Occurrence of Infusion-Related Reactions due to Obinutuzumab Therapy for Follicular Lymphoma

Obinutuzumab is used to treat follicular lymphoma in Japan. Its characteristic adverse event is infusion- related reactions(IRRs). Although interruption of administration improves many IRRs, serious symptoms can occur; thus, timing the interruption to correspond with the onset of these symptoms is necessary. However, the specific symptoms and timing of IRRs caused by obinutuzumab remain unclear. Therefore, the purpose of this study was to clarify the specific symptoms and timing of the onset of IRRs with obinutuzumab treatment.

Thirty patients were administered obinutuzumab for one year from October 2018 to September 2019. The frequency of IRRs, expression time, severity, symptoms, and correspondence were investigated.

IRRs occurred in 13 patients(43.3%), and all occurred after the first dosing. In 9 of 13 cases(69.2%), IRRs occurred within 90 min of the first dosage. Grade 3 symptoms were expressed in 1 of 13 cases (7.7%). The symptoms of IRRs were throat discomfort, breathing difficulty, skin rash, chills, and fever.

Most IRRs due to obinutuzumab occurred within 90 min of the first dosage. They were mostly Grade 2 or lower, and the frequency of serious IRRs was low. Thus, careful observation of symptoms during treatment with obinutuzumab is necessary.