Cancer relies on a variety of tricks that essentially render it invisible to the body’s disease fighting mechanisms.
Tumors are able to co-opt “checkpoint” proteins found on the immune system’s T cells. The checkpoints are activated they can turn a T cell from a warrior ready for a fight into a dozing sentinel. This is when cancer takes full advantage.
However, new drugs that are able to disable these checkpoint proteins are showing a keen ability to awaken T cells. Studies tsting a handful of these drugs have demonstrated eye-opening results against melanoma and tangible gains against other malignancies.
Melanoma is the deadliest form of skin cancer.
Checkpoint drug inhibits the inhibitors of the immune system. The newer approach “releases the parking brake” on T cells that have reached a tumor only to turn dormant.
The results are an exciting breakthrough for the research community that was becoming doubtful about harnessing the immune system to fight cancer.
Clinical trials reported in 2014 suggested positive results for checkpoint drugs in patients who had run out of options against melanoma and cancers of the kidney, bladder and lung.
New studies additionally fed the optimism with promising results against those caners and others. Some of the first trials combined two checkpoint stoppers in patients have yielded impressive results. Although the dual-dose approach can cause some side effects, it is unclear whether these are worse than the downsides of chemotherapy.
Unfortunately, not all patients benefit from the checkpoint drugs, in part because tumors have found multiple ways to sabotage immune reactions. But the early data suggests that 20 to 35 percent of cancer patients might benefit from overriding the checkpoints.
Several pharmaceutical companies are working on prospective checkpoint drugs.
Scientists are testing these drugs on all kinds of malignancies, not only melanoma.