Non-small cell lung cancer, diagnosed in over 235,000 Americans each year, remains a formidable challenge despite advances in treatment [[2]]. now,researchers are investigating a novel approach to combat the disease,specifically targeting the *KRAS* mutation present in roughly 30% of cases [[1]]. A new study published in the *Journal of Clinical Examination* details promising preclinical results for an experimental compound that may restore the effectiveness of existing therapies and overcome drug resistance.
A new experimental approach may improve treatment for non-small cell lung cancer, the second most common cancer and leading cause of cancer death in the United States, by keeping a tumor-suppressing protein active and reducing the development of resistance to existing therapies.
More than 80% of lung cancer cases are classified as non-small cell lung cancer, a form characterized by larger tumor cells and a slower progression than small cell lung cancer. Understanding the nuances of this disease is crucial for developing more effective treatments and improving patient outcomes.
A significant number of genetic mutations are linked to non-small cell lung cancer, including mutations in the KRAS gene, which plays a role in cell growth and division. These mutations are present in approximately 30% of cases.
Patients whose tumors harbor these KRAS mutations generally experience shorter survival rates and frequently develop resistance to available treatments. This highlights the urgent need for new therapeutic strategies targeting this specific genetic alteration.
Researchers at the University of Michigan have identified a new protein target and developed an experimental compound aimed at treating KRAS-mutated non-small cell lung cancer, according to a study published in Journal of Clinical Investigation – JCI. The research builds on existing knowledge of the disease’s complex genetic drivers.
While several drugs approved by regulatory authorities target the KRAS gene in pancreatic, colorectal, and lung cancers, their effectiveness is often limited over time as tumor cells develop resistance. This underscores the need to understand and overcome resistance mechanisms.
The recent study focused on protein phosphatase 2A (PP2A), which has previously been shown to inhibit the development of lung cancer. PP2A is comprised of three proteins that must associate to function correctly, and disruption of this assembly is commonly observed in lung, prostate, and liver cancers.
Based on this observation, the researchers investigated whether stabilizing the PP2A complex could inhibit tumor growth. Their work suggests a potential pathway for enhancing the efficacy of existing cancer therapies.
Using non-small cell lung cancer cell lines with KRAS mutations, the team found that the anti-cancer drugs adagrasib and trametinib destabilize the PP2A complex – a mechanism that may explain the development of treatment resistance.
Adding an experimental compound that acts as a “molecular glue,” called RPT04402, stabilized the PP2A complex, leading to cancer cell death. This stabilization effectively restored the protein’s tumor-suppressing function.
These results were confirmed in animal models, where administering the compound reduced tumor size. The findings suggest a promising avenue for future drug development.
In mouse models, the combination of adagrasib or trametinib and RPT04402 delayed the onset of resistance and increased treatment effectiveness for over 150 days. This extended response time is a significant finding.
The researchers caution that while they tested the combination on multiple cell lines and in animal models, they cannot yet determine if it will work in all cases of non-small cell lung cancer. They also note that the results apply to approximately 20–30% of non-small cell lung cancer cases. Further research is needed to determine the full scope of its potential.
The team plans to initiate clinical trials in the near future, in collaboration with pharmaceutical companies SpringWorks Therapeutics and Merck. These trials will be critical in evaluating the safety and efficacy of the combination therapy in humans.
Researchers also aim to expand their investigations to other tumors with KRAS mutations, to assess whether this treatment combination could be effective in pancreatic or colorectal cancer as well. This broader investigation could potentially expand the benefits of this approach to other cancer types.
RPT04402 is an experimental compound and is not currently approved for clinical use.
