Losmapimod Safety and Efficacy in COVID-19

The therapeutic hypothesis for the use of losmapimod in COVID-19 disease is that increased disease severity and consequent increased mortality is caused by p38 mitogen-activated protein kinase (MAPK)-mediated exaggerated acute inflammatory response resulting from SARS-CoV-2 infection.

It is anticipated that the early initiation of p38α/β inhibitor therapy in patients with moderate COVID-19 will prevent further clinical deterioration and reduce the need for both increased respiratory support as well as mortality. This is the main hypothesis for this study.

To address this hypothesis, Fulcrum Therapeutics is conducting a Phase 3, multicenter, randomized, double-blind, placebo-controlled study that will evaluate the safety and efficacy of losmapimod versus placebo in subjects with COVID-19 disease.

Losmapimod is currently in Phase 2 clinical trials for the treatment of facioscapulohumeral dystrophy (FSHD) and has previously been administered to more than 3600 adult healthy volunteers and subjects including participants in a large Phase 3 trial which evaluated clinical outcomes and safety after major cardiovascular events.

Patients will participate in this study for approximately 34 days. The total treatment duration will be 14 days. Subjects will be evaluated during a 3 day pre-treatment period (Screening and Baseline Visits) to establish pre-treatment baseline assessments and eligibility. Subjects will then be randomized to treatment with losmapimod or placebo for 14 days and assessed frequently for changes from pre-treatment in various clinical outcome assessments. Patients must have a confirmed diagnosis of COVID-19 by viral PCR prior to randomization and first dosing. Patients will receive 15 mg of losmapimod, or placebo twice daily given as two 7.5 mg tablets per dose by mouth: for a total of 4 pills or 30 mg daily for 14 consecutive days. All study visits during the first week of treatment are anticipated to be conducted in the inpatient setting while later visits are anticipated to be conducted as outpatient.

The primary endpoint of the study is to assess the efficacy of losmapimod tablets compared with placebo for the treatment of COVID-19 when administered concurrently with the local standard of care. Secondary endpoints include evaluating the effect of losmapimod compared with placebo on clinical outcomes, clinical status, effect on survival, safety, and tolerability and to characterize changes in the levels of SARS-CoV-2 infection.