Cobimetinib

Cobimetinib is a prescription medication that is used with the drug Zelboraf to treat advanced melanoma. Cobimetinib belongs to a group of drugs called kinase inhibitors. These work by blocking the activity of the enzyme MEK to prevent or slow cancer cell growth.

This medication comes in a tablet form and is taken once a day with or without food for 21 days followed by a 7 day period of no medication for a 28 day cycle.

Common side effects of cobimetinib include diarrhea, sunburn, and nausea.

Cobimetinib is a prescription medication used with Zelboraf to treat melanoma (skin cancer) that has spread to other parts of the body or cannot be removed by surgery and has a certain type of abnormal "BRAF" gene.

This medication may be prescribed for other uses. Ask your doctor or pharmacist for more information.

Cobimetinib may be found in some form under the following brand names:

• Cotellic

Serious side effects have been reported with cobimetinib. See the "Drug Precautions" section.

Common side effects of cobimetinib include the following:

• diarrhea
• sunburn
• sun sensitivity
• nausea
• fever
• vomiting
• changes in blood tests

This is not a complete list of cobimetinib side effects. Ask your doctor or pharmacist for more information.

Tell your doctor if you have any side effect that bothers you or that does not go away.

Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.

Tell your doctor about all the medicines you take, including prescription and non-prescription medicines, vitamins, and herbal supplements. Especially tell your doctor if you take:

• medications that block a protein in the body (CYP3A4) such as some macrolide antibiotics (clarithromycin, erythromycin, telithromycin), some HIV protease inhibitors (atazanavir, indinavir, nelfinavir, ritonavir, saquinavir), some HCV protease inhibitors (boceprevir, telaprevir), some azole antifungals (ketoconazole, itraconazole, posaconazole, voriconazole), conivaptan (Vaprisol), delavirdine (Rescriptor), and nefazodone

• medications that increase the activity of the enzyme CYP3A4 such as carbamazepine (Tegretol, Equetro, Carbatrol), efavirenz, phenobarbital, phenytoin (Dilantin), rifampin (Rifadin), St John's wort, and nimodipine (Nimotop)

This is not a complete list of cobimetinib drug interactions. Ask your doctor or pharmacist for more information.

Serious side effects have been reported with cobimetinib including the following:

Risk of skin cancer. People who take cobimetinib may be at risk for developing new onset skin cancer, as well as other types of cancer.

Increased risk of bleeding. Ccobimetinib can cause bleeding inside the body that can be serious and require urgent medical attention. Alert your doctor if you develop signs or symptoms of a hemorrhage (bleed) such as:

• bleeding that is severe or you cannot control
• red, pink, or brown urine
• red or black stools (looks like tar)
• coughing up blood
• vomit blood or your vomit looks like coffee grounds
• headaches, feeling dizzy or weak
• menstrual bleeding or vaginal bleeding that is heavier than normal

Heart problems that can lead to inadequate pumping of the blood by the heart. Toxicity from cobimetinib may occur that causes disease of the heart muscles. Your doctor might order tests before you start cobimetinib and while taking this medication to monitor your heart function.

Rash. Severe rash and other skin reactions can occur with cobimetinib. Tell your doctor if you experience any signs of a rash or changes in your skin.

Eye problems. Toxicity can occur from cobimetinib that affects your eyes where fluid build ups under layers of the retina (a layer of tissue at the back of your inner eye). Your doctor may recommend eye exams while you are on cobimetinib. Alert your doctor if you develop any problems with your vision.

Abnormal liver test or liver injury. Cobimetinib may cause a decline in your liver function. Tell your healthcare provider about any signs or symptoms of liver damage, which include the following:

• loss of appetite or start losing weight (anorexia)
• nausea or vomiting
• feel tired
• stomach pain or tenderness
• dark urine or light colored stools
• yellowing of your skin or the whites of your eyes
• fever or rash

Increased levels of an enzyme in the blood. Cobimetinib can cause serious muscle problems that can lead to problems with your kidneys. Tell your healthcare provider if you develop any of these symptoms:

• dark colored urine
• decreased urine output
• feeling weak or tired
• muscle stiffness or muscle pain
• muscle weakness

Photosensitivity. Cobimetinib can make your skin sensitive to the sun and the light from sunlamps and tanning beds. Avoid sunlamps, tanning beds, and try to limit your time in the sun. Make sure you wear clothes that protect your skin and use broad-spectrum sunscreen and protective lip balm when outdoors. You could get severe sunburn, blisters or swelling of your skin. If you get any of these symptoms while taking cobimetinib, call your doctor right away.

