Researchers from the University of Pennsylvania School of Medicine and colleagues at Merck Serono Research in Germany have found that two drugs bind to receptor sites on some tumors in different places at the same time, suggesting the possibility of a new combination therapy for certain types of cancer.

An increasing number of therapies targeting tumors that have proteins called epidermal growth factor receptors (EGFRtermtermterm) sitting on their surface are already being used in the clinic or are in late stages of development. For example, Herceptin is an established treatment for certain types of breast cancer and Erbituxterm and Vectibixterm are in use for other types of cancer. An additional drug called matuzumab is in phase II clinical trials.

ImClone Systems Incorporated (NASDAQ:IMCL) and Bristol-Myers Squibb Company (NYSE:BMY) today announced that a Phase III study of ERBITUXterm(R) (Cetuximabtermterm) plus gemcitabine (a chemotherapyterm) in patients with locally advanced unresectable or metastaticterm pancreatic cancer did not meet its primary endpoint of improving overall survival.

Conducted by the Southwest Oncology Group (SWOG), a cancer center network sponsored by the National Cancer Institute, the open-label, randomized study compared ERBITUX plus gemcitabine to gemcitabine alone in more than 700 patients with pancreatic cancer in the first-line treatment setting. The study was conducted in centers throughout the United States and Canada. It was completed in a significantly shorter time than projected, providing a timely answer to an important research question. SWOG has informed ImClone and Bristol-Myers Squibb that the primary study endpoint of statistically improving overall survival was not met. The three parties -- SWOG, ImClone, and Bristol-Myers Squibb -- will engage in joint efforts to fully interpret these results.

    Crucell in a partnership with DSM have announced that production of monoclonal antibodies has reached 10g/L (grams per liter) of cell culture, using the PER.C6 platform to produce the yields. Current standard methods yield monoclonal antibodies around 1-2g/L. This order of magnitude increase in yield could help lower the cost for producing the current monoclonal antibodies used in treatments for cancer today. The price of drugs has soared for cancer treatment and the monoclonal antibodyterm is no exception. Herceptin costs around $3,000 a month, Avastinterm is at $4,400, Erbituxterm costs around $10,000 a month, and Rituxanterm can range from $4,200 to $13,000 a month depending on treatment. A great article on recent drug costs can be found here on the USA Today site.

    BioWa, Inc has a patented technology platform called Potelligent which modifies monoclonal antibodies so that they have enhanced binding to increase Antibodyterm-dependent cellular cytotoxicity (ADCC). ADCC is the mechanism by which some antibodies can kill cancer cells. Once an antibody binds to a cell, Natural Killer (NK) cells and Monocytes in the immune system attack the bound cell, ultimately killing it.

    UCB biopharmaceutical company has been has been allowed to use Potelligent in order to develop new antibodies toward novel targets. The enhanced ADCC could help bring new antibodies to market that have greater efficacy while possibly lowering production costs of the treatment. Erbituxterm and Herceptin are antibodies whose efficacy is dependent on ADCC.

Antibodies that selectively bind and destroy cancer cells represent some of the most promising cancer therapy approaches being developed today. Several of these antibodies have reached the market, including cetuximabtermterm (Erbituxterm, ImClone Systems), which targets the epidermal growth factor receptor (EGFRtermtermterm) protein. However, a study conducted at the Dana-Farber Cancer Institute and the Ludwig Center at Dana-Farber/Harvard Medical School now suggests that antibodies binding a particular protein conformation, caused by hyperactivation, might have distinct therapeutic advantages over antibodies, like cetuximab, that bind to wild-type (normal) target proteins.

Panitumumabtermterm, otherwise known as Vectibixterm, is the first fully human monoclonal antibodyterm directed against the EGFRtermtermterm receptor which is expressed on the surface of 75% of colorectal cancers. It was also approved by the fda this month, so knowledge of its efficacy could help you in discussing options in the treatment of your cancer. Be sure to ask your doctor about this human antibody and be sure to use the name of the drug when discussing it rather than the term "antibody" as there are many antibodies currently being used or approved for the treatment of cancer. What is the difference between Erbituxterm and Vectibix? Vectibix, (the fully human derived antibody) showed a 3% lesser amount of rash type immunolgical reactions than Erbitux.

While Vectibixterm (Amgen) alone only shows an 8% partial response rate, it shows a 46% reduction in tumor progression. Using the agent in combination with irinotecantermterm is therefore a novel and interesting approach which many centers are now exploring. If you center is not using this, or Erbituxterm (another monoclonal antibodyterm, ImClone, 10% response rate), then you should be asking why?

[via Entrez PubMed]: