Cobimetinib is used to treat a type of skin cancer (melanoma). It is also used to treat a certain group of blood cancers (histiocytic neoplasms). It works by slowing or stopping the growth of cancer cells.

Read the Patient Information Leaflet if available from your pharmacist before you start taking cobimetinib and each time you get a refill. If you have any questions, ask your doctor or pharmacist.

Take this medication by mouth with or without food as directed by your doctor, usually once daily for 21 days, then stopping the medication for 7 days. This is one cycle of treatment. Keep taking the medication this way as directed by your doctor.

If you vomit after taking a dose, do not take another dose at that time. Take your next dose at the regular time.

The dosage is based on your medical condition, response to treatment, and other medications you may be taking. Be sure to tell your doctor and pharmacist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).

Take this medication regularly to get the most benefit from it. To help you remember, take it at the same time each day.

Do not increase your dose or use this drug more often or for longer than prescribed. Your condition will not improve any faster, and your risk of side effects will increase.

Since this drug can be absorbed through the skin and lungs and may harm an unborn baby, women who are pregnant or who may become pregnant should not handle this medication or breathe the dust from the tablets.

Diarrhea, nausea, or vomiting may occur. If any of these effects last or get worse, tell your doctor or pharmacist promptly.

Pain or sores in the mouth and throat may occur. Brush your teeth carefully/gently, avoid using mouthwash that contains alcohol, and rinse your mouth often with cool water mixed with baking soda or salt. It may also be best to eat soft, moist foods.

People using this medication may have serious side effects. However, you have been prescribed this drug because your doctor has judged that the benefit to you is greater than the risk of side effects. Careful monitoring by your doctor may decrease your risk.

This medication may raise your blood pressure. Check your blood pressure regularly and tell your doctor if the results are high.

Tell your doctor right away if you have any serious side effects, including:

• unusual skin changes (such as skin sores/lumps, warts, change in the size/color of a mole)
• easy bleeding/bruising (such as bleeding of the gums)
• unusual vaginal bleeding
• black/bloody stools
• vomit that contains blood or looks like coffee grounds
• blood in the urine
• muscle pain/tenderness/weakness
• signs of kidney problems (such as change in the amount of urine)
• signs of heart failure (such as shortness of breath, swelling ankles/feet, unusual tiredness, unusual/sudden weight gain)
• vision changes (such as blurred vision, vision loss, seeing halos)
• signs of liver disease (such as nausea/vomiting that doesn't stop, loss of appetite, stomach/abdominal pain, yellowing eyes/skin, dark urine)

Get medical help right away if you have any very serious side effects, including:

• signs of bleeding in the brain (such as severe headache, weakness on one side of the body, sudden vision changes, trouble speaking, seizures, confusion)

A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including:

• rash
• itching/swelling (especially of the face/tongue/throat)
• severe dizziness
• trouble breathing

This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.

In the US - Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch.

In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

Before taking cobimetinib, tell your doctor or pharmacist if you are allergic to it; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.

Before using this medication, tell your doctor or pharmacist your medical history, especially of:

• bleeding problems
• high blood pressure
• heart disease (heart failure)
• eye problems
• liver disease

This drug may cause blurred vision. Do not drive, use machinery, or do anything that needs clear vision until you are sure you can perform such activities safely. Limit alcoholic beverages.

This medication may make you more sensitive to the sun. Limit your time in the sun. Avoid tanning booths and sunlamps. Use sunscreen/lip balm and wear protective clothing when outdoors. Tell your doctor right away if you get sunburned or have skin blisters/redness.

Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).

Since this drug can be absorbed through the skin and lungs and may harm an unborn baby, women who are pregnant or who may become pregnant should not handle this medication or breathe the dust from the tablets.

Tell your doctor if you are pregnant or plan to become pregnant. You should not become pregnant while using cobimetinib. Cobimetinib may harm an unborn baby. Ask about reliable forms of birth control while using this medication and for 2 weeks after the last dose. If you become pregnant, talk to your doctor right away about the risks and benefits of this medication.

It is unknown if this drug passes into breast milk. Because of the possible risk to the infant, breastfeeding is not recommended while using this drug and for 2 weeks after the last dose. Consult your doctor before breastfeeding.

Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval.

Other medications can affect the removal of cobimetinib from your body, which may affect how cobimetinib works. Examples include azole antifungals (such as itraconazole), efavirenz, rifamycins (such as rifampin), St. John's wort, drugs used to treat seizures (such as carbamazepine, phenytoin), among others.

If someone has overdosed and has serious symptoms such as passing out or trouble breathing, call 911. Otherwise, call a poison control center right away. US residents can call 1-800-222-1222. Canada residents can call 1-844-764-7669.

Do not share this medication with others.

Lab and/or medical tests (such as BRAF testing, heart/liver function, skin/eye exams, CPK/creatinine levels, complete blood count, blood mineral levels, blood pressure) should be done before you start taking this medication and while you are taking it. Keep all medical and lab appointments. Consult your doctor for more details.

It is important to take this medication as scheduled. If you miss a dose, contact your doctor or pharmacist for instructions. Do not double the dose to catch up.

Store at room temperature away from light and moisture. Keep all medications away from children and pets.

Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company.