Spanish Scientists Cure Pancreatic Cancer in Mice: The Science Behind the Breakthrough

Pancreatic ductal adenocarcinoma, the most common type of pancreatic cancer, is notorious for its poor prognosis. The disease is often detected at an advanced stage, spreads aggressively, and shows strong resistance to conventional treatments such as chemotherapy and radiation. Survival rates remain grim, with fewer than 10 per cent of patients living beyond five years after diagnosis.

A key reason for this lethality lies in a genetic mutation. Most pancreatic cancers are driven by a faulty gene known as KRAS, which acts like a permanently pressed accelerator pedal, constantly signalling cancer cells to grow and divide uncontrollably. Over the past decade, scientists have developed drugs that target KRAS signalling, offering new hope in a field long considered nearly untreatable.

One such drug, daraxonrasib, has already demonstrated an ability to extend survival in some patients. However, the promise of KRAS inhibitors has been limited by cancer’s ability to adapt. When the primary KRAS pathway is blocked, tumours often activate alternative molecular routes to survive, leading to relapse within a short period.

To counter this, Barbacid’s team adopted a radically different approach: shutting down not just one pathway, but every major survival mechanism the tumour could use.

The researchers combined three drugs with complementary roles. Daraxonrasib was used to block the primary KRAS-driven growth signal. Afatinib was added to inhibit EGFR and HER2 pathways, which cancer cells commonly exploit as escape routes when KRAS is suppressed. A third compound, SD36, was included to disable STAT3, a molecular backup system that helps tumour cells survive stress and resist treatment.

The results were striking. In mice treated with all three drugs simultaneously, pancreatic tumours shrank completely and did not return — even more than 200 days after treatment was stopped. The same outcome was observed in genetically engineered mouse models and in tumour samples derived from human patients and grown in laboratory conditions.

Equally significant was the safety profile. The treated animals did not exhibit serious side effects, suggesting that the drug combination could be tolerable enough to move toward human testing.

In simple terms, the study demonstrates that pancreatic cancer can be defeated by blocking its main engine, cutting off its escape routes, and disabling its emergency survival system — all at once. Deprived of every adaptive option, the cancer cells were unable to recover.

While these findings are currently limited to experimental models, experts say the results are robust enough to justify clinical trials. If similar outcomes are observed in humans, this multi-targeted strategy could represent a turning point in the fight against pancreatic cancer, long considered one of the most difficult cancers to treat.