ESMO Breast 2022 | PerELISA: de-escalated therapy for HR+/HER2+ BC with Ki67 response following 2-week letrozole

Gaia Griguolo, MD, University of Padova, Padova, Italy, provides an overview of the Phase II PerELISA (NCT02411344) trial assessing the activity of neoadjuvant pertuzumab plus trastuzumab in combination with letrozole without chemotherapy in patients with HR-positive/HER2-positive (HR+/HER2+) breast cancer. Patients were selected based on their antiproliferative response following 2-weeks on letrozole alone, identified by inhibition of Ki67. Previous analyses had demonstrated the HER2 enriched subtype to be associated with higher pathologic complete response (pCr) in this patient cohort. Indeed, the primary endpoint was met, reaching the pre-specific pCRs. This interview took place at the European Society for Medical Oncology (ESMO) Breast Cancer 2022 congress in Berlin, Germany.