Background B cells (BC) play a critical role in progressive systemic sclerosis (SS). BC depletion therapy is an attractive option.

Objectives to evaluate the efficacy of an intensified B cell depletion therapy in patients with progressive SS

Methods Eighteen patients with SS [2 males, mean age 58.33 yrs (46–82)] with severe multiorgan involvement including skin [16], lung, with pulmonary fibrosis (17 patients) and pulmonary hypertension (5), esophagous [9], with polyarthralgias [2] have been prospectively treated with an intensified B cell depletion therapy (IBCDT) protocol due to their resistance or intolerance to previous therapy (4 cases) or as a front line treatment in 14 patients with unsatisfactory therapeutic compliance. IBCDT included: Rituximab (RTX) 375mg/sm on days 1, 8, 15, 22, and 2 more doses after 1 and 2months, associated with 2 IV administrations of 10mg/kg of cyclophosphamide and 3 methylprednisolone pulses (15mg/kg) followed by oral prednisone (0.8mg/kg/day, rapidly tapered to 5mg/day by the end of the 3rd month after RTX). No further immunosuppressive maintenance therapy has been given.

Results Patients had been followed-up for a mean of 21,67 ± ds 11,05 (06–43) months. Significant decreases (p<0.05) were found in Rodnan skin score (baseline: 12.28; end of follow-up: 11.67), visual activity score (baseline mean value: 6.8 mm; end of follow-up: 4.2. A significant increase (p<0.05) FVC (baseline: 92.35; end of follow-up: 95.44), FEV (baseline: 86.5; end of follow-up: 90.43), DLCO (baseline: 57.15; end of follow-up: 66.75), and NTpro BNP (baseline: 345.19; end of follow-up: 62.29). PAP values did not change during the observation (baseline: 29.77mmHg; end of follow-up: 26.57). During the follow-up, pulmonary fibrosis, as established on a radiological level, was found to be ameliorated in 2 out of the 14 evaluable patients, worsened in 3, and unchanged in 9.

Conclusions A promising role of RTX in an intensified protocol of induction therapy can be envisaged in patients for whom avoiding prolonged immunosuppressive therapy particularly appealing. Our data confirm the opportunity to consider the regimens of BL depletion in the treatment of the most severe or refractory forms of SS.

Disclosure of Interest None declared