3 Clinical Trials Examine Sirukumab for RA; Plus TNF-α Combination & Monotherapies Are Compared for Treating PsA

Sirukumab in Phase 3 Trials for RA
Sirukumab is a subcutaneously administered human, anti-interleukin 6 monoclonal antibody. It is currently being investigated in Phase 3 clinical trials for treating patients with moderate to severe active rheumatoid arthritis (RA): SIRROUND-D, SIRROUND-H and SIRROUND-T.¹ These three trials are multicenter, randomized and double blind. Additionally, SIRROUND-D and SIRROUND-T are placebo controlled.

SIRROUND-D is evaluating patients (n=1,670) with moderate to severe active RA who were nonresponsive to disease-modifying antirheumatic drugs (DMARDs). Its primary efficacy objective will be measured by the reduction of RA signs and symptoms and inhibition of radiographic progression. In SIRROUND-H, the primary study objective is to assess sirukumab efficacy when compared with subcutaneous adalimumab in biologic naive patients (n=559) with moderate to severe active RA who are intolerant to methotrexate (MTX). Patients could be either unresponsive to MTX or inappropriate MTX candidates. Finally, SIRROUND-T is assessing the efficacy of sirukumab as measured by the reduction of RA signs and symptoms in patients with active RA (n=878) who were intolerant to or unresponsive to anti-tumor necrosis factor alpha (TNF-α) therapies. Sirukumab is being administered in 50 mg or 100 mg doses every two or four weeks, depending on the study.

Two additional trials include SIRROUND-M in Japanese patients who are unresponsive to sulfasalazine or MTX, and SIRROUND-LTE, the long-term extension study for patients who complete the SIRROUND-T and SIRROUND-D studies.

PsA Treatment Persistence Similar with Biologic Therapy vs. Biologic + DMARD
A recent study evaluated the comparative effectiveness of combination therapy with a TNF-α inhibitor plus a conventional DMARD vs. monotherapy with only a TNF-α inhibitor in treating adult patients with psoriatic arthritis (PsA) who were enrolled in a large U.S. database known as Corrona.² Patients who had started a TNF-α inhibitor had to have been biologic therapy naive and have had a follow-up appointment ≥90 days after therapy initiation. The time to Clinical Disease Activity Index (CDAI) remission (<2.8) and staying on TNF-α inhibitor therapy (persistence) were the study end points.

Demographics and treatment history were similar for both study groups. A total of 318 patients received combination therapy, and 201 patients received monotherapy. The mean follow-up was 2.1 years, and the mean patient age was 51.6 years. Treatments included MTX (91%), sulfasalazine, leflunomide, etanercept, adalimumab and infliximab. The final analysis included 497 patients for TNF-α persistence and 380 patients for time to remission.

There was no statistically significant difference between monotherapy and combination therapy for TNF-α persistence (31 months vs. 32 months, p=0.73), nor for time to remission (25 months vs. 21 months, p=0.56). Predictors of TNF-α persistence included longer persistence for Hispanic patients and longer duration of PsA. Predictors of shorter persistence included history of MTX use, BI and disease activity.

Michele B. Kaufman, PharmD, CGP, RPh, is a freelance medical writer based in New York City and a pharmacist at New York Presbyterian Lower Manhattan Hospital.

References

1. New release: GSK receives positive top-line results from sirukumab phase III program supporting regulatory filings for rheumatoid arthritis in 2016. 2015 Dec 16.
2. Mease PJ, Collier DH, Saunders KC, et al. Comparative effectiveness of biologic monotherapy versus combination therapy for patients with psoriatic arthritis: Results from the Corrona registry. RMD Open. 2015;1:e000181. doi:10.1136/rmdopen-2015-000181