Description and Brand Names

Drug information provided by: Merative, Micromedex®

US Brand Name

  1. Zynyz


Retifanlimab-dlwr injection is used to treat a type of skin cancer called Merkel cell carcinoma (MCC) that has returned or spread.

This medicine is to be given only by or under the direct supervision of your doctor.

This product is available in the following dosage forms:

  • Solution

Before Using

In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For this medicine, the following should be considered:


Tell your doctor if you have ever had any unusual or allergic reaction to this medicine or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods, dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.


Appropriate studies have not been performed on the relationship of age to the effects of retifanlimab-dlwr injection in the pediatric population. Safety and efficacy have not been established.


Appropriate studies performed to date have not demonstrated geriatric-specific problems that would limit the usefulness of retifanlimab-dlwr injection in the elderly.


There are no adequate studies in women for determining infant risk when using this medication during breastfeeding. Weigh the potential benefits against the potential risks before taking this medication while breastfeeding.

Drug Interactions

Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. Tell your healthcare professional if you are taking any other prescription or nonprescription (over-the-counter [OTC]) medicine.

Other Interactions

Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur. Discuss with your healthcare professional the use of your medicine with food, alcohol, or tobacco.

Other Medical Problems

The presence of other medical problems may affect the use of this medicine. Make sure you tell your doctor if you have any other medical problems, especially:

  • Colitis (inflammation of the bowels) or
  • Diabetic ketoacidosis or
  • Hepatitis (inflammation of the liver) or
  • Hyperthyroidism (high levels of thyroid hormone) or
  • Hypophysitis (inflammation of the pituitary gland) or
  • Hypothyroidism (low levels of thyroid hormone) or
  • Immune system problems or
  • Nephritis (inflammation of the kidneys) or
  • Nervous system problems (eg, Guillain-Barré syndrome, myasthenia gravis) or
  • Pneumonitis (inflammation of the lungs) or
  • Type 1 diabetes—Use with caution. May make these conditions worse.
  • Organ transplant (eg, kidney or liver transplant) or tissue transplant (eg, cornea transplant), recent—Use with caution. May increase risk for organ or tissue transplant rejection.
  • Patients who have had allogeneic hematopoietic stem cell transplant (HSCT)—Use with caution. May cause side effects to become worse.

Proper Use

A nurse or other trained health professional will give you this medicine. It is given through an IV catheter that is placed into one of your veins. It must be given slowly, so the IV will have to remain in place for at least 30 minutes every 4 weeks.

This medicine comes with a Medication Guide. Read and follow these instructions carefully. Ask your doctor if you have any questions.

Missed Dose

This medicine needs to be given on a fixed schedule. If you miss a dose, call your doctor, home health caregiver, or treatment clinic for instructions.


It is very important that your doctor check your progress at regular visits to make sure that this medicine is working properly. Blood and urine tests may be needed to check for unwanted effects.

Receiving this medicine while you are pregnant can harm your unborn baby. If you are a woman who can bear children, your doctor may give you a pregnancy test before you start using this medicine to make sure you are not pregnant. Use an effective form of birth control to keep from getting pregnant during treatment with this medicine and for 4 months after the last dose. If you think you have become pregnant while receiving the medicine, tell your doctor right away.

Tell your doctor right away if you have a cough, chest tightness, or any type of breathing problem with this medicine. These could be symptoms of a serious lung problem.

Colitis (swelling of the colon or bowel) may occur with this medicine. Tell your doctor right away if you have stomach pain or tenderness, watery or bloody diarrhea, or a fever after receiving the medicine.

Check with your doctor right away if you have pain or tenderness in the upper stomach, pale stools, dark urine, loss of appetite, nausea, unusual tiredness or weakness, or yellow eyes or skin. These could be symptoms of a serious liver problem.

Serious problems with the adrenal, pituitary, or thyroid glands (hormone glands) may occur while you are receiving this medicine. Tell your doctor if you start having continuing or unusual headaches, changes in mood or behavior (eg, being irritable or forgetful), lightheadedness, dizziness, or fainting, unusual sluggishness, or an increase in weight.

This medicine may affect blood sugar levels. If you notice a change in the results of your blood or urine sugar tests or if you have any questions, check with your doctor.

This medicine may cause serious kidney problems (eg, nephritis, kidney failure). Tell your doctor right away if you have bloody or cloudy urine, nausea, vomiting, trouble breathing, swelling of the face, feet, or lower legs, unusual tiredness or weakness, or unusual weight gain.

