Pfizer Inc announced the discontinuation of the SUN 1170 phase-3 open-label study of Sutent (sunitinib malate) in advanced hepatocellular carcinoma (HCC), or liver cancer. Following a review by the independent Data Monitoring Committee (DMC), the study was discontinued based on a higher incidence of serious adverse events in the sunitinib arm compared to the sorafenib arm and the fact that sunitinib did not meet the criteria to demonstrate that it was either superior or non-inferior to sorafenib in the survival of patients with advanced hepatocellular cancer. No new or unexpected types of a serious adverse events were observed in the SUN 1170 trial.

“There is a great need for effective new therapies for patients with advanced liver cancer. The disappointing outcome of this trial challenges all of us to work harder to understand the complex biology of this disease. The result of this trial in hepatocellular cancer patients does not diminish our confidence in Sutent for the treatment of patients with renal cell cancer and GIST. We are committed to patient safety and are working with investigators to better understand these trial results and their implications for clinical practice,” said Dr Mace Rothenberg, senior vice president of Clinical Development and Medical Affairs for Pfizer's Oncology Business Unit. “We continue to study the potential role of Sutent in the treatment of various types of cancer in late-stage trials.”

The company has notified SUN 1170 clinical investigators and all involved regulatory agencies of the discontinuation of SUN 1170. Investigators have been instructed to work with all of their patients in the SUN 1170 study on an individual basis to determine an appropriate course of action.

Sunitinib is currently approved for both gastrointestinal stromal tumours (GIST) after disease progression on or intolerance to imatinib mesylate, and advanced/metastatic renal cell carcinoma (RCC) based on efficacy and safety data from large, randomized phase-3 clinical trials. To date, more than 82,000 patients have been treated with sunitinib in the clinical setting and in trials.

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.