New Cancer Drug Shrinks Tumors in 6 Hard-to-Treat Types

Cancer cells have been hiding from treatment, but a new drug just stripped away their disguise.

In a groundbreaking trial spanning four countries, researchers tested a tablet called GRWD5769 on 83 patients with six of the world's most common cancers. These weren't just any patients. They had already tried everything else, and nothing worked.

The results stunned oncologists. Tumors shrank in 26 patients, with 15 seeing reductions of at least 30%. The drug worked across cervical, bladder, liver, bowel, lung, and head and neck cancers.

Here's what makes this special. Immunotherapy has revolutionized cancer treatment by training the body's T-cells to hunt and destroy tumors. But it fails in about two-thirds of patients because cancer cells can literally hide from the immune system.

Cancer pulls off this vanishing act by manipulating an enzyme called ERAP1. Think of it as throwing on an invisibility cloak that lets tumor cells slip past the body's defenses undetected.

GRWD5769 blocks that enzyme. When patients took the tablet alongside standard immunotherapy, their cancer cells became visible again. The immune system could finally see what it was supposed to fight.

The drug kept disease from progressing for at least six months in half of bowel and lung cancer patients. It halted cervical cancer in 18% of patients, liver cancer in 32%, bladder cancer in 36%, and head and neck cancer in 38%.

Professor Fiona Thistlethwaite, who led the trial at Christie NHS Foundation Trust in Manchester, called the results impressive for such an early study. "This is a new drug with a new mechanism that clearly helps immunotherapy perform more effectively," she told reporters at the American Society of Clinical Oncology's annual meeting in Chicago.

The Ripple Effect

Oxford-based Greywolf Therapeutics developed the tablet to be taken at home, and patients tolerated it well with few side effects. That matters because quality of life shouldn't stop when treatment starts.

The implications reach beyond these six cancer types. If a single drug can unmask tumor cells across such different cancers, it suggests the hiding mechanism is more universal than doctors realized. That opens doors for treating other resistant cancers.

Dr. Samuel Godfrey from Cancer Research UK, who wasn't involved in the trial, noted how unusual it is to see such outcomes in patients whose cancers had already stopped responding to treatment. "These results are encouraging," he said, though he cautioned that larger trials are needed.

Professor Stefan Symeonides from Edinburgh Cancer Centre described watching patients benefit from this new approach as "fantastic." The trial continues, with a larger study already planned.

For the first time, doctors have a tool that works specifically on cancer's ability to hide, and it's showing promise exactly where it's needed most: in patients who had nowhere else to turn.