Classification: kinase inhibitor
About Cobimetinib (Cotellic®)
BRAF is a protein kinase that plays a role in regulating genes that are responsible for cell replication and survival. It is estimated that 50% of melanomas contain an abnormal form of BRAF (also called a mutation). This mutated form of BRAF promotes overgrowth of these cancer cells. This medication works by interfering with the actions of the abnormal BRAF, inhibiting cell replication and potentially causing cell death.
How to take Cobimetinib
Cobimetinib is a tablet taken orally (by mouth). It taken once a day for the first 21 days of a 28 day cycle. It can be taken with or without food. If you miss a dose, or vomit soon after taking your dose, take the next dose as scheduled. Do not take an extra dose to make up for a missed / vomited dose.
The blood levels of this medication can be affected by certain foods and medications, so they should be avoided. These include: grapefruit, grapefruit juice, verapamil, ketoconazole, rifampin, phenytoin, St. John’s wort, modafanil, and many others. Be sure to tell your healthcare provider about all medications and supplements you take.
Because this medication only works in melanoma that has one of two specific BRAF mutations, called V600E or V600K, this abnormality must be tested for prior to starting the medication to identify patients appropriate for therapy. In order to test for mutated BRAF, a sample of the tumor is sent to a special laboratory that performs this test.
Storage and Handling
Store this medication at room temperature in the original container. If you prefer to use a pillbox, discuss this with your oncology pharmacist. Ask your oncology team where to return any unused medication for disposal. Do not flush down the toilet or throw in the trash.
Where do I get this medication?
Cobimetinib is available through select specialty pharmacies. Your oncology team will work with your prescription drug plan to identify an in-network specialty pharmacy for distribution of this medication and shipment directly to your home.
This medication may be covered under your prescription drug plan. Patient assistance may be available to qualifying individuals without prescription drug coverage. Co-pay cards, which reduce the patient co-pay responsibility for eligible commercially (non-government sponsored) insured patients, may also be available. Your care team can help you find these resources, if they are available.
Possible Side Effects
There are a number of things you can do to manage the side effects of cobimetinib. Talk to your doctor or nurse about these recommendations. They can help you decide what will work best for you. These are some of the most common side effects:
Your oncology 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 breads, 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 on non-alcoholic, un-caffeinated fluid a day to prevent dehydration.
Nausea and/or Vomiting
Talk to your doctor or nurse so they can prescribe medications to help you manage nausea and vomiting. In addition, dietary changes may help. Avoid things that may worsen the symptoms, such as heavy or greasy/fatty, spicy or acidic foods (lemons, tomatoes, oranges). Try antacids, (e.g. milk of magnesia, calcium tablets such as Tums), saltines, or ginger ale to lessen symptoms.
Call your doctor or nurse if you are unable to keep fluids down for more than 12 hours or if you feel lightheaded or dizzy at any time.
Fever can be a serious side effect of this medication. If you develop a fever of 101 or greater, call your healthcare team right away and before taking the next dose of medication.
New Skin Cancer
In clinical trials, some patients developed a new skin cancer (Basal cell or squamous cell cancer). You should have skin examinations prior to starting treatment, and then every 2 months while on therapy, and for 6 months after the medication has been stopped. Check your own skin regularly and report any new growths, sores or bumps that bleed or do not heal, or notice any changes in moles to your healthcare provider.
Some patients may develop a rash, with or without itching, that can become severe or become infected if left untreated. Use an alcohol free moisturizer on your skin and lips; avoid moisturizers with perfumes or scents. If your skin does crack or bleed, be sure to keep the area clean to avoid infection. Be sure to notify your healthcare provider of any rash that develops, as this can be a serious reaction. They can give you more tips on caring for your skin and prescribe topical or oral therapy to help with the itching and rash.
This medication can make your skin more sensitive to the sun, which can result in severe sunburn or rash. Sun sensitivity can last even after chemotherapy is completed. Avoid the sun between 10-2pm, when it is strongest. Wear sunscreen (at least SPF 15) everyday; wear sunglasses, a hat and long sleeves/pants to protect your skin, a lip balm with SPF>30, and seek out shade whenever possible.
Notify your care team if you develop red, painful or itchy skin, "sunburn", skin irritation, bumps or thick, dry skin.
While receiving cobimetinib, some patients may develop eye problems, including retinopathy, which is a build-up of fluid underneath the retina. Notify your healthcare team if you develop any eye pain, swelling or redness of the eye, or any vision changes, including blurry vision, sensitivity to light, or seeing halos (bright circles that appear around a light, such as a car headlight).
This medication may increase the risk of bleeding. If you experience headaches, dizziness, cough up blood or blood clots, vomit blood, have red or black tar like looking stools, excessive vaginal bleeding, blood in the urine or bleeding gums, contact your care team immediately.
Cobimetinib can cause heart problems, including heart failure. Your healthcare team may check your baseline heart function with an echocardiogram or MUGA scan before you start taking this medication. Your heart function will be checked one month after starting treatment with cobimetinib, and then every three months until you stop taking the medication. Notify your provider if you develop rapid weight gain, swelling of ankles or feet, shortness of breath, coughing or wheezing, or feel like your heart is pounding or racing.
Rhabdomyolosis is a condition in which muscle damage occurs and breaks down, releasing cells into the bloodstream. This quick breakdown of muscle cells can become severe and lead to kidney damage and even death. Notify your provider if you develop muscle pain or weakness, confusion, vomiting, and dark or brown colored urine.
This medication can cause liver toxicity, which your doctor may monitor for using blood tests called liver function tests. Notify your healthcare provider if you notice yellowing of the skin or eyes, your urine appears dark or brown or pain in your abdomen, as these can be signs of liver toxicity.
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 2 weeks 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 consult with your healthcare team before breastfeeding while receiving this medication.