MedImmune Inc announced results showing that elevated levels of EphA2 frequently contribute to ovarian cancer progression and that high levels of this protein may relate to decreased patient survival.

Data from the study, conducted at The University of Texas M. D. Anderson Cancer Centre, were published in the August 1, 2004 issue of Clinical Cancer Research. The study documented significantly higher levels of EphA2 in ovarian cancer cell lines and malignant ovarian tumours than in non-cancerous cell lines or benign ovarian masses.

"The identification of a biomarker that could predict disease progression is promising to those of us fighting this disease in the clinic as well as the lab," said Anil K Sood, associate professor, gynaecologic oncology at M. D. Anderson and lead author of the study. "We now have rationale for developing a strategy to target this protein, EphA2, to increase patient survival," he added.

Data from the study, entitled "EphA2 Expression is Associated with Aggressive Features in Ovarian Carcinoma," showed that laboratory models and clinical specimens of ovarian cancer had high levels of EphA2. At least 76 per cent of the invasive ovarian tumour samples in the study over expressed EphA2, with the highest levels of the protein consistently found on the most aggressive cancers. Consistent with this result, high levels of EphA2 predicted shorter survival and poorer patient outcome. These studies suggest that EphA2 might be used to identify the most aggressive forms of ovarian cancer, release from MedImmune said.

"By demonstrating EphA2 over expression to be an indicator of ovarian cancer survival, we believe that the development of products targeting EphA2 could potentially result in significantly improved outcomes for women stricken with this deadly form of cancer," Peter Kiener, vice president, research at MedImmune said adding, "MedImmune researchers are applying their expertise in monoclonal antibody therapy and vaccines against EphA2 as well as other important targets in cancer. In light of data linking high levels of EphA2 with poor survival, this emphasizes the potential opportunity that targeted intervention could provide in the battle against the most deadly forms of this disease."

In addition to ovarian cancers, EphA2 is overexpressed by other types of human cancers, including melanoma (skin cancer), breast and prostate. The highest levels of EphA2 have been found on the most aggressive cancer cells, which is consistent with evidence linking EphA2 to clinical features of metastasis (cancer spread). Research to date indicates that EphA2 functions differently on malignant cells than it does on normal cells, and these differences may help facilitate the selective targeting of cancer cells while minimizing unwanted toxicities to normal cells.

MedImmune continues to build a body of scientific evidence demonstrating the role of EphA2 in uncontrolled tumour growth and metastasis, as well as the potential for EphA2 antibodies and vaccines to specifically treat or prevent certain cancers. The company is also pioneering new therapeutic strategies to exploit EphA2 as a target for cancer therapy.