Interpreting Phase 3 Efficacy Data: Seizure Reduction and Global Clinical Improvement in CDD

In rare epileptic encephalopathies such as CDKL5 deficiency disorder (CDD), even modest reductions in seizure frequency can have meaningful implications for daily functioning, caregiver burden, and overall quality of life. As newer therapies emerge, clinicians are increasingly focused not only on seizure reduction, but also on broader measures that reflect real-world clinical improvement.

As part of this Special Report, Sam Amin, MD, discusses efficacy findings from a recent phase 3 randomized, double-blind, placebo-controlled study evaluating fenfluramine in patients with CDD. Amin, a study author and pediatric neurologist with expertise in developmental and epileptic encephalopathies, contextualizes the magnitude of seizure reduction observed in the study and explains how responder analyses and global impression measures may help clinicians interpret the therapy’s broader clinical impact.

In this episode, Amin walks through the study’s primary and secondary efficacy findings, including reductions in countable motor seizure frequency, responder rates across multiple seizure reduction thresholds, and improvements observed on the Clinical Global Impression Improvement scale from both investigator and caregiver perspectives.