Benitec Biopharma has submitted an application for orphan drug designation with the U.S. Food and Drug Administration (FDA) for its lead gene therapy candidate, BB-301, for the treatment of oculopharyngeal muscular dystrophy (OPMD).
If granted, the orphan drug status will guarantee seven-year market exclusivity upon treatment approval, but it also will provide Benitec assistance in regulatory proceedings, tax credits, and exemption of FDA’s product registration fees.
“This submission follows on from receiving earlier this year orphan designation from the European Medicines Agency and is an exciting first step in our effort to secure orphan status for BB-301 in the U.S. where we believe BB-301 has the potential to be a valuable asset in the treatment of OPMD,” Greg West, CEO of Benitec, said in a press release.
The company also has completed pre-investigational new drug application (pre-IND) meetings with the FDA, Health Canada, and several European agencies. This followed several scientific advice meetings with the regulatory agencies to ensure the proposed clinical development program for BB-301 satisfied all the necessary requirements. Benitec expects to submit an IND application with the FDA during the fourth quarter of 2018.
“The Benitec team is executing on the key initiatives required to advance BB-301 into human clinical trials.” West said. “Our meetings with the FDA and other regulatory agencies were very productive and their guidance will be most valuable in assessing the appropriate clinical and regulatory strategies for BB-301.”
“Assuming approval on a normal time-frame, we should be in an initial human clinical study by the end of 2018,” he stated.
OPMD is a genetic disease caused by mutations on the PABPN1 gene, which leads to the production of a faulty protein that can form insoluble aggregates. This disease is characterized by muscle weakness, with patients commonly presenting drooping eyelids, difficulty standing upright, and difficulty swallowing.
Benitec has developed a gene therapy that was designed to correct the PABPN1 gene defect associated to OPMD. BB-301 is intended to destroy the expression of the mutated PABPN1 gene, and at the same time drive the expression of the normal version of the gene.
Preclinical results have showed that BB-301 can effectively reduce the expression of the faulty version of PABPN1 protein and prevent the formation of protein aggregates. This strategy significantly improved the expression of the correct version of the protein in mice.
In addition, administration of BB-301 was shown to significantly improve muscle weight and strength in an OPMD mice model.
These results were presented during the 22nd International Annual Congress of the World Muscle Society, in France, in a presentation titled “Gene therapy for Oculopharyngeal Muscular Dystrophy.”