Isatuximab-irfc (Sarclisa®)

Isatuximab-irfc is a monoclonal antibody. Monoclonal antibodies are made in a lab to attach to the targets found on certain types of cancer cells. The antibody “calls” the immune system to attack the cell it is attached to, causing the immune system to kill the cell. These antibodies can work in different ways, such as by stimulating (revving up) the immune system to kill the cell, blocking cell growth or other things needed for cell growth. 

Isatuximab-irfc is an antibody directed against a protein called CD38, found on the surface of multiple myeloma cells. Once isatuximab-irfc attaches itself to the cells that have CD38, it tells the body's immune system to attack and kill those cells.

How to Take Isatuximab-irfc

Isatuximab-irfc is given by intravenous infusion (IV, into a vein). The dose and how often you receive this medication will be decided by your provider. 

Medications are given before and after the infusion to prevent reactions to this medicine. These medications include:

• A steroid, such as IV corticosteroid (methylprednisolone) to prevent an infusion reaction.
• Acetaminophen (Tylenol) to prevent a fever.
• Oral or IV antihistamine (diphenhydramine/Benadryl) to prevent an infusion reaction.
• You will also receive an oral corticosteroid to take after treatment to lower your risk of a delayed infusion reaction.

Isatuximab-irfc can affect blood type testing (cross-matching and antibody screening). If you need a blood transfusion, be sure your provider and the blood bank know you have received this medication. A type and screen (blood test to check what type of blood you have) may be done before treatment with isatuximab-irfc.

Possible Side Effects

There are a number of things you can do to manage the side effect of isatuximab-irfc. Talk to your care team about these recommendations. They can help you decide what will work best for you. These are some of the most common or important side effects:

Low Red Blood Cell Count (Anemia)

Your red blood cells are responsible for carrying oxygen to the tissues in your body. When the red cell count is low, you may feel tired or weak. You should let your oncology care team know if you experience any shortness of breath, difficulty breathing, or pain in your chest. If the count gets too low, you may receive a blood transfusion.

Low White Blood Cell Count (Leukopenia or Neutropenia)

This medication can cause life-threatening infections, with or without a decrease in white blood cell counts.

White blood cells (WBC) are important for fighting infection. While receiving treatment, your WBC count can drop, putting you at a higher risk of getting an infection. You should let your doctor or nurse know right away if you have a fever (temperature greater than 100.4°F or 38°C), sore throat or cold, shortness of breath, cough, burning with urination, or a sore that doesn't heal.

Tips for preventing infection:

• Washing hands, both yours and your visitors, is the best way to prevent the spread of infection.
• Avoid large crowds and people who are sick (i.e.: those who have a cold, fever, or cough or live with someone with these symptoms).
• When working in your yard, wear protective clothing including long pants and gloves.
• Do not handle pet waste.
• Keep all cuts or scratches clean.
• Shower or bathe daily and perform frequent mouth care.
• Do not cut cuticles or ingrown nails. You may wear nail polish, but not fake nails.
• Ask your oncology care team before scheduling dental appointments or procedures.
• Ask your oncology care team before you, or someone you live with has any vaccinations.

Low Platelet Count (Thrombocytopenia)

Platelets help your blood clot, so when the count is low you are at a higher risk of bleeding. Let your oncology care team know if you have any excess bruising or bleeding, including nose bleeds, bleeding gums, or blood in your urine or stool. If the platelet count becomes too low, you may receive a transfusion of platelets.

• Do not use a razor (an electric razor is fine).
• Avoid contact sports and activities that can result in injury or bleeding.
• Do not take aspirin (salicylic acid), non-steroidal, anti-inflammatory medications (NSAIDs) such as Motrin/Advil (ibuprofen), Aleve (naproxen), Celebrex (celecoxib) etc. as these can all increase the risk of bleeding. Please consult with your healthcare team regarding the use of these agents and all over the counter medications/supplements while on therapy.
• Do not floss or use toothpicks and use a soft-bristle toothbrush to brush your teeth.

Infusion-Related Side Effects

The infusion can cause a reaction that may lead to shortness of breath, chills, fever, high blood pressure, nausea, and vomiting. You will receive steroids, acetaminophen, heartburn medication, and diphenhydramine prior to the infusion to help prevent these reactions. Your oncology care team will tell you what to do if this happens.

Pneumonia/Upper Respiratory Infection

This medication can cause pneumonia or upper respiratory infection. Report coughing, shortness of breath, and fever to your oncology care team.

Diarrhea

Your oncology care team can recommend medications to relieve diarrhea. Also, try eating low-fiber, bland foods, such as white rice and boiled or baked chicken. Avoid raw fruits, vegetables, whole-grain bread, cereals, and seeds. Soluble fiber is found in some foods and absorbs fluid, which can help relieve diarrhea. Foods high in soluble fiber include applesauce, bananas (ripe), canned fruit, orange sections, boiled potatoes, white rice, products made with white flour, oatmeal, cream of rice, cream of wheat, and farina. Drink 8-10 glasses of non-alcoholic, un-caffeinated fluid a day to prevent dehydration.

Less common, but important side effects include:

• Secondary Cancer: A secondary cancer is one that develops as a result of cancer treatment for another cancer. This is quite rare, but you should be aware of the risk. This medication is linked with skin cancer and other solid tumors. This can happen years after treatment. Risk is higher with repeated treatments or high doses. Your provider will monitor your labs closely. Consider having a complete blood count with differential checked every year by your primary care provider if you received high-risk therapies. Because this medication has been linked with skin cancers, it is important to practice sun safety. Avoid the sun between 10-2 pm, when it is strongest. Wear sunscreen (at least SPF 15) everyday; wear sunglasses, a hat, and long sleeves/pants to protect your skin and seek out shade whenever possible.

Reproductive Concerns

Exposure of an unborn child to this medication could cause birth defects, so you should not become pregnant or father a child while on this medication. Effective birth control is necessary during treatment and for at least 5 months after treatment. Even if your menstrual cycle stops or you believe you are not producing sperm, you could still be fertile and conceive. You should not breastfeed while receiving this medication.

This medication is given in combination with pomalidomide which can also cause serious birth defects. Talk with your care team about this medication.