“Whatever subset we look at, the hazard ratio is always less than one,” said Dr. Moore, who concluded that the combination treatment improved overall survival by 19% (hazard ratio 0.81) and progression-free survival by 24% (hazard ratio 0.76).
Dr. Abbruzzese, chairman of gastrointestinal medical oncology at M.D. Anderson Cancer Center in Houston, noted that the trial had aimed for a 33% increase in median survival, not 8%. “I do not feel these results clearly alter the standard of care for patients with advanced pancreatic cancer,” he said, emphasizing that the benefit was less than a month.
Although Dr. Moore said adding erlotinib had no detrimental effects, Dr. Abbruzzese questioned whether the small survival benefits justified exposing patients to any added toxicity. He called for more studies to identify subgroups that would benefit from erlotinib, which causes a skin rash in patients who respond to therapy.
Based on the data so far, Dr. Moore said that erlotinib seemed to be most effective for subgroups of patients who were male, had poor performance status, were younger than 65 years, or had metastatic disease.
The trial's greatest benefits, he suggested, may be to focus oncologists on better understanding molecular responses to therapy, on earlier intervention in pancreatic cancer, and on determining how to identify patients who will benefit from targeted therapy.
Dr. Moore disclosed a consulting relationship with OSI Pharmaceuticals, which applied to the FDA in April for supplemental approval of erlotinib with gemcitabine in advanced pancreatic cancer. Erlotinib was approved in 2004 for use against locally advanced or metastatic non-small cell lung cancer.