Hormone receptor-positive (HR+), HER2-negative metastatic breast cancer accounts for roughly 70% of all breast cancer diagnoses. For the past decade, standard first-line therapy has combined an aromatase inhibitor with a CDK4/6 inhibitor. Yet nearly 40% of patients develop acquired resistance mutations in the estrogen receptor gene (ESR1), rendering further aromatase inhibition completely ineffective.
Eli Lilly's standard full FDA approval for Inluriyo (imlunestrant) in combination with Verzenio (abemaciclib) marks the arrival of the oral selective estrogen receptor degrader (SERD) plus CDK4/6 combination era. In this deep dive, we analyze the clinical data, companion diagnostic exclusivity, market positioning against AstraZeneca's camizestrant, and the oncology revenue models forming around ctDNA surveillance.
