Molecular Glue Approach Shows promise in Combating KRAS-Mutant Lung Cancer
A novel strategy combining a “molecular glue” with existing KRAS inhibitors is demonstrating important potential in overcoming treatment resistance and shrinking tumors in laboratory models of non-small cell lung cancer (NSCLC), offering new hope for patients with this challenging disease.
Lung cancer remains the leading cause of cancer-related deaths in the United States, with limited therapeutic options. Approximately 30% of NSCLC cases involve a mutated KRAS gene, frequently leading to shorter survival rates and resistance to current therapies.
Researchers at the University of Michigan have identified a new protein target and developed a corresponding drug aimed at addressing KRAS-mutant NSCLC. Their study, published December 1, 2025, in The Journal of Clinical Investigation, centers on the role of protein phosphatase 2A (PP2A), a protein complex known to suppress lung cancer growth.
PP2A functions optimally when its three protein components are correctly assembled.Disruption of this assembly is frequently observed in various cancers, including lung, prostate, and liver cancers, leading researchers to explore weather stabilizing the complex could effectively inhibit tumor growth.
Currently approved drugs like adagrasib (Krazati; Mirati Therapeutics) and trametinib (Mekinist; Novartis) target KRAS in pancreatic, colon, and lung cancers. Though, tumor cells frequently enough develop resistance to these treatments relatively quickly. “There are several FDA-approved drugs that target KRAS in pancreatic, colon, and lung cancer. Although they work well,tumor cells gain resistance after a short period of time,” explained a senior researcher involved in the study.
The University of Michigan team discovered that both adagrasib and trametinib destabilize the PP2A complex in KRAS-mutant NSCLC cell lines, potentially explaining the emergence of resistance. To counteract this effect, they tested a novel “molecular glue,” RPT04402, specifically designed to stabilize PP2A. When added to the existing treatment regimen,RPT04402 restored PP2A function and triggered cancer cell death. Remarkably,in mouse models,this combination not only reduced tumor size but also significantly delayed the onset of resistance,extending treatment effectiveness to over 150 days.
Further experiments confirmed these findings, demonstrating that combining RPT04402 with RAS/MAPK inhibitors slowed cancer cell proliferation and increased programmed cell death (apoptosis) in both commercially available cell lines and patient-derived models. The research suggests that restoring PP2A activity can effectively overcome the resistance mechanisms driven by disrupted negative feedback in KRAS-mutant tumors.
While these results are encouraging, researchers caution that the combination may not be universally effective for all NSCLC cases.The study’s focus is currently limited to approximately 20% to 30% of all NSCLC cases – those with KRAS mutations. The research team is planning to initiate clinical trials in collaboration with Spring Works therapeutics and Merck, with the long-term goal of extending this approach to KRAS-mutant pancreatic and colon cancers.
This study highlights a potentially groundbreaking new approach to cancer treatment: combining “molecular glues” that stabilize tumor-suppressing proteins with targeted inhibitors to improve patient outcomes and delay the development of resistance.if prosperous in human trials, this strategy could offer a critical new treatment option for patients with KRAS-mutant NSCLC, a population currently facing limited and frequently enough short-lived therapeutic success.
