Safety and efficacy of cyclin-dependent kinase inhibitor rechallenge following ribociclib-induced limiting hypertransaminasemia

Cyclin-dependent kinase inhibitors (CDKIs) and endocrine therapy (ET) are the corner-stone of systemic therapy for patients with hormone-positive (HR+) HER2-negative metastatic breast cancer (MBC). However, limited data exist regarding rechallenge treatment strategies with CDKIs after limiting toxicity. In this report, we provide evidence of the safety and efficacy of sequential treatment with palbociclib or abemaciclib in 6 HR+/HER- MBC patients who experienced grade ≥3 ribociclib-induced hypertransaminasemia. Until results from large observational or randomized studies are communicated, empirical evidence may help make individualized decisions on CDKI rechallenge beyond ribociclib-induced unacceptable liver toxicity.