New Drugs Unleash Immune System to Attack Tumors

Lung, Skin, Kidney Tumors Shrink in Early-Stage Trials

June 4, 2012 (Chicago) -- Two experimental drugs that recharge the body's immune system to seek out and attack tumors are showing promise for the treatment of certain advanced lung, skin, and kidney cancers.

The drugs disable a molecular shield that tumors put up to block attacks from the immune system. In early-stage studies, the drugs shrank tumors in some people with certain types of lung, skin, and kidney cancers who had not been helped by other treatments.

Researcher Julie Brahmer, MD, associate professor of oncology at Johns Hopkins Kimmel Cancer Center, tells WebMD that she is optimistic because "in some patients, tumors did not grow back even after treatment was stopped."

"These patients had been through several types of therapy and were very ill," she says.

It's too soon to say whether the drugs will extend lives and whether they are safe in the long run. A larger, longer study is planned to test that.

But the early studies suggest the drugs work at least as well as chemotherapy drugs currently in use, and possibly with fewer side effects, Brahmer says.

The research was presented here at the annual meeting of the American Society of Clinical Oncology and published online by the New England Journal of Medicine. Both drugs are made by Bristol-Myers Squibb, which helped fund the work.

One of the new drugs blocks a protein called programmed death-1 (PD-1) that sits on the surface of immune cells. The other drug blocks a protein called programmed death ligand-1 (PD-L1) that is on the surface of cancer cells. When PD-1 and PD-L1 join together, they form a biochemical shield that protects tumor cells from the immune system.

"We showed that blocking either of these proteins works to get tumor shrinkage," Brahmer says.

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New Drugs Unleash Immune System to Attack Tumors