For more than a century, scientists have been attempting to harness the immune system to fight cancer — trying to get the antibodies and cells that protect us from bacteria and viruses to kill diseased cells. Every once in a while, a tantalizing success occurred. But time and again the treatment could not be repeated.
The case begins with a drug called ipilimumab, approved in 2011 for advanced melanoma treatment. The drug turns the immune system into a cancer-killer, bringing some patients back from the brink of death. Melanoma is one of the deadliest forms of skin cancer, striking 76,000 Americans and killing more than 9,000 every year. Because there are few treatments for advanced melanoma, the new drug was greeted with excitement by doctors and patients. But ipilimumab, sold under the brand named Yervoy by Bristol Myers Squibb, works in only 10 to 20 percent of patients. Until now, no one knew why.
Valerie Esposito, a 42-year-old mother of three, was taking ipilimumab for advanced melanoma and it wasn’t working very well. The cancer was spreading through her body. One huge tumor, in fact, was pressing on her spine. To relieve the pressure, her doctors at Memorial Sloan Kettering Cancer Center in New York radiated the lump. Within weeks, other tumors throughout her body started shrinking dramatically.
This has occurred before in cancer immunology. But this time oncologist Dr. Jedd Wolchok and his team of melanoma specialists at Sloan Kettering think they have figured out, at the molecular level, exactly how that shot of radiation altered her immune system to allow the drug to kill far more cancer cells. It created pieces of tumors — proteins called antigens — that sparked specific changes in how antibodies and disease-fighting white cells recognized the cancer cells as foreign and thus destroyed them. Already the researchers are planning a nationwide clinical trial to determine if the findings can allow the drug to help many more patients with advanced melanoma. They also believe the same approach could work for kidney, lung and other cancers.