GlaxoSmithKline (GSK) has initiated a Phase III clinical development programme of its investigational, rheumatoid arthritis (RA) drug otilimab.
The drug is a monoclonal antibody that targets the granulocyte macrophage colony-stimulating factor (GM-CSF) protein associated with many immune-mediated diseases.
GSK acquired exclusive global rights to develop and commercialise the therapeutic across all indications in 2013 from MorphoSys.
The Phase III programme will involve head-to-head comparisons of otilimab with existing therapies across three pivotal trials and a long-term extension study.
It will recruit a broad range of difficult-to-treat moderate to severe RA patients who did not achieve an adequate response or are intolerant to current treatments.
One Phase III trial called contRAst-1 will assess the safety and efficacy of GSK’s drug, compared to placebo and tofacitinib, in combination with methotrexate (MTX).
The study will take place over 52 weeks in up to 1,700 subjects with inadequate response to MTX.
A second trial, contRAst-2, will involve a similar approach, except all study arms will see the combination with conventional synthetic DMARDs instead of MTX.
Patients who have an inadequate response to conventional synthetic or biologic DMARDs will be enrolled into this trial.
The contRAst-3 trial will be conducted to compare otilimab to placebo and sarilumab, all in combination with conventional synthetic DMARDs. The study will take place over 24 weeks and will feature 500-600 patients with inadequate response to biological DMARDs and / or JAK inhibitors.
Participants who complete these pivotal studies may be eligible for the contRAst-X long-term extension study, which will further investigate the efficacy and safety of the drug candidate for up to four years.
The primary endpoint for the pivotal studies is the proportion of patients reaching the American College of Rheumatology criteria (ACR20) at week 12, compared to placebo.
The studies will also track secondary endpoints, including the clinical disease activity index (CDAI) score or response criteria, health assessment questionnaire disability index (HAQ-DI) score and pain.
GSK R&D chief scientific officer and president Dr Hal Barron said: “The unique Phase III studies, designed in consultation with regulators, will help us understand how this potential new medicine could benefit appropriate patients living with rheumatoid arthritis.”
The Phase III programme will be conducted across 32 countries.