Arobase: A phase III trial of exemestane (Exe) and bevacizumab (BEV) as maintenance therapy in patients (pts) with metastatic breast cancer (MBC) treated in first line with paclitaxel (P) and BEV—A Gineco study.

Breast Cancer - HER2/ER
Session Type and Session Title: 
Oral Abstract Session, Breast Cancer - HER2/ER
Abstract Number: 
J Clin Oncol 32:5s, 2014 (suppl; abstr 501)
Olivier Tredan, Philippe Follana, Isabelle Moullet, Claire Cropet, Stéphanie Trager-Maury, Jérôme Dauba, Sandrine Lavau-Denes, Veronique Dieras, Dominique Beal-Ardisson, Marie-Claude Gouttebel, Hubert Orfeuvre, Eric Pujade-Lauraine, Thomas Denis Bachelot; Département d'Oncologie Médicale, Centre Léon Bérard, Lyon, France; Département d'Oncologie Médicale, Centre Antoine Lacassagne, Nice, France; Département d'Oncologie Médicale, Clinique de la Sauvegarde, Lyon, France; Unité de Biostatistique et d'Evaluation des Thérapeutiques - Direction de la Recherche et d l'Innovation, Centre Léon Bérard, Lyon, France; Département d'Oncologie Médicale, Groupe Hospitalier Public du sud de l'Oise, Senlis, France; Département d'Oncologie Médicale, Centre Hospitalier de Mont-de-Marsan, Mont-de-Marsan, France; Unité de Recherche Clinique, Hôpital Dupuytren, Limoges, France; Département d'Oncologie Médicale, Institut Curie - Hopital Claudius Régaud, Paris, France; Département d'Oncologie Médicale, Hôpital Privé Jean Mermoz, Lyon, France; Unité Médico-Chirurgicale de Courte Durée, Hôpitaux Drôme Nord - Site de Romans, Romans-sur-Isère, France; Département d'Onco-hématologie, Centre Hospitalier Fleyriat, Bourg-en-Bresse, France; Département d'Oncologie Médicale, Université Paris Descartes, AP-HP, Hôpitaux Universitaires Paris Centre, Site Hôtel-Dieu, Paris, France; Département d'Oncologie Médicale, Centre Léon Berard, Lyon, France

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Abstract Disclosures


Background: Combination of P+BEV significantly improves progression-free survival (PFS) in MBC pts, but is associated with adverse events (AEs), mainly neuropathy and fatigue worsening over time. Endocrine therapy (ET) combined to BEV has been proven tolerable and may be a option as maintenance therapy after P+BEV. Methods: in this prospective, randomized, open label, phase III study, pts with histologically confirmed ER+ HER2- locally advanced or MBC, who had not progressed after 16-24 weeks of 1st-line P+BEV therapy, were randomized to P+BEV continuation vs ET+BEV (Exe 25 mg/d+BEV 15 mg/kg q3w). Primary endpoint was PFS. To demonstrate an improvement in the 6-month PFS rate (PFS-6m) from 50% with P+BEV to 65% with ET+BEV (2-sided α=5%) with 80% power, 141 events were requiered and 198 pts were planned. An interim analysis (IA) was planned after 40% of required events. Secondary endpoints included overall survival (OS) and toxicity. Results: At the cut-off date for the IA (May 2013), 113 pts were included, 98 were analyzable. Median age was 55 (range 35-86). ET was given as adjuvant therapy in 64% of pts and in the metastatic setting in 24%. Median follow up was 9.7 months (range 0.8-28.3). PFS-6m was 70% (95% confidence interval (CI) 54, 81.5) with P+BEV and 54% (95% CI 38.5, 67.2) with ET+BEV (HR 1.2, 95% CI (0.7, 1.9), p=0.56). Given these interim results, the probability to show statistically significant PFS at the end of the study was 7%. Deaths were reported for 11 pts in the P+BEV arm vs 6 pts in the ET+BEV arm (median OS not reached). Grade 3-4 AEs rates were lower with ET+BEV (fatigue: 4% of pts vs 14%); neuropathy: 0% vs 12%; pain: 2% vs 8%; neutropenia: 0% vs 12%), as well as serious AEs related to treatment (13% vs 24%). Based on both safety and efficacy results, the IDMC decided to definitely stop the enrollment and to keep patients under tretment in the protocol.Follow-up data will be updated for the final analysis. Conclusions: The efficacy hypothesis was not reached, despite a better safety profile of the ET+BEV maintenance therapy. Exploratory analyses are planned to identify potential subgroups benefiting from it. Clinical trial information: NCT01303679..