Extended Data Fig. 3: mRNA expression prior to treatment.

a, Heatmap showing three subtypes of glioblastoma microenvironment in samples from this trial on the basis of enrichment for immune cell types using partition around medoids clustering. Scores for functional orientation markers, signature scores, and expression of immune checkpoints and biomarkers are overlayed on the heatmap. b, Distribution of expression of PD-1(PDCD-1) and PD-L1 (CD274) across different tumor size comparisons. n = 19 independent patients top row, n = 31 independent patients middle row, n = 38 independent patients bottom row. Central bars indicate medians, the box defines the upper and lower quartiles of the distribution, and whiskers define the 1.5× IQR. Statistical comparisons were performed using Welch’s two-sided t-test. c, Stacked barplot showing the rate of clinical benefit (stable disease or objective response) stratified by microenvironment subtypes in this study (left) and previously published cohort examining adjuvant PD-1 monotherapy in recurrent glioblastoma (right). Dashed box represents the proportion of objective responses by mRANO criteria in this study. d, Distribution of overall survival of patients in this trial (left) and previously published trial (right) stratified by immune microenivronment subtypes. e, Heatmap showing three subtypes of glioblastoma microenvironment on previously published cohort examining adjuvant PD-1 monotherapy in recurrent glioblastoma.