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 used in adults 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.

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

Cobimetinib is also used alone to treat adults with blood cancers called histiocytic neoplasms.

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

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

Tell your doctor if you have ever had:

• 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).

Cobimetinib may affect fertility in men or women. Pregnancy could be harder to achieve while either parent is using this medicine.

How should I take cobimetinib?

Follow all directions on your prescription label and read all medication guides or instruction sheets. Your doctor may occasionally change your dose. Use the medicine exactly as directed.

Your doctor will perform tests to make sure cobimetinib is the right treatment for you.

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.

If you vomit shortly after taking cobimetinib, do not take another dose. Take your next dose as scheduled.

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

You will need frequent medical tests.

What happens if I miss a dose?

Use the medicine as soon as you remember, and then go back to your regular schedule. Do not use two doses at one time.

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, upset stomach, heartburn;
• bumps similar to acne on face, scalp, chest, or upper back;
• dry skin, itching, rash;
• tiredness;
• swelling of arms, legs, or feet;
• pain and burning when you urinate;
• lung problems;
• fever;
• increased sensitivity to sunlight; or
• abnormal blood 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?

Sometimes it is not safe to use certain medicines at the same time. Some drugs can affect your blood levels of other drugs you use, which may increase side effects or make the medicines less effective.

Other drugs may affect cobimetinib, including prescription and over-the-counter medicines, vitamins, and herbal products. Tell your doctor about all other medicines you use.

Where can I get more information?

Your doctor or pharmacist can provide more information about cobimetinib.