Immunotherapy Combination: Irradiated PD-L1 CAR-NK Cells Plus Pembrolizumab Plus N-803 for Subjects With Recurrent/Metastatic Gastric or Head and Neck Cancer

N-803 will be given via subcutaneous injection at a dose of 15 mcg/kg every 4 weeks (1 week after starting treatment with the PDL-1 CAR-NK cells).

Pembrolizumab 400 mg will be administered as a 30-minute IV infusion every 6 weeks. Pembrolizumab will be administered on the same day as the PD-L1 CAR-NK cells.

PD-L1 CAR NK cells (2x109) will be administered by IV infusion over approximately 30 minutes every week. After the week 6 treatment, these cells will be given every 2 weeks.