Phase II study of gemcitabine and cisplatin in the treatment of patients with advanced pancreatic carcinoma.

Background: Pancreatic carcinoma is considered among the most chemoresistant of human malignancies. The most commonly used cytotoxic single agents, 5-fluorouracil and 2'-deoxy-2',2'-difluorocytidine (gemcitabine), have objective response rates of less than 10% in large studies. Hypothesizing noncross resistance and a synergistic interaction between gemcitabine and cisplatin, early clinical studies have demonstrated significant activity with this combination in patients with several types of malignant disease. A Phase II study was undertaken to determine the efficacy of gemcitabine in combination with cisplatin in patients with locally advanced and metastatic pancreatic carcinoma based on these considerations.

Methods: The eligibility criteria included histologically confirmed, locally advanced, unresectable or metastatic exocrine carcinoma of the pancreas with no prior gemcitabine therapy; prior adjuvant therapy was allowed provided the last day of therapy was at least 6 months prior to starting treatment; clinically measurable or evaluable disease; a Southwest Oncology Group scale performance status of 0-2; a life expectancy of > 12 weeks; and adequate bone marrow, hepatic, and renal function. A total of 42 patients, 4 patients with locally advanced, unresectable disease and 38 patients with metastatic disease, were treated and received a total of 211 cycles of therapy between May 1997 to March 1999. The median age of patients was 61.5 years. The patients were treated in the outpatient setting with a combination of gemcitabine 1,000 mg/M(2) intravenously over 30 minutes administered on Days 1, 8, and 15 of each cycle and cisplatin 50 mg/M(2) intravenously administered after gemcitabine infusion on Days 1 and 15 with adequate prehydration accompanied by adequate urinary output. Cycles were repeated every 28 days. Response and toxicity were assessed according to World Health Organization and standard criteria.

Results: The complete and partial response rate among all 42 registered patients was 11 of 42 patients (26%; 95% confidence interval, 0.14-0.42). Stabilization of disease was seen in 15 patients (38%). Two additional patients with metastatic disease who achieved major responses to chemotherapy were rendered free of disease surgically, achieving a complete response status. The median overall survival was 7.1 months (95% confidence interval [CI], 6.3-9.1 months), with 64% of patients alive at 6 months and 19% of patients alive at 12 months. The median time to disease progression was 5.4 months (range, 0.9-20.8 months). Major toxicities were neutropenia and thrombocytopenia, with one episode of neutropenic fever.

Conclusions: The combination of gemcitabine and cisplatin appeared to have significantly greater activity than single-agent gemcitabine in this Phase II study, with tolerable toxicity. The antitumor activity of this combination needs to be confirmed in multi-institutional or comparative trials.