The obinutuzumab group had more serious adverse events (47% vs 41%) and more grade 3 to grade 5 adverse events (75% vs 69%).7 The obinutuzumab group had fewer total deaths (7%) compared with rituximab (9%), but the same rates of adverse events resulting in death (both 4%). The most common adverse events in the obinutuzumab group included infection, neutropenia, infusion-related reactions, cardiac events, and thrombocytopenia. It is important to note that both groups had evidence of a second neoplasm ― 5% of the obinutuzumab group compared with 4% of the rituximab group. These neoplasms included nonmelanoma skin cancer and hematological malignancies.
Obinutuzumab administration includes induction and maintenance dosing.5,6,7 The initial dose for FL is 1000 mg on days 1, 8, and 15 of cycle 1, followed by 1000 mg on day 1 of cycle 2 through cycle 8, and then 1000 mg every 2 months for up to 2 years.7
Based on the documented infusion reactions both in prior CLL studies and in the GALLIUM trial, it is important to be cognizant of the recommended premedication regimen. Most of the infusion reactions occurred during the first infusion. Therefore, the prescribing information recommends acetaminophen, an antihistamine, and a glucocorticoid prior to the first infusion. Premedication prior to future cycles is dependent on the patient’s reaction (or lack thereof) during the first infusion.
Another factor to consider is that obinutuzumab also has a black box warning for hepatitis B reactivation and progressive multifocal leukoencephalopathy (PML).7 Therefore, it is important to counsel the patient on these risks, as well as check the appropriate hepatitis B serology prior to treatment initiation with obinutuzumab. It is also crucial to monitor patients for signs or symptoms of tumor lysis syndrome and to remember not to administer any live vaccines to patients receiving obinutuzumab therapy.
- Morton LM, Wang SS, Devesa SS, et al. Lymphoma incidence patterns by WHO subtype in the United States, 1992-2001. Blood. 2006;107(1):265-276.
- Solal-Céligny P, Roy P, Colombat P, et al. Follicular lymphoma international prognostic index. Blood. 2004;104(5):1258-1265.
- Martin AR, Weisenburger DD, Chan WC, et al. Prognostic value of cellular proliferation and histologic grade in follicular lymphoma. Blood. 1995;85(12):3671-3678.
- Korsmeyer SJ. Bcl-2 initiates a new category of oncogenes: regulators of cell death. Blood. 1992;80(4):879-886.
- Marcus R, Davies A, Ando K, et al. Obinutuzumab for the first-line treatment of follicular lymphoma. N Eng J Med. 2017;377(14):1331-1344.
- Hiddemann W, Barbui AM, Canales MA, et al. Immunochemotherapy with obinutuzumab or rituximab for previously untreated follicular lymphoma in the GALLIUM study: influence and chemotherapy on efficacy and safety. J Clin Oncol. 2018;36(23):2395-2404.
- Obinutuzumab® [package insert]. South San Franscisco, CA: Genentech, Inc; 2017.