Table 1. Baseline characteristics of the patients.

Characteristics	No. of patients (%)
	All patients (n=125)	IBP group (n=39)	Non-IBP group (n=86)
Median age (range), years	59 (33–82)	56 (33–82)	59 (33–79)
Sex
Male	91 (72.8)	29 (74.4)	62 (72.1)
Female	34 (27.2)	10 (25.6)	24 (27.9)
ECOG performance status
0–1	105 (84.0)	36 (92.3)	69 (80.2)
≥2	20 (16.0)	3 (7.7)	17 (19.8)
Smoking history
Ever	75 (60.0)	23 (59.0)	52 (60.5)
Never	50 (40.0)	16 (41.0)	34 (39.5)
Histology
Squamous	47 (37.6)	17 (43.6)	30 (34.9)
Non-squamous	78 (62.4)	22 (56.4)	56 (65.1)
Liver metastases
Yes	23 (18.4)	5 (12.8)	18 (20.9)
No	102 (81.6)	34 (87.2)	68 (79.1)
Brain metastases
Yes	38 (30.4)	10 (25.6)	28 (32.6)
No	87 (69.6)	29 (74.3)	58 (67.4)
Tumor stage
IIIB	21 (16.8)	4 (10.3)	17 (19.8)
IV	104 (83.2)	35 (89.7)	69 (80.2)
EGFR mutation status
Positive	25 (20.0)	6 (15.4)	19 (22.1)
Negative	58 (46.4)	24 (61.5)	34 (39.5)
Unknown	42 (33.6)	9 (23.1)	33 (38.4)
ALK fusion status
Positive	6 (4.8)	2 (5.1)	4 (4.6)
Negative	87 (69.6)	30 (76.9)	57 (66.3)
Unknown	32 (25.6)	7 (18.0)	25 (29.1)
Previous lines of therapy
1	33 (26.4)	12 (30.8)	21 (24.4)
2	38 (30.4)	8 (20.5)	30 (34.9)
≥3	54 (43.2)	19 (48.7)	35 (40.7)
Best response to previous line
PR	24 (19.2)	12 (30.8)	12 (14.0)
SD	49 (39.2)	14 (35.9)	35 (40.7)
PD	52 (41.6)	13 (33.3)	39 (45.3)
Initial immunotherapy regimen
Monotherapy	55 (44.0)	12 (30.8)	43 (50.0)
Combination therapy	70 (56.0)	27 (69.2)	43 (50.0)
Chemotherapy	43 (34.4)	16 (41.0)	27 (31.4)
Antiangiogenic therapy	16 (12.8)	7 (17.9)	9 (10.5)
Chemotherapy and antiangiogenic therapy	11 (8.8)	4 (10.3)	7 (8.1)

ECOG, Eastern Cooperative Oncology Group; IBP, immunotherapy beyond progression; PR, partial response; SD, stable disease; PD, progressive disease.