Benzinga | Aug 11, 2020 07:03AM EDT

Fulcrum Therapeutics Announces Interim Analysis Data From Its ReDUX4 Trial In Facioscapulohumeral Muscular Dystrophy

Reduction in DUX4-driven gene expression observed in biopsies with highest baseline levels of DUX4-driven gene expression

Topline data on-track for Q1 2021 with full data in Q2 2021

Company to review clinical data on second quarter earnings call today at 8:00am ET

CAMBRIDGE, Mass., Aug. 11, 2020 (GLOBE NEWSWIRE) -- Fulcrum Therapeutics, Inc.(NASDAQ:FULC), a clinical-stage biopharmaceutical company focused on improving the lives of patients with genetically defined rare diseases, today announced results from a pre-specified interim analysis of the primary endpoint of the Phase 2 ReDUX4 trial in subjects with facioscapulohumeral muscular dystrophy (FSHD). The primary endpoint is the reduction from baseline of DUX4-driven gene expression in affected skeletal muscle after subjects have been treated with losmapimod or placebo. Secondary and exploratory endpoints were not assessed as part of this analysis. Results from the interim analysis in the first 29 randomized subjects indicate that DUX4-driven gene expression did not show a separation from placebo at 16 weeks. However, in a pre-specified sensitivity analysis, those with the highest pre-treatment DUX4-driven gene expression in their muscle biopsy sample showed a 38-fold reduction in DUX4-driven gene expression following treatment with losmapimod compared to a 5.4 fold reduction with placebo.

FSHD is a rare, progressive and disabling disease for which there are no approved treatments. FSHD is caused by aberrant expression ofDUX4in skeletal muscle, resulting in the inappropriate presence of the DUX4 protein, which causes the death of muscle and its replacement by fat. In preparatory studies, the range of DUX4 expression levels within affected muscles throughout a patient's body have been shown to be relatively stable over time at the site of a muscle biopsy.

"Preliminary evidence from our interim analysis suggests that muscleswith higher DUX4-driven gene expression in pre-treatment biopsiesshowgreater reductionof DUX4-driven gene expression following treatment withlosmapimodcompared to placebo. These results, which provide evidence of the ability of losmapimod to reduce DUX4-driven gene expression, are very encouraging," said Robert J. Gould, Ph.D., president and chief executive officer. "This initial data represents the first time a treatment is being evaluated to impact the root cause of FSHD in a placebo-controlled trial and are helping to inform our longer-term clinical strategy for losmapimod. We look forward to further leveraging the open label study to evaluate the long-term effects of losmapimod in additional FSHD subjects. We remain on track to share topline results on the primary endpoint in the first quarter of 2021 and full data, including all secondary and exploratory endpoints, in the second quarter of 2021."