Fulcrum Therapeutics has entered an exclusive global licence agreement with GlaxoSmithKline (GSK) for rights to investigational drug losmapimod.

The agreement includes all development and commercialisation rights, along with existing drug substance and materials for use in clinical trials.

The deal provides a right of reference to investigational new drug (IND) applications filed in the US and an exclusive licence to all associated patents and data.

Developed by GSK, losmapimod is a selective inhibitor of p38α/β mitogen-activated protein kinase (MAPK). The compound has previously been assessed for a wide variety of indications, but never for muscular dystrophies.

In GSK’s studies, the compound was found to be generally well-tolerated.

“The agreement shows confidence in our unique approach to rebalancing gene expression in severe genetically defined disorders.”

Fulcrum Therapeutics intends to evaluate the drug candidate as a potential treatment for facioscapulohumeral muscular dystrophy (FSHD), a progressive and degenerative disease that is caused by a mutation in the DUX4. This leads to the generation of a protein that is toxic to muscle tissue.

Fulcrum Therapeutics identified that losmapimod could act as a potent regulator of DUX4 gene expression.

Preclinical testing by Fulcrum using patient-derived cell models demonstrated potent downregulation of DUX4 expression and restoration of a healthy muscle phenotype without impacting myogenesis.

The company is planning to launch a Phase IIb clinical trial of losmapimod in FSHD patients at several sites across the US and Europe over the coming months.

Fulcrum Therapeutics president and CEO Robert Gould said: “Losmapimod is a foundational clinical asset for Fulcrum that has the potential to become the first approved therapy that targets the root cause of FSHD.

“Fulcrum believes losmapimod has the potential to slow or halt the progressive muscle weakness that characterises the condition, which would significantly improve patients’ quality of life.

“The agreement shows confidence in our unique approach to rebalancing gene expression in severe genetically defined disorders. We will work urgently to advance the compound through the clinic.”

Fulcrum handed GSK a high single-digit equity stake in the company as a payment for the license.

In addition, the UK-based pharmaceutical giant is eligible for milestone payments and royalties.