Sept. 19 (UPI) -- A triple-drug combination may be an effective weapon in the fight against lung cancer, a new study says.

A trio of mTOR, IGF1R, and MEK inhibiting compounds shrunk lung tumors in mice and cancer cells in humans with a mutation in the KRAS gene, according to research published Wednesday in Science Translational Medicine.


The mutation, which makes up about 14 percent of lung adenocarcinomas, triggers fast-growing, uncontrollable cancer growth.

Lung adenocarcinomas are the most common type of lung cancer. Overall, lung cancer kills about 150,000 people annually, according to the Centers for Disease Control and Prevention.

"It's likely that tumors will develop resistance to the new drugs, so we need to stay one step ahead," senior author Julian Downward, a researcher at The Institute of Cancer Research and study senior author, said in a news release. "We found a three-drug combination that significantly shrank lung tumors in mice and human cancer cells."

A G12C KRAS inhibitor initially shrunk tumors lung tumors, but they grew back within a couple of weeks.

The researchers developed the combination therapy by editing human tumor cells that contained the G12C KRAS mutation to block activity from more than 16,000 distinct genes. Then they applied the drug combinations that are known to effectively combat KRAS cancers, finding it kept the tumors small after initially shrinking them.

In addition to the compounds blocking KRAS, the researchers say inhibitors of both MTOR and IGF1R have been tested in cancer patients. Licensed mTOR inhibitors are available for treatment now, but IFG1R inhibitors are still in trial -- and the drug combination needs to be tested in human patients.

"When we blocked all three pathways, the mutant cancer cells were simply unable to survive," said Miriam Molina-Arcas, a researcher at Francis Crick Institute and study first author. "This makes it a promising avenue for human trials in coming years, although this is still early research."

"Promising research in mice and cells can tell us what's worth trying, but it's impossible to predict how patients will respond until we actually try," Molina-Arcas said.