When Jingfang Ju and her team at the Stony Brook Cancer Center in New York tested their experimental drug on mice with lung cancer, the tumors shrank by more than 95 percent. That striking result, published this month in the journal Molecular Therapy: Nucleic Acids, has the research team hopeful they have found a powerful new way to treat a disease that remains a leading cause of cancer deaths in the United States.
Lung cancer kills more Americans than any other cancer. While newer targeted drugs have improved survival for some patients, roughly half of tumors develop resistance to these treatments within a year or two. When that happens, patients are left with few options.
"Resistance is the primary reason why current lung cancer therapies stop working for cancer patients," Ju said. "And for that reason, this approach is highly promising."
The new drug, called Gem-miR-129, works by combining two cancer-fighting tools. The first is gemcitabine, a chemotherapy drug already used to treat lung cancer. The second is a molecule called miRNA-129, which naturally acts as a tumor suppressor in the body. By joining them together, Ju's team created a drug that can slip into cancer cells on its own, without needing a special delivery vehicle.
Unlike older treatments that target just one weakness in cancer cells, Gem-miR-129 attacks three at once. It shuts down proteins called HMGB1, YAP1, and PBX3 that help tumors grow and resist therapy. This multi-pronged approach appears to prevent resistance from developing in the first place.
The mice treated with Gem-miR-129 not only had dramatically smaller tumors; they also lived longer. Ju estimates that the extended survival time seen in the animals could translate to roughly five to fifteen additional years of life for human patients. So far, the researchers have not observed any serious side effects.
The findings offer particular hope for patients whose cancers have stopped responding to a class of drugs called tyrosine kinase inhibitors, a common type of targeted therapy. These patients currently have limited alternatives once resistance sets in.
Before Gem-miR-129 could become available to patients, it must undergo a process called Investigational New Drug studies, which test a treatment's safety profile and lay the groundwork for human clinical trials. Ju says that is the team's next step.
"We believe this new approach provides a proof of concept for future studies that could lead to clinical trials in NSCLC patients," she said.
For patients and families facing a diagnosis of lung cancer, the Stony Brook findings represent not a cure, but a meaningful step forward: a therapy that could one day stop resistant tumors in their tracks and buy precious time.