Rituximab for Inflammatory Myopathies in a Colombian Cohort

Rituximab (RTX) is a treatment for refractory inflammatory myopathies, such as dermatomyositis (DM) and polymyositis (PM). This study describes the characteristics of patients receiving RTX for myositis in our institution to evaluate its efficacy.

We collected demographic data from all patients diagnosed with DM or PM who received RTX between 2011 and 2018. Clinical and serological variables (including creatine phosphokinase [CPK] levels) were analyzed. Remission of disease was defined as no evidence of disease activity (active myositis) for longer than a 6-month continuous period while undergoing myositis therapy or no medication.

Eighteen patients who had received first-line immunosuppressants were included. Fifteen (83%) had DM, 2 (11%) had PM, 1 had juvenile dermatomyositis, and 14 (77%) were women. All patients received glucocorticoids. Three patients (16.6%) were treated with RTX as monotherapy, and 15 (83.3%) were treated with RTX combined with other immunosuppressants. On average, there were 2 RTX treatment cycles. Improved muscular weakness was found in 13 cases (72%), and improved serum CPK levels were found in 15 cases (83%). Twelve patients (66%) achieved remission.

Most patients experienced an objective improvement, as reflected in their serum CPK values and degree of muscular weakness. This suggests that RTX could be helpful in treating refractory myositis.