Tocilizumab as monotherapy or in combination with nonbiologic disease-modifying antirheumatic drugs: twenty-four-week results of an open-label, clinical practice study

To assess the safety and tolerability of tocilizumab (TCZ) as monotherapy or in combination with nonbiologic disease-modifying antirheumatic drugs (DMARDs) in patients with moderate to severe rheumatoid arthritis (RA) who had an inadequate response at study entry to their current treatment with biologic agents or DMARDs.

This 24-week, multicenter, open-label, phase IIIb study conducted in the US enrolled 886 patients. Treatments were allocated to patients based on their current therapy at study entry. Patients receiving monotherapy with biologic agents were assigned to TCZ 8 mg/kg monotherapy. All other patients were randomized to either TCZ 4 mg/kg + DMARDs or TCZ 8 mg/kg + DMARDs. The primary end point was the number and percentage of patients with serious adverse events (SAEs) during 24 weeks of TCZ treatment. Efficacy assessments were evaluated as secondary outcomes. Data were analyzed descriptively.

Overall, 69 patients (7.8%) reported ≥1 SAEs. The rate of SAEs per 100 person-years was 28.3 (95% confidence interval [95% CI] 23.1-34.4) overall and was similar across treatment groups: 29.1 (95% CI 21.0-39.2), 30.3 (95% CI 22.2-40.2), and 20.6 (95% CI 10.3-36.9) in the TCZ 4/8 mg/kg + DMARDs, TCZ 8 mg/kg + DMARDs, and TCZ 8 mg/kg monotherapy groups, respectively. The most common SAEs were infections (i.e., pneumonia [1.0%] and cellulitis [0.9%]). In addition, American College of Rheumatology response rates and reductions in mean Disease Activity Score based on a 28-joint count were generally similar among treatment groups.

The safety findings in this study were consistent with the previously identified safety profile of TCZ. TCZ had an AE profile consistent with prior randomized blinded studies and was effective when administered as either monotherapy or in combination with DMARDs for the treatment of RA.