MET Inhibitor Swelling (Edema)

What is a MET Inhibitor?

MET Inhibitors are a group of medicines used to treat a few types of cancer. These medicines work by stopping the activity of the mesenchymal-epithelial transition (MET) gene. These medicines include:

• Capmatinib (Tabrecta™)
• Tepotinib (Tepmetko®)
• Crizotinib (Xalkori®) – an ALK inhibitor with an effect on MET

What is edema?

Edema is swelling that is caused by a buildup of fluid. It can happen anywhere in your body. MET inhibitors can cause swelling in your feet and legs or hands and arms. It may start in your feet/hands and spread up your leg/arm. You might first notice your socks and shoes, watch, or jewelry feel tight. Let your provider know if this happens. It can be helpful to try to manage it early on.

Some people have a fluid build-up caused by other medical issues, such as heart failure. Medicines called diuretics or water pills can help with swelling caused by heart failure, but these tend to not work as well with MET inhibitor swelling.

What can I do to manage this swelling?

Swelling is a common side effect of these medicines. Report any swelling in your feet or hands to your provider. Some tips to help manage swelling include:

• Keep the swollen limb (legs or arms) above the level of your heart whenever possible. Sit in a chair with your feet or arms propped up on pillows.
• Some things can make swelling worse including:
  • Eating foods high in salt (or sodium).
  • Heat and humidity.
• Talk to your provider about compression stockings, gloves, or sleeves. These can help move the extra fluid back toward the heart. (more on these below)
• You may benefit from seeing a lymphedema therapist. These are physical therapists who can help a patient manage a type of swelling called lymphedema. MET inhibitor swelling is a lot like lymphedema. Look for a therapist who is certified and has the credentials “CLT” or Certified Lymphedema Therapist. CLTs provide massage to help drain fluid and prescribe custom compression garments and pumps or devices.

Using Compression Garments

Compression garments are tight socks, stockings, gloves, or sleeves that help move fluid from the arm or leg back to the heart. They come in different levels of tightness and coverage areas.

Levels of Tightness

Compression garments can be bought in pharmacies or through medical supply stores. They come in different levels of compression.

• Over-the-counter garments can be bought at a pharmacy. These are 15-18 mmHg of compression. These might be called running socks. These are the least tight and also the least expensive.
• Medical grade compression is tighter, and you might need help putting these garments on. There are two levels of compression:
  • Compression below 20 mmHg - This level is called class 1. It may not be covered by insurance and can be expensive.
  • 20-30mmHg compression – This may also be called class 2. This level may be covered by insurance. If it is not covered by insurance, it may cost $50-300 or more.
  • 30-40mmHg compression – This may also be called class 3.
  • There are higher levels of compression that can be used for more severe cases called class 4.
  • Your CLT will work with you to determine the right class for you based on your situation and how you do wearing the garment.
  • Medicare does not have any coverage for garments. If you have private insurance, contact your company to find out what is covered.

Area of Compression Coverage

Start with less coverage. For instance, if you have swelling in the foot and/or ankle, start with a knee-high compression stocking. If it moves up your leg, you may move to a thigh-high or full leg garment. If your hand is swollen, start with a compression glove and move to a sleeve if it moves up your arm.

Your lymphedema therapist can help you with garment selection and understanding what costs insurance may cover.

When should I contact my provider?

You should report any of the following to your provider:

• At the first sign of swelling, contact your provider. If you notice your jewelry, clothing or shoes feel tight, this is important to share with your provider.
• One concern with swelling is the risk of infection or cellulitis. If you notice any redness or warmth in the swollen limb, or if you develop a fever, contact your provider right away.
• Try to protect the swollen limb from cuts or insect bites.
  • Use insect repellent.
  • If you get a cut or scratch, clean it well with soap and water. Cover with antibiotic ointment and a band-aid.
• If you develop swelling that is not the same on both sides – one leg or arm is worse than the other, or if you have any difficulty breathing, call 911 or go to the nearest emergency room as these can be signs of a blood clot.

Coping with Swelling

Lymphedema therapy, compression garments, and diuretics can help to reduce the swelling, but it often does not go away completely. Swelling may become a chronic side effect that you need to find ways to cope with. If swelling is affecting your quality of life, your oncology team may reduce your dose or have you take a break from the medication, which can reduce swelling.

Swelling can make you feel uncomfortable about your appearance, in social situations, or affect your self-confidence. It is okay to have these feelings about the changes in your appearance. You can ask for help from your team and a skilled mental health practitioner.