PTC Therapeutics has shared interim data from the 12-week portion of the PIVOT-HD Phase II study of PTC518 in Huntington’s disease (HD) patients.
The study demonstrated dose-dependent lowering of Huntingtin (HTT) protein levels in peripheral blood cells, reaching a mean 30% reduction in mutant HTT levels at the 10mg dose level.
In addition, PTC518 exposure in the cerebrospinal fluid (CSF) was consistent with or higher than plasma unbound drug levels.
PTC518 treatment was also demonstrated to be well tolerated, with no treatment-related serious adverse events, no reports of peripheral neuropathy or dose-limiting toxicities.
Furthermore, there were no CSF neurofilament light chain protein (NfL) treatment-related spikes, with an overall trend towards lowering of CSF NfL levels following 12 weeks of PTC518 treatment.
“We are very pleased with the encouraging data from the PIVOT-HD interim analysis demonstrating dose-dependent HTT lowering, desired CSF exposure and a favourable tolerability profile without evidence of treatment-related serious adverse events or CSF NfL spikes,” said Dr Matthew Klein, Chief Executive Officer of PTC Therapeutics.
PIVOT-HD is a global, placebo-controlled study and consists of two parts: an initial 12-week placebo-controlled phase focused on PTC518 pharmacology and pharmacodynamic effect, followed by a nine-month placebo-controlled portion. The study will initially include two dose levels, 5mg and 10mg, with the ability to include a third dose level of up to 20mg.
