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# Warning on CDK 4/6 Inhibitors Lung Condition
- URL: https://www.fdaweb.com/warning-on-cdk-4-6-inhibitors-lung-condition/
- Published: 2019-09-13T12:00:00.000Z
- Updated: 2026-09-15T01:49:49.000Z
- Author: David McFarland
- Tags: Drugs, #legacy-id-D5145000

FDA is warning that Pfizer’s Ibrance (palbociclib), Novartis’ Kisqali (ribociclib), and Eli Lilly’s Verzenio (abemaciclib) used to treat some patients with advanced breast cancers may cause a rare and severe inflammation in the lungs. “We have 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,” an [agency notice](https://www.fda.gov/drugs/drug-safety-and-availability/fda-warns-about-rare-severe-lung-inflammation-ibrance-kisqali-and-verzenio-breast-cancer?ref=fdaweb.com) says. FDA says the products’ benefits continue to outweigh their risks.

The drugs 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 says. The agency approved Ibrance in 2015, and both Kisqali and Verzenio in 2017.

The FDA notice says patients should notify their health care professionals if they have any new or worsening symptoms involving their lungs. Symptoms to watch for include difficulty or discomfort with breathing and shortness of breath. And healthcare providers are instructed to monitor patients for pulmonary symptoms indicative of interstitial lung disease or pneumonitis. Signs and symptoms may include hypoxia, cough, dyspnea, or interstitial infiltrates on radiologic exams in patients in whom infectious, neoplastic, and other causes have been excluded, the notice says.