Chiron and XOMA initiate Phase I trial

Chiron Corporation and XOMA have initiated a Phase I clinical trial to test CHIR-12.12, a fully human, antagonist antibody that targets the CD40 antigen.

Treatment has begun in the first Phase I trial, for patients with advanced chronic lymphocytic leukaemia (CLL). CHIR-12.12 is the first drug candidate to enter clinical testing under the collaborative agreement between Chiron and XOMA for the development and commercialisation of antibody products for the treatment of cancer.

'We are pleased to move forward with Phase I studies of CHIR-12.12 as part of Chiron's translational-medicine approach to early stage oncology drug development, said Dr Stephen Dilly, chief medical officer, Chiron BioPharmaceuticals. 'Based on compelling preclinical data, we believe that this unique compound and its dual mechanisms of action could prove effective in the treatment of a variety of B-cell malignancies.'

'For patients with advanced CLL, today's announcement is very encouraging,' said John Castello, president, chairman and ceo of XOMA. 'The news also demonstrates how well our collaboration strategy is working to rapidly advance promising new therapeutics into the clinic.'

The single-agent, open-label Phase I study of CHIR-12.12 is designed to evaluate the safety, dose tolerability and pharmacokinetic profile of CHIR-12.12 in patients with advanced CLL. Translational medicine will be used to monitor biomarkers in real time. The study is expected to enroll up to 40 patients at three leading cancer centres in the United States. Chiron and XOMA also plan to initiate clinical testing of CHIR-12.12 in patients with multiple myeloma in 2005.

About CHIR-12.12

CHIR-12.12 is a fully human, antagonist antibody that targets the CD40 antigen. As shown in vitro in cell lines, in vivo in animal models and ex vivo in patient cells, CHIR-12.12 binds to tumour cells that express CD40 and antagonises (prevents) CD40 ligand-mediated growth and survival of malignant B cells. CHIR-12.12 also induces antibody-dependent cellular cytotoxicity (ADCC), killing CD40 expressing tumor cells by immune effector cells. This dual mechanism of action makes CHIR-12.12 a promising drug candidate for the treatment of B-cell malignancies.

About Chronic Lymphocytic Leukaemia

Chronic lymphocytic leukaemia (CLL) is a form of slow-progressing leukaemia, a disease characterised by an accumulation of abnormal lymphocytes in the blood and bone marrow. These lymphocytes interfere with production of other blood cells that are necessary for the normal functioning of the blood. In CLL, B lymphocytes, or B cells, are the most commonly affected lymphocytes. CLL is most common in individuals 50 years of age and older, and the five-year survival rate for CLL patients is approximately 46%. According to the American Cancer Society, approximately 9,730 new cases of CLL will be diagnosed in the United States during 2005.