cobimetinib

What is the most important information I should know about cobimetinib?

Follow all directions on your medicine label and package. Tell each of your healthcare providers about all your medical conditions, allergies, and all medicines you use.

What is cobimetinib?

Cobimetinib is a cancer medicine that interferes with the growth and spread of cancer cells in the body.

Cobimetinib is used to treat a certain type of metastatic melanoma (skin cancer) that has spread to other parts of the body and cannot be removed with surgery. Cobimetinib is usually given together with another medicine called vemurafenib (Zelboraf).

Cobimetinib is used only if your tumor has a specific genetic marker, for which your doctor will test.

Cobimetinib may also be used for purposes not listed in this medication guide.

What should I discuss with my healthcare provider before taking cobimetinib?

To make sure cobimetinib is safe for you, tell your doctor if you have:

• heart disease, heart rhythm disorder;
• a history of eye problems (especially a problem with your retina);
• liver or kidney disease;
• skin problems not related to melanoma;
• a muscle disorder;
• a bleeding or blood clotting disorder such as hemophilia; or
• a condition for which you take a blood thinner such as warfarin (Coumadin, Jantoven).

Using cobimetinib may increase your risk of developing other types of skin cancer. Ask your doctor about your specific risk.

How should I take cobimetinib?

Your doctor will perform blood tests to make sure you have the correct tumor type to be treated with cobimetinib.

Follow all directions on your prescription label. Do not use this medicine in larger or smaller amounts or for longer than recommended.

Read all patient information, medication guides, and instruction sheets provided to you. Ask your doctor or pharmacist if you have any questions.

Cobimetinib is given in a 28-day treatment cycle. You may need to use the medicine only during the first 21 days of each cycle. Your doctor will determine how long to treat you with cobimetinib.

Do not change your doses or medication schedule without your doctor's advice.

You may take cobimetinib with or without food.

Check your skin on a regular basis while you are using cobimetinib. Tell your doctor if you notice any new skin symptoms such as redness, sores that will not heal, a new wart, or a mole that has changed in size or color.

Your heart function may need to be checked with an electrocardiograph or ECG (sometimes called an EKG) while you are using this medicine. You may also need regular vision examinations.

What happens if I miss a dose?

Take the missed dose as soon as you remember. Skip the missed dose if it is almost time for your next scheduled dose. Do not take extra medicine to make up the missed dose.

What happens if I overdose?

What should I avoid while taking cobimetinib?

What are the possible side effects of cobimetinib?

• vision changes, partial vision loss, seeing halos around lights;
• unexplained muscle pain, tenderness, or weakness (especially if you also have fever and dark colored urine);
• easy bruising or bleeding (nosebleeds, bleeding gums);
• signs of bleeding inside the body --weakness, dizziness, headache, red or pink urine, bloody or tarry stools, coughing up blood or vomit that looks like coffee grounds;
• signs of a heart problem --cough, wheezing, shortness of breath (even with mild exertion), chest pain, fast heartbeats, swelling in your feet or ankles;
• low levels of sodium in the body --headache, confusion, slurred speech, severe weakness, vomiting, loss of coordination, feeling unsteady;
• liver problems --nausea, upper stomach pain, tired feeling, loss of appetite, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes); or
• severe skin reaction --skin pain, itching, redness, bumps or pimples, thickened or wrinkled skin, skin rash that spreads and causes blistering and peeling.

Your cancer treatments may be delayed or permanently discontinued if you have certain side effects.

Common side effects may include:

• nausea, vomiting, diarrhea;
• fever;
• sunburn or increased sensitivity to sunlight;
• low sodium levels; or
• abnormal laboratory tests.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

What other drugs will affect cobimetinib?

Many drugs can interact with cobimetinib. This includes prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible interactions are listed in this medication guide. Tell your doctor about all medicines you use, and those you start or stop using during your treatment with cobimetinib. Give a list of all your medicines to any healthcare provider who treats you.

Where can I get more information?

Your pharmacist can provide more information about cobimetinib.