PTC Therapeutics, Inc. shared interim results from the Phase 2 PIVOT-HD study of PTC518 in Huntington's disease (HD) patients. At Month 12, PTC518 treatment resulted in dose-dependent lowering of mutant huntingtin (mHTT) protein in the blood and cerebrospinal fluid (CSF) in the interim cohort of patients. In addition, favorable trends were demonstrated on several relevant HD clinical assessments including Total Motor Score (TMS) and Composite Unified Huntington's Disease Rating Scale (cUHDRS).

In addition, at Month 12, PTC18 treatment resulted in a notable slowing in progression of motor symptoms as assessed by the TMS (2.0 points worsening for 5mg and 1.3 points worsening for 10mg vs. 4.9 points worsening for placebo). In addition, PTC announced that the FDA has lifted the partial clinical hold on the program based on review of the PIVOT-HD data.