Obinutuzumab (Gazyva)
The US Food and Drug Administration (FDA) has expanded the approved use of obinutuzumab (Gazyva®).
The drug is now approved for use in combination with chemotherapy to treat patients with previously untreated follicular lymphoma (FL) that is advanced (stage II bulky, stage III, or stage IV) .
In patients who respond to this treatment, obinutuzumab monotherapy can be given as maintenance.
The FDA granted this new approval of obinutuzumab to Genentech, Inc. The application for obinutuzumab in this indication received priority review.
The latest FDA approval means obinutuzumab is available in the US for the following indications:
- In combination with chlorambucil to treat chronic lymphocytic leukemia (CLL) in adults who have not had previous CLL treatment
- In combination with bendamustine, followed by obinutuzumab alone, to treat FL in adults who did not respond to a rituximab-containing regimen or whose FL returned after such treatment
- In combination with chemotherapy, followed by obinutuzumab alone in responders, to treat stage II bulky, stage III, or stage IV FL in adults who have not had previous FL treatment.
Phase 3 results
The latest approval of obinutuzumab is based on results from the phase 3 GALLIUM study, which were presented at the 2016 ASH Annual Meeting and published in NEJM in October.
The following are updated data from the obinutuzumab prescribing information.
GALLIUM included 1385 patients with previously untreated non-Hodgkin lymphoma, and 1202 of these patients had advanced FL.
Half of the FL patients (n=601) were randomized to receive obinutuzumab plus chemotherapy (followed by obinutuzumab maintenance for up to 2 years), and half were randomized to rituximab plus chemotherapy (followed by rituximab maintenance for up to 2 years).
The different chemotherapies used were CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisolone), CVP (cyclophosphamide, vincristine, and prednisolone), and bendamustine.
At a median observation time of 38 months, the overall response rate was 91% in the obinutuzumab arm and 88% in the rituximab arm. The complete response rates were 28% and 27%, respectively.
The median progression-free survival was not reached in either arm. The hazard ratio, for obinutuzumab compared to rituximab, was 0.72 (95% CI, 0.56-0.93, P=0.0118).
Safety was evaluated based on all 1385 patients in the study, 86% of whom had previously untreated FL and 14% of whom had marginal zone lymphoma.
Serious adverse events (AEs) occurred in 50% of patients in the obinutuzumab arm and 43% in the rituximab arm. Fatal AEs occurred in 5% and 4%, respectively. Infections and second malignancies were the leading causes of these deaths.
The most common AEs (incidence ≥ 20%) observed at least 2% more patients in the obinutuzumab arm were infusion-related reactions, neutropenia, upper respiratory tract infection, cough, constipation, and diarrhea.
The most common grade 3 to 5 AEs (incidence ≥ 5%) observed more frequently in the obinutuzumab arm were neutropenia, infusion-related reactions, febrile neutropenia, and thrombocytopenia.
