Anti-PD-1 antibody HX008 combined with oxaliplatin plus capecitabine for advanced gastric or esophagogastric junction cancer: a multicenter, single-arm, open-label, phase Ib trial

Figures & data

Table 1. Demographics and baseline characteristics

Demographic or characteristic	Evaluable patients (N = 35)
Median age, years (range)	63 (21–71)
Sex
Males	27 (77.1)
Females	9 (22.9)
ECOG PS
0	14 (40.0)
1	21 (60.0)
Histological subtype
Intestinal	19 (54.3)
Diffuse	4 (11.4)
Mixed	7 (20.0)
Unknown	5 (14.3)
G/GEJ cancer
Advanced	23 (65.7)
Recurrent	12 (34.3)
Primary location
Gastric	28 (80.0)
Gastroesophageal junction	7 (20.0)
Metastatic stage
M0	5 (14.3)
M1	30 (85.7)
Prior surgery	10 (28.6)
Prior adjuvant chemotherapy	7 (20.0)
Metastatic disease sites
Lymph nodes	33 (94.3)
Liver	15 (42.9)
Lung	4 (11.4)
Others	9 (25.7)
Tumor PD-L1 quantifiable
CPS < 1	9 (25.7)
CPS ≥ 1	12 (34.3)
NE	14 (40.0)
MMR status
dMMR	2 (5.7)
pMMR	20 (57.1)
NE	13 (37.1)

Unless otherwise indicated, all data are n (%); CPS, combined positive score; dMMR, mismatch repair deficient; ECOG PS, Eastern Cooperative Oncology Group performance status; G/GEJ cancer, gastric cancer/gastroesophageal junction cancer; NE, not evaluated; PD-L1, programmed death-ligand 1; pMMR, mismatch repair proficient.

Table 2. TRAEs of any grade occurring in ≥10% of patients

Treatment-related AEs^a n (%)	Total N = 35
	Any grade	Grade 3	Grade 4	Grade 5
Any TRAE	34 (97.1)	25 (71.4)	2 (5.7)	1 (2.9)
Treatment-related SAEs	6 (17.1)	3 (14.3)	1 (2.9)	1 (2.9)
TRAEs leading to discontinuation	4 (11.4)	1 (2.9)	1 (2.9)	1 (2.9)
TRAE leading to dose delay or reduction	17 (48.6%)	12 (34.3)	0	0
Hematologic
Neutropenia	23 (65.7)	6 (17.1)	1 (2.9)	0
Thrombocytopenia	22 (62.9)	5 (14.3)	1 (2.9)	0
Anemia	21 (60.0)	9 (25.7)	0	0
Leukopenia	19 (54.3)	6 (17.1)	0	0
Non-hematologic
Aspartate aminotransferase increased	15 (42.9)	0	0	0
Blood bilirubin increased	14 (40.0)	0	0	0
Fatigue	11 (31.4)	6 (17.1)	0	0
Anorexia	9 (25.7)	0	0	1 (2.9)
Vomiting	9 (25.7)	0	0	0
Hypoalbuminemia	9 (25.7)	0	0	0
Alanine aminotransferase increased	8 (22.9)	0	0	0
Proteinuria	8 (22.9)	0	0	0
Nausea	7 (20.0)	1 (2.9)	0	0
Palmar-plantar erythrodysesthesia syndrome	7 (20.0)	4 (11.4)	0	0
Hypertriglyceridemia	6 (17.1)	0	0	0
Hyperuricemia	5 (14.3)	0	0	0
Creatinine increased	5 (14.3)	1 (2.9)	0	0
Hypothyroidism	5 (14.3)	0	0	0
Weight loss	5 (14.3)	2 (5.7)	0	0
Rash	4 (11.4)	1 (2.9)	0	0
Fever	4 (11.4)	0	0	0
Hyperthyroidism	4 (11.4)	0	0	0

^aAttribution of AEs to study treatment was determined by the investigator.

Table 3. Immune-related TRAEs

Immune-related AEs^a n (%)	Total N = 35
	Any grade	Grade 3
Fatigue	8 (22.9)	5 (14.3)
Proteinuria	7 (20.0)	0
Hypothyroidism	5 (14.3)	0
Rash	4 (11.4)	1 (2.9)
Hyperthyroidism	4 (11.4)	0
Diarrhea	3 (8.6)	1 (2.9)
Arthralgia	2 (5.7)	0
Pruritus	1 (2.9)	0

^aAttribution of AEs to study treatment was determined by the investigator. TRAEs, treatment-related adverse events.

Table 4. Summary of response and survival data (FAS population)

Category	Total
	N = 35
ORR, n (%) (95% CI)^a	21 (60.0) (42.1–76.1)
BOR, n (%)
CR, n (%)	1 (2.9)
PR, n (%)	20 (57.1)
SD, n (%)	6 (17.1)
PD, n (%)	5 (14.3)
Not evaluable, n (%)	3(8.6)
DCR, n (%) (95% CI)^a	27 (77.1) (59.9–89.6)
PFS^b, median (95% CI), months	9.2 (5.4-NR)
6-month rate (95% CI)	59.3 (40.1–74.1)
Median (range) time to response (months)	1.4 (1.3–2.9)
Median (range) duration of response (months)	12.3 (1.4–17.9+)

^aBased on the Clopper-Pearson exact method.

^bEstimated using the Kaplan–Meier method.

BOR, best overall response; CI, confidence interval; CR, complete response; DCR, disease control rate; FAS, full analysis set; NR, not reached; ORR, objective response rate; PD, progressive disease; PFS, progression-free survival; PR, partial response; SD, stable disease

Figure 1. Overall tumor responses of HX008 with oxaliplatin plus capecitabine as assessed by site investigators in patients with ≥ 1 assessable postbaseline image assessment (N = 32). (A) Best change from baseline in the size of target tumor lesion. Color code defines the best of response of target tumor lesion. (B) Percent change in the size of target tumor lesion from baseline in each patient

Figure 2. Kaplan-Meier estimates of progression-free survival (A) and overall survival (B)