Performance of the CD8xPD-L1 signature, its components, and manual PD-L1 scoring in durvalumab-treated patients

MeasureGroup (n)PrevalencePPV(95% CI)Median OS, months(95% CI)OS p-valueMedian PFS, months(95% CI)PFS p-value
Training Set (n = 84)
 CD8xPD-L1positive (26)0.310.42 (0.23–0.63)18.9 (8.2–NR)0.0245.3 (2.6–9.3)0.00042
negative (58)0.690.09 (0.03–0.19)8.9 (4.1–12.9)1.4 (1.2–1.4)
 CD8+ cell densityhigh (32)0.380.34 (0.19–0.53)18.9 (12.9–NR)0.0124.4 (1.4–7.6)0.00045
low (52)0.620.10 (0.03–0.21)8.8 (4.3–11.1)1.4 (1.2–2.3)
 PD-L1+ cell densityhigh (26)0.310.39 (0.20–0.59)18.9 (5.6–NR)0.0714.7 (1.6–7.6)0.023
low (58)0.690.10 (0.04–0.21)8.9 (4.1–13.1)1.4 (1.3–1.7)
 PD-L1 TC≥25% (49)0.580.29 (0.17–0.43)17.9 (8.9–NR)0.0182.8 (1.4–5.3)0.0048
< 25% (35)0.420.06 (0.01–0.19)7.6 (3.4–12.9)1.4 (1.2–1.4)
Test Set (n = 79)
 CD8xPD-L1positive (33)0.420.36 (0.20–0.55)24.2 (14.5–NR)0.000117.3 (3.1–9.8)0.00095
negative (46)0.580.07 (0.01–0.18)6.5 (4.2–9.8)2.6 (1.4–3.9)
 CD8+ cell densityhigh (42)0.530.24 (0.12–0.40)20.3 (14.0–27.8)0.00445.5 (3.1–9.2)0.0054
low (37)0.470.14 (0.05–0.29)6.5 (3.6–9.8)2.5 (1.4–4.1)
 PD-L1+ cell densityhigh (29)0.370.38 (0.21–0.58)24.3 (6.5–NR)0.0457.3 (2.6–9.2)0.087
low (50)0.630.08 (0.02–0.19)9.3 (6.0–15.5)2.8 (1.7–5.2)
 PD-L1 TC≥25% (47)0.590.28 (0.16–0.43)15.5 (7.7–24.2)0.194.8 (2.6–7.3)0.25
< 25% (32)0.410.06 (0.01–0.21)7.8 (5.7–15.5)2.8 (1.4–6.5)

Abbreviations: CD8 Cluster of differentiation 8, CI Confidence interval, NR Not reached, OS Overall survival, PD-L1 Programmed death ligand-1, PFS Progression-free survival, PPV Positive predictive value, TC Tumor cell