Neutrophil:lymphocyte ratios and serum cytokine changes after hepatic artery chimeric antigen receptor modified T cell infusions for liver metastases

INTRODUCTION: Our phase I Hepatic Immunotherapy for Metastases (HITM) trial tested the safety of chimeric antigen receptor modified T cell (CAR-T) hepatic artery infusions (HAI) for unresectable CEA+ liver metastases (LM). High neutrophil:lymphocyte ratios (NLR) predict poor outcome in cancer patients and we hypothesized that NLR changes would correlate with early responses to CAR-T HAI. METHODS: Six patients completed the protocol. Three patients received CAR-T HAI in dose escalation (1 × 10(8), 1 × 10(9), and 1 × 10(10)cells) and the remainder received 3 doses (1 × 10(10) cells) with IL2 support. Serum cytokines and NLR were measured at multiple time points. RESULTS: The mean NLR for all patients was 13.9 (range 4.8-38.1). NLR increased in four patients following treatment with a mean fold change of 1.9. Serum IL6 levels and NLR fold-changes demonstrated a trend towards a positive correlation (r=0.77, p=0.10). Patients with poor CEA responses were significantly more likely to have higher NLR level increases (p=0.048). CONCLUSIONS: Increased NLR levels were associated with poor responses following CAR-T HAI. NLR variations and associated cytokine changes may be useful surrogates of response to CAR-T HAI.