For decades, pancreatic cancer has been one of medicine’s greatest challenges. It often grows silently, causing only vague symptoms such as stomach discomfort, weight loss, tiredness or back pain.
Many people are diagnosed only after the cancer has spread beyond the pancreas. At that stage, treatment options become limited and survival remains poor despite improvements in chemotherapy.
Researchers now believe that understanding the genetic changes inside each tumour may be the key to developing better treatments. One of the most important genetic changes is called KRAS G12D.
This mutation is found in about four out of every ten pancreatic cancers and acts as the engine that keeps cancer cells multiplying. Scientists tried for many years to stop this faulty protein but had little success.
A new experimental medicine called zoldonrasib has been designed specifically to block KRAS G12D. Researchers from Dana-Farber Cancer Institute tested whether adding this targeted medicine to standard chemotherapy could produce stronger results than chemotherapy alone. Their early findings were reported at the ESMO Gastrointestinal Cancers Congress 2026.
The study involved 81 people with previously untreated metastatic pancreatic cancer carrying the KRAS G12D mutation. Participants received one of two common chemotherapy combinations together with zoldonrasib. Doctors then monitored tumour size, blood tests and side effects.
The results gave researchers reasons for optimism. Most patients experienced tumour shrinkage, with response rates reaching 82% in one chemotherapy group and 61% in the other. Almost every patient achieved disease control, meaning the cancer either became smaller or stopped growing for a period of time.
Another encouraging sign came from blood testing. Scientists measured circulating tumour DNA, which can provide an early indication of how well treatment is working.
Every patient who could be evaluated experienced at least a 50% reduction in cancer DNA carrying the KRAS G12D mutation. Many patients even had complete disappearance of detectable mutant DNA from their bloodstream.
The combination treatment appeared reasonably manageable. Most side effects were those doctors commonly expect from chemotherapy, including fatigue, nausea, diarrhoea and reduced infection-fighting white blood cells. Importantly, researchers did not identify any unexpected safety problems caused by adding the new drug, and no treatment-related deaths occurred.
Cancer specialists say these findings are important because pancreatic cancer has historically been resistant to many new medicines. A treatment that specifically targets the genetic driver of the disease could represent a major shift toward precision medicine, where therapy is matched to the biology of each patient’s tumour rather than using the same treatment for everyone.
The promising results have already supported a large worldwide phase III clinical trial called RASolute 305. This study will determine whether patients receiving zoldonrasib together with chemotherapy live longer than those receiving chemotherapy alone. Only a trial of this size can show whether the treatment should become part of routine care.
This research marks an important scientific step because it successfully targets a mutation that was once considered impossible to treat. Nevertheless, caution is necessary. The study included a limited number of participants and focused mainly on early tumour responses instead of long-term survival.
Future studies must show that these early improvements lead to meaningful benefits such as longer life, fewer symptoms and better quality of life. Even with these limitations, the results provide genuine hope for patients with one of the deadliest forms of cancer.
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The research was presented at the ESMO Gastrointestinal Cancers Congress 2026.
Source: Dana-Farber Cancer Institute
