PRIMABioMed Limited, the cancer and immunotherapy research and therapeutic development company, announced that a pivotal patent application for Cancer Vac Limited, its dendritic cell based therapy subsidiary, has been accepted by the Australian Patent Office.

The accepted application covers the procedure for manipulating dendritic cells and the immunotherapeutic vaccine used by Cancer Vac in its Phase I clinical trial. The application will proceed to become a full granted patent following completion of various formalities and the absence of opposition by third parties. This Australian patent will be valid until 2018.

CEO Marcus Clark commented, "This patent will be a significant step in securing a leading position for Cancer Vac in the field of dendritic cell based cancer immunotherapeutics. The further strengthening of the Company''s intellectual property portfolio creates an attractive partnering proposition, which is in line with PRIMA''s commercialization strategy."

The success of the initial stage of the Phase I trial was announced in July 2002. All participants generated immune responses to their tumors and no unacceptable adverse reactions to the therapy occurred. Phase II trials are expected to commence before the end of 2002.

The therapy involves extraction of dendritic cells from the blood of patients and priming them with Cancer Vac''s proprietary immunotherapeutic product, a mannan-MUCI conjugate. These primed cells are then re-administered to the patient to stimulate a specific immune response.

Cancer Vac has exclusively licensed four "families" of patent applications from the Austin Research Institute in Melbourne. These families cover Cancer Vac''s immunotherapeutic vaccine, process of administration to dendritic cells and immunogenic antigens that can be used as cancer immunotherapeutics.

The patent applications have been filed in the United States, Europe, Japan, Australia and Canada and are at various stages of examination for compliance with relevant National Patent Law. Some have already progressed to granted, enforceable Patents.