The investigators at the American Society of Clinical Oncology (ASCO) 2010 Annual Meeting here in Chicago earlier this summer were enthusiastic about new immune therapy drugs that unleash the powers of the immune system on cancer. One experimental therapy gaining the most attention is Bristol-Myers Squibb's skin cancer treatment, ipilimumab. In recent trials, ipilimumab has been effective in keeping terminal melanoma patients alive for nearly a year longer than existing treatments.
Ipilimumab is an antibody that blocks CTLA-4. It was discovered about 10 years ago by Dr. James Allison, then at the University of California, Berkeley, and now head of the immunology department at Sloan-Kettering. Allison found that the antibody had the remarkable ability to completely knock out tumors in mice. In initial human clinical trials, the drug was almost quashed after patients were getting sicker and tumors kept growing. Scientists soon discovered, however, that these were actually signs that the drug was doing its job, rather than making patients sicker.
Scientists are also exploring possible uses for ipilimumab in the treatment of tumors of the lung and prostate. If testing continues to be successful, ipilimumab and other immune therapy drugs have the potential to evolve into more than just one-target treatments. Next-generation immunotherapy drugs have the potential to train the immune system to attack cancer cells, similarly to the way a virus is killed.
If all goes according to plan, ipilimumab will be available to physicians and patients in 2012, and analysts are predicting that ipilimumab could reach $1 billion in annual sales within its first 5 years on the market.
While it's still too early to claim that we've found a cure for cancer, researchers are optimistic that ipilimumab has the potential to change cancer from a terminal disease to a chronic, yet manageable condition.
