Stereotactic body radiation therapy plus adoptive vNKT cell therapy for pancreatic cancer: protocol of a phase II trial.

Aims: Novel and multimodal immunotherapy approaches are required for pancreatic cancer. A novel subset of NKT cells, called CD8+ NKT-like cells or variant NKT (vNKT) cells, which are CD8⁺ CD56⁺, CD1d-independent with variant TCR, have been reported to provide potent anti-tumor immunity. With positive immune regulations of stereotactic body radiation therapy (SBRT) reported in previous studies, we hypothesize that there might be a synergy of SBRT with immunotherapy. The aim of this study is to evaluate the efficacy and safety of SBRT plus vNKT cells as adoptive cell therapy for advanced pancreatic cancer.

Methods: The prescription dose of SBRT ranges from 35 to 40 Gy/5f. Transfer of allogeneic vNKT cells is initiated 1-2 weeks after SBRT. Patients receive transfusion of vNKT cells twice a month with a 12-24 h interval within 6 months after SBRT and once a month thereafter. A 12-month transfer is defined as a cycle. The primary outcome is overall survival. The secondary outcomes are progression-free survival, adverse events, and quality of life.

Conclusion: Therapeutic potential of SBRT plus vNKT cells may provide a novel insight into the treatment for advanced pancreatic cancer, and further investigations on the clinical benefits compared to standard chemoradiotherapy are warranted.

Clinical trial registration: www.clinicaltrials.gov identifier is NCT05783076.