Dose escalation (DE) was shown to minimize the rates of Grade 3 diarrhea in the setting for HER2+ breast cancer. DE can improve tolerability for drugs such as abemaciclib. This is a post-marketing single arm, phase IV trial in which patients with high-risk early-stage HR+HER2- breast cancer will receive adjuvant abemaciclib in combination with endocrine therapy (ET) After study intervention, participants will remain on combination abemaciclib + ET at the discretion of their treating providers
In this study, the investigators we will test the hypothesis that gradual up-titration of abemaciclib dose over a course of 2-3 weeks will decrease the rate of G3 or worse diarrhea, permitting more patients to remain at the intended dose when evaluated at day 84
