An ongoing phase I clinical trial shows that a new anticancer agent, CCI-779, is well-tolerated and may have antitumor activity. CCI-779 is a derivative of rapamycin, an immunosuppressive agent. Results of the study were presented at the International Conference on Molecular Cancer Therapeutics sponsored by the American Association of Cancer Research (AACR), National Cancer Institute (NCI), and European Organization for Research and Treatment of Cancer (EORTC). Jerome Alexander, a physician-in-training and researcher working with senior investigator, Eric Raymond, MD, made the presentation.
By interfering with key proteins that regulate cell growth, CCI-779 may stop the progression of tumors. This is a unique mechanism of action for an anticancer agent, said Dr. Raymond, associate professor of oncology at the Institut Gustave Roussy in Villejuif, France. If these preliminary results are confirmed in future observations, this may represent a new and safer treatment for cancer patients.
For this ongoing phase I study, 12 patients received CCI-779. Three patients with renal cell cancer experienced tumor regression after other treatments had failed. At the doses used so far, the main adverse effects of CCI-779 have been mild skin reactions and inflammation of the mucous membranes, which occurred at all dose levels studied but did not increase in intensity with higher doses or longer duration of treatment.
The new agent appears to block the effect of mTOR, an enzyme that has an important role in regulating the synthesis of proteins that control cell division. Therefore, CCI-779 may stop the production of proteins essential for cancer cell proliferation and possibly survival of cancer cells. According to the researchers, ongoing studies are evaluating other dose levels and a longer treatment duration to confirm the safety and efficacy of CCI-779 before advancing to phase II studies to confirm efficacy in several types of cancer.
Axel Hanauske, MD, PhD, from the Oncology Institute in Munich, Germany, and the sponsor, Wyeth-Ayerst Research in Radnor, Pennsylvania/Genetics Institute in Munich, Germany, are collaborating on the study.