Use of broad-spectrum antibiotics impacts outcome in patients treated with immune checkpoint inhibitors

Figures & data

Table 1. Baseline Characteristics of Patients

Parameters	Antibiotics (n = 17)	No antibiotics (n = 43)	p value
Age (years)
Median	52	66	0.008
Range	16–81	24–84
Gender
Female	6	19
Male	11	24	n.s.
ECOG score
0–1	8	30
> 1	9	13	n.s.
DL-1 expression
Median	35.5	22.5
Range	0–100	0–100	n.s.
Diagnosis
Lung cancer	10	24	n.s.
Renal cancer	1	3	n.s.
Hepatocellular cancer	0	5	n.s.
Head and neck cancer	0	3	n.s.
Urothelial cancer	1	4	n.s.
Malignant melanoma	2	1	n.s.
Osteoblastic sarcoma	1	0
Ewing’s sarcoma	1	0
Metastatic breast cancer	0	0	1
Poorly differentiated cancer	0	1
Mesothelioma	1	0
Hodgkin’s disease	0	1
Neutrophil:Lymphocyte ratio
Median	6.15	4.3	n.s.
Range	(1.6 – 15)	(0.9 – 46)
N:L ratio > 5	10 (54%)	14 (33%)	0.08
Dose of ICI received
Median	3	6
Range	1–28	1–81	n.s.
ICI usage
First line therapy	8	12	n.s.
Second line therapy	9	31	n.s.
ICI with chemotherapy	4	4	n.s.
Pembrolizumab	4	6	n.s.
Nivolumab	8	31	0.08
Atezolizumab	1	2	n.s.

Table 2. Types of antibiotics

Antibiotics	Number (n)
Narrow-spectrum
Vancomycin	7
Daptomycin	1
Linezolid	2
Broad-spectrum
Cephalosporins	11
Ciprofloxacin	5
Piperacillin/Tazobactam	3
Meropenem	3
Tetracyclines	2
Bactrim	1
Azithromycin	1
Nitrofurantoin	1

Figure 1. Progression-free survival in patients who had received any antibiotics within 2 weeks before and/or after starting ICI compared to those who had not. Antibiotic-treated patients had significantly more inferior PFS (p = 0.048)

Figure 2. Progression-free survival in patients who had received broad-spectrum antibiotics within 2 weeks before and/or starting ICI compared to those who had not. Patients who had not received any broad-spectrum antibiotics had significantly superior PFS (p = 0.012)

Figure 3. Progression-free survival in patients who had received broad-spectrum antibiotics within 10 weeks before disease progression compared to those who had not. Patients who had received antibiotics showed a trend towards significance in shorter PFS (p = 0.1)

Figure 4. Patients who did not receive antibiotics enjoyed longer overall survival compared to those who did (p = 0.003)