Fluoxetine in progressive multiple sclerosis: The FLUOX-PMS trial

Area of Science:

• Neuroscience
• Clinical Neurology
• Pharmacology

Background:

• Preclinical studies indicated fluoxetine possesses neuroprotective qualities potentially mitigating axonal degeneration in multiple sclerosis (MS).
• This phase 2 trial aimed to investigate if fluoxetine could impede disability accumulation in patients with progressive MS.

Discussion:

• The study design involved a double-blind, multicenter trial over 108 weeks, assessing fluoxetine's impact on primary and secondary outcomes in progressive MS.
• Despite the trial's rigorous methodology, an unexpectedly slow progression rate in the placebo group limited statistical power to detect fluoxetine's potential benefits.

Key Insights:

• Fluoxetine (40 mg/day) did not demonstrate a statistically significant effect on slowing disability progression compared to placebo in progressive MS patients.
• No significant differences were observed between fluoxetine and placebo groups for secondary outcomes, including ambulation, cognition, fatigue, and brain MRI changes.

Outlook:

• The trial did not confirm the hypothesized neuroprotective effect of fluoxetine in progressive multiple sclerosis.
• Future research may explore different dosages, patient populations, or therapeutic combinations to potentially harness fluoxetine's neuroprotective properties in MS.