Palbociclib

ISSUE: FDA is warning that palbociclib (Ibrance ® ), ribociclib (Kisqali ® ), and abemaciclib (Verzenio ® ) used to treat some patients with advanced breast cancers may cause rare but severe inflammation of the lungs. FDA has approved new warnings about this risk to the prescribing information and Patient Package Insert for the entire class of these cyclin-dependent kinase 4/6 (CDK 4/6) inhibitor medicines. The overall benefit of CDK 4/6 inhibitors is still greater than the risks when used as prescribed.

BACKGROUND: CDK 4/6 inhibitors are a class of prescription medicines that are used in combination with hormone therapies to treat adults with hormone receptor (HR)-positive, human epidermal growth factor 2 (HER2)-negative advanced or metastatic breast cancer that has spread to other parts of the body. CDK 4/6 inhibitors block certain molecules involved in promoting the growth of cancer cells. FDA approved palbociclib in 2015, and both ribociclib and abemaciclib in 2017. CDK 4/6 inhibitors have been shown to improve the amount of time after the start of treatment the cancer does not grow substantially and the patient is alive, called progression-free survival (See List of FDA-Approved CDK 4/6 Inhibitors below).

RECOMMENDATION:Patients should notify your health care professional right away if you have any new or worsening symptoms involving your lungs, as they may indicate a rare but life-threatening condition that can lead to death. Symptoms to watch for include:

• Difficulty or discomfort with breathing
• Shortness of breath while at rest or with low activity

Do not stop taking your medicine without first talking to your health care professional. All medicines have side effects even when used correctly as prescribed, but in general the benefits of taking these medicines outweigh these risks. It is important to know that people respond differently to all medicines depending on their health, the diseases they have, genetic factors, other medicines they are taking, and many other factors. Specific risk factors to determine how likely it is that a particular person will experience severe lung inflammation when taking palbociclib, ribociclib, or abemaciclib have not been identified.

Health care professionals should monitor patients regularly for pulmonary symptoms indicative of interstitial lung disease (ILD) and/or pneumonitis. Signs and symptoms may include:

• hypoxia
• cough
• dyspnea
• interstitial infiltrates on radiologic exams in patients in whom infectious, neoplastic, and other causes have been excluded.

Interrupt CDK 4/6 inhibitor treatment in patients who have new or worsening respiratory symptoms, and permanently discontinue treatment in patients with severe ILD and/or pneumonitis.

The last 20 years have seen the cost of medical care increase about 70% faster than the rate of general inflation as measured by the Consumer Price Index (CPI), the Research Division of the Federal Reserve Bank of St. Louis Healthcare inflation dropped to a historical low after 2010 but is again on the rise as of 2018, according to Bloomberg.

🔔 Why is this medication prescribed?

Palbociclib is used in combination with anastrozole (Arimidex), exemestane (Aromasin), or letrozole (Femara) to treat a certain type of hormone receptor–positive, advanced breast cancer (breast cancer that depends on hormones such as estrogen to grow) or breast cancer that has spread to other parts of the body in women who have experienced menopause (change of life; end of monthly menstrual periods) or in men. Palbociclib is also used along with fulvestrant (Faslodex) to treat a certain type of hormone receptor–positive, advanced breast cancer (breast cancer that depends on hormones such as estrogen to grow) or breast cancer that has spread to other parts of the body in people who have been treated with an antiestrogen medication such as tamoxifen (Nolvadex). Palbociclib is in a class of medications called kinase inhibitors. It works by blocking the action of the abnormal protein that signals cancer cells to multiply. This helps stop or slow the spread of cancer cells.

🔔 How should this medicine be used?

Palbociclib comes as a capsule to take by mouth. It is usually taken with food once daily for the first 21 days of a 28-day cycle. Your doctor will decide how many times you should repeat this cycle. Take palbociclib at around the same time every day. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take palbociclib exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.

Swallow the capsules whole; do not open, chew, or crush them. Do not take capsules that are broken or cracked.

If you vomit after taking palbociclib, do not take another dose. Continue your regular dosing schedule.

Your doctor may decrease your dose or temporarily or permanently stop your treatment if you experience certain side effects. Be sure to tell your doctor how you are feeling during your treatment with palbociclib.

Ask your pharmacist or doctor for a copy of the manufacturer’s information for the patient.

🔔 Other uses for this medicine

This medication may be prescribed for other uses; ask your doctor or pharmacist for more information.