Introgen Therapeutics, Inc. has announced that the publication of data in Cancer, the journal of the American Cancer Society, highlighting the results of a phase 2 studies with Advexin therapy in the treatment of women with locally advanced breast cancer. Advexin was combined with chemotherapy to shrink the tumours prior to their surgical removal.

Objective clinical responses with a greater than 50 per cent reduction in tumour size were seen following combined Advexin and chemotherapy in all of the patients. Complete tumour removal by subsequent surgery was achieved in 100 per cent of the patients. At a median follow-up of 37 months, the estimate breast cancer-specific survival rate at 3 years was 84 per cent. These results with Advexin are better than what would be expected from chemotherapy treatment alone. Dr Massimo Cristofanilli, associate professor in the Department of Breast Medical Oncology, conducted the study at The University of Texas M D Anderson Cancer Center.

"These data are very encouraging and suggest that Advexin may be combined with chemotherapy to improve patient outcomes and to enable less invasive surgeries that facilitate breast conservation," said Dr Cristofanilli, the principal investigator of the study.

In a novel finding, activation of a local immune response at the site of the tumour was observed. Treated tumours were infiltrated with cells of the immune system that are known to participate in immune responses against tumours, which may be useful in controlling local disease as well as disease outside the breast.

In the phase 2 clinical trial, Advexin was locally administered to breast tumours in conjunction with doxorubicin and docetaxel chemotherapy in twelve patients who subsequently underwent surgery to remove residual tumour. Treatments administered prior to surgery are termed neoadjuvant therapies and represent a novel and increasingly applied approach to make surgical tumour resections either more complete improving outcomes or less invasive facilitating breast conservation.

The p53 tumour suppressor, the active component of Advexin, has been shown to sensitize cancer cells to the effects of chemotherapy. The results of this study suggest that tumours treated with Advexin and chemotherapy had a greater reduction in size compared to what would be expected with chemotherapy treatment alone. The observation of an immune response at the tumour site suggests that Advexin may also work through additional immune mechanisms of action to eradicate tumour cells.

Preliminary data from this trial were initially reported at the 2004 San Antonio Breast Cancer Symposium and updated at the 2005 San Antonio Breast Cancer Symposium. These study results are published in the September 1, 2006 issue of the medical journal Cancer.

Advexin p53 therapy is a targeted molecular therapy with broad applicability in a wide range of tumour types and clinical settings because it targets one of the most fundamental and common molecular defects, abnormal p53 tumour suppressor function, associated with cancer initiation, progression and treatment resistance.

Advexin has demonstrated increased survival and durable tumour growth control in recurrent head and neck cancer patients. Advexin has demonstrated clinical activity in a number of solid tumour types in multiple phase 1, 2 and 3 clinical trials conducted worldwide. A request for accelerated approval for Advexin is now pending at the US Food and Drug Administration (FDA).