced in plant cells and is designed to replace the faulty alpha-GAL-A enzyme and restore normal function in patients with Fabry disease.

The FDA’s decision to grant fast track status resulted from promising interim results from the Phase 1/2 trial PB-102-F01 and its extension trial, PB-102-F02, two dose-ranging studies to evaluate the safety, pharmacokinetics, and efficacy parameters on patients treated with pegunigalsidase alfa administered intravenously every other week.

The results showed effectiveness in various disease parameters, including stability in kidney function, stability in cardiac function, and reduction in plasma and kidney biopsy-assessed biomarker levels.

Of the 18 patients who received the medication, 17 experienced a total of 223 adverse events, mostly mild to moderate, and two of four serious adverse events were considered likely to be due to the medication.

Pegunigalsidase alfa is now being studied globally in three Phase 3 clinical trials. The trials (NCT02795676, NCT03180840 and NCT03018730) are being conducted in 20 centers worldwide and are presently recruiting. Estimated times for top-line data releases will be announced when the enrollment for each individual trial is completed.

“We are very pleased that the FDA has recognized the potential for pegunigalsidase alfa to fill an unmet need for Fabry patients,” Moshe Manor, Protalix’s president and CEO, said in a press release.

“The data generated in our clinical trials of pegunigalsidase alfa thus far, as well as nonclinical data, as presented to the FDA with Protalix’s application for Fast Track designation, demonstrate that pegunigalsidase alfa has the potential to address an unmet medical need for Fabry patients, such as the prevention of renal failure, improved survivability and a positive impact on quality of life,” Manor said.

“We believe that Fast Track designation will help facilitate our development program for pegunigalsidase alfa and may shorten the timelines to an anticipated approval, which will greatly benefit Fabry patients,” he added.