Embryo-Fetal Toxicity. Cobimetinib can cause serious harm to unborn babies if being given to a pregnant woman. Females of reproductive age should use an effective method of birth control during treatment with cobimetinib and for 2 weeks after finishing cobimetinib. Talk to your healthcare provider about birth control methods that may be right for you. Tell your doctor immediately if you become pregnant or think you might be pregnant with taking cobimetinib.

Do not take cobimetinib if you are allergic to cobimetinib or to any of its ingredients.

Medications can interact with certain foods. In some cases, this may be harmful and your doctor may advise you to avoid certain foods. In the case of cobimetinib, there are no specific foods that you must exclude from your diet when receiving this medication.

Before taking cobimetinib, tell your doctor about all of your medical conditions. Especially tell your doctor if you:

• are allergic to cobimetinib or to any of its ingredients
• have any previous or current skin problems other than melanoma
• have any medical conditions or take any medications that increase your risk of bleeding
• have any eye problems
• have any liver problems
• have any heart problems
• have any muscle problems
• have any other medical conditions
• are pregnant or plan to become pregnant
• are breastfeeding or plan to breastfeed

Tell your doctor about all the medicines you take including prescription and non-prescription medicines, vitamins, and herbal supplements.

Tell your doctor if you are pregnant or plan to become pregnant.

Although there have been no well-done studies in humans with cobimetinib, studies in pregnant animals have shown serious harm to unborn babies. Because of this, cobimetinib should not be taken if you are pregnant.

Females of reproductive age should use an effective method of birth control during treatment with cobimetinib and for at least 2 weeks after finishing cobimetinib. Talk to your healthcare provider about birth control methods that may be right for you. Tell your doctor immediately if you become pregnant or think you might be pregnant with taking cobimetinib.

Tell your doctor if you are breastfeeding or plan to breastfeed.

It is not known if cobimetinib crosses into human milk. Because many medications can cross into human milk and because of the possibility for serious adverse reactions in nursing infants with use of this medication, you should not breastfeed while taking cobimetinib or for 2 weeks after finishing cobimetinib.

Talk to your healthcare provider about the best way to feed your baby during this time.

Take cobimetinib exactly as prescribed.

Cobimetinib comes in tablet form and is taken once daily, with or without food. Cobimetinib is usually taken once daily for 21 days followed by a 7-day rest period (no drug) for a 28-day cycle. 

Do not change your dose or stop taking cobimetinib unless your healthcare provider tells you to. 

If you miss a dose of cobimetinib or vomiting occurs, take the next dose as scheduled.

Avoid sunlight while you are taking cobimetinib. Cobimetinib can make your skin sensitive to sunlight. You may burn more easily and get severe sunburns. To help protect against sunburn:

• When you go outside, wear clothes that protect your skin, including your head, face, hands, arms, and legs.
• Use lip balm and a broad-spectrum sunscreen with SPF 30 or higher

Cobimetinib can cause changes in blood tests. Your healthcare provider will take blood tests during treatment with cobimetinib. 

Take this medication exactly as prescribed by your doctor. Follow the directions on your prescription label carefully.

The dose your doctor recommends may be based on the following:

• other medical conditions you have
• other medication you are taking
• how you respond to this medication

The recommended dose of Cotellic (cobimetinib) is 60 mg (three 20 mg tablets) taken once daily for 21 days, followed by a 7-day rest period (where you take no drug) for each 28-day cycle.

If you take too much cobimetinib, call your healthcare provider or local Poison Control Center, or seek emergency medical attention right away.

• Store cobimetinib at room temperature.
• Keep this and all medicines out of the reach of children.