Your UW Health Surgical Oncology Team suggests Imlygic as part of your treatment. This handout tells you what to expect before, during and after your Imlygic treatment.

Imlygic ("im m-LY-jik") is a drug that is made by changing weakened herpes simplex virus type I (the cold sore virus). Imlygic grows only in melanoma cancer cells, not in healthy cells. When it grows, the cancer cells burst open and are damaged. This may “boost” your immune system to fight the melanoma.

About Your Treatment

Your treatment will be given by injection (shot) into your tumor(s). Your health care team will decide which tumor(s) to inject and may not inject each one. The injected tumors will be covered with a clear plastic bandage for at least 7 days. You will get your second treatment 3 weeks after your first treatment. After that, you can get your treatments every 2 weeks. Your team will tell you how many cycles you will get. You may be treated for 6 months or longer.

Before Your Treatment

Before your treatment your team needs to know all the medicines you are taking. Tell us about your prescription and over the counter medicines, vitamins and herbal supplements.
Please tell us if you:

  • Take steroids or other medicines that can weaken your immune system.

  • Take antiviral medicines to treat or prevent herpes, such as acyclovir.

  • Have or have ever had HIV or AIDS, blood or bone marrow cancer, autoimmune diseases or other diseases that can weaken your immune system.

  • Have had any vaccines lately.

  • Have close contact with someone who has a weakened immune system or is pregnant.

  • Are pregnant, plan to become pregnant, or are breastfeeding or plan to breastfeed. Imlygic can harm your unborn baby. You will need to use birth control before, during, and for many months after this treatment. Do not get pregnant and do not get anyone else pregnant. Talk to your care team about your birth control options.

Side Effects

The most common side effects are flu-like symptoms that can last for 1-2 days. Other rare side effects can occur. Your doctor will discuss this with you. The most common side effects are:

  • Chills

  • Feeling tired

  • Fever

  • Nausea

  • Pain at the injection site

Tell your care team right away if you have any of these signs and symptoms of a herpes infection:

  • Pain, burning or tingling in a blister around your mouth

  • Eye pain, light sensitivity, discharge from your eyes or blurry vision

  • Weakness in your arms or legs

  • Extreme tiredness

Injection Site Care

  • Keep the lesion covered with the bandage for at least 7 days, or longer if there is drainage on the gauze.

  • Wear gloves while putting on or taking off your bandage.

  • Avoid contact of body fluids with others. Wear condoms during sex. Use other birth control.

  • If you have mouth sores, do not kiss anyone. Let your care team know about your symptoms right away.

  • Avoid getting any vaccines during treatment.

You can take the bandage off 7 days after the shot. You may need to keep it on longer if the lesions are leaking or oozing. We will give you gloves that you can throw away after each use and plastic bags. Follow the steps below:

  1. Wash your hands well with soap and water.

  2. Put on the gloves, gently take the dirty bandage off, and place it in the bag we gave you.

  3. Take the gloves off by turning them inside out and put them in the bag.

  4. Seal the plastic bag and throw it away in the garbage.

  5. Wash your hands well with soap and water.

If the bandage gets loose or comes off before 7 days, follow the steps below and replace it right away. We will give you extra supplies. You may need help changing the bandage.

  1. Wash your hands well with soap and warm water.

  2. Lay out all the supplies, such as alcohol swabs, new bandage, and a plastic bag.

  3. Put on the gloves and place the dirty bandage in the plastic bag.

  4. Wipe the area with the alcohol swab.

  5. Change gloves, as these are now dirty from the old bandage.

  6. Put the gloves and the used alcohol swab into the bag as well.

  7. Put on a fresh pair of gloves and apply the new bandage. Avoid touching the site while you put on the new bandage.

  8. Take the gloves off by turning them inside out and put them into the bag.

  9. Seal the plastic bag and throw it away in the trash.

  10. Wash your hands well with soap and warm water (wash for at least 20 seconds).


If there are signs that the skin under the bandage (not the injection site but skin that is in contact with the bandage) is getting irritated/red, please contact your care team. You may need to use a different dressing or you may need a cream to help prevent irritation.

Do not:

  • Put salves or ointments on the site

  • Scratch or pick at the site

  • Touch (with bare hands) uncovered skin that has been injected with the study drug.

What if someone is exposed to Imlygic?

If a loved one is exposed to the Imlygic HSV 1 virus (for example, leakage through the bandage onto you or a loved one):

  1. Clean the site very well with soap and water.

  2. Watch for these signs/symptoms of infection:

  • Fever

  • Aches

  • Nausea

  • Malaise (feeling uneasy or uncomfortable)

  • Pain

  • Redness/Swelling

If you think that a loved one has symptoms related to your treatment with Imlygic, contact your doctor and ask for advice. We may give them a prescription medicine, if needed.