First-in-human trial of engineered NK cells in lung cancer refractory to immune checkpoint inhibitors.

Abstract

Background: Non-small cell lung cancer (NSCLC) remains the leading cause of cancer-related mortality necessitating the exploration of alternate therapeutic approaches. Tumor reactive or activated-by-cytokine killers (TRACK) are PD-L1+ highly cytolytic natural killer (NK) cells derived from umbilical cord blood NK cells and engineered to express soluble IL15 (sIL15), showing promise in preclinical studies against NSCLC.

Methods: We assessed safety, persistence, homing and cytotoxic activity in six patients with advanced, refractory, and progressing NSCLC who received a low dose of unmatched, allogeneic, off-the-shelf sIL15_TRACK NK cells. We evaluated NK cell presence and persistence with droplet digital (dd) PCR, flow cytometry, and immunofluorescent staining.

Results: sIL15_TRACK NK cells had peak measurements at one hour and became undetectable four hours after each in fusion. Cognate ligands to activating NK cell receptors were found in NSCLC. sIL15_TRACK NK cells were observed in a lung tumor biopsy seven days after the final infusion, confirming their sustainment and tumor-homing ability. They retained cytolytic function following isolation from the lung tumor. Three out of six patients achieved disease stabilization on repeat imaging, while the others progressed.

Conclusion: Unmatched, allogeneic, cryopreserved, off-the-shelf sIL15_TRACK NK cells express activating receptors, home to tumor sites that express their cognate ligands, and retain cytolytic activity after infusion, underscoring their potential as a therapeutic approach in solid tumors. At low doses, the therapy was safely administered and showed preliminary evidence of activity in three of six patients with advanced and progressive NSCLC. Additional dose escalation cohorts and co-administration with atezolizumab are planned.

Trial registration:

Clinicaltrials: gov NCT05334329FUNDING. Funding was provided by CytoImmune Therapeutics; CA266457; CA033572; CA210087.