Epcoritamab

Say it: ep-kor-IT-ah-mab · Brand names: Epkinly

Epcoritamab is an immunotherapy medicine that links your immune cells to lymphoma cells so your body can attack the cancer.

What it is

It is a special antibody with two arms. One arm grabs a protein called CD20 on lymphoma cells, and the other arm grabs a protein called CD3 on your T cells (a type of immune cell). This brings your immune cells right next to the cancer so they can attack it.

Often used for

• diffuse large B-cell lymphoma that has come back after other treatments
• follicular lymphoma that has come back, together with the medicines lenalidomide and rituximab
• follicular lymphoma that has come back after 2 or more other treatments

How you get it

You get epcoritamab as a shot under the skin. The first month uses small step up doses, and some people stay in the hospital for about a day after the first full dose. After that, shots are given weekly at first, then less often over time, such as every 2 or 4 weeks. Your schedule may be different.

Common side effects and what helps

• Fever, often from cytokine release syndrome. Check your temperature and call as your team tells you.
• Feeling tired. Rest and short walks can help.
• Redness, swelling, or soreness where the shot was given. A cool cloth may help.
• Muscle or bone pain. Ask your team what pain medicine is safe.
• Belly pain, nausea, or diarrhea. Drink fluids and eat small meals.
• Low blood counts, which raise the risk of infection. Wash your hands often.

Call your care team right away if you have

• Fever, chills, fast heartbeat, dizziness, or trouble breathing (possible signs of cytokine release syndrome, a strong immune reaction)
• Confusion, trouble speaking or writing, shaking, very bad sleepiness, seizures, or feeling not like yourself
• A fever of 100.4 degrees Fahrenheit (38 degrees Celsius) or higher
• Cough, burning when you pee, or other signs of infection
• Bleeding or bruising that is not normal for you

Before you start, tell your team

• If you have an infection now or get infections often
• If you have had hepatitis B or other long term infections
• If you have ever had a seizure or other nervous system problem
• If you are pregnant, may become pregnant, or are breastfeeding
• All the medicines, vitamins, and herbal products you take

Good to know

• This medicine can cause cytokine release syndrome, a strong immune reaction that causes fever, low blood pressure, and trouble breathing. It is most common after the first few doses and can be life threatening, so you will be watched closely.
• This medicine can cause nervous system problems, such as confusion, trouble speaking, or seizures. Do not drive or use heavy machines during the early doses and for as long as your team tells you.
• You will get medicines before the early doses to lower the chance of a reaction, and you may need to drink extra fluids.
• Serious infections can happen. Your team may give you medicines to help prevent them.
• You will have blood tests to check your blood counts.

At home

• Stay close to your treatment center after the early doses, as your team tells you.
• Have a caregiver with you during the first weeks who can watch for confusion or other changes.
• Take any medicines your team gives you for the days after each shot exactly as directed.

Questions to ask

• Will I need to stay in the hospital for any doses?
• When can I drive again?
• How long will I be on this medicine?
• Who do I call after hours if I get a fever?

Side effect guides

• Fatigue (tiredness)
• Nausea and vomiting
• Diarrhea
• Low white blood cells and infection risk
• Pain

Last updated: 2026-10-27. Medically reviewed by Veli Bakalov, MD, medical oncologist (October 2026). General education from Step by Step, the patient portal of HemeOncBuddy.