Goyal, Namita A

Background: Losmapimod is an orally administered small molecule and selective p38α/β mitogen-activated protein kinase (MAPK) inhibitor able to reduce aberrant expression of DUX4 in vitro and thereby potentially slowing disease progression in patients with facioscapulohumeral muscular dystrophy (FSHD). Objective: This global, randomized, placebo-controlled, double-blind phase 3 study in patients with FSHD1 and FSHD2 examined the efficacy and safety of losmapimod over a 48-week treatment period compared to placebo (NCT05397470, EUDRACT 2022-000389-16). Methods: The primary endpoint was change in quantification of reachable workspace (RWS) expressed as relative surface area (RSA). Other endpoints included measures of muscle composition (fat content and lean muscle) using magnetic resonance imaging (MRI), muscle strength using quantitative dynamometry, and quality of life measures. Results: 130 participants received losmapimod and 130 participants received placebo, with 252 participants completing the 48-week treatment period. There were no statistically significant differences between groups in change in RSA and all secondary efficacy endpoints from baseline to Week 48. Losmapimod treatment was well-tolerated, and most adverse events were mild. Conclusions: Losmapimod was generally well tolerated with a favorable safety profile at a dose of 15 mg twice daily. Although none of the efficacy endpoints were met, study design and data from the study may inform future studies of FSHD therapies.

Background/Objectives: Overall survival in patients with amyotrophic lateral sclerosis (ALS) is linked to the rate of predicted respiratory vital capacity (PVC) loss. The objective of this study was to test whether changes in quantitative PVC measures over time linked to survival would define an immunopathogenic subset of ALS responsive to NP001, a regulator of innate immunity. Methods: In a retrospective study, data from intent-to-treat (ITT) population of two phase 2 trials of NP001 were evaluated for over time changes in PVC, time-to-event (TTE) loss of 15% PVC and PVC change from baseline, as linked to survival outcomes in patients treated with NP001 vs placebo. Results: Treatment with NP001 was associated with a significantly lower risk compared to placebo in the loss of 15% PVC over six months (p = 0.01; HR = 0.60, 95% CI: 0.39, 0.90). Data from the two trials were subsequently divided by a disease progression rate (DPR) value of 0.50 units of ALSFRS-R score lost per month for analysis of slow vs. rapid disease. In ALS patients with slowly progressive disease (DPR < 0.50), TTE PVC changes from baseline were slowed (p < 0.0005) and overall survival extended significantly (18.5 months) in NP001-treated vs. placebo groups. The rapidly progressive ALS patients (DPR ≥ 0.50) treated with NP001 showed no significant difference in PVC change or survival from the placebo group. Conclusions: These hypothesis-generating observations suggest that inflammation might play a significant role in the loss of respiratory function in a major subset of ALS patients.