Sarilumab monotherapy vs sarilumab and methotrexate combination therapy in patients with rheumatoid arthritis

Objective Sarilumab, as monotherapy or in combination with conventional synthetic DMARDs, such as MTX, has demonstrated improvement in clinical outcomes in patients with RA. The primary objective of this post hoc analysis was to compare the efficacy of sarilumab (200 mg every 2 weeks) monotherapy (MONARCH study) with that of sarilumab and MTX combination therapy (MOBILITY study) at week 24. Methods The endpoints assessed were mean change from baseline in the Clinical Disease Activity Index (CDAI), 28-joint Disease Activity using CRP (DAS28-CRP), CRP, haemoglobin (Hb), pain visual analogue scale (VAS) and Functional Assessment of Chronic Illness Therapy (FACIT)-Fatigue. Least square (LS) mean change from baseline (95% CI) at week 24 for all endpoints was compared between the treatment arms for adjusted comparisons. Results This analysis included 184 patients on sarilumab monotherapy and 399 patients on sarilumab plus MTX. Differences (P < 0.05) were observed in ethnicity, region, body mass index group, rheumatoid factor, anti-cyclic citrullinated peptide antibodies, swollen joint count, CRP, CDAI and oral glucocorticoid use between these treatment groups. After adjusting for these differences in a mixed-effect model repeated measure, LS mean change from baseline for all assessments was similar between the treatment groups with overlapping CIs: CDAI, -28.79 vs -26.21; DAS28-CRP, -2.95 vs -2.81; CRP, -18.31 vs -16.46; Hb, 6.59 vs 8.09; Pain VAS, -33.62 vs -31.66; FACIT-Fatigue, 9.90 vs 10.24. Conclusion This analysis demonstrated that the efficacy of sarilumab monotherapy was similar to that of sarilumab and MTX combination therapy.