Efficacy of Endocrine Therapy Plus Trastuzumab and Pertuzumab vs De-escalated Chemotherapy in Patients with Hormone Receptor–Positive/ERBB2-Positive Early Breast Cancer: The Neoadjuvant WSG-TP-II Randomized Clinical Trial

Mené sur 207 patientes atteintes d'un cancer du sein HR+ ERBB2+ de stade précoce (âge médian : 54 ans), cet essai multicentrique de phase II compare l'efficacité, du point de vue du taux de réponse complète, et la toxicité d'une chimiothérapie néoadjuvante avec désescalade de doses (paclitaxel) et d'un traitement endocrinien (inhibiteur de l'aromatase ou tamoxifène), tous deux dispensés en combinaison avec le trastuzumab et le pertuzumab

Résumé en anglais

Importance : Combination of chemotherapy with (dual) ERBB2 blockade is considered standard in hormone receptor (HR)-positive/ERBB2-positive early breast cancer (EBC). Despite some promising data on endocrine therapy (ET) combination with dual ERBB2 blockade in HR-positive/ERBB2-positive BC, to our knowledge, no prospective comparison of neoadjuvant chemotherapy vs ET plus ERBB2 blockade in particular with focus on molecular markers has yet been performed.

Objective : To determine whether neoadjuvant de-escalated chemotherapy is superior to endocrine therapy, both in combination with pertuzumab and trastuzumab, in a highly heterogeneous HR-positive/ERBB2-positive EBC.

Design, Setting, and Participants : This prospective, multicenter, neoadjuvant randomized clinical trial allocated 207 patients with centrally confirmed estrogen receptor–positive and/or progesterone receptor–positive (>1%) HR-positive/ERBB2-positive EBC to 12 weeks of standard ET (n = 100) vs paclitaxel (n = 107) plus trastuzumab and pertuzumab. A total of 186 patients were required to detect a statistically significant difference in pathological complete response (pCR) (assumptions: 19% absolute difference in pCR; power,