The immunoglobulin G1 monoclonal antibody namilumab has demonstrated efficacy and safety in patients with rheumatoid arthritis (RA) with inadequate response to methotrexate (MTX-IR) or anti-tumour necrosis factor therapy (TNF-IR).
The phase 2 dose finding study of namilumab in combination with methotrexate in participants with moderate to severe RA (NEXUS) trial compared the efficacy of subcutaneous namilumab to placebo in MTX-IR (n=92) or TNF-IR (n=16) patients on stable background methotrexate therapy.
A total of 108 patients were randomised to receive placebo (n=27) or namilumab 20 mg (n=28), 80 mg (n=25) or 150 mg (n= 28) at baseline and again at weeks two, six and 10. The primary endpoint was mean change from baseline in the 28-joint Disease Activity Score, C-reactive protein version (DAS28-CRP) at week 12.
A dose-response effect was observed. A statistically significant difference in DAS28-CRP was seen for namilumab 150 mg versus placebo (P=.005), with separation of effect seen as early as week 2 (P<.05>
The most common treatment-emergent adverse events (AEs) were nasopharyngitis, dyspnoea, bronchitis and headache. There was no apparent dose relationship for AEs. No serious infections were observed. One serious AE (myocardial infarction) was observed with 150 mg of namilumab.