Cancer is not one thing, it's a huge zoo of many many many ways that cells start to break the social contract and divide in an uncontrolled manner.
One of the most commonly observed broken mechanisms is mutation in the gene KRAS that turns this on/off growth switch into the permanently on position.
This has been known for decades, of course. And there have been huge amounts of effort to try to develop drugs that target KRAS in cancer, but for decades it's always been thought of as 'undruggable' because of the difficulty of finding any molecules that would affect it.
This new drug, that finally treats KRAS mutated cancers, goes about it in a new way. Instead of trying to gum up the works of a single protein by sticking a small chemical in it, it effectively "glues" the KRAS protein to another protein, CypA, which keeps the switch away from reaching the normal areas where it's "on switch" activity works.
So this new drug means two things: 1) a lot of the most difficult to treat cancers are now far more treatable, and in the next 1-5 years clinical trials will tell us which cancers this particular drug works well for, 2) there's an entire new class of drug activity that everybody is chasing at this very moment, so in 5-25 years we'll likely have a huge number more of these sorts of treatments.
