Gemcitabine vs. GEMOX (gemcitabine + oxaliplatin) in non-resectable pancreatic adenocarcinoma: Interim results of GERCOR/GISCAD intergroup Phase III
Reviewer: Tracy d'Entremont, MD
Last Modified: June 2, 2003
Presenter: C. Louvet
Presenter's Affiliation: Hospital St. Antoine; Paris, France
Type of Session: Scientific
- Gemcitabine 1g/m2 in a 30 min infusion remains the reference regimen for non-resectable pancreatic cancer.
- Oxaliplatin and Gemcitabine have different mechanisms of action and resistance
- The toxicity profiles of these two drugs is non-overlapping.
- In vitro data suggests synergy between the two agents.
- A multi-institution phase II study of GEMOX demonstrated promising results with 30% RR, 40% clinical benefit rate, PFS of 5.3 months, and OS of 9.2 months.
- Therefore this randomized phase III trial was designed to compare the two regimens head to head.
Materials and Methods
- The primary endpoint was OS
- 300 patients were required to demonstrate an increase in MS from 6-8 months.
- 313 patients were randomized and treated.
- The two groups were well balanced with median age of 60, 70% had metastatic disease, only 15% had PS=2.
- The patients in the Gem alone arm recieved gemcitabine at 1g/m2 qweek for 7/8 weeks in cycle number 1, then qweek for 3/4 weeks of each subsequent cycle.
- The patients in the GEMOX arm received the same dose of gemcitabine but received it in a fixed infusion rate schedule at the rate of 10mg/m2/min. on d1 plus oxaliplatin 100mg/m2 on d2 on a q2week schedule.
- 44% of patients are still alive therefore, the survival data is not yet mature.
- 81% of patients on the GEM arm progressed where as only 73% on the GEMOX arm did.
- The median dose intensity of the gemcitabine was equivalent in both arms at 90%.
- RR was superior in the GEMOX arm 25.8% vs. 16.1%
- The median PFS was 25 weeks vs. 16 weeks in favor of the GEMOX arm.
- The following Gr 3/4 toxicities were worse in the GEMOX arm: thrombocytopenia, nausea/vomiting, neuropathy
- The following Gr3/4 toxicities were worse in the GEM arm: neutropenia and anemia.
- Although the survival data is not yet mature, this trial demonstrates an improved clinical benefit rate of GEMOX over GEM.
- The data from this trial are not yet mature so final conclusions cannot be drawn.
- But, one thing we will have to remember as we analyze the data, the experimental arm in this trial really has two variables; the fixed infusion rate of gemcitabine and the oxaliplatin.
- Even if this trial surprises us and is positive at it's conclusion, we will not be able to address the question of why is it better? Is it the rate of administration of gemcitabine or is it the oxaliplatin?
- Obviously adding oxaliplatin to the regimen adds toxicity, maybe the clinical benefit that we are seeing in this trial is from the infusion of gemcitabine alone and maybe we could achieve improved RR and TTP without the toxicity of oxaliplatin.
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