How Does Immunotherapy Work to Treat Melanoma?

Checkpoint inhibitors

T cells are a type of white blood cell in your immune system that help fight off cancer.

To stop T cells from attacking healthy cells in your body, your immune system uses certain proteins known as “checkpoints.” Sometimes melanoma skin cancer cells use checkpoint proteins to prevent T cells from killing them.

Checkpoint inhibitors are a type of medication that block checkpoint proteins. They attach to antigens on the outside of cancer cells, which allows T cells to attack and kill those cells.

Checkpoint inhibitors may be prescribed to treat stage 3 or stage 4 melanomas that can’t be removed with surgery. Or, they may also be prescribed in combination with surgery.

The Food and Drug Administration (FDA) has approved three types of checkpoint inhibitors to treat melanoma: ipilimumab (Yervoy), pembrolizumab (Keytruda), and nivolumab (Opdivo).

Ipilimumab (Yervoy)

Yervoy blocks a type of checkpoint protein known as CTLA-4.

If your doctor prescribes Yervoy, you’ll receive four doses of the medication through intravenous (IV) infusion. You’ll receive one dose every 3 weeks.

Pembrolizumab (Keytruda)

Keytruda targets a kind of checkpoint protein called PD-1.

Keytruda is administered by IV infusion, usually once every 3 weeks.

Nivolumab (Opdivo)

Like Keytruda, Opdivo targets PD-1.

If you get treated with Opdivo, you will receive the drug by IV infusion once every 2 to 3 weeks. Your doctor might prescribe Opdivo alone or in combination with Yervoy.

Potential side effects

Treatment with checkpoint inhibitors may cause side effects, such as:

• fatigue
• diarrhea
• headache
• skin rash
• coughing
• difficulty breathing
• liver problems, which may cause yellow skin and eyes
• lung problems, which may cause coughing or difficulty breathing
• thyroid problems, which may cause changes in your body weight, body temperature, blood pressure, or heart rate

In rare cases, treatment with checkpoint inhibitors causes life threatening immune responses. Let your doctor know right away if you think may be experiencing side effects.

Cytokine therapy

Cytokines are a type of protein that your body produces naturally. Scientists can also create man-made cytokines in a laboratory.

Cytokines act as chemical messengers that allow immune cells to communicate with each other. This helps control how your immune system responds to diseases.

Treatment with man-made cytokines may help give your immune system a boost and trigger a stronger response against cancer cells.

Three types of man-made cytokines have been approved to treat melanoma skin cancer: interferon alfa-2b (Intron A), pegylated interferon alfa-2b (Sylatron), and interleukin-2 (aldesleukin, Proleukin).

Interferon alfa-2b (Intron A)

Intron A is used to treat early stage melanoma skin cancer.

It’s also used to treat some advanced cases of melanoma, when the cancer has only spread to nearby areas. This is known as locally advanced melanoma.

Intron A is typically administered after surgery, as an adjuvant treatment. It may help reduce the chances that the cancer will come back after being surgically removed.

If your doctor prescribes Intron A, you will likely receive high-dose injections of the drug several days per week for a year.

Pegylated interferon alfa-2b (Sylatron)

Like Intron A, Sylatron is typically administered as an adjuvant treatment after surgery. It may help stop the cancer from returning.

Sylatron is injected under the skin. If you receive this medication, your doctor will likely prescribe a starting dose of 6 mg per week for 8 weeks. After you receive those initial doses, your doctor may prescribe a smaller dose of 3 mg per week for up to 5 years.

Interleukin-2 (aldesleukin, Proleukin)

Your doctor may prescribe Proleukin if you have stage 3 or stage 4 melanoma skin cancer that has spread to other parts of your body.

Sometimes, this drug is also used when melanoma has returned after treatment and there are too many tumors on the skin to remove them surgically.

Treatment with Proleukin may help shrink and limit the growth of melanoma tumors.

If your doctor prescribes Proleukin, a healthcare professional will inject it directly into the tumor. You will need to get multiple injections, two to three times per day for 1 to 2 weeks.

Potential side effects

Treatment with cytokine therapy may cause side effects, such as:

• fever
• chills
• muscle aches
• joint pain
• fatigue
• nausea
• vomiting
• diarrhea
• loss of appetite
• itchy skin
• red skin
• rash
• hair loss
• fluid build-up
• mood changes

These drugs can also cause your blood cell count to drop. This may raise your risk of infection.

If you think you may have developed side effects, let your doctor know right away.

Oncolytic virus therapy

Oncolytic viruses are viruses that have been genetically modified to kill cancer cells, without harming healthy cells.

When an oncolytic virus is injected into a melanoma skin cancer tumor, it enters the cancer cells and starts to multiply. This causes the cancer cells to burst and die.

When the infected cancer cells die, they release antigens. That triggers your immune system to target other cancer cells in your body that have the same antigens.

There’s one type of oncolytic virus used to treat melanoma. It’s known as talimogene laherparepvec (Imlygic), or T-VEC.

Potential side effects

Treatment with T-VEC may cause side effects, such as:

• fatigue
• fever
• chills
• nausea

If you think you may be experiencing side effects, contact your doctor.

The takeaway

If you have melanoma skin cancer, your doctor may prescribe one or more types of immunotherapy to help improve your immune system’s ability to find and kill cancer cells.

Immunotherapy is often combined with other treatments for melanoma, such as surgery, radiation therapy, or chemotherapy drugs. Talk to your doctor to learn more about your treatment options.