EBNK-001 Allogeneic NK Cells With Low-Dose IL-15 ± Pembrolizumab in Advanced Solid Tumors

Inclusion Criteria: * Age ≥18 years. * Histologically confirmed advanced/metastatic solid tumor that is relapsed/refractory after standard therapy (or no standard therapy available). * Measurable disease per RECIST v1.1 (or iRECIST if applicable). * ECOG performance status 0-1 (or 0-2 as allowed). * Adequate organ function (thresholds modeled on NK protocols): * Platelets ≥ 75,000/µL; hemoglobin ≥ 9 g/dL; ANC ≥ 1,000/µL (unsupported by growth factors/transfusions as defined). * eGFR ≥ 60 mL/min/1.73m². * AST/ALT ≤ 3× ULN. * Oxygen saturation ≥ 90% on room air (with PFT requirements if indicated). * LVEF ≥ 40% (by ECHO/MUGA/CMR). * If brain metastases are present, they must be stable for a defined period (example: ≥3 months) and not requiring escalating steroids. Exclusion Criteria: * Pregnant or breastfeeding. * Any condition requiring systemic immunosuppression (e.g., \>5 mg prednisone/day or equivalent) during dosing window (topical/inhaled may be allowed). * Active autoimmune disease requiring systemic immunosuppression. * Uncontrolled bacterial, fungal, or viral infection. * Receipt of investigational agent within 28 days before first study drug. * Live vaccine within 6 weeks prior to lymphodepletion. * Known HIV positivity or active hepatitis B/C with detectable viral load (protocol may allow chronic asymptomatic hepatitis depending on risk plan). * Known allergy to investigational product components (example: albumin/human or DMSO). * Any medical/social condition likely to interfere with study compliance or increase risk.