Serious skin reactions (eg, exfoliative dermatitis, Stevens-Johnson syndrome, drug rash with eosinophilia and systemic syndrome (DRESS), and toxic epidermal necrolysis) can occur with this medicine. Check with your doctor right away if you have blistering, peeling, or loosening of the skin, chills, cough, diarrhea, itching, joint or muscle pain, red irritated eyes, red skin lesions, often with a purple center, severe acne or skin rash, sores or ulcers on the skin, mouth or lips, or swollen glands, unusual bleeding or bruising, or unusual tiredness or weakness with this medicine.

This medicine may cause infusion-related reactions, which can be life-threatening and require immediate medical attention. Tell your doctor right away if you start to have a fever, chills or shaking, dizziness, trouble breathing, itching or rash, lightheadedness or fainting after receiving this medicine.

This medicine may increase your risk for possible organ transplant rejection. Talk to your doctor about this risk.

Call your doctor right away if you have difficulty with breathing, swallowing, or talking, muscle weakness, severe tiredness, or sudden numbness and weakness in the arms or legs. These could be symptoms of a nervous system problem.

Check with your doctor if you have a headache, confusion, seizures, stiff neck, or vomiting while receiving this medicine. These may be symptoms of encephalitis.

Pancreatitis (swelling of the pancreas) may occur while you are receiving this medicine. Tell your doctor right away if you have sudden and severe stomach pain, chills, constipation, nausea, vomiting, fever, or lightheadedness.

Tell your doctor right away if you have changes in your eyesight, severe or persistent muscle or joint pain, or severe muscle weakness after receiving this medicine.

Side Effects

Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor or nurse immediately if any of the following side effects occur:

More common

  1. Back pain
  2. black, tarry stools
  3. blistering, peeling, or loosening of the skin
  4. bone pain
  5. chest pain
  6. chills
  7. constipation
  8. cough
  9. depressed mood
  10. diarrhea
  11. dizziness
  12. dry skin and hair
  13. fainting
  14. fast or irregular heartbeat
  15. feeling cold
  16. fever
  17. hair loss
  18. hoarseness or husky voice
  19. itching
  20. joint pain
  21. muscle cramps and stiffness
  22. nervousness
  23. painful or difficult urination
  24. red irritated eyes
  25. red skin lesions, often with a purple center
  26. sensitivity to heat
  27. slowed heartbeat
  28. sore throat
  29. sores, ulcers, or white spots in the mouth or on the lips
  30. swollen glands
  31. trouble breathing
  32. unusual bleeding or bruising
  33. unusual tiredness or weakness
  34. weight gain or loss

Less common

  1. Bloody or cloudy urine
  2. dark urine
  3. drowsiness
  4. general feeling of discomfort or illness
  5. headache
  6. light-colored stools
  7. nausea and vomiting
  8. stomach cramps
  9. swelling of the face, feet, or lower legs
  10. thickening of bronchial secretions
  11. upper right abdominal or stomach pain
  12. watery or bloody diarrhea
  13. yellow eyes and skin


  1. Anxiety
  2. bleeding gyms
  3. bloating
  4. blurred vision
  5. burning feeling in the chest or stomach
  6. chest discomfort or tightness
  7. chest pain, possible moving to the left arm, neck, or shoulder
  8. confusion
  9. constipation
  10. darkening of the skin
  11. decreased amount of urine
  12. difficulty in breathing, chewing, swallowing, or talking
  13. difficulty in moving
  14. double vision
  15. drooping eyelids
  16. dry mouth
  17. eye pain or redness
  18. flushing
  19. fruit-like breath odor
  20. heavier menstrual periods
  21. inability to move the arms and legs
  22. increased blood pressure
  23. increased hunger
  24. increased thirst
  25. increased urination
  26. indigestion
  27. irritability
  28. joint pain, swelling, or redness
  29. loss of appetite
  30. loss of consciousness
  31. lower back or side pain
  32. mental depression
  33. muscle aches or cramps
  34. nosebleeds
  35. numbness or tingling in the fingers, face, or feet
  36. pains in the stomach, side, or abdomen, possibly radiating to the back
  37. pale skin
  38. pinpoint red spots on the skin
  39. redness, soreness, or itching skin
  40. seizures
  41. sensitivity to light
  42. skin rash
  43. stiff neck or back
  44. stomach pain, discomfort, or upset
  45. sudden numbness and weakness in the arms and legs
  46. sweating
  47. tearing
  48. tenderness in the stomach area
  49. throbbing pain

Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

More common

  1. Lack or loss of strength
  2. pain in the arms or legs

Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.

Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.