PRIME provides a pathway for expedited assessment and review by the EMA, potentially enabling the drug to reach patients sooner.
“We are very pleased that the European Medicines Agency has granted PRIME designation for RG6042, as there is an urgent medical need to find treatment options for families affected by Huntington’s disease,” Sandra Horning, MD, chief medical officer and head of global product development at Roche, said in a press release.
RG6042, formerly known as IONIS-HTTRx, is an antisense oligonucleotide (ASO) treatment. It is designed to target and destroy all forms of mutant huntingtin protein (mHTT), the underlying cause of Huntington’s disease.
RG6042 is the most advanced compound in clinical development to target toxic mHTT, and has the potential to slow or stop the progression of Huntington’s disease in all patients. PRIME status is granted to therapies that may offer a major advantage over existing treatments, or benefit patients who have been without treatment options.
The designation was primarily based on data collected from 46 adults with early-stage Huntington’s disease who received the investigational therapy in an exploratory Phase 1/2 trial (NCT02519036).
The study showed that those who received either the highest or second-highest dose of the treatment for three months showed an average reduction of 40% in mHTT levels in their cerebral spinal fluid. Some patients had reductions as high as 60%. The levels of mutated protein were still declining in about 70% of patients as of the last measurement in the study.
RG6042 was found to be safe and well-tolerated. Mild adverse effects reported were found to be unrelated to the treatment.
The company is launching an open-label extension study (NCT03342053) for the patients who completed the Phase 1/2 trial. The new trial will assess the long-term safety and effectiveness of the investigational treatment.
“Preliminary data on RG6042 were the first to show that levels of toxic mutant huntingtin protein can be lowered in adults with Huntington’s disease,” Horning said. “We are working closely with the EMA and other health authorities to initiate a global Phase 3 study as soon as possible.”
The Phase 3 study is expected to include a larger patient population to further characterize RG6042 and evaluate its potential to slow the progression of Huntington’s disease.