A randomised controlled trial of the monoaminergic stabiliser (-)-OSU6162 in treatment of myalgic encephalomyelitis/chronic fatigue syndrome.

Observed Findings

• Both treatment and placebo groups showed significant improvements on Mental Fatigue Scale and Clinical Global Impression of Change during the 2-week treatment period, but improvements did not persist at 6-week follow-up.
• Significant dose-response correlation was observed between (-)-OSU6162 concentration (0.1-0.7 µM) and improvement in mental fatigue, fibrofatigue, and depression scores.
• The drug showed superior efficacy to placebo specifically in ME/CFS patients who were concurrently receiving antidepressant medication.
• (-)-OSU6162 was well-tolerated with no reported safety concerns.
• Both groups showed similar improvements on secondary outcome measures (FibroFatigue scale, Beck Depression Inventory, pain scales).

Inferred Conclusions

• (-)-OSU6162 was not significantly superior to placebo when analyzed across the entire ME/CFS population.
• The drug appears to be a safe and potentially beneficial option for ME/CFS patients with comorbid depression receiving antidepressant therapy, though this finding requires validation in larger, prospective studies.
• The rapid offset of improvement after treatment cessation suggests that sustained dosing may be necessary for maintaining benefits.
• Pharmacological heterogeneity in ME/CFS populations may require stratified or personalized treatment approaches.

Remaining Questions