A phase II study of temozolomide in advanced untreated pancreatic cancer

Temozolomide (SCH 52365) is an imidazotetrazine derivative which exhibits broad spectrum activity against murine tumors and is structurally related to dacarbazine (DTIC). Temozolomide cytotoxicity is schedule dependent in vivo with a daily x 5 schedule showing the highest activity. Oral temozolomide is rapidly and completely absorbed with minimal interpatient and intrapatient variability in pharmacokinetics. Clinical studies have demonstrated activity against melanoma and glioma. The present study examined the activity of oral temozolomide against patients with pancreatic cancer. Patients with advanced pancreatic adenocarcinoma previously untreated with chemotherapy received temozolomide 200 mg/m2/day once daily orally for 5 days with cycles repeated every 28 days. There were 16 patients entered on study with 15 evaluable for response and toxicity. There were no responses seen in 15 evaluable patients with 14 manifesting progressive disease within 2 months of starting therapy. Toxicity was primarily hematological with 3 patients experiencing > or = grade 3 neutropenia and thrombocytopenia respectively. Other toxicities were relatively modest. In conclusion, temozolomide in the once daily x 5 schedule is inactive against adenocarcinoma of the pancreas.