CHIRON AND XOMA BEGIN TRIAL FOR CHIR-12.12 IN MULTIPLE MYELOMA

Chiron and XOMA have announced the initiation of a second clinical trial of CHIR-12.12, a novel, fully human, antagonist antibody that targets the CD40 antigen. The Phase I trial is for patients with multiple myeloma, a type of cancer that is associated with expression of the CD40 antigen on the cancer cell surface. The companies announced the initiation of a Phase I clinical trial of CHIR-12.12 in patients with chronic lymphocytic leukemia in April 2005. CHIR-12.12 is the first drug candidate to enter clinical testing under the collaborative agreement between Chiron and XOMA for the development and commercialization of antibody products for the treatment of cancer.

The single-agent, open-label study is designed to evaluate the safety, dose tolerability and pharmacokinetic profile of CHIR-12.12 in patients with multiple myeloma. Translational medicine will be used to monitor biomarkers and allow correlation of these markers with response to CHIR-12.12 therapy, guiding the dosing regimen and the selection of responsive patient populations. The study is expected to enroll up to 40 patients at four leading cancer centers in the U.S.