Kimmtrak
Kimmtrak (tebentafusp or tebentafusp-tebn) is a bispecific antibody used to treat adults with a type of eye cancer called uveal melanoma. It only works if you have a specific biomarker known as HLA-A*02:01, which your oncologist will check with a blood test before starting treatment. Kimmtrak (tebentafasp) is given as an intravenous (IV) infusion by a healthcare professional. The first 3 doses are given in a hospital so your care team can monitor you for serious side effects, like cytokine release syndrome (CRS). After those first doses, you’ll typically receive treatment once a week in an infusion center or clinic. Common side effects include fever, rash, and tiredness.
What is Kimmtrak (tebentafasp)?
What is Kimmtrak (tebentafasp) used for?
Advanced or metastatic uveal melanoma in adults with the HLA-A*02:01 biomarker
How Kimmtrak (tebentafasp) works
Kimmtrak (tebentafasp) is a bispecific T-cell engager (BiTE), a type of monoclonal antibody designed to bind to two different targets. One side of the antibody attaches to gp100, a protein presented by HLA-A*02:01 on cancer cells, while the other side binds to CD3, a protein on T-cells in your immune system. This connection brings T-cells close to the cancer cells, allowing your immune system to attack and destroy the cancer cells.
Drug Facts
What are the side effects of Kimmtrak (tebentafasp)?
Common Side Effects
- Lower blood cell counts (up to 91%)
- High liver enzymes (up to 97%)
- Cytokine release syndrome (89%)
- Rash (83%)
- Fever (76%)
- Itching (69%)
- Rise in blood sugar (66%)
- Tiredness (64%)
- Low electrolyte levels (up to 51%)
- Nausea (49%)
- Chills (48%)
- Stomach pain (45%)
- Swelling (45%)
- Low blood pressure (39%)
- Dry skin (31%)
- Headache (31%)
- Vomiting (30%)
Other Side Effects
- Pale skin
- Redness
- Diarrhea
- Joint pain
- Hair color changes
- Back pain
- Reduced appetite
- Constipation
- Dizziness
- Muscle pain
- Hair loss
- Night sweats
Serious Side Effects
- Cytokine release syndrome: fever, tiredness, weakness, vomiting, chills, nausea, low blood pressure, dizziness, lightheadedness, headache, trouble breathing, rash.
- Skin reactions: rash, itching, swelling
- Liver problems: pain in the right side of the stomach, yellowing of the eyes or skin, dark urine, muscle weakness
Source: DailyMed
The following side effects have also been reported
Side effects that you should report to your care team as soon as possible:
- Allergic reactions—skin rash, itching, hives, swelling of the face, lips, tongue, or throat
- Fever, chills, unusual weakness or fatigue, loss of appetite, nausea, headache, dizziness, feeling faint or lightheaded, shortness of breath, fast or irregular heartbeat, which may be signs of cytokine release syndrome
- Liver injury—right upper belly pain, loss of appetite, nausea, light-colored stool, dark yellow or brown urine, yellowing skin or eyes, unusual weakness or fatigue
Side effects that usually do not require medical attention (report these to your care team if they continue or are bothersome):
Pros and cons of Kimmtrak (tebentafasp)
Pros
Given once a week over 15-20 minutes
Recommended option for advanced or metastatic uveal melanoma with specific biomarkers
Activates your own immune system to attack cancer cells
Cons
Requires hospital stay with the first 3 doses
Can cause serious side effects like CRS and skin reactions
Only works for people with the HLA-A*02:01 biomarker
Pharmacist tips for Kimmtrak (tebentafasp)
Kimmtrak (tebentafasp) can cause cytokine release syndrome (CRS), a serious reaction where your immune system becomes overly activated. Let your oncologist know right away if you have symptoms like fever, chills, headache, trouble breathing, nausea, vomiting, or tiredness.
Each Kimmtrak (tebentafasp) infusion lasts 15 to 20 minutes, but you’ll likely stay in the hospital for a day after your first 3 doses so your care team can watch for serious side effects like CRS. If you handle the first doses well, you can get the rest of your treatments at an infusion center or clinic, where your care team will monitor you for at least 30 minutes after each dose.
Kimmtrak (tebentafasp) commonly causes rashes. If you develop a rash during treatment, tell your care team right away. They might recommend antihistamines, like diphenhydramine, to help with itching or steroid creams to treat the rash.
Kimmtrak (tebentafasp) can raise your liver enzyme levels. Your care team will check your blood tests for liver problems. Let your oncologist know if you experience symptoms like pain in the right side of your stomach, yellowing of the eyes or skin, dark urine, or muscle weakness.
Kimmtrak (tebentafasp) can cause harm to unborn babies. If you can get pregnant, you might need to take a pregnancy test before starting treatment. To be safe, it’s recommended to use birth control during treatment and for 1 week after your last dose.
