GSK Presents Data Of Anti GM-CSF Antibody In Patients With Rheumatoid Arthritis

(RTTNews) - GlaxoSmithKline plc (GSK, GSK.L) announced encouraging results from a phase II dose-ranging study of GSK3196165 or "GSK165", an investigational anti-granulocyte macrophage colony-stimulating factor monoclonal (anti GM-CSF) antibody, in patients with moderate to severe rheumatoid arthritis who have an inadequate response to methotrexate or MTX.

The primary objective of this double-blind, placebo-controlled, dose-ranging study was to assess the efficacy of GSK165 in adult patients with active, moderate to severe RA. A total of 222 patients were randomised equally to receive placebo or GSK165 (37 patients per arm) at doses of 22.5mg, 45mg, 90mg, 135mg or 180mg starting with an induction regimen of five weekly subcutaneous injections followed by every other week (EOW) injections until Week 50.

Major secondary endpoints including a number of traditional measures to assess the efficacy of GSK165 were also improved in line with the DAS28 (CRP) reduction. The magnitude of improvement in patient-based measures (swollen and tender joint counts, pain and clinical disease activity index (CDAI)) were particularly marked.

The safety profile GSK165 was similar to that reported in previous studies. All doses of GSK165 were well-tolerated, and adverse events (AEs), including serious AEs (SAEs), were reported similarly across treatment groups. The percentage of patients experiencing any AE or SAE respectively, was 49% and 0% for placebo, 51% and 5% for 22.5mg GSK165, 65% and 3% for 45mg GSK165, 59% and 5% for 90mg GSK165, 51% and 3% for 135mg GSK165, 65% and 0% for 180mg GSK165.

There were no treatment limiting safety findings including serious infections, injection site reactions or laboratory abnormalities which were closely monitored throughout the study. No pulmonary toxicity, including pulmonary alveolar proteinosis, was observed.