Cobimetinib

Cobimetinib is used in adults to treat a specific kind of metastatic melanoma (skin cancer) that has spread to other areas of the body and cannot be removed by surgery. Cobimetinib is typically given along with another medicine called vemurafenib.

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

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

Cobimetinib may also be used for reasons not mentioned in this medication guide.

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 ensure 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 decide 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 regularly while you are using cobimetinib. Tell your doctor if you notice any new skin changes such as redness, sores that do not heal, a new wart, or a mole that has changed in size or color.

You will need frequent medical tests.

Store at room temperature away from moisture and heat.

Follow all instructions on your medicine label and package. Inform each of your healthcare providers about all your medical conditions, allergies, and all medicines you are taking.

You should not use cobimetinib if you are allergic to it.

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).

May harm an unborn baby. Do not use if you are pregnant. Use effective birth control while using cobimetinib and for at least 2 weeks after your last dose. Tell your doctor if you become pregnant.

Do not breastfeed while using cobimetinib, and for at least 2 weeks after your last dose.

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

Get emergency medical help if you have signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Cobimetinib may cause serious side effects. Call your doctor right away if you have:

• 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 stopped if you have certain side effects.

Common side effects of cobimetinib 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.

Usual Adult Dose for Melanoma -- Metastatic:

60 mg orally once a day for first 21 days of each 28-day cycle until disease progression or unacceptable toxicityComments: -The presence of BRAF V600E or V600K mutation in tumor specimens should be confirmed with an FDA-approved test prior to therapy initiation; information on FDA-approved tests available at http://www.fda.gov/CompanionDiagnostics.Use: In combination with vemurafenib, indicated for treatment of patients with unresectable or metastatic melanoma with a BRAF V600E or V600K mutation.

Usual Adult Dose for Histiocytic Neoplasm:

60 mg orally once a day for first 21 days of each 28-day cycle until disease progression or unacceptable toxicityUse: Treatment of adult patients with histiocytic neoplasms

Use the medicine as soon as you remember, and then return to your normal schedule. Do not take two doses at once.

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

Cobimetinib could make you more sensitive to sunlight, leading to sunburn. Avoid direct sunlight or tanning beds. When you are outside, wear protective clothing and use sunscreen with an SPF of 30 or higher.

Sometimes, it is not safe to use certain medicines together. Some drugs can change the levels of other drugs in your blood, 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 are using.