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Cyclin-Dependent Kinase 4/6 Inhibitors May Cause Rare but Serious Lung Inflammation

On September 13, 2019, FDA issued a warning that cyclin-dependent kinase 4/6 (CDK 4/6) inhibitors can cause rare but serious lung inflammation when used to treat advanced breast cancers. Cyclin-dependent kinase 4/6 inhibitors are medications used in combination with hormone therapies to treat patients with hormone receptor-positive, human epidermal growth factor 2-negative advanced or metastatic breast cancer. Examples of CDK 4/6 inhibitors include, abemaciclib (Verzenio), palbociclib (Ibrance), and ribociclib (Kisqali). These medications can improve progression-free survival and benefits generally outweigh the risk of developing severe lung inflammation. FDA approved new warnings about the risk of serious lung inflammation in the prescribing information and patient package inserts for all CDK 4/6 inhibitors.

Inform your healthcare provider if you experience new or worsening lung symptoms including difficulty breathing or shortness of breath at rest. These symptoms may represent a rare but life-threatening condition. Continue to take your medications until you talk with your healthcare provider. Providers should monitor for cough, dyspnea, hypoxia, or interstitial infiltrates on radiologic exams, as these may be indicative of interstitial lung disease or pneumonitis. Exclude other potential causes of lung-related symptoms including infection and neoplasm. Hold CDK 4/6 inhibitors in patients who have new or worsening symptoms. Discontinue CDK 4/6 inhibitors in patients who develop interstitial lung disease or pneumonitis. Patients and healthcare providers are encouraged to report any adverse events to FDA MedWatch: www.accessdata.fda.gov/scripts/medwatch/index.cfm.

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