Sunday, November 12, 2017

Improving cancer immunotherapy by harnessing new technology

6:17 AM    
Checkpoint-inhibiting drugs like Genentech's

Tecentriq and Bristol-Myers Squibb’s Yervoy have transformed the treatment of some cancers by removing barriers that in the past would prevent patients’ immune systems from attacking and killing tumor cells. But these drugs don’t work for some patients, and for others they cause dangerous autoimmune responses. That’s why researchers around the world have been searching for ways to improve checkpoint inhibition.
Two ideas for doing just that were proposed this week. The first came from tissue engineers at the University of Chicago, who have been experimenting with peptides that attach to checkpoint-inhibiting drugs. The peptides bind to tissues in and near tumors, allowing the drugs to be injected directly into the cancer—potentially limiting off-target effects.
When the researchers tried their technology in mice, they were surprised by the results. When they attached the peptides to two types of checkpoint inhibitors—an anti-PD-L1 drug and an anti-CTLA4 compound—the medicines tethered themselves to the tumor sites and very little of the medication entered the bloodstream, as expected. None of the mice that got the conjugate drugs developed autoimmune responses, whereas all of the animals that were given standard checkpoint blockers did.
But the modified drugs also seemed to be more effective. They slowed down tumor growth and extended survival in mice with melanoma and breast tumors, according to the researchers, who detailed their findings in the journal Science Translational Medicine.