Clin Cancer Res: HR-HER2 - Brain metastasis breast cancer patients benefit the most from Abemaciclib treatment

Abemaciclib (Verzenio), an oral cell cycle protein-dependent kinase CDK4/6 inhibitor, was approved by the FDA on February 26, 2018 for the treatment of post-menoptosteroid hormone-like (HR) positive HER2-negative advanced or metastase breast cancer.
NCT02308020 study was a non-random Phase II study that recruited breast cancer (MBC) patients with brain metastasis into four subgroups, Group A: HR-HER2-; Group: HR-;D group: brain metastasis surgery excision, Abemaciclib 200 mg (2/day) single-drug treatment or combined endocrine therapy, or 150 mg (2/day) combined monotherapy.
study process was designed to assess intracranial objective remission rates (iORRs) in patients with secondary LM who were treated with Abemaciclib, as well as to assess extracranial response, Abemaciclib pharmacodynamics, brain metastasis tissue exposure and safety.
intracranial and intracranial remission was found in group A (n-58), with 3 patients in remission, iORR at 5.2% and intracranial clinical benefit at 24%.
total survival rate (OS) was 12.5 months.
38% of patients had a decrease in intracranial lesions.
group B (n-27), no patients received intracranial remission, with iCBR at 11%.
OS is 10.1 months.
22% of patients had a reduced intracranial lesions.
in Group C (n-10), one patient was shown to be in complete substantial remission.
the concentration of Abemaciclib active adesthasis in various sampling tissues in the surgical queue was in Group D (n-9), and the total concentration of Abemaciclib active adesthases in brain metastases was 96 times (CDK4) and 19 times higher (CDK6) in in-body IC50.
security is consistent with previous research.
the study did not meet its main endpoint.
24% of pretreated HR-HER2-MBC patients were treated with Abemaciclib to obtain iCBR.
abemaciclib can reach therapeutic concentrations in brain metastasis tissue and originally exceeded the desired concentrations of CDK4 and CDK6.