Letrozole and ribociclib are used together in combination to treat HR-positive, HER2-negative breast cancer.

This medicine is used when the cancer has spread to other parts of the body (metastatic).

Letrozole and ribociclib are two different medicines that are packaged together. Letrozole tablets are yellow and ribociclib tablets are violet.

Letrozole and ribociclib may also be used for purposes not listed in this medication guide.

You should not use this medicine if you are allergic to letrozole (Femara) or ribociclib (Kisqali).

Your doctor will perform medical tests to make sure you do not have conditions that would prevent you from safely using this medicine.

Tell your doctor if you have any signs of infection, such as fever or chills, or if you have ever had:

• heart disease, heart failure;
• a heart attack;
• heart rhythm problems, including slow heartbeats;
• long QT syndrome;
• low levels of calcium, phosphorus, potassium, or magnesium in your blood; or
• liver disease.

If you have not gone through menopause, you may need an additional hormonal medication while taking letrozole and ribociclib. Tell your doctor if you have begun having symptoms of menopause such as irregular menstrual periods, hot flashes, night sweats, sleep problems, or vaginal dryness.

You may need to have a negative pregnancy test before starting this treatment.

Letrozole and ribociclib may harm an unborn baby. Use effective birth control to prevent pregnancy while you are using this medicine and for at least 3 weeks after your last dose. Tell your doctor right away if you become pregnant.

This medicine may affect fertility (ability to have children) in both men and women. However, it is important for women to use birth control to prevent pregnancy because letrozole and ribociclib may harm the baby if a pregnancy does occur.

You should not breastfeed while using this medicine and for at least 3 weeks after your last dose.

Use Kisqali Femara Co-Pack 600 Mg-2.5 Mg Dose (Oral) exactly as directed on the label, or as prescribed by your doctor. Do not use in larger or smaller amounts or for longer than recommended.

Get emergency medical help if you have signs of an allergic reaction (hives, difficult breathing, swelling in your face or throat) or a severe skin reaction (fever, sore throat, burning eyes, skin pain, red or purple skin rash with blistering and peeling).

Call your doctor at once if you have:

• trouble breathing, shortness of breath, cough with or without mucus, chest pain;
• fast or pounding heartbeats, fluttering in your chest, and sudden dizziness (like you might pass out);
• liver problems--loss of appetite, right-sided stomach pain, tiredness, easy bruising or bleeding, dark urine, jaundice (yellowing of the skin or eyes);
• low red blood cells (anemia)--pale skin, unusual tiredness, feeling light-headed or short of breath, cold hands and feet; or
• low white blood cell counts--fever, mouth sores, skin sores, sore throat, cough, trouble breathing.

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

Common side effects may include:

• low white blood cells, infections;
• anemia;
• tiredness;
• nausea, vomiting, diarrhea, constipation;
• headache;
• rash;
• back pain; or
• hair loss.

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.

Grapefruit may interact with letrozole and ribociclib and lead to unwanted side effects. Avoid the use of grapefruit products.