Predicting success: optimizing phase II ALS trials for the transition to phase III

Area of Science:

• Neurology
• Clinical Trials
• Pharmacology

Background:

• Amyotrophic Lateral Sclerosis (ALS) research faces significant hurdles in translating phase II trial findings to phase III success.
• Phase II ALS trials are challenged by small patient numbers and outcome measures similar to phase III, complicating safety, dosage, and efficacy assessments.

Purpose of the Study:

• To identify key challenges in phase II trials for Amyotrophic Lateral Sclerosis (ALS).
• To propose improvements for designing more effective phase II clinical trials in ALS research.

Main Methods:

• Analysis of pharmacokinetic data in cerebrospinal fluid (CSF) to assess drug concentration and target engagement.
• Evaluation of pharmacodynamic markers to confirm biological activity.
• Review of outcome measure specification and goal achievement in ALS trials.

Main Results:

• Phase II ALS trials often lack specified primary outcome measures or fail to meet significance goals.
• Pharmacokinetic and pharmacodynamic markers are crucial for demonstrating target engagement but are not consistently utilized.

Conclusions:

• Future phase II ALS trials should integrate pharmacokinetic (ideally in CSF) and pharmacodynamic markers for target engagement.
• Pre-specification of primary endpoints and the use of stringent inclusion criteria to reduce heterogeneity are recommended.
• Conducting multiple phase II trials may be necessary before initiating large-scale phase III studies in ALS.