Statistical Considerations for an Adaptive Design for a Serious Rare Disease

Area of Science:

• Neurology
• Clinical Trials
• Immunology

Background:

• Neuromyelitis optica spectrum disorder (NMOSD) is a rare, debilitating autoimmune disease affecting the central nervous system.
• Clinical trials for NMOSD face significant design and statistical hurdles in accurately assessing treatment efficacy and patient risk.

Purpose of the Study:

• To evaluate the efficacy and safety of MEDI-551, an anti-CD19 B-cell depleting monoclonal antibody, in patients diagnosed with NMOSD.
• To implement novel statistical methodologies within a clinical trial setting for NMOSD research.

Main Methods:

• The N-MOmentum trial randomized patients with NMOSD to receive MEDI-551 or placebo in a 3:1 ratio for up to 197 days.
• Key design features include investigator-assessed NMOSD attacks confirmed by an independent adjudication committee, with time to first relapse as the primary endpoint.
• Interim analyses for sample size re-estimation and futility, alongside novel multiplicity adjustment methods and inter/intrarater reliability assessments, were incorporated.

Main Results:

• The study design aims to minimize placebo exposure for individual participants.
• Novel statistical approaches were applied to maintain scientific rigor while prioritizing patient safety.

Conclusions:

• The N-MOmentum trial introduces innovative statistical methods to the field of NMOSD research.
• These methods seek to optimize the balance between minimizing patient risk and ensuring the scientific validity of the study findings.