Pertuzumab is a single-agent antibody designed to bind to the HER2 receptor and inhibit the ability of HER2 to pair with other HER family members (HER1, HER2, HER3 and HER4). If the pairing process (called dimerization) is not interrupted, the binding of these growth factors activates an intracellular signaling pathway that leads to tumor proliferation.

While other drugs such as docetaxel have shown to benefit men with advanced prostate cancer, no other second-line therapy (a treatment given when an initial treatment (first-line therapy) does not work or stops working) to date has shown to prolong survival.

Previous research published by cancer researchers at Cedars-Sinai and other institutions has shown that pertuzumab affects the growth of several other types of cancers, including breast, ovarian and lung cancer, and that the drug may also prolong survival for patients with advanced ovarian cancer.

In the current study, the pertuzumab was well-tolerated but no objective tumor shrinkages were observed. No decline in PSA (prostate-specific antigen; a tumor marker) levels was detected in patients during the study. According to the researchers, this study raises a question long debated in prostate cancer literature: what should clinical outcome standards or end point be the for studies involving patients with advanced, intractable prostate cancer who have limited treatment options.

The next step for researchers is to test the pertuzumab on a larger group of patients in a randomized fashion, and to analyze data that is not retrospective.

Prostate cancer is the most common type of cancer found in American men, other than skin cancer and is the second leading cause of cancer death in men. The American Cancer Society estim
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Contact: Simi Singer
simi.singer@cshs.org
310-423-4768
Cedars-Sinai Medical Center
16-Feb-2007