Researchers are making progress in unleashing the body's immune system to fight various cancers. / Jupiterimages
For more than a century, doctors have dreamed of using the body's own defenses to keep cancer in check, but most efforts either did nothing or over-revved the immune system causing terrible side effects or even death.
A half dozen experimental trials presented at the ongoing American Society of Clinical Oncology conference in Chicago show that researchers are finally making significant progress in both melanoma where therapies began, as well as in other cancers.
"The revolution is here, it's ongoing and it's bursting out of melanoma into solid tumors," said Steven O'Day, a melanoma specialist in Beverly Hills, Calif., who helped run a Monday morning news conference. "This meeting is evidence of further progress in melanoma and in other very difficult to treat solid cancers."
Immune therapy has been one of the hottest areas of cancer research since 2011 when the Food and Drug Administration approved a drug called ipilimumab, which effectively treated melanoma, a deadly form of skin cancer. Then in 2012, it became clear that the same drug could also help people with other cancers, perhaps even a type of lung cancer that kills about 130,000 Americans a year.
But that drug, now sold under the name Yervoy, helps only a fraction of patients and has potentially dangerous side effects.
So for the last few years, researchers have been trying to figure out how to help more patients with fewer side effects, and determine who will benefit before subjecting them to potentially dangerous treatment.
The new studies show some major advances in those areas.
It's now clear that immune treatments can help patients with bladder, genitourinary, head and neck cancers, and malignant brain tumors, as well as melanoma and lung cancer.
Most of the excitement this week surrounds new therapies that "take the brakes" off the immune system. Yervoy was the first drug to exploit the discovery that cancer can put a brake on the immune system, preventing it from fighting cancer. Lifting the brake with Yervoy helps about 20% of melanoma patients.
There are several new papers looking at lifting two different brakes that seem to be more effective with fewer side effects. One, called programmed cell death or PD-1, is a protein on the surface of a type of immune cell known as a T cell; the other, called PD-L1, is a protein on the tumor, which interacts with PD-1.
Disrupting the relationship between PD-1 and PD-L1 removes the brake, "so the T cell recognizes the tumor and attacks it," according to Alise Reicin, vice president of Oncology for Merck Research Laboratories in Kenilworth, N.J. Merck makes a drug that combats PD-1 called pembrolizumab.
Today, researchers presented data showing that pembrolizumab helps more than 40% of melanoma patients survive at least three years, with few side effects.
Not long ago, most advanced melanoma patients survived just 6-9 months, said Antoni Ribas, an oncologist at the University of California, Los Angeles. So many patients in the pembrolizumab trial are still alive at 18 months that Ribas said he can't yet determine how much of a boost they're getting from the drug.
Another study found even more patients benefited when a similar drug called nivolumab, made by Bristol-Myers Squibb, was combined with Yervoy â?? though most patients suffered serious side effects. Both nivolumab and pembrolizumab are expected to receive FDA approval in the next year.
A different immune therapy approach, called adoptive T cell therapy helps combat the virus that causes cervical cancer, according to another new study. With adoptive T cell therapy, doctors harvest immune cells that are naturally fighting a patient's cancer, expand them in the lab, and then put them back in the body â?? essentially enlarging the immune system's anti-tumor army.
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Read the original story: Immune therapies improve treatment of cancers