Strong pooled Ph III safety data for Amgen's Vectibix

US biotechnology major Amgen has reported strong interim pooled, blinded, safety results from two Phase III trials evaluating Vectibix (panitumumab) in combination with standard chemotherapy in earlier lines of metastatic colorectal cancer. Updated data from these trials, as well as the first prospective evaluation of the impact of the clinical biomarker KRAS on Vectibix efficacy in combination with chemotherapy, were presented at the 2008 American Society of Clinical Oncology's annual meeting in Chicago.

The PRIME study is a global, Phase III trial investigating Vectibix in combination with FOLFOX chemotherapy as first-line treatment for mCRC among wild-type KRAS and all randomized patients. Final enrollment was completed in February 2008 with a total of 1,183 patients.

Pooled safety data from a planned interim analysis, conducted by an independent Data Monitoring Committee, of 903 patients, of whom 99% received at least one cycle of therapy, showed the following pooled grade 3/4 adverse events: neutropenia (28%), diarrhea (11%), fatigue (4%), nausea (3%), dehydration (3%) and hypomagnesemia, pulmonary embolism, febrile neutropenia and deep vein thrombosis (2%, respectively). 56% of the pooled patient population had skin and subcutaneous tissue system organ class events of any grade; 10% grade 3 and less than 1% grade 4. Based upon this interim safety analysis, the DMC recommended that the PRIME study should continue per protocol.