ATLANTAA study comparing two experimental regimens with standard 30-minute gemcitabine (Gemzar) infusions for advanced pancreatic cancer found temporary improvements in tumor response, but no survival benefit, according to the ECOG 6201 trial, which was presented at the 42nd Annual Meeting of the American Society of Oncology (abstract LBA4004).
Smaller prior studies suggested that a fixed-dose gemcitabine regimen or adding oxaliplatin (Eloxatin) to standard gemcitabine improved survival substantially. "We sought to determine which of these was really the best," stated Elizabeth Poplin, MD, associate professor of Medicine at the Cancer Institute of New Jersey, New Brunswick. She noted that median survival with standard gemcitabine in advanced pancreatic cancer is 5.7 months, with 1-year survival of 18%.
In the ECOG 6201 trial, patients were randomized to one of three treatment arms: standard gemcitabine (GEM) infusion (1,000 mg/m2 for 30 minutes, once weekly for 7 of the first 8 weeks, followed by the same infusion once weekly for 3 of the next 4 weeks); fixed-dose rate (FDR) gemcitabine (1,500 mg/m2 for 150 minutes, once weekly for 3 out of every 4 weeks); or gemcitabine/oxaliplatin (GEMOX) (gemcitabine, 1,000 mg/m2 for 30 minutes, once weekly, followed on the next day by oxaliplatin, 100 mg/m2, with the cycle repeated every 14 days).
The 832 patients (mean age, about 62 years) had locally advanced or metastatic pancreatic adenocarcinoma. Prior adjuvant chemotherapy/radiotherapy was permitted, but not prior oxaliplatin or gemcitabine.
At the 8-week evaluation, 10% of the patients in the FDR group had a partial or complete tumor response, as did 9% of those on GEMOX. This compared favorably with 5% of those in the standard gemcitabine group, Dr. Poplin said. These positive short-term changes, however, did not translate into a significant survival benefit.
Dr. Poplin reported that by study end at 1 year, 87% of the patients had died, and none of the regimens had been more effective than the others in slowing the disease.
Median survival for the GEM group was 4.9 months, with 17% still alive at the 1-year mark. For the FDR group, the median survival was slightly increased to 6 months, and the 1-year survival was 21%. For the GEMOX patients, median survival was 5.9 months, with a 1-year survival of 21%.