Breakthrough NK Cell Therapy Shows Promise Against Resistant Cancers in Early Trials

A new cancer treatment combining modified NK cells with an immunotherapy drug has shown promising results in early trials. Researchers from ImmunityBio and the National Cancer Institute tested the approach on small-cell lung cancer models and a small group of patients with advanced cancers. The findings suggest a potential breakthrough for tumours that resist traditional T cell-based therapies.

The study focused on neuroendocrine tumours, which often lack MHC class I expression, making them resistant to T cell immunotherapies. Instead, these tumours may respond better to NK cell-based treatments. Preclinical tests in two small-cell lung cancer xenograft models demonstrated significant tumour shrinkage when treated with M-ceNK cells alongside ANKTIVA, an IL-15 superagonist.

In the Phase I **QUILT-3.076** trial, ten patients with recurrent or refractory cancers—including breast, colon, pancreatic, and renal cell carcinoma—received the combination therapy. No severe side effects, such as grade 4/5 toxicities or cytokine storms, were reported across 23 administered doses. The trial confirmed the safety of using patient-derived NK cells, which showed cytotoxic activity comparable to those from healthy donors, even against resistant tumour types. ImmunityBio also announced progress in scaling up production. Their platform can now generate up to five billion NK cells from a single leukapheresis procedure—enough for eight to ten doses in about twelve days. This advancement supports broader clinical and commercial use. Regulatory milestones followed, with ANKTIVA receiving its first global conditional approval from China's SFDA for metastatic non-small cell lung cancer. The drug is now approved in 33 countries. Additionally, ImmunityBio submitted a supplemental Biologics License Application (BLA) to the FDA for ANKTIVA combined with BCG in BCG-unresponsive bladder cancer. Financially, ANKTIVA's net product revenue reached $113 million in 2025, marking a roughly 700 percent increase over the previous year.

The results highlight the potential of NK cell therapies in treating cancers that evade T cell-based treatments. With no severe adverse events reported and scalable production now validated, the approach moves closer to wider clinical application. Further trials will determine its effectiveness across more tumour types.