|The following article features coverage from the 61st American Society of Hematology Annual Meeting and Exposition. Click here to read more of Hematology Advisor’s conference coverage.|
Among patients with a nonmalignant immune-mediated hematologic disease (NMIHD), rituximab is linked to neutropenia in fewer than 1 in 20 cases, according to research presented at the 61st American Society of Hematology (ASH) Annual Meeting in Orlando, Florida.1
Rituximab-related neutropenia is well-documented among patients with hematologic malignancies, with a known incidence rate when used in combination with chemotherapy of between 3% and 27%. There are, however, limited data about the incidence rate of neutropenia among patients treated with rituximab monotherapy for an NMIHD. For this study, researchers evaluated the frequency, time to onset and resolution, and severity of neutropenia among patients with NMIHD treated with rituximab, alone or in conjunction with a steroid or other immunosuppressant.
The analysis included 197 patients, among whom 34 had autoimmune hemolytic anemia, 22 had acquired coagulation factor deficiency, 34 had thrombotic thrombocytopenic purpura, 94 had immune thrombocytopenic purpura, and 13 had antiphospholipid syndrome. All patients were diagnosed between January 2013 and October 2017; 73% received rituximab monotherapy.
The 1-year risk of neutropenia was 18%, and the median time from treatment initiation to neutropenia development was 4.4 months. Gender, age, disease type, and rituximab dosing were not independent predictors of neutropenia development.
Patients who received rituximab for at least 4 doses, as well as those who received the drug in conjunction with a nonsteroid immunosuppressant, were significantly more likely to develop neutropenia. Severe neutropenia was also more likely among those who received a nonsteroid immunosuppressant compared with patients who received rituximab monotherapy or in combination with steroids (36% vs 2%).
“Our analysis demonstrates an 18% rate of neutropenia at 1 year, mostly mild neutropenia,” the authors wrote. “Neutropenia is more frequent if [rituximab] is given with other immunosuppressant other than steroids, and when the number of doses of [rituximab] given are higher.”
1. Malpica Castillo LE, Palmer S, Deal A, et al. Incidence and time course of neutropenia in patients treated with rituximab-based therapy for non-malignant immune-mediated hematologic diseases. Oral presentation at: 61st ASH Annual Meeting and Exposition; December 7-10, 2019; Orlando, FL. Abstract 390.