Interstitial lung disease or pneumonitis with CDK 4/6 inhibitors

Abstract

In the UK, there have been reports of interstitial lung disease or pneumonitis in patients treated with cyclindependent kinase 4 and 6 (CDK 4/6) inhibitors. The CDK 4/6 inhibitors are authorised to treat patients with HR+, HER2–, locally advanced or metastatic breast cancer. At 21 January 2021, the number of reports of interstitial lung disease or pneumonitis received in the UK for abemaciclib, palbociclib or ribociclib was 8, 18 and 1, respectively, with 4, 7 and 0 fatal reports. Product information notes that in abemaciclib clinical trials involving 768 patients, interstitial lung disease or pneumonitis were reported in 3.4% of patients (0.4% grade 3, 0.1% grade 4), although fatalities have been reported post-marketing. Similarly, the adverse events were reported in 1.4% of palbociclib recipients (0.1% grade 3, no grade 4). For ribociclib, 0.3% of recipients reported interstitial lung disease (0.1% grade 3), with no cases in placebo recipients. Pneumonitis (0.4%) was reported in both ribociclib and placebo recipients, with no grade 3 or grade 4 events in either group. The Summary of Product Characteristis (SmPC) and Patient Information Leaflets (PILs) for these CDK 4/6 inhibitors has been updated to include the risk of interstitial lung disease or pneumonitis. Patients who develop new or worsening respiratory symptoms are advised to seek medical advice. Healthcare professionals are advised to consider dose interruption, modification, or discontinuation for patients who develop symptoms, depending on event severity. Adverse events should continue to be reported.