Early-like differentiation status of systemic PD-1+CD8+ T cells predicts PD-1 blockade outcome in non-small cell lung cancer

Abstract

Objectives: Despite remarkable advances in the treatment of non-small cell lung cancer (NSCLC) with anti-programmed death (PD)-1 therapy; only a fraction of patients derives durable clinical benefit. In this study, we investigated whether the differentiation status of systemic CD8+ T cells predicts the outcome of PD-1 blockade in NSCLC. Methods: We carried out a prospective study on a total of 77 NSCLC patients receiving anti-PD-1 blockers, among which 47 patients were assigned as a discovery cohort and 30 patients as a validation cohort. Peripheral blood samples were obtained at baseline and upon multiple therapy cycles and analyzed by multi-parameter flow cytometry. Results: We found that a higher baseline ratio of PD-1+ early effector memory CD8+ T cells (CD28+CD27−CD45RO+, TEEM) to PD-1+ effector CD8+ T cells (CD28−CD27−CD45RO−, TE) delineated responders to PD-1 blockade from progressors and was associated with prolonged progression-free survival (PFS) and durable clinical benefit. Moreover, PD-1+CD8 TEEM cells exhibited early responses after anti-PD-1 therapy and was the major fraction of cycling PD-1+Ki67+CD8+ T cells to expand specifically with positive impact on PFS. Conclusion: These findings provide insights into how the baseline differentiation status of the peripheral immune system determines responses to PD-1-targeted therapies.