Avoid breastfeeding while taking Kimmtrak (tebentafasp) and for 1 week after the last dose. It’s not known if this medication passes into breast milk, but it could potentially harm a nursing infant.
Frequently asked questions about Kimmtrak (tebentafasp)
How to save using GoodRx
What are the risks and warnings for Kimmtrak (tebentafasp)?
Kimmtrak (tebentafasp) can cause some serious health issues. This risk may be even higher for certain groups. If this worries you, talk to your doctor or pharmacist about other options.
Cytokine release syndrome
Cytokine release syndrome (CRS) is a common and potentially life-threatening side effect of Kimmtrak (tebentafasp). CRS happens when immune proteins called cytokines overreact to the medication. Most people experience CRS during the first 3 injections, as their oncologist gradually raises the dose. Symptoms of CRS include fever, low blood pressure, trouble breathing, chills, nausea, vomiting, rash, fatigue, and headache. In more serious cases, CRS can lead to organ damage.
To keep you safe, your care team will have you stay in the hospital for a day after your first 3 doses of Kimmtrak (tebentafasp) to watch for symptoms and provide treatment if needed. If you develop CRS, your care team will pause treatment. Once you recover, you might be able to restart the medication. If your symptoms are severe, your oncologist might stop the treatment altogether.
Skin reactions
In studies, more than half of the people taking Kimmtrak (tebentafasp) had rash, itching, or skin swelling during treatment. These skin problems were usually mild, started as early as 1 day after a dose, and improved within a week. If you notice any skin changes, tell your care team. They might recommend antihistamines or steroids, depending on how long or severe the symptoms are. If the reactions are serious, your oncologist might pause or stop Kimmtrak (tebentafasp).
Liver problems
Sometimes, people taking Kimmtrak (tebentafasp) have higher liver enzyme levels, usually within the first 3 treatments. Typically, these were often mild and improved within about a week. Your care team will check your liver with lab tests, as you likely won’t notice symptoms or feel different. If your liver enzymes rise, your oncologist might pause or adjust your treatment based on how severe the changes are. Let your care team know if you have any symptoms of liver problems, like yellowing of the skin or eyes, dark urine, or pain in the upper right side of your stomach.
Harm to unborn baby
Based on the way Kimmtrak (tebentafasp) works, it might harm an unborn baby if taken during pregnancy. To avoid this risk, if you can get pregnant, use birth control while taking Kimmtrak (tebentafasp) and for 1 week after your last dose. Your oncologist might require a negative pregnancy test before starting treatment. Let them know right away if you become pregnant while taking Kimmtrak (tebentafasp).
Kimmtrak (tebentafasp) dosage forms
Typical dosing for Kimmtrak (tebentafasp)
Kimmtrak (tebentafasp) is given as an IV infusion by a healthcare professional once a week. Your care team will start with a lower dose and slowly increase it to the typical maintenance dose of 68 mcg.
Day 1: 20 mcg
Day 8: 30 mcg
Day 15, and weekly after that: 68 mcg
What is the latest news about Kimmtrak (tebentafasp)?
Get savings updates for Kimmtrak (tebentafasp)
Receive price alerts, news, and other messages from GoodRx about Kimmtrak (tebentafasp) and other healthcare topics and relevant savings offers.By signing up, I agree to GoodRx's Terms and Privacy Policy, and to receive marketing messages from GoodRx.
References
Best studies we foundAmerican Cancer Society. (n.d.). Chemotherapy.
Immunocore Commercial LLC. (2024). Kimmtrak- tebentafusp injection, solution, concentrate [package insert]. DailyMed.
Menon, A. P., et al. (2023). Modulating T cell responses by targeting CD3. Cancers.
Nathan, P., et al. (2021). Overall survival benefit with tebentafusp in metastatic uveal melanoma. The New England Journal of Medicine.
National Cancer Institute. (n.d.). HLA-A*02:01 antigen.
National Cancer Institute. (n.d.). Median survival.
National Cancer Institute. (n.d.). Metastasis.
National Cancer Institute. (n.d.). T cell.
National Cancer Institute. (n.d.). Uveal melanoma.
National Cancer Institute. (2025). Intraocular (uveal) melanoma treatment (PDQ®) – Patient version.
Seth, R., et al. (2022). Systemic therapy for melanoma: ASCO guideline rapid recommendation update. Journal of Clinical Oncology.
Shimabukuro-Vornhagen, A., et al. (2018). Cytokine release syndrome. Journal for Immunotherapy of Cancer.
U.S. Food and Drug Administration. (2022). FDA approves tebentafusp-tebn for unresectable or metastatic uveal melanoma.
Browse medications
View AllResearch prescriptions and over-the-counter medications from A to Z, compare drug prices, and start saving.