Engineered NK cells shrank mouse tumors 60%

Scientists have engineered natural killer (NK) cells to become more effective at attacking solid tumors, and in mouse studies the modified cells slowed the growth of melanoma, head‑and‑neck cancers and other tumours. When combined with the antibody drug cetuximab, the cells worked even better, suggesting a new way to boost existing cancer treatments.

NK cells are part of the body’s first‑line immune defence. They can recognise and kill abnormal cells without prior exposure, but they normally struggle to penetrate the dense tissue of solid tumours. Researchers have long sought ways to enhance their ability to infiltrate and persist inside tumours, a key hurdle that has limited the success of immunotherapy for many cancers.

The team used a genetic tweak that turns the NK cells into “tissue‑resident” variants that can stay inside tumour tissue and keep fighting. In mice, the engineered cells reduced tumour size by up to 60 % and extended survival times. Adding cetuximab, an antibody that blocks a protein over‑expressed in many cancers, amplified the effect, cutting tumour growth by an additional 30 %. The combination also lowered the number of immune‑cell‑recruited inflammatory cells that can protect tumours, giving the engineered NK cells a clearer path to kill cancer cells.

Next steps involve scaling up the production of these cells and testing safety and efficacy in early‑phase human trials. If the results mirror the mouse studies, the therapy could be paired with existing antibody drugs to treat patients with stubborn solid tumours. The approach also opens the door to combining engineered NK cells with other immunotherapies, potentially creating a versatile new weapon in the fight against cancer.