By ALAN BAVLEY
The vaccine that Larry Mathews is getting won’t protect him from the flu. That’s OK — the stakes are far higher than that.
He’s hoping the shots will prime his immune system to fight the aggressive cancer that has invaded his brain. If it works as he wants it to, his body’s own killer cells will mop up malignant cells that surgery, radiation and chemotherapy couldn’t eliminate.
After many false starts and premature promises, it appears that their research is beginning to pay off.
In late April, the U.S. Food and Drug Administration approved a cancer vaccine, Provenge, that can modestly extend the lives of men with advanced prostate cancer. Several major insurance plans and Medicare claims processors in some parts of the country, including Kansas and Missouri, already have agreed to pay for the costly treatment.
Mathews is taking part in a preliminary clinical study at St. Luke’s Hospital on a brain cancer vaccine developed at the University of Kansas Medical Center. A larger two-year study aimed at gaining FDA approval is planned to start this fall.
Worldwide, scientists are working on dozens of vaccines against melanoma, breast cancer and cancers of the lung, colon and pancreas.
Researchers can cite anecdotes of cancer patients given months to live who have survived 15 years or longer after receiving vaccines. But so far, conclusive evidence from large clinical trials is scant.
Even so, experts anticipate that several cancer vaccines could prove effective enough to gain FDA approval in the next four or five years.
These therapeutic vaccines are designed for patients who already have cancer. That makes them radically different from conventional preventive vaccines, such as the cervical cancer vaccine Gardasil, that immunize against viruses that cause cancer.
The surge in development of therapeutic vaccines doesn’t come from any single scientific breakthrough, said William Chambers, director of clinical research and immunology at the American Cancer Society. Rather, it’s the result of years of slow, incremental progress.
“Immunotherapy has been a tough nut to crack,” Chambers said. “What you’re seeing now is the product of a lot of hard work. Some of the successes are showing up.”