Pfizer Inc announced that a phase-3 clinical trial of Sutent (sunitinib malate) has been stopped early after the drug showed significant benefit in patients with advanced pancreatic islet cell tumours, also known as pancreatic neuroendocrine tumours.

An independent Data Monitoring Committee (DMC) recommended halting the trial after concluding that Sutent demonstrated greater progression-free survival compared to placebo plus best supportive care in patients with pancreatic islet cell tumours.

"We are delighted by these findings which demonstrate that Sutent provides a benefit for patients with advanced, well-differentiated pancreatic islet cell tumours - a rare cancer with limited treatment options," said Dr Mace Rothenberg, senior vice president of medical development and clinical affairs for Pfizer's Oncology Business Unit. "These and previously reported phase-2 data contribute to the growing body of evidence indicating activity with sunitinib in patients with pancreatic islet cell tumours."

Pfizer has notified clinical trial investigators involved in the trial and regulatory agencies of the DMC recommendations. All patients in the trial will have the option to continue taking Sutent or be switched from placebo to Sutent. The full data set from this trial is being analyzed and more details will be presented at an upcoming scientific meeting.

This phase-III trial of sunitinib in patients with advanced pancreatic islet cell tumors was initiated based on the results of a earlier phase II trial published in the Journal of Clinical Oncology (July 2008).

In contrast to exocrine pancreatic adenocarcinoma, pancreatic islet cell tumours are rare, indolent tumours of the endocrine pancreas with an incidence of 5-10 per million worldwide annually. Pancreatic islet cell tumours include insulinomas, glucagonomas and gastrinomas. Current treatment options are limited.

Sutent is currently approved for both advanced renal cell carcinoma (RCC) and second-line gastrointestinal stromal tumor (GIST), based on efficacy and safety data from large, randomized phase-3 clinical trials. Sutent has played an important role in reshaping the treatment landscape for these two difficult-to-treat cancers. To date, more than 38,000 patients globally have been treated with Sutent in the clinical setting and trials.

This is the second phase-III Sutent trial Pfizer has stopped early on the recommendation of an independent data monitoring committee due to benefit. In January 2005, a phase-III trial in GIST was unblinded early when a planned interim analysis showed significantly longer time to tumour progression with Sutent compared to placebo.

Sutent is an oral multi-kinase inhibitor approved for the treatment of advanced RCC and GIST after disease progression on or intolerance to imatinib mesylate.