The decision represents a major advance for OPMD, a rare congenital myopathy, for which the currently used therapeutic strategies involve repetitive surgical interventions that have limited effectiveness.
Orphan Drug status means Benitec will now receive protocol assistance, access to the EU’s centralized authorization procedure with a single application, and incentives such as administrative and procedural assistance and fee reductions, and market exclusivity for 10 years after approval.
“This is a key program in our pipeline and we are happy to see the [European Medicines Agency] recognizing the urgent and unmet medical need for a safe and effective treatment for OPMD patients,” David Suhy, Benitec’s chief scientific officer, said in a press release.
“We believe that our innovative approach may offer new treatment options for patients who might not otherwise be able to receive benefit in treating their disease. Having European Orphan Drug Designation will allow us to optimize steps to further advance BB-301 towards regulatory approval,” he said.
Oculopharyngeal MD is a genetic condition that’s characterized by muscle weakness in multiple parts of the body and is typically not diagnosed until patients older than 50. Symptoms include droopy eyelids (ptosis), difficulty swallowing (dysphagia), weakness in the legs and arms, and altered and weak voice.
The swallowing difficulties begin with food, but as the condition progresses, liquids can be difficult to swallow as well, and patients can become malnourished, lose significant weight, become dehydrated and suffer from repeated episodes of aspiration pneumonia, which may result in death.
BB-301 used DNA-directed RNA interference (ddRNAi), Benitec’s unique platform for silencing unwanted genes. The treatment is comprised of a single expression construct for the “knockdown and replace strategy” of mutant PABPN1, the principle cellular component behind OPMD.
BB-301 is currently being evaluated in preclinical studies, but Benitec is planning to begin investigational new drug (IND)-enabling studies in humans later this year. The company is expecting to start clinical trials of BB-301 in OPMD patients in 2018, subject to toxicity results and future review by regulatory agencies.