Long-term outcomes of patients treated with rituximab as second-line treatment for adult immune thrombocytopenia – Follow-up of the RITP study

Abstract

RITP was a double‐blind randomized, 78‐week follow‐up trial in which 109 adults with immune thrombocytopenias (ITP) who failed to achieve adequate response to steroids, were randomized to receive rituximab or placebo. Here, we provide the duration of response, splenectomy and mortality rates based on extended follow‐up after completion of the RITP study. Extended follow‐up data were retrospectively collected for 72 (83%) patients out of the 84 patients who were not splenectomized during the initial RITP study. For the present analysis, median [interquartile range] duration of follow‐up after randomization was 72 [62–82] months. Median duration of response among patients who achieved an initial response was significantly longer in patients who received rituximab (8·2 [5·5–16·7] months) as compared to placebo (1·8 [1·3–3·6] months), P = 0·036. Overall, 35 patients underwent splenectomy (13 in the rituximab, and 22 in the placebo arm, P = 0·12). Eleven patients (10%) died during the study: five in the rituximab and six in the placebo arms, including four deaths from severe bleeding. Although most rituximab‐treated patients eventually relapsed, a longer duration of response and a trend towards lower splenectomy rate were observed in rituximab‐treated patients.