TABLE 1.
Baseline Characteristics in Patients with CIP
| Characteristic | Overall N=60 | Nonrefractory CIP N=44 | Refractory CIP N=16 | P |
|---|---|---|---|---|
| Gender, n (%) | — | — | — | 1.000 |
| Female | 2 (3.3) | 2 (4.5) | 0 (0) | — |
| Male | 58 (96.7) | 42 (95.5) | 16 (100) | — |
| Age, years, n (%) | — | — | — | 0.701 |
| >65 | 22 (36.7) | 15 (34.1) | 7 (43.8) | — |
| ≤65 | 38 (63.3) | 29 (65.9) | 9 (56.2) | — |
| Smoking status, n (%) | — | — | — | 0.240 |
| Current | 30 (50) | 20 (45.5) | 10 (62.5) | — |
| Former | 22 (36.7) | 19 (43.2) | 3 (18.8) | — |
| Never | 8 (13.3) | 5 (11.4) | 3 (18.8) | — |
| Composite obstructive lung disease history, n (%) | — | — | — | 0.681 |
| No | 27 (45.0) | 21 (47.7) | 6 (37.5) | — |
| Yes | 33 (55.0) | 23 (52.3) | 10 (62.5) | — |
| Histology, n (%) | — | — | — | 0.445 |
| Adenocarcinomas | 34 (56.7) | 25 (56.8) | 9 (56.2) | — |
| Squamous | 18 (30.0) | 14 (31.8) | 4 (25) | — |
| Small cell carcinoma | 3 (5.0) | 1 (2.3) | 2 (12.5) | — |
| Others | 5 (8.3) | 4 (9.1) | 1 (6.2) | — |
| Tumor staging, n (%) | — | — | — | 0.719 |
| II | 2 (3.3) | 2 (4.5) | 0 (0) | — |
| III | 11 (18.3) | 7 (15.9) | 4 (25) | — |
| IV | 47 (78.3) | 35 (79.5) | 12 (75) | — |
| PD-L1 expression, n (%) | — | — | — | 0.426 |
| <1% | 11 (18.3) | 7 (15.9) | 4 (25) | — |
| 1-50% | 28 (46.7) | 23 (52.3) | 5 (31.2) | — |
| >50% | 8 (13.3) | 6 (13.6) | 2 (12.5) | — |
| Unknown | 13 (21.7) | 8 (18.2) | 5 (31.2) | — |
| ECOG PS, n (%) | — | — | — | 1.000 |
| ≤1 | 42 (70.0) | 31 (70.5) | 11 (68.8) | — |
| ≥2 | 18 (30.0) | 13 (29.5) | 5 (31.2) | — |
| ICI agents, n (%) | — | — | — | 0.643 |
| PD-1 inhibitor | 52 (86.7) | 39 (88.6) | 13 (81.2) | — |
| PD-1+ CTLA-4 inhibitor | 1 (1.7) | 1 (2.3) | 0 (0) | — |
| PD-L1 inhibitor | 6 (10.0) | 3 (6.8) | 3 (18.8) | — |
| PD-L1+ CTLA-4 inhibitor | 1 (1.7) | 1 (2.3) | 0 (0) | — |
| Regimen of immune therapy, n (%) | — | — | — | 0.199 |
| ICI | 35 (58.3) | 23 (52.3) | 12 (75) | — |
| ICI+ chemotherapy | 25 (41.7) | 21 (47.7) | 4 (25) | — |
| Treatment line, n (%) | — | — | — | 0.356 |
| 1st line | 34 (56.7) | 27 (61.4) | 7 (43.8) | — |
| 2nd or later line | 26 (43.3) | 17 (38.6) | 9 (56.2) | — |
| Prior surgery, n (%) | — | — | — | 1.000 |
| No | 48 (80.0) | 35 (79.5) | 13 (81.2) | — |
| Yes | 12 (20.0) | 9 (20.5) | 3 (18.8) | — |
| Prior chest radiotherapy, n (%) | — | — | — | 1.000 |
| No | 42 (70.0) | 31 (70.5) | 11 (68.8) | — |
| Yes | 18 (30.0) | 13 (29.5) | 5 (31.2) | — |
| Best response of ICIs, n (%) | — | — | — | 0.029 |
| PR | 26 (43.3) | 21 (47.7) | 5 (31.2) | — |
| SD | 22 (36.7) | 18 (40.9) | 4 (25) | — |
| PD | 5 (8.3) | 3 (6.8) | 2 (12.5) | — |
| Unknown | 7 (11.7) | 2 (4.5) | 5 (31.2) | — |
CIP indicates checkpoint inhibitor-related pneumonitis; CTLA-4, cytotoxic T-lymphocyte-associated antigen-4; ECOG PS, Eastern Cooperative Oncology Group Performance Status; ICI, immune checkpoint inhibitor; PD, progression of disease.PD-1, programmed cell death-1; PD-L1, programmed cell death-ligand 1; PR, partial response; SD, stable disease.