Chemists have discovered a new approach to blocking cancer-drug resistance that could be applied to any type of cancer.

The approach, which calls for chemically combining two existing drugs in a new way, resulted in 50 percent smaller tumors in mice when compared to a more traditional treatment plan with the same drugs given separately.

Part of how the drug works is by targeting a tumor's metabolism. When it's just beginning, a cancerous tumor is like an out-of-shape runner: It's growing so quickly and burning so much energy that it can't get enough oxygen. Just like the out-of-shape runner panting for air, in this early stage, a tumor's metabolism is abnormal, making it vulnerable, so this is when cancer drugs tend to work the best. The chemists' innovation was in connecting an anti-cancer toxin to a molecule that can keep tumors from breathing normally.

This new combination of existing drugs shows promise that it could be much more effective at shrinking the size of cancerous tumors than current treatments.

"The best part is that our combined drug candidate was so much more effective than one of the most powerful cancer drugs on the market," said Jonathan Sessler, co-lead author of a study published over the weekend in the journal Chem. "The difference is mind blowing."