Factor | n | Objective response rate | Progression-free survival | Overall survival | |||||
% (95% CI) | P value* | Median (95% CI), months | HR (95% CI)† | P value† | Median (95% CI), months | HR (95% CI)† | P value† | ||
PD-L1 TPS | |||||||||
≥50% | 23 | 17.4 (4.95 to 38.78) | 0.53‡ | 1.94 (1.41 to 4.60) | 1.225 (0.685 to 2.190) | 0.49 | 10.41 (5.85 to 13.93) | 1.997 (0.955 to 4.178) | 0.07 |
1%–49% | 41 | 7.3 (1.54 to 19.92) | 0.047§ | 3.75 (2.07 to 6.44) | 0.692 (0.410 to 1.170) | 0.17 | 9.72 (6.80 to 12.39) | 1.824 (0.975 to 3.412) | 0.06 |
<1% | 32 | 25.8 (11.86 to 44.61) | 3.88 (2.99 to 5.36) | 1.00 (reference) | 14.72 (9.49 to NR) | 1.00 (reference) | |||
Duration of PD-1 inhibitor treatment | |||||||||
≥12 weeks | 83 | 20.0 (11.89 to 30.44) | 0.59 | 3.94 (2.53 to 4.63) | 0.773 (0.580 to 1.028) | 0.08 | 11.79 (8.02 to 13.60) | 0.753 (0.534 to 1.062) | 0.11 |
<12 weeks | 160 | 16.9 (11.43 to 23.59) | 2.76 (2.27 to 3.88) | 1.00 (reference) | 9.00 (7.33 to 10.58) | 1.00 (reference) | |||
Objective response for PD-1 inhibitor | |||||||||
CR or PR | 35 | 23.5 (10.75 to 41.17) | 0.34 | 3.29 (1.84 to 5.52) | 0.909 (0.605 to 1.363) | 0.64 | 10.18 (7.20 to NR) | 0.882 (0.550 to 1.414) | 0.60 |
SD or PD | 203 | 16.9 (12.01 to 22.83) | 3.22 (2.53 to 4.04) | 1.00 (reference) | 9.59 (8.02 to 11.66) | 1.00 (reference) | |||
Interval from last dose of PD-1 inhibitor to start of subsequent chemotherapy | |||||||||
≥4 weeks | 124 | 18.7 (12.24 to 26.72) | 0.87 | 2.96 (2.10 to 3.91) | 1.023 (0.780 to 1.341) | 0.87 | 8.54 (7.29 to 10.58) | 1.140 (0.831 to 1.563) | 0.42 |
<4 weeks | 119 | 17.1 (10.77 to 25.16) | 3.75 (2.53 to 4.37) | 1.00 (reference) | 10.78 (7.85 to 12.65) | 1.00 (reference) | |||
EGFR or ALK alteration status | |||||||||
Positive | 32 | 21.9 (9.28 to 39.97) | 0.62 | 4.60 (2.50 to 6.83) | 0.879 (0.582 to 1.328) | 0.54 | 13.11 (9.59 to NR) | 0.595 (0.354 to 0.999) | 0.0496 |
Negative or unknown | 211 | 17.3 (12.43 to 23.15) | 2.96 (2.40 to 3.88) | 1.00 (reference) | 8.67 (7.49 to 10.78) | 1.00 (reference) | |||
History of curative radiotherapy | |||||||||
Yes | 17 | 18.8 (4.05 to 45.65) | >0.99 | 2.40 (1.74 to 6.90) | 1.030 (0.586 to 1.809) | 0.92 | 13.47 (6.34 to NR) | 0.656 (0.322 to 1.337) | 0.25 |
No | 226 | 17.9 (13.07 to 23.51) | 3.29 (2.53 to 3.98) | 1.00 (reference) | 9.10 (7.89 to 10.84) | 1.00 (reference) |
*P values were determined with Fisher’s exact test.
†HRs with 95% CI and p values were calculated with the Cox proportional hazards regression model.
‡P value is for comparison between ≥50% and<1%.
§P value is for comparison between 1%–49% and <1%.
CAP, chemotherapy after PD-1 inhibitor treatment; CR, complete response; NR, not reached; PD, progressive disease; PR, partial response; SD, stable disease; TPS, tumor proportion score.