Federal drug regulators warn that the side effects of Ibrance, Kisqali and Verzenio may increase the risk of severe lung inflammation among users of the breast cancer drugs.
The FDA issued a drug safety communication on September 13, announcing that new label warnings will be required for a class of advanced breast cancer medications, known as cyclin-dependent kinase 4/6 (CDK 4/6) inhibitors. According to the agency, the entire class increases the risk of rare, but severe inflammation of the lungs.
Ibrance (palbociclib), Kisqali (robociclib), and Verzenio (abemaciclib) are used in combination with hormone therapies to treat some forms of advanced or metastatic breast cancer which has spread to other parts of the body. The first, Ibrance, was approved by the FDA in 2015. Kisqali and Verzenio were approved in 2017.
According to clinical trial data, one to three percent of patients taking the drugs will develop the inflammation. Less than one percent of cases to date have been fatal.
The FDA indicates it has approved new warnings about the lung inflammation risks which will be added to the drugs’ prescribing information and Patient Package Insert. It is also advising doctors to monitor patients taking these drugs regularly for pulmonary symptoms which look like interstitial lung disease (ILD) or pneumonitis. Symptoms can include:
Interstitial filtrates on radiological exams for patients where other causes have been eliminated.
The FDA recommends that doctors who see these symptoms pause treatment with the drugs in patients with respiratory problems, and permanently remove the therapy for patients with severe ILD or pneumonitis.
The agency recommends patients taking the drug let their health care professional know immediately if they develop new or worsening lung problems, including difficulty or discomfort breathing, and shortness of breath when at rest or after low activity.
The FDA indicates that it believes the benefits of these drugs still outweigh the risks and recommends patients do not stop taking the medications without first talking to their health care professional.
Doctors and patients are encouraged to report any adverse events or side effects to the FDA’s MedWatch adverse event reporting program.