Immune system therapies tested on advanced melanoma, kidney or lungtumors; side effects seen. By Amanda Gardner HealthDay Reporter SATURDAY, June 2 (HealthDay News) — Two related “immunotherapy”drugs show early evidence of being able to thwart a variety oftough-to-treat, advanced cancers. About one-quarter of patients with advanced melanoma, kidney orlung cancer saw their tumors shrink when taking one of the twodrugs, researchers reported Saturday. But the findings are extremely preliminary.
Phase 1 studies such asthis aren’t designed to look at tumor shrinkage at all, but simplyto establish dosage. And the therapies produced some serious side effects. While seeing results in a study such as this is “exciting,” saidDr. Len Lichtenfeld, deputy chief medical officer at the AmericanCancer Society, “this was not the focus of the study.” The two experimental drugs are antibodies that target two proteinsin a key pathway of the immune system.
“Cancers seem to have co-opted this pathway to enable them to flybelow the radar of the immune system,” explained study lead authorDr. Suzanne Topalian, professor of surgery and oncology at JohnsHopkins University School of Medicine in Baltimore. One protein, programmed death-1 (PD-1), is produced on the surfaceof immune-system cells; the second protein, programmed deathligand-1 (PD-L1), is produced on the cancer cells themselves,Topalian said. When the proteins interlock, they “form a shield that protects thetumor [from the immune system],” she said. Panel Mount Keyboard
The first trial tested a drug currently known as BMS-936558, whichblocks PD-1, in 236 patients with either advanced non-small-celllung cancer, melanoma or kidney cancer. None of the patients hadbenefited from prior therapies. Depending on the type of cancer, 18 percent to 28 percent of thepatients saw their tumors shrink. In 20 of the 31 people whoresponded to the drug, those responses lasted one year or more, theresearchers said. “These are notable results,” Topalian said. Industrial Desktop Keyboard
“These patients had anaverage life expectancy of less than a year coming into the trial.” The patients most likely to respond to the drug had so-called PD-L1positive tumors, indicating that this biomarker might help identifypatients who would be good candidates for this therapy. The second study assessed a drug known currently as BMS-936559,which blocks the PD-L1 protein. Ten percent to 17 percent of about200 patients responded to BMS-936559. But, the drugs also caused side effects that were “notinsignificant,” Lichtenfeld noted. Three of the patients receiving anti-PD-1 therapy died. China POS Touch Screen Monitors
Although there’s no indication yet of what effect the therapiesmight have on overall survival, “we think this pathway is animportant one to target for cancer therapy,” Topalian said. And, she added, “we are having a significant impact on multiplecancers, [which is] unusual.” Added Lichtenfeld: “The mechanism of action is intriguing, workingin a way applicable to a number of cancers so it may be broadlyapplicable. We will just have to follow this with interest.” The study findings were presented Saturday at the annual meeting ofthe American Society of Clinical Oncology in Chicago, and publishedsimultaneously in the New England Journal of Medicine . The trials were funded by Bristol-Myers Squibb and OnoPharmaceuticals Co., Ltd. More information The American Cancer Society has more on immunotherapy for cancer.
SOURCES: Suzanne Topalian, M.D., professor of surgery and oncology,Johns Hopkins University School of Medicine, Baltimore; LenLichtenfeld, M.D., deputy chief medical officer, American CancerSociety, Atlanta; June 2, 2012, presentation, American Society ofClinical Oncology annual meeting, Chicago; June 2, 2012, New England Journal of Medicine , online Copyright © 2012 HealthDay . All rights reserved.