Background

A prospective, randomized Phase III trial was performed to determine whether, compared with gemcitabine (GEM) alone, the addition of cisplatin (CDDP) to GEM was able to improve the time to disease progression and the clinical benefit rate in patients with advanced pancreatic adenocarcinoma. The objective response rate, overall survival rate, and toxicity patterns of patients in the two treatment arms were evaluated as secondary end points.

Methods

Patients with measurable, locally advanced and/or metastatic pancreatic adenocarcinoma were randomized to receive GEM (Arm A) or a combination of GEM and CDDP (Arm B). In Arm A, a dose of 1000 mg/m(2) GEM per week was administered for 7 consecutive weeks, and, after a 2-week rest, treatment was resumed on Days 1, 8, and 15 of a 28-day cycle for 2 cycles. In Arm B, CDDP was given at a dose of 25 mg/m(2) per week 1 hour before GEM at the same dose that was used in Arm A. On Day 22, only GEM was administered. Patients were restaged after the first 7 weeks of therapy and then again after the other 2 cycles.

Results

A total of 107 patients entered the trial: Fifty-four patients were randomized to Arm A, and 53 patients were randomized to Arm B. The median time to disease progression was 8 weeks in Arm A and 20 weeks in Arm B; this difference was statistically significant (P = 0.048). In Arm A, one complete response and four partial responses were recorded on the basis of an intent-to-treat analysis, with an overall response rate of 9.2% (95% confidence interval [95%CI], 3-20%). In Arm B, there were no complete responses, whereas 14 partial responses were achieved, with an overall response rate of 26.4% (95%CI, 15-40%). This difference in the overall response rates was statistically significant (P = 0.02). The tumor growth control rate (i.e., total number of patients who achieved complete responses, partial responses, and stable disease) was 42.6% (95%CI, 29-57%) in Arm A and 56.6% (95%CI, 42-70%) in Arm B. A clinical benefit was observed in 21 of 43 patients (49%) in Arm A and in 20 of 38 patients (52.6%) in Arm B without any significant difference. The median overall survival was 20 weeks for patients in Arm A and 30 weeks for patients in Arm B (P = 0.43). Toxicity was mild in both treatment arms, with no significant differences between the two groups except for the statistically higher incidence of Grade 1-2 asthenia in Arm B (P = 0.046).

Conclusions

The addition of CDDP to GEM significantly improved the median time to disease progression and the overall response rate compared with GEM alone. The clinical benefit rate was similar in both arms, whereas the median overall survival rate was more favorable for Arm B, although the difference did not attain statistical significance. The authors conclude that the combination of CDDP and GEM currently may be considered as an optimal treatment for patients with locally advanced and/or metastatic adenocarcinoma of the pancreas.