Maraviroc, a chemokine receptor-5 antagonist, fails to demonstrate efficacy in the treatment of patients with rheumatoid arthritis in a randomized, double-blind placebo-controlled trial.

INTRODUCTION: The purpose of this study was to determine whether maraviroc, a human CC chemokine receptor 5 (CCR5) antagonist, is safe and effective in the treatment of active rheumatoid arthritis (RA) in patients on background methotrexate (MTX). METHODS: This phase IIa study comprised two distinct components: an open-label safety study of the pharmacokinetics (PK) of MTX in the presence of maraviroc, and a randomized, double-blind, placebo-controlled, proof-of-concept (POC) component. In the PK component, patients were randomized 1:1 to receive maraviroc 150 or 300 mg twice daily (BID) for four weeks. In the POC component, patients were randomized 2:1 to receive maraviroc 300 mg BID or placebo for 12 weeks. Patients were not eligible for inclusion in both components. RESULTS: Sixteen patients were treated in the safety/PK component. Maraviroc was well tolerated and there was no evidence of drug-drug interaction with MTX. One hundred ten patients were treated in the POC component. The study was terminated after the planned interim futility analysis due to lack of efficacy, at which time 59 patients (38 maraviroc; 21 placebo) had completed their week 12 visit. There was no significant difference in the number of ACR20 responders between the maraviroc (23.7%) and placebo (23.8%) groups (treatment difference -0.13%; 90% CI -20.45, 17.70; P = 0.504). The most common all-causality treatment-emergent adverse events in the maraviroc group were constipation (7.8%), nausea (5.2%), and fatigue (3.9%). CONCLUSIONS: Maraviroc was generally well tolerated over 12 weeks; however, selective antagonism of CCR5 with maraviroc 300 mg BID failed to improve signs and symptoms in patients with active RA on background MTX. TRIAL REGISTRATION: ClinicalTrials.gov: NCT00427934.

Ocrelizumab, a humanized anti-CD20 monoclonal antibody, in the treatment of patients with rheumatoid arthritis: a phase I/II randomized, blinded, placebo-controlled, dose-ranging study.

OBJECTIVE: Ocrelizumab, a humanized anti-CD20 monoclonal antibody, was studied in a first-in-human trial in rheumatoid arthritis (RA) patients receiving concomitant methotrexate (MTX). METHODS: The ACTION trial was a combined phase I/II study of placebo plus MTX versus ocrelizumab plus MTX in 237 RA patients (intent-to-treat population). During phase I, 45 patients were treated with 1 of 5 escalating doses of study drug (infusions on days 1 and 15, 10-1,000 mg per each infusion). An additional 192 patients were randomized during phase II. Eligible patients had active disease, an inadequate response to treatment with at least MTX, rheumatoid factor positivity, and elevated levels of acute-phase reactants. The total study duration was 72 weeks. B cell pharmacodynamics over time was investigated. RESULTS: Baseline demographics were similar among the treatment groups. Based on the entire 72-week data set, the incidence of serious adverse events in the ocrelizumab-treated patients was 17.9%, as compared with 14.6% in placebo-treated patients. The incidence of serious infections was 2.0% in all ocrelizumab-treated patients and 4.9% in placebo-treated patients. Infusion-associated adverse events were mostly grade 1 or grade 2 and were more frequent around the time of the first infusion. No serious infusion-associated adverse events were reported in the ocrelizumab group. Evidence of clinical activity was observed at all doses evaluated. Peripheral B cell depletion after infusion was rapid at all doses, with earlier repletion of B cells at doses of 10 mg and 50 mg. Human anti-human antibodies were detected in 19% and 10%, respectively, of those receiving 10 mg and 50 mg of ocrelizumab, compared with 0-5% of those receiving 200, 500, and 1,000 mg. CONCLUSION: Ocrelizumab therapy in combination with MTX was well tolerated. Doses of 200 mg (2 infusions) and higher showed better clinical responses, better reduction of C-reactive protein levels, and very low immunogenicity.