Anti-interleukin 6 Therapy Effect for Refractory Joint and Skin Involvement in Systemic Sclerosis: A Real-world, Single-center Experience

Abstract

ObjectiveTo examine the efficacy and safety of interleukin-6 inhibition by tocilizumab (TCZ) in difficult-to-treat, real-world patients with systemic sclerosis (SSc).MethodsTwenty-one patients (20 women; 16 diffuse cutaneous SSc; mean age: 52 ± 10 yrs; 10 with early disease [< 5 yrs]; and 11 with long-standing disease [mean disease duration 6.4 ± 3.7 yrs]) with active joint and/or skin involvement refractory to corticosteroids (n = 21), methotrexate (n = 19), cyclophosphamide (n = 10), mycophenolate mofetil (n = 7), rituximab (n = 1), leflunomide (n = 2), hydroxychloroquine (n = 2), and hematopoietic stem cell transplantation (n = 2), who received weekly TCZ (162 mg subcutaneously) in an academic center, were monitored prospectively. Changes in modified Rodnan skin score (mRSS), Disease Activity Score in 28 joints (DAS28), lung function tests (LFTs), and patient-reported outcomes (PROs) were analyzed after 1 year of treatment and at end of follow-up.ResultsOne patient discontinued TCZ after 3 months due to inefficacy. During the first year of treatment, improvement was evident in the remaining 20 patients regarding skin involvement (mean mRSS change: –6.9 ± 5.9, P < 0.001), polyarthritis (mean DAS28 change: –1.9 ± 0.8, P < 0.001), and PROs (all P < 0.001); LFT stabilization was observed in 16/20 patients. During the second year, 3 patients discontinued TCZ (cytomegalovirus infection in 1, inefficacy in 2) and 1 died. Beneficial effects were sustained in all 16 patients at end of follow-up (2.2 ± 1.1 yrs), except LFT deterioration in 3 patients. Apart from recurrent digital ulcer infection in 3 patients, TCZ was well tolerated.ConclusionTCZ was effective in refractory joint and skin involvement regardless of SSc disease duration or subtype. Long-term retention rates and disease stabilization for most real-world patients suggest that TCZ might be a valuable choice for difficult-to-treat SSc.