Propionic Acid Trial Reports Biomarker Signal in Multiple Sclerosis

Key Takeaways

• Adjunctive propionic acid was associated with a lower serum neurofilament light readout at 90 days, including a reported 17.9% reduction.
• The finding came from a double-blind, randomized, placebo-controlled phase 2b trial in adults with clinically stable multiple sclerosis.
• The trial also included clinical, immunologic, safety, and tolerability reporting.

Adults with clinically stable multiple sclerosis who received add-on propionic acid in a phase 2b trial in Brain had a 17.9% reduction in serum neurofilament light after 90 days. The study was double-blind, randomized, and placebo-controlled, with serum neurofilament light as the prespecified endpoint. Propionic acid was evaluated as adjunctive rather than stand-alone therapy in this setting. The finding centered on biomarker change within a clinically stable cohort.

The phase 2b trial enrolled adults with clinically stable multiple sclerosis and compared adjunctive propionic acid with placebo under double-blind randomization. Serum neurofilament light was the main prespecified biomarker endpoint in the reported analysis. The add-on design remained central, without shifting focus to a primary clinical outcome. Placebo control provided a concurrent reference within the same clinically stable population, with the 90-day biomarker assessment as the main reference point.

At 90 days, the adjusted mean difference versus placebo was 0.91 pg/mL for serum neurofilament light. That value represented the between-group separation in the biomarker analysis. The percentage change highlighted in the lead was reported alongside the adjusted mean difference. Both numbers referred to serum neurofilament light rather than to a clinical efficacy endpoint. The result remained limited to the biomarker outcome. The trial also included clinical, immunologic, safety, and tolerability data.