Fig. 4: Responders to bintrafusp alfa have a more immune-permissive microenvironment and increased T cell activation when compared to nonresponders.

a Infiltrating immune cell populations of all mice treated with bintrafusp alfa (green bars, n = 10), its isotype control (black bars, n = 10), anti-PD-L1 (blue bars, n = 10), or TGFβ trap (pink bars, n = 10) after mass cytometric analysis and clustering. b Infiltrating immune cell populations of responder (green bars, n = 5) and nonresponder (black bars, n = 5) subpopulations of bintrafusp alfa-treated mice, with population differences determined as in (a) (P < 0.0001, F = 11.17, df = 10), with P-values for significant multiple comparisons as shown. c PD-1 expression on CD8 T cells from (b) as quantified by mass cytometry (n = 5). Tumor digests from mice treated as in (a) were treated for 4 h with brefeldin-A, ionomycin, and PMA and the proportion of d CD8⁺ IFNα⁺TNFα⁺ and e CD8⁺ Granzyme B⁺ cells are shown (n = 7 nonresponders in black, n = 8 responders in green). Population differences for (a) (P < 0.0001, F = 2.617, df = 30) and (b) (P < 0.0001, F = 11.17, df = 10) were determined by two-way ANOVA and Sidak’s multiple comparisons test with significantly altered populations as shown. Unpaired two-tailed t tests were performed for (c–e), and all error bars represent the SEM.