Phase II study of paclitaxel plus the protein kinase C inhibitor bryostatin-1 in advanced pancreatic carcinoma

Purpose: To determine the efficacy and toxicity of the protein kinase C inhibitor bryostatin-1 plus paclitaxel in patients with advanced pancreatic carcinoma. Methods: Each treatment cycle consisted of paclitaxel 90 mg/m by intravenous infusion over 1 hour on days 1, 8, and 16, plus bryostatin 25 mcg/m as a 1-hour intravenous infusion on days 2, 9, and 15, given every 28 days. Patients were evaluated for response after every 2 treatment cycles, and continued therapy until disease progression or prohibitive toxicity. The primary objective was to determine whether the combination produced a response rate of at least 30%. Results: Nineteen patients with locally advanced or metastatic pancreatic adenocarcinoma received a total of 52 cycles of therapy (range: 1-10). Patients received the combination as first-line therapy for advanced disease (N = 5) or after prior chemotherapy used alone or in combination with local therapy. No patients had a confirmed objective response. The median time to treatment failure was 1.9 months (95% confidence intervals: 1.2, 2.6 months). Reasons for discontinuing therapy included progressive disease or death in 14 patients (74%) or because of adverse events or patient choice in 5 patients (26%). The most common grade 3 to 4 toxicities included leukopenia in 26%, anemia in 11%, myalgias in 11%, gastrointestinal bleeding in 11%, infection in 10%, and thrombosis in 10%. Conclusion: The combination of weekly paclitaxel and bryostatin-1 is not an effective therapy for patients with advanced pancreatic carcinoma.