GAZYVA
Clinical safety rating: caution
Comprehensive clinical and safety monograph for GAZYVA (GAZYVA).
Obinutuzumab is a type II anti-CD20 monoclonal antibody that binds to the CD20 antigen on B cells, inducing direct cell death, antibody-dependent cellular cytotoxicity, and antibody-dependent cellular phagocytosis.
| Metabolism | Obinutuzumab is a monoclonal antibody expected to be degraded into small peptides and amino acids via catabolic pathways, similar to endogenous immunoglobulins; not metabolized by CYP450 enzymes. |
| Excretion | Obinutuzumab is eliminated primarily through intracellular catabolism, with no significant renal or biliary excretion. <1% of the dose is excreted unchanged in urine. |
| Half-life | The terminal elimination half-life is approximately 28 days (range 14-42 days) following the last dose, supporting a 6-month dosing interval for maintenance therapy. |
| Protein binding | Obinutuzumab binds specifically to CD20 antigen on B-cells; plasma protein binding is negligible (<1%) as it is a monoclonal antibody. |
| Volume of Distribution | The volume of distribution is approximately 3.8 L (0.05 L/kg for a 70 kg adult), reflecting limited extravascular distribution primarily to lymphoid tissues. |
| Bioavailability | Obinutuzumab is only administered intravenously; oral bioavailability is 0%. Subcutaneous formulations are not available. |
| Onset of Action | Intravenous administration: Maximum plasma concentration is reached at the end of infusion. Pharmacodynamic effects (B-cell depletion) are observed within 24 hours. |
| Duration of Action | B-cell depletion persists for at least 6 months after the last dose. Recovery of B-cell counts begins after 9-12 months, with normalization typically within 12-18 months. |
100 mg intravenously on day 1, 8, 15 of cycle 1, then 100 mg on day 1 of subsequent 28-day cycles for 6 cycles total.
| Dosage form | INJECTABLE |
| Renal impairment | No dose adjustment required for mild to moderate renal impairment (CrCl >=30 mL/min). Safety and efficacy not established in severe renal impairment (CrCl <30 mL/min). |
| Liver impairment | No dose adjustment required for mild hepatic impairment (Child-Pugh A). Not recommended for moderate to severe hepatic impairment (Child-Pugh B or C). |
| Pediatric use | Safety and efficacy not established in pediatric patients. |
| Geriatric use | No specific dose adjustment required; monitor for infusion-related reactions and hematologic toxicities more frequently. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for GAZYVA (GAZYVA).
| Breastfeeding | No data on presence in human milk; however, IgG antibodies are excreted in breast milk. M/P ratio unknown. Discontinue breastfeeding or avoid drug due to potential for B-cell depletion in infant. |
| Teratogenic Risk | First trimester: limited human data, but based on mechanism (anti-CD20 monoclonal antibody), potential B-cell depletion in fetus. Second/third trimesters: IgG crosses placenta; fetal B-cell depletion and cytopenias possible. Avoid unless benefit outweighs risk. |
| Fetal Monitoring |
■ FDA Black Box Warning
Hepatitis B virus reactivation, including fulminant hepatitis, hepatic failure, and death; Progressive multifocal leukoencephalopathy (PML) resulting in death.
| Serious Effects |
["Known hypersensitivity to obinutuzumab or any excipient","Active hepatitis B infection"]
| Precautions | ["Infusion reactions (including severe and life-threatening reactions)","Tumor lysis syndrome","Neutropenia and thrombocytopenia","Infections (including severe and opportunistic infections)","Hepatitis B reactivation","Progressive multifocal leukoencephalopathy (PML)","Immunization with live viral vaccines"] |
Loading safety data…
| Monitor maternal CBC with differential, LFTs, and hepatitis B serology before and during treatment. For pregnant women, fetal ultrasound for growth and amniotic fluid assessment; consider monitoring for neonatal cytopenias and infections after birth. |
| Fertility Effects | No human data. In animal studies, no significant adverse effects on male or female fertility observed; however, B-cell depletion in reproductive tissues may occur. |