CDK4/6 Biomarkers: Issues and Opportunities

Topics of Discussion

Introduction

The Need for Prognostic Biomarkers

Genomic Tests to Identify Long-Term Responders to Endocrine Therapy Alone

Circulating DNA to Identify Failures to Conventional Therapy

Four Populations of Patients Regarding Prognosis

Questions

Efficacy of Abemaciclib According to HR Status

PALOMA-3 Final Analysis: Effect by ER and PR Expression Level in Patients With HR-Positive MBC

PIK3CA Mutation and Resistance to CDK4/6 Inhibitors

ESR1 Mutations and Resistance to CDK4/6 Inhibitors

Hypothesis: Can the Amplification of Cyclin D1 Predict Sensitivity?

Hypothesis: Can the Loss of p16 Be Predictive for Sensitivity?

CCND1 Amplification and/or p16 Loss and Efficacy of CDK4/6 Inhibitors

Two Hypotheses Related to pRb

pRB Expression and Efficacy of CDK4 Inhibitors

Modulation of pRb and Clinical Efficacy

Modulation of pRb and Clinical Efficacy (cont)

Take-Home Messages

Mechanisms of Adaptation and Resistance

Future Treatment Landscape for Endocrine Sensitive Patients*

Concluding Remarks