Skip to nav Skip to content

An illustration of an immune cell in action.

Immunotherapy is a cancer treatment that is showing increasing promise for patients with metastasized Merkel cell carcinoma (MCC) – an uncommon form of skin cancer that tends to spread rapidly. This therapy stimulates the patient’s own immune system to seek out and attack cancer cells by using drugs known as immune checkpoint inhibitors.

What are immune checkpoint inhibitors?

A healthy immune system focuses on destroying “invaders” like viruses and bacteria with the help of immune checkpoints, which are proteins on immune cells that essentially function as on/off switches. Turning an immune checkpoint on or off can spark an immune response, depending on the scenario. Cancer cells can sometimes take advantage of these checkpoints to avoid being targeted by the immune system.  

One example of an immune checkpoint protein is PD-1, which is located on immune cells known as T cells. PD-1 serves as a switch that controls whether or not T cells target cancer and other cells in the body. This switch can be turned off when it comes in contact with PD-L1, a protein that is found in large quantities on some cancer cells. Immune checkpoint inhibitor drugs like pembrolizumab (Keytruda®), nivolumab (Opdivo®) and avelumab (Bavencio®) work to disrupt the PD-1/PD-L1 partnership and promote a more effective cancer-fighting immune response.

In general, immunotherapy has proven to be a more successful treatment for metastasized Merkel cell carcinoma than chemotherapy with a lower potential for severe side effects.  More immunotherapy drugs for Merkel cell carcinoma are currently being evaluated by the Federal Drug Administration (FDA) and are expected to be available for patients in the future.

Side effects of immune checkpoint inhibitors

Many patients report minimal disruption to their quality of life while receiving immunotherapy. Like most other cancer treatments, though, immunotherapy is associated with a few side effects. Some of the most common include:

  • Cough
  • Fatigue
  • Itching or rashes
  • Nausea
  • Loss of appetite
  • Joint pain

Less commonly, severe reactions can occur, including:

  • Pneumonitis (lung inflammation)
  • Hepatitis
  • Diarrhea
  • Hormonal changes
  • Nerve damage

The best way for a patient to prevent these side effects is to stay in contact with his or her oncologist and promptly report any unexpected discomfort. Immunotherapy treatment may need to be paused or adjusted based on the severity of side effects and the overall health of the patient.

Merkel cell carcinoma immunotherapy and treatment at Moffitt

Moffitt Cancer Center’s Cutaneous Oncology Program is home to a collaborative team of physicians from multiple specialties who focus exclusively on skin cancers. As Moffitt is a high-volume cancer center trusted by patients throughout the country, our specialists have a unique level of experience treating uncommon and complex malignancies like Merkel cell carcinoma – expertise that translates into more positive outcomes and improved quality of life for our patients.

Moffitt stands at the forefront of skin cancer treatment and offers a full spectrum of care under one roof, including surgery, radiation therapy, chemotherapy, immunotherapy and cosmetic procedures once treatment is complete. Moreover, our ambitious clinical trials for Merkel cell carcinoma and other cancers have led to our status as a National Cancer Institute-designated Comprehensive Cancer Center. Moffitt is currently the only Florida-based cancer center with this designation.

Reading about the details of immunotherapy for Merkel cell carcinoma may leave you feeling overwhelmed. But, as a Moffitt patient, you’ll always have a place to turn for support and the guidance you need to make confident decisions about your cancer treatment. If you’d like to speak with a Moffitt oncologist about immunotherapy and our approach to Merkel cell carcinoma treatment, submit a new patient registration form online or call 1-888-663-3488. A referral is not required to visit Moffitt.