Early results presented at a cancer research conference show tumor shrinkage and slowed disease progression in patients who had few other options
By Xavier MartinezFollow
April 19, 2026 at 2:00 pm ET
Lung cancer cells, shown in purple, carry the KRAS mutation that drives their growth. NATIONAL CANCER INSTITUTE/HUNTSMAN CANCER INSTITUTE AT THE UNIV. OF UTAH
Doctors may be getting closer to having a potent weapon against a genetic driver of lung cancer that has long lacked any targeted treatment options.
Researchers on Sunday presented early results of clinical trials of two experimental drugs targeting a gene called KRAS, one of the most common and challenging drivers of human cancers. Each drug takes aim at a different KRAS mutation that drives lung cancer, which kills more people worldwide each year than any other form of the disease.
KRAS mutations act as an accelerator in cancer cells. Both drugs shrank tumors and slowed disease progression in patients with advanced cancer that had progressed despite standard chemotherapy and immunotherapy, raising hopes that doctors may be homing in on a new option for a form of cancer that has long resisted treatment.
“I’ve never been this hopeful about KRAS mutations,” said Dr. Lei Deng, an oncologist at Fred Hutch Cancer Center in Seattle who wasn’t involved in either study. The research was presented at the American Association for Cancer Research annual meeting.
KRAS mutations have stumped researchers for decades. Some nicknamed the protein the “Death Star” for its smooth, featureless surface, which makes it hard for drugs to attach to. The first approved drug targeting it didn’t reach patients until 2021. There are currently two approved drugs, from Amgenand Bristol-Myers Squibb, that target the most common KRAS variant in lung cancer and work in about a third of patients with the variant.
The experimental pill produced by Revolution Medicines, zoldonrasib, targets a different KRAS variant, which appears in roughly 4% of people with the most common form of lung cancer. The drug kept the disease from progressing for a median of 11.1 months in a 27-person trial. Around half of patients had tumors shrink.
“These are substantially different numbers than have been reported historically,” RevMed Chief Executive Mark Goldsmithsaid in an interview.
Earlier this month, RevMed said a different experimental drug it is testing nearly doubled overall survival in pancreatic cancer patients when compared with chemo, causing its stock to surge. The company will release more data on that drug in pancreatic cancer patients on Tuesday.
RevMed was briefly in talks with several pharmaceutical companies to be acquired for as much as $30 billion, The Wall Street Journal reported in January, but no deal materialized.
The other experimental lung cancer drug being presented at the scientific meeting, Shanghai-based D3 Bio’s elisrasib, took aim at the more common variant of KRAS that Amgen and Bristol’s drugs target. Nearly six out of 10 patients who hadn’t previously received a KRAS-targeted therapy saw their tumors shrink after taking D3 Bio’s drug—roughly double the rate seen with existing drugs. The experimental medication kept the disease from progressing for a median of 12.2 months in that same group of patients.
It also worked in patients whose cancer had already progressed on earlier KRAS treatment and in patients whose cancer had spread to the brain, which many earlier therapies couldn’t reach.
These were early studies, and bigger trials are typically needed to confirm the results. Still, researchers say the results mark a turning point for a disease that has long had few answers.
“It definitely shows that you can safely and effectively target this mutation in a very difficult to treat cancer,” said Dr. Alice Shaw, chair of medical oncology at the Dana-Farber Cancer Institute and one of the conference organizers.
