PracticeUpdate: Oncology - Winter 2018

CONFERENCE COVERAGE 34

Rituximab Yields Durable Response in AdultsWith Persistent or Chronic Immune Thrombocytopenia No unexpected long-term complications recorded after 12 months of follow-up A fter treatment with rituximab (RTX), a durable response has been demonstrated in more than 30% of adults with persistent or chronic immune thrombocytopenia (ITP), according to new research findings presented at EHA 2018.

electronic case report form. In keeping with interna- tional guidelines, complete response was defined by a platelet count >100x10 9 /L and response by a plate- let count between 30–100x10 9 /L with at least a twofold increase from baseline. One-year follow-up data have previously been published (Khellaf et al, Blood 2014). In total, there were 248 patients included in the reg- istry (64% female, mean age at ITP diagnosis: 51 ± 20 years). Of all patients, 102 (41%) had persistent ITP and 146 (59%) had chronic ITP at the time RTX was first administered. Ten percent of these registry patients were splenectomized. After the first RTX infusion, the median follow-up time was 69 (IQR, 55–79] months, with a follow-up ≥60 months for 177 (71%) patients. At the last follow-up visit, 77 (31%) patients had a lasting response (70 CR; 7 R), stated the research team, led by Samuel Deshayes, MD, with the Department of Internal Medicine at the Centre Hospitalier Universitaire de Caen in France. Among the 177 patients with a follow-up ≥60 months, 50 (28%) had a lasting response (46 CR; 4 R). Accord- ing to National Cancer Institute Common Terminology Criteria, 34 (14%) grade 3 or 4 infections were observed, but only 10 (4%) of these occurred within the 12 months following the last RTX infusion, including 1 pneumo- cystis pneumonia and 1 aspergillosis sinusitis. There were no cases of progressive multifocal encephalop- athy observed. Malignancies, however, were found in 24 (10%) patients and occurred at a median age of 71 (62–79) years of age after a median of 48 (39–62) months from RTX (incidence rate of 1.4 [CI 95%, 1.1–2.5] for 100 patient-years, similar to that observed in the French general population. No over-representation of any type of malignancy was found. The research team recorded 47 adverse effects related directly to the RTX infusion. This included 22 (9%) patients who developed or exacerbated another auto-immune disease; 21 (8%) patients who had cardi- ovascular complications; and 16 (6%) who experienced at least 1 venous thromboembolic event. In all, 31 (12%) patients died (median age: 80 [IQR, 71–84] years) after a median time of 30 (IQR, 14–54) months after the first RTX infusion, corresponding to a mortality rate of 2.4 (CI 95%, 1.7–3.4) for 100 patient-years. Deaths were mainly related to infections (n=6), malignancies (n=5), or bleeding (n=4), the researchers stated. Among the adverse effects, only 24 AE ≥ grade 3 were possibly related to RTX. This comprised 10 (4%) infec- tions and 10 (4%) events related to RTX infusion. Four patients (2%) died (3 from infectious origin, 1 from an unexplained cause). Gammaglobulin levels were not systematically moni- tored in the study. Among the 142 (57%) patients from whom data was available, 6 (2%) patients developed a hypogammaglobulinemia <5 g/L during follow-up. www.practiceupdate.com/c/70105

In addition, the research team noted in their abstract, no unexpected long-term complications were recorded after 12 months of follow-up. At present, the long-term safety and efficacy of RTX in treating ITP are not well known. Current data are based only on retrospective studies. The purpose of this study was to assess long-term outcomes after 5 to 7 years of follow-up. A large nationwide prospective registry was set up in France in 2010 that included 248 adult patients with ITP (ClinicalTrials.Gov: NCT1101295). ITP is a bleeding disorder characterized by a low number of platelets or thrombocytes that results in the blood clotting improperly. Excessive bleeding and bruising can result. In this study, consecutive patients ≥18 years of age who received RTX for a diagnosis of primary ITP based on international criteria were prospectively included between 2010 and 2012. Patients with secondary ITP or who had received a previous course of RTX were excluded. A prospective and periodic assessment of the safety and the efficacy of RTX were recorded through an

© EHA 2018

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