Recent findings from a post-hoc analysis of the ROCK-ALS trial suggest that fasudil for ALS could potentially attenuate the spread of lower motor neuron involvement. Researchers investigated the safety and efficacy of this Rho kinase inhibitor in a multicenter, placebo-controlled phase 2 trial. Specifically, the study focused on how fasudil affects the progressive spread of muscle weakness, a hallmark of amyotrophic lateral sclerosis (ALS). By utilizing the Motor Unit Number Index (MUNIX), the team quantified lower motor neuron integrity across multiple body regions over a 180-day period.

The analysis included 118 participants from the intention-to-treat population. Among these, 78 individuals provided complete MUNIX datasets at baseline. Investigators measured MUNIX in ten different muscles at four distinct time points. They also evaluated baseline serum biomarkers, including neurofilament light chain (NfL) and glial fibrillary acidic protein (GFAP), to explore prognostic relationships. Consequently, the data revealed that baseline MUNIX-10 sum scores significantly correlated with subsequent declines in the ALS Functional Rating Scale-Revised (ALSFRS-R).

Clinical Efficacy of Fasudil for ALS

The post-hoc results demonstrated that fasudil significantly reduced the number of newly affected muscles by day 90. This reduction occurred in a dose-dependent manner across various MUNIX decline thresholds, including 10%, 20%, and 30%. Furthermore, these findings highlight MUNIX as a highly sensitive biomarker for monitoring disease spreading in clinical settings. Although the primary trial focused on safety, this exploratory objective provides evidence that Rho kinase inhibition may modify the disease course by slowing motor neuron degeneration.

Moreover, the correlation between electrophysiological measures and clinical progression suggests that quantitative biomarkers can improve prognostic accuracy. While standard measures like slow vital capacity remain essential, MUNIX offers a more localized view of disease activity. Ultimately, these results support further investigation of fasudil in larger, long-term clinical trials to confirm its potential as a disease-modifying therapy for ALS patients.

Frequently Asked Questions

What is the MUNIX biomarker in ALS?

MUNIX stands for Motor Unit Number Index. It is a quantitative electrophysiological tool used to estimate the number of functioning motor units in a muscle, serving as a marker for lower motor neuron integrity.

How does fasudil work for ALS?

Fasudil is a Rho kinase (ROCK) inhibitor. It is thought to improve neuronal survival, promote axonal regeneration, and modulate neuroinflammation, which are all critical factors in slowing ALS progression.

What did the ROCK-ALS post-hoc analysis conclude?

The analysis concluded that fasudil significantly reduced the spread of muscle weakness to new body regions by day 90 and confirmed that MUNIX is an effective biomarker for tracking this progression.

Disclaimer: This content is for informational and educational purposes only. It does not constitute medical advice or establish a doctor-patient relationship. Healthcare professionals should exercise their clinical judgment when applying this information. Refer to the latest local and national guidelines for clinical practice.

References

Wolff AW et al. Effects of fasudil on disease spreading in ALS - A MUNIX-based post-hoc analysis of the ROCK-ALS trial. Neurotherapeutics. 2026 Jun 03. doi: undefined. PMID: 42235092.

Koch JC, et al. Safety, tolerability, and efficacy of fasudil in amyotrophic lateral sclerosis (ROCK-ALS): a phase 2, randomised, double-blind, placebo-controlled trial. Lancet Neurol. 2024;23(11):1133-1146.

ClinicalTrials.gov. Inhibition of Rho Kinase (ROCK) With Fasudil as Disease-modifying Treatment for ALS (ROCK-ALS). NCT03792490.