Safety and efficacy of ocrelizumab in patients with rheumatoid arthritis and an inadequate response to methotrexate: results of a forty-eight-week randomized, double-blind, placebo-controlled, parallel-group phase III trial

Objective: To evaluate the efficacy and safety of treatment with ocrelizumab plus methotrexate (MTX) in patients with active rheumatoid arthritis (RA) and an inadequate response to MTX.

Methods: STAGE was a phase III randomized, double-blind, parallel-group international study to evaluate the safety and efficacy of ocrelizumab compared with placebo in patients with active RA continuing MTX treatment. Patients receiving stable doses of MTX were randomized to receive 2 infusions of placebo (n = 320), ocrelizumab 200 mg (n = 343), or ocrelizumab 500 mg (n = 343) on days 1 and 15 as well as weeks 24 and 26. Coprimary end points were the proportion of patients with an American College of Rheumatology 20% improvement criteria (ACR20) response at weeks 24 and 48. Secondary end points included the change from baseline in the modified Sharp/van der Heijde score (SHS) and the ACR50/70 responses.

Results: The ACR20 response rates were 35.7% in the placebo group, 56.9% in the ocrelizumab 200 mg group, and 54.5% in the ocrelizumab 500 mg group at 24 weeks, and 27.6%, 58.3%, and 62.1%, respectively, at 48 weeks (P < 0.0001 versus placebo for each dose at both time points). At week 48, both of the ocrelizumab doses improved the ACR50 and ACR70 response rates 3-fold as compared with placebo and showed a statistically significant (P < 0.0001) reduction in joint damage progression relative to placebo (mean change in SHS reduced by 85% and 100% for the 200-mg and 500-mg doses, respectively). Rates of serious infection were comparable in the placebo (3.48 per 100 patient-years) and ocrelizumab 200 mg (3.54 per 100 patient-years) groups but were elevated in the ocrelizumab 500 mg group (8.66 per 100 patient-years).

Conclusion: With both ocrelizumab doses, the primary end point was met, and the signs and symptoms of RA were significantly improved at weeks 24 and 48. Ocrelizumab also significantly inhibited the progression of joint damage. A higher rate of serious infections was observed with 500 mg of ocrelizumab as compared with ocrelizumab 200 mg or placebo.