Background: Emerging evidence during the last two decades supports a pivotal role of Interleukin 6 (IL-6) in the pathogenesis of Systemic Sclerosis (SSc). Standard immunosuppressive agents are often inadequate to control disease activity in SSc patients and treatment failure of multiple regimens is frequent in real-world practice.

Objectives: To examine the efficacy and safety of interleukin-6 receptor inhibition by tocilizumab in selected real-world patients with SSc.

Methods: Twenty-one patients (20 women, 16 diffuse SSc, mean age: 52±10 years, mean disease duration: 6.4±3.7 years, all with negative rheumatoid factor and anti-cyclic citrullinated antibodies, none with overlap syndrome with RA) with active joint and skin involvement refractory to corticosteroids (n=21), methotrexate (n=17), cyclophosphamide (n=10), mycophenolate (n=7), rituximab (n=1), leflunomide (n=2), hydroxychloroquine (n=2), and hematopoietic stem cell transplantation (n=2) who received weekly tocilizumab (162 mg subcutaneously) in an academic center, were monitored prospectively. Changes in Eustar modified activity index (MAI), modified Rodnan skin score (mRSS), disease activity score (DAS)28, lung function tests (LFTs) and patient reported outcomes (PROs) were analyzed at one year of treatment and at the end of follow-up.

Results: One patient discontinued tocilizumab after 3 months due to inefficacy. During the first year of treatment, 12 patients achieved low disease activity (mean MAI change -2.9±1.8, p<0.001) and significant clinical improvement was evident in 12 patients regarding skin involvement (mean mRSS change: -6.9±5.9, p<0.001) and in 16 patients regarding polyarthritis (mean DAS28 change: -1.9±0.8, p<0.001); Accordingly, improvements were recorded for all PROs (all p<0.001) ( Table 1 ). Lung function tests’ stabilization was also observed in 16/20 patients. During the second year, 3 patients discontinued tocilizumab (cytomegalovirus infection in 1, inefficacy in 2) and one died. Beneficial effects were sustained in all 16 patients at follow-up end (mean duration of Tocilizumab treatment 2.2 ± 1.1 years), apart from LFTs deterioration in 3. Except for recurrent digital ulcer infection in 3 patients, tocilizumab was well-tolerated.

Conclusion: Tocilizumab was effective in refractory joint and skin involvement irrespective of SSc disease duration or subtype. Long-term retention rates and disease stabilization for most real-world patients suggest that tocilizumab might be a valuable choice for difficult-to-treat SSc.

Disclosure of Interests: None declared