Objectives: The aim of the study was to assess the clinical efficacy and toxicity of single-agent imatinib mesylate in patients with advanced, unresectable metastatic pancreatic cancer.
Methods: Previously treated or untreated patients with histologically proven, unresectable pancreatic adenocarcinoma with adequate organ and bone marrow function were enrolled. Patients received imatinib 400 mg orally twice a day for a 28-day cycle. Response was evaluated every 4 weeks by imaging scans. Response was defined as lack of tumor progression at 3 months.
Results: Eleven patients were enrolled, and 9 were evaluable for response. Best response was stable disease in 3 patients after 2 cycles of therapy. All of them subsequently progressed. No patients remained on treatment for 3 months or longer, which was the response end point. Median time to tumor progression was 47 days (range, 19-76 days) and median overall survival was 118 days (range, 40-221 days). The first 3 patients received imatinib 400 mg orally twice a day. Due to unexpected grades 2 and 3 toxicities, the dose was reduced to 600 mg daily which was well tolerated. Most common adverse events included grades 1 to 2 edema, liver enzyme elevations, nausea, and rash.
Conclusion: Single-agent imatinib does not have a significant activity in pancreatic cancer.