Conventional chemotherapy for unresectable or metastatic adenocarcinoma of the pancreas has had little effect on palliation or survival. Almost all studies of systemic therapy have involved empiric use of a variety of Phase II or conventional agents alone or in combination. On the basis of recent studies using a human tumor pancreatic cancer (PC) xenograft in nude mice, a Phase I clinical trial of cisplatin, high-dose cytosine arabinoside (Ara-C), and caffeine (CAC) was performed in patients with advanced incurable PC. A tolerable dose and schedule of the three agents were developed. Seven of 18 patients with measurable disease in this Phase I trial had partial responses to CAC. A Phase III comparison of CAC versus standard treatment using streptozotocin, mitomycin, and 5-fluorouracil (SMF) was performed. Eighty-two patients with advanced PC were entered into this random assignment trial. The two treatment arms were well balanced for the usual prognostic factors. Although the acute (e.g., nausea and vomiting) toxicities of CAC were greater than those of SMF, both groups of patients tolerated treatment resonably well. Ninety percent of patients were evaluable for response. Two patients (5.5%) on the CAC treatment arm (95% confidence interval [CI], 0% to 15%) and four patients (10.2%) on the SMF treatment arm (95% CI, 1% to 22%) had objective responses (partial response in measurable disease or improvement in evaluable disease). No complete remissions were observed. The 95% confidence limits of response for CAC and SMF overlapped. The median duration of survival for all patients on the SMF treatment arm was 10 months, although it was 5 months on the CAC treatment arm (P = 0.008). In this Phase III comparison, CAC was not superior to conventional therapy with SMF in terms of response and was inferior for survival. Neither regimen is effective treatment for advanced PC.