Dual targeting of HER1/EGFR and HER2 with cetuximab and trastuzumab in patients with metastatic pancreatic cancer after gemcitabine failure: results of the "THERAPY"phase 1-2 trial

Eric Assenat (1, 2) , David Azria (3, 2) , Caroline Mollevi (2) , Rosine Guimbaud (4) , Nicole Tubiana-Mathieu (5) , Denis Smith (6) , Jean-Pierre Delord (7) , Emmanuelle Samalin (2) , Fabienne Portales (2) , Christel Larbouret (3, 2) , Bruno Robert (3, 2) , Frédéric Bibeau (2, 3) , Jean-Pierre Bleuse (2) , Evelyne Crapez (2) , Marc Ychou (3, 1, 2) , André Pèlegrin (3, 2)

1 CHRU Montpellier - Centre Hospitalier Régional Universitaire [Montpellier]
2 ICM - Institut régional de Cancérologie de Montpellier
3 IRCM - U1194 Inserm - UM - Institut de Recherche en Cancérologie de Montpellier
4 CHU Toulouse - Centre Hospitalier Universitaire de Toulouse
5 Service d'Oncologie médicale [CHU Limoges]
6 CHU Bordeaux
7 Institut Claudius Regaud

To improve treatment efficacy, we decided to simultaneously target HER1 and HER2 with trastuzumab and cetuximab. Following promising preclinical results, we conducted a phase 1-2 trial in advanced pancreatic cancer patients after first-line gemcitabine-based chemotherapy failure. In this single-arm, non-randomized, multicenter trial, patients received weekly cetuximab (400mg/m², then 250mg/m²). They were sequentially included in two trastuzumab dose levels: 3.0 or 4.0mg/kg, then 1.5 or 2.0mg/kg/weekly. Endpoints were the objective response rate, safety, progression-free (PFS) and overall survival (OS). During phase 1 (n=10 patients), toxicities were evenly distributed except for skin toxicities that frequently caused compliance issues. The higher dose level was defined as the trastuzumab recommended dose. During phase 2 (n=39 patients), toxicities were mainly cutaneous reactions and asthenia. No objective response was observed. Nine patients were stabilized but arrested treatment due to toxicity. Median PFS was 1.8 months (95%CI: 1.7-2.0 months) and median OS was 4.6 months (95%CI: 2.7-6.6 months). Both were positively correlated with skin toxicity severity (P=0.027 and P=0.001, respectively). Conventional phase 1 dose-escalation schedules are unsuitable for targeted therapies because most cutaneous toxicities are not considered dose-limiting toxicities. The compliance issues caused by skin toxicities were particularly detrimental because of the toxicity-response correlation.

Mots clés: antibody combination; cetuximab; pancreatic cancer; phase 1/2; trastuzumab

Domaines: Sciences du Vivant [q-bio]

Eric Assenat, David Azria, Caroline Mollevi, Rosine Guimbaud, Nicole Tubiana-Mathieu, et al.. Dual targeting of HER1/EGFR and HER2 with cetuximab and trastuzumab in patients with metastatic pancreatic cancer after gemcitabine failure: results of the "THERAPY"phase 1-2 trial. Oncotarget, 2015, 6 (14), ⟨10.18632/oncotarget.3473⟩. ⟨hal-02005981⟩