Reversal of CAR T-cell exhaustion following anti–PD-1 therapy. (A) PD-1 occupancy in CAR–positive and –negative subsets after anti–PD-1 administration on day 227 post–CAR T-cell infusion (vertical dotted line). (B) Frequency of total T-cell subsets after anti–PD-1. (C) Frequency of CAR T-cell populations after anti–PD-1. In panels A and C, circles represent individual animals (A15106 and A15108), and lines represent means (n = 2). (D) Longitudinal plasma viral loads after anti–PD-1. (E) Overlays of plasma viral load and total CAR T-cell frequency from panels C-D. LOD (horizontal dotted line), limit of detection for plasma viral load assay (30 copies/mL).