Effectiveness and safety of rituximab for the treatment of refractory systemic sclerosis associated calcinosis: A case series and systematic review of the literature

Objective: To analyze the effectiveness and safety of rituximab (RTX) for the treatment of refractory systemic sclerosis (SSc) associated calcinosis. Methods: We undertook an observational study of patients with this complication treated with 1 or more cycles of RTX (1 g x 2 weeks) and evaluated for at least 12 months after RTX treatment in a single center. The primary outcome measures of the study were the improvement of calcinosis symptoms (pain, signs of local inflammation, and new episodes of skin ulceration) and the radiologic evolution of the calcification(s). Results: We treated 8 patients with refractory SSc-related calcinosis with RTX (off-label use). The main indications for RTX were complicated calcinosis unresponsive to previous therapies with concomitant arthritis in 2 patients and refractory arthritis or interstitial lung fibrosing disease in the remaining 6 patients. The mean number of RTX cycles administered was 3.12 +/- 2.1 (range, 1-7), the median duration of RTX treatment was 9 months (interquartile range [IQR], 7.5-36 months), and the median follow-up after the first infusion of RTX dose was 19 months (IQR, http://catsalut.gencat.cat/web/.content/minisite/catsalut/proveidors_professionals/medicaments_farmacia/phf_mhda/informes_camse/esclerosi_sistemica/DictamenCAMS_-ES_-web.pdf (n.d.) 5-45 months). Four patients (50%) had a significant improvement in clinical symptoms (sustained improvement in the visual analog scale for pain of at least 50% and no new episodes of local inflammation or skin ulceration). Two of these patients (25%) also had a complete resolution or significant reduction in the size of the calcification(s) on X-ray, according with the radiographical scoring system for calcinosis developed by the Scleroderma Clinical Trials Consortium. In the remaining 4 patients (50%), RTX did not provide any significant clinical or radiologic benefit for calcinosis. The frequency of adverse effects was low, occurring in only 1 patient (12.5%), who developed upper respiratory tract infections not requiring hospitalization. Conclusion: Our preliminary data suggest that RTX may be helpful as a rescue therapy in selected cases of severe and refractory SSc-related calcinosis.