PD-006 - Gemcitabine and Oxaliplatin (GEMOX) with or without Panitumumab as First-Line Treatment in Advanced Biliary Tract Cancer; final results and subgroup...

Date 04 July 2015
Event WorldGI 2015
Session Posters
Topics Anti-Cancer Agents & Biologic Therapy
Hepatobiliary Cancers
Presenter D. Marino
Citation Annals of Oncology (2015) 26 (suppl_4): 101-107. 10.1093/annonc/mdv234
Authors D. Marino1, F. Leone2, S. Cereda1, S. Siena3, R. Filippi1, C. Belli1, R. Spadi4, G. Nasti5, M. Montano6, A. Amatu7, S. Lutrino8, C. Cagnazzo1, L. Ferrari9, L. Ciuffreda10, M. Reni11, M. Aglietta1
  • 1Department Of Medical Oncology, University of Turin Medical School, Candiolo Cancer Institute, FPO, IRCCS, Turin/IT
  • 2Department of Medical Oncology, University of Turin Medical School, Candiolo Cancer Institute, FPO, IRCCS, Turin/IT
  • 3Ospedale Niguarda Ca' Granda, Milano/IT
  • 4San Giovanni Battista Hospital, Turin/IT
  • 5Istituto Nazionale per lo Studio e la Cura dei Tumori Fondazione G. Pascale, Napoli/IT
  • 6National Cancer Institute "G. Pascale" Foundation, Naples/IT
  • 7Ospedale Niguarda Ca' Granda, Milan/IT
  • 8University and General Hospital, Udine/IT
  • 9University Hospital Udine, Udine/IT
  • 10Molinette Hospital, Turin/IT
  • 11Istituto di Ricovero e Cura a Carattere Scientifico, Milan/IT

Abstract

Introduction

The Vecti-BIL study is a randomized phase II study of gemcitabine and oxaliplatin (GEMOX) with or without panitumumab as first-line treatment for KRAS wild-type biliary tract cancer (BTC). Preliminary results have shown a trend towards better progression-free survival (PFS) and objective response rate (RR) for the combination with panitumumab, although it was not statistically significant.

Methods

Eighty-nine patients (pts) were randomized to GEMOX (gemcitabine, 1000 mg/m2 and oxaliplatin, 100 mg/m2) chemotherapy with (arm A, 45 pts) or without (arm B, 44 pts) panitumumab (6 mg/kg), every 2 weeks for up to 12 cycles. Maintenance therapy with panitumumab alone was allowed in arm A in case of clinical benefit after 12 cycles. Stratification factors were ECOG status (0-1 vs. 2) and histology (intrahepatic-IHC vs. extrahepatic-EHC and gallbladder carcinoma-GB). The primary endpoint was PFS. Secondary endpoints were RR (RECIST version 1.1), overall survival (OS), and safety.

Results

After a median follow-up of 10.1 months (mo), median PFS was 5.3 mo in arm A (95% CI 3.3–7.2) and 4.4 mo (95% CI 2.6–6.2) in arm B (p = 0.27). Among the 84 evaluable pts, RR was 26.6% in arm A and 18.1% in arm B, with disease control rate favoring the experimental arm (75.5% and 68.1% respectively). No survival differences were observed, being median OS 9.9 mo (95% CI 5.4–14.3) in arm A and 10.2 mo in arm B (95% CI 6.4–13.9, p= 0.42).

Subgroup analysis showed that median PFS for the 42 IHC pts was 5.7 in Arm A (95% CI 2.7–8.7) and 6.2 mo in Arm B (95% CI 3.1–9.2). Median PFS for EHC (19 pts) and GB (28 pts) was 4.9 mo in arm A (95% CI 2.4–7.4) and 3.8 mo in arm B (95% CI 2.3–5.3). However, pts with IHC exposed to panitumumab had an improvement in OS of 3.3 mo compared to control group (15.1 mo vs. 11.8 mo; p = 0.13). The safety profile was similar to that observed in other panitumumab-based combinations, being skin toxicity (80%), asthenia (64.4%) and diarrhea (55.5%) the most common toxicities in arm A, and neurotoxicity (56.8%), nausea (54.5%) and asthenia (52.2%) in arm B.

Conclusion

Although the study did not meet its primary endpoint, a trend toward better RR was observed in pts treated with panitumumab. Pts with IHC may particularly benefit from P-GEMOX treatment. Further analyses on potential markers of response/resistance are currently ongoing.