Objective: To evaluate the longterm efficacy and safety of subcutaneous tocilizumab (TCZ-SC) every 2 weeks (q2w) over 2 years in patients with rheumatoid arthritis who have an inadequate response to disease-modifying antirheumatic drugs (DMARD).
Methods: Patients (n = 656) were randomized 2:1 to TCZ-SC 162 mg q2w or placebo-SC q2w plus DMARD. After a 24-week double-blind period, patients (n = 457) were rerandomized to open-label TCZ-SC q2w by means of prefilled syringe or autoinjector. Escape therapy with weekly TCZ-SC was available for patients with inadequate efficacy from Week 12. Maintenance of response and safety to 2 years was assessed. Analyses used nonresponder imputation.
Results: The American College of Rheumatology (ACR) 20 response after TCZ-SC was maintained beyond Week 24 and was > 70% at each timepoint. ACR50/70, 28-joint Disease Activity Score remission, and ≥ 0.30 decrease from baseline in the Health Assessment Questionnaire-Disability Index response rates were also maintained after Week 24 in the TCZ-SC arm (≥ 50%, > 25%,> 32% and > 56%, respectively). Following escape for inadequate efficacy, many patients achieved ACR20 at the end of the study, 35% after escape from TCZ-SC, and 63% from placebo. The rates of serious adverse events [(11.20/100 patient-years (PY)] including serious infections (3.25/100 PY) were stable through Week 96. No association between anti-TCZ antibody development and loss of efficacy or adverse events was observed.
Conclusion: Efficacy and safety of TCZ-SC q2w was maintained up to 2 years and remained comparable with previously published data for intravenous TCZ. Dose escalation to weekly TCZ-SC was associated with ACR responses in prior nonresponders and was well tolerated.
Keywords: BIOLOGICAL THERAPY; CLINICAL TRIAL; RHEUMATOID ARTHRITIS.