Oncology Drug Reference Sheet: Glofitamab-Gxbm
After an open-label, multicenter, single-arm trial demonstrated a 56% objective response rate, with 43% achieving complete responses, and an estimated 18.4-month median duration of response, the U.S. Food and Drug Administration granted (https://www.fda.gov/drugs/drug-approvals-and-databases/fda-grants-accelerated-approval-glofitamab-gxbm-selected-relapsed-or-refractory-large-b-cell) glofitamab-gxbm (Columvi™) accelerated approval in June 2023.
Category/Class
Mechanism of Action
Binds to CD20 expressed (https://www.accessdata.fda.gov/drugsatfda_docs/label/2023/761309s000lbl.pdf) on the surface of B cells and to CD3 receptor expressed on the surface of T cells resulting in T-cell activation and proliferation, cytokine secretion, and CD20-expressing B cell lysis
Indication
Adults with relapsed or refractory diffuse large B-cell lymphoma (https://www.accessdata.fda.gov/drugsatfda_docs/label/2023/761309s000lbl.pdf), not otherwise specified (DLBCL, NOS), or large B-cell lymphoma (LBCL) arising from follicular lymphoma who have received two or more lines of systemic therapy
| Treatment Cycle (21 Days) | Day | Administration |
|---|---|---|
| Cycle 1 | 1 |
Obinutuzumab 1,000 mg (no glofitamab-gxbm) |
| 8 |
Glofitamab-gxbm 2.5 mg (step-up dose 1) |
|
| 15 |
Glofitamab-gxbm 10 mg (step-up dose 2) |
|
| Cycle 2-12 | 1 |
Glofitamab-gxbm 30 mg |
Administration
On cycle 1, day 1, give pretreatment (https://www.accessdata.fda.gov/drugsatfda_docs/label/2023/761309s000lbl.pdf) with a single dose of obinutuzumab (1,000 mg) via IV at 50 mg/hour with the option to titrate in 50 mg/hour increments every 30 minutes to a maximum of 400 mg/hour. Administer additional premedications per the chart below.
Infuse glofitamab-gxbm via a dedicated line with a sterile 0.2 micron in-line filter. Infuse cycles 1 and 2 over four hours; cycles 3–12 may be infused over two hours. If a patient experienced cytokine release syndrome (CRS) with the previous dose during cycles 3-12, the infusion time should be maintained at four hours.
| Treatment Cycle | Premedication | Administration |
|---|---|---|
| Cycle 1, day 8 and 15; Cycle 2; Cycle 3 | IV dexamethasone 20 mg | Complete at least one hour prior to glofitamab-gxbm |
| Oral acetaminophen 500–1,000 mg |
Administer at least 30 minutes prior to glofitamab-gxbm |
|
|
Oral or IV diphenhydramine 50 mg (or equivalent) |
Complete at least 30 minutes prior to glofitamab-gxbm |
|
| All subsequent infusions |
Oral acetaminophen 500–1,000 mg |
Administer at least 30 minutes prior to glofitamab-gxbm |
|
Oral or IV diphenhydramine 50 mg (or equivalent) |
Complete at least 30 minutes prior to glofitamab-gxbm |
Note. Patients who experienced any grade CRS with a previous dose of glofitamab-gxbm should receive IV dexamethasone 20 mg one hour prior to infusion.
Adverse Reactions
More than 20% of patients (https://www.accessdata.fda.gov/drugsatfda_docs/label/2023/761309s000lbl.pdf) in the clinical trial experienced CRS, musculoskeletal pain, rash, and fatigue. Laboratory abnormalities (grade 3 or 4) included decreased lymphocyte count, decreased phosphate, decreased neutrophil count, decreased fibrinogen, and increased uric acid. The package insert contains warnings for CRS, neurologic toxicity, serious infection, tumor flare, and embryo-fetal toxicity.
Nursing Considerations
Patients should be hospitalized (https://www.accessdata.fda.gov/drugsatfda_docs/label/2023/761309s000lbl.pdf) during administration and for 24 hours after their first dose and as indicated for any subsequent doses (e.g., CRS with previous dose). Administer glofitamab-gxbm in a setting equipped to monitor and treat CRS. Patients at risk for tumor lysis syndrome (TLS) should be adequately hydrated and receive antihyperuricemics before glofitamab-gxbm. Verify pregnancy status prior to infusion. Monitor patients for neurologic toxicity.
Patient Education
Use effective contraception (https://www.accessdata.fda.gov/drugsatfda_docs/label/2023/761309s000lbl.pdf) during and for one month after treatment with glofitamab-gxbm. Do not breastfeed during and for one month after treatment. Carry a wallet card at all times that describes CRS’s symptoms and when to seek medical attention. Glofitamab-gxbm treatment may need step-up dosing and hospitalization for monitoring after infusion.
Safe Handling
Glofitamab-gxbm can cause (https://www.accessdata.fda.gov/drugsatfda_docs/label/2023/761309s000lbl.pdf) embryo-fetal toxicity; use safe-handling precautions (https://www.ons.org/ascoons-chemotherapy-administration-safety-standards).
Patient Assistance
Call 866-422-2377 or refer to the Columvi Financial Support Tool (https://www.columvi.com/financial-support/tool.html).