SC and IV Tocilizumab Have Comparable Safety, Efficacy in Rheumatoid Arthritis

SAN DIEGO, CA—Subcutaneous (SC) tocilizumab has a comparable safety and efficacy profile when compared with intravenous (IV) tocilizumab in patients with rheumatoid arthritis, a study presented at the 2013 ACR/ARHP Annual Meeting has found.

Gerd R. Burmester, MD, professor of medicine of Charité-Universitätsmedizin Berlin and Free University and Humboldt University of Berlin, Berlin, Germany, and colleagues conducted the randomized, active controlled, parallel group, Phase 3 SUMMACTA trial to compare SC and IV tocilizumab over a 24-week double-blind period followed by a 72-week open-label extension.

A total of 1,262 patients were enrolled, 631 in the SC tocilizumab arm and 631 in the IV arm. During the double-blind period, patients were randomized 1:1 to SC tocilizumab weekly or IV tocilizumab every 4 weeks in combination with traditional DMARDs.

At the end of the double-blind period, patients who had received SC tocilizumab 162mg every 4 weeks were re-randomized 1:1 to SC tocilizumab 162mg weekly or IV tocilizumab 8mg/kg every 4 weeks. Patients who previously received IV tocilizumab 8mg/kg every 4 weeks were re-randomized 2:1 to IV tocilizumab 8mg/kg every 4 weeks or SC tocilizumab 162mg weekly.

At Week 25, 48 patients switched from SC tocilizumab to IV tocilizumab and 186 switched from IV tocilizumab to SC tocilizumab. A total of 61 patients (12%) receiving SC tocilizumab and 43 (12%) receiving IV tocilizumab withdrew from the study during the open-label period, most commonly due to safety; 521 and 372 patients continued SC tocilizumab and IV tocilizumab, respectively.

Of the patients who continued treatment, the percentage who achieved American College of Rheumatology (ACR)20/50/70 responses, DAS28 remission, and an improvement from baseline in HAQ-DI ≥0.3 were comparable between the groups and were sustained for up to 49 weeks. Efficacy and safety was comparable between patients who switched from IV tocilizumab to SC tocilizumab or from SC tocilizumab to IV tocilizumab and patients who were treated continuously, they found.

The number of adverse events, serious adverse events, serious infections, and malignancies was comparable for the IV tocilizumab and SC tocilizumab groups between 24 and 49 weeks. Injection site infections decreased over time, but were higher in patients in the SC tocilizumab arm compared with the IV tocilizumab arm, as previously reported at week 24. Three deaths occurred in each arm between Weeks 24 and 49. Development of anti-tocilizumab antibodies remained low through Week 48, and no anaphylaxis was reported.

“Subcutaneous tocilizumab could provide an additional administration option for patients with rheumatoid arthritis,” they concluded.