Glofitamab-gxbm (Columvi™)

A targeted therapy works by targeting receptors specific to cancer cells. Glofitamab-gxbm is a CD20-directed CD3 T-cell engager. This medication binds to the CD3 receptor found on the surface of some T-cells and CD20 which is found on some lymphoma cells.

How to Take Glofitamab-gxbm

This medication is given as an intravenous (IV, into a vein) infusion. One week before you are given this medication, you will be given a medication called obinutuzumab. Before your dose of glofitamab-gxbm, you will be given pre-medications to prevent a reaction including a steroid (prednisone or dexamethasone), a histamine-1 (H1) receptor antagonist (such as diphenhydramine/Benadryl), and an antipyretic (such as acetaminophen/Tylenol). You may also be given antiviral medications and medications to prevent pneumonia. You will need to be in the hospital while receiving this medication and for at least 24 hours after your dose is done.

Possible Side Effects of Glofitamab-gxbm

There are a number of things you can do to manage the side effects of glofitamab-gxbm. Talk to your care team about these recommendations. They can help you decide what will work best for you. These are some of the most common or important side effects:

Cytokine Release Syndrome (CRS)

CRS can occur. T cells are activated by this medication, causing them to release many cytokines. The cytokines cause an inflammatory response in the body. This reaction, if left untreated, can be very dangerous. Signs and symptoms may be fever, having a hard time breathing, chills, low blood pressure, fast heart rate, headache, and higher levels of liver enzymes in your blood. Your care team will monitor you closely for CRS while you are receiving this medication. You should call your provider right away if you have any signs or symptoms of CRS so that treatment can be started.

Infection and Low White Blood Cell Count (Leukopenia/Neutropenia)

This medication can cause life-threatening infections, with or without a decrease in white blood cell counts.

White blood cells (WBC) are important for fighting infection. While receiving treatment, your WBC count can drop, putting you at a higher risk of getting an infection. You should let your doctor or nurse know right away if you have a fever (temperature greater than 100.4 °F or 38°C), sore throat or cold, shortness of breath, cough, burning with urination, or a sore that doesn't heal.

Tips to preventing infection:

• Washing hands, both yours and your visitors, is the best way to prevent the spread of infection.
• Avoid large crowds and people who are sick (i.e.: those who have a cold, fever, or cough or live with someone with these symptoms).
• When working in your yard, wear protective clothing including long pants and gloves.
• Do not handle pet waste.
• Keep all cuts or scratches clean.
• Shower or bathe daily and perform frequent mouth care.
• Do not cut cuticles or ingrown nails. You may wear nail polish, but not fake nails.
• Ask your oncology care team before scheduling dental appointments or procedures.
• Ask your oncology care team before you, or someone you live with has any vaccinations.

Muscle or Joint Pain/Aches

Your healthcare provider can recommend medications and other strategies to help relieve pain.

Fatigue

Fatigue is very common during cancer treatment and is an overwhelming feeling of exhaustion that is not usually relieved by rest. While on cancer treatment, and for a period after, you may need to adjust your schedule to manage fatigue. Plan times to rest during the day and conserve energy for more important activities. Exercise can help combat fatigue; a simple daily walk with a friend can help. Talk to your healthcare team for helpful tips on dealing with this side effect.

Rash

Some patients may develop a rash. Use an alcohol free moisturizer on your skin and lips; avoid moisturizers with perfumes or scents. If your skin does crack or bleed, be sure to keep the area clean to avoid infection. Be sure to notify your oncology care team of any rash that develops, as this can be a reaction. They can give you more tips on caring for your skin.

Electrolyte Abnormalities

This medication can affect the normal levels of electrolytes (phosphate, etc.) in your body. Your levels will be monitored using blood tests. If your levels become too low, your care team may prescribe specific electrolytes to be given by IV or taken by mouth. Do not take any supplements without first consulting with your care team.

High Uric Acid Levels

This medication can cause higher than normal levels of uric acid in your body. Your care team will monitor for this and other things with blood work.

Important but Less Common Side Effects

• Neurologic Toxicity including ICANS:This medication can cause neurologic toxicity and immune effector cell-associated neurotoxicity. Aphasia (being unable to understand speech or speak normally), being more tired than usual, tremors, confusion, and seizures have happened in patients who received this medication. Your care team will be monitoring you very closely for any changes in your mental status. If you notice any changes, contact your care team right away.
• Tumor Flare: While taking this medication, you can experience a "tumor flare" which can result in symptoms of the cancer getting temporarily worse. Notify your care team if you develop any swollen lymph nodes, fever, or pain.

Reproductive Concerns

Exposure of an unborn child to this medication could cause birth defects, so you should not become pregnant while on this medication. Effective birth control is necessary during treatment and for at least 1 month after the last dose. Even if your menstrual cycle stops or you believe you are not producing sperm, you could still be fertile and conceive. You should not breastfeed during treatment and for at least 1 month after the last dose.