The impact of immune checkpoint inhibitors on infection in patients with solid malignancies: a systematic review and meta-analysis of randomised controlled trials
In brief
Immune checkpoint inhibitors raise any-grade infection risk by about 25%
A meta-analysis of 141 randomized trials involving 87,000 patients found that checkpoint inhibitor therapy increased the chance of any-grade infections by roughly one quarter and severe infections by about 30 percent, compared with placebo or chemotherapy alone. The risk appears modest and varies with treatment context, so clinicians must balance it against the survival benefits and await more precise prospective data.
- Journal
- EClinicalMedicine (Q1)
- Published
- 31 July 2026
- Study design
- Systematic review / meta-analysis of RCTs
- Evidence level
- Level 1, High (CEBM 1a)
- Authors
- Chunlan Wu, Luying Wan, Qing Wu, Ping Li, Jingyi Li, Yifan Xu, et al.
- PMID
- 42576934
- DOI
- 10.1016/j.eclinm.2026.104113
Why clinicians should know about it
- Picked for Breast and Endocrine Surgery (top studies of the week, 16 August 2026): ICIs and infection meta‑analysis, not surgical
- Picked for Oncology and Radiation Oncology (top studies of the week, 16 August 2026).
Abstract
BACKGROUND: Immune checkpoint inhibitors (ICIs) revolutionised cancer treatment but may alter infection risk. The effect of ICIs on infection susceptibility remains unclear. METHODS: We searched PubMed, the Cochrane Library, and EMBASE from database inception to October 10, 2025 for randomised controlled trials (RCTs). The primary endpoint was the risk ratio (RR) of all-grade infections; the secondary endpoint was the RR of severe (Grade 3-5) infections. Stratified analyses by ICI agent, regimen, treatment timing, infection site, and cancer type were performed separately for treatment-emergent adverse events (TEAEs) and treatment-related adverse events (TRAEs). Publication bias was assessed using funnel plots, Egger's test, and trim-and-fill; heterogeneity was evaluated by I 2 statistic. This study is registered with PROSPERO, number CRD420251231682. FINDINGS: A total of 141 RCTs (87,484 participants) were included. In TEAE-based analyses, ICIs were associated with increased risks of any-grade infections [RR = 1.25; 95% confidence interval (CI): 1.12-1.39; I 2 = 71.1%] and severe infections (RR = 1.30; 95% CI: 1.17-1.44), driven by symmetric comparisons (ICI vs. Placebo and ICI plus chemotherapy vs. chemotherapy). For TRAEs, no significant increase was seen for any-grade infections (RR = 1.01; 95% CI: 0.84-1.22; I 2 = 67.3%) or severe infections (RR = 0.96; 95% CI: 0.81-1.14). However, symmetric comparisons again showed increased TRAE risks for ICI vs. placebo and ICI plus chemotherapy vs. chemotherapy. Publication bias was suggested for any-grade infectious TRAEs (Egger's P = 0.015); after trim-and-fill correction, the pooled RR was strengthened (RR = 1.24). INTERPRETATION: The relationship between ICI therapy and infection risk is nuanced and context-dependent. In symmetric comparisons, ICIs are associated with modestly increased TEAE- and TRAE-based infection risks. This risk should be weighed against the expected survival benefit, underscoring the need for individualised assessment. Future prospective studies with time-to-event analyses and standardised infection surveillance are needed to clarify the temporal relationship between ICI exposure and infection risk. FUNDING: There was no funding source for this study.
Abstract as published, via PubMed.
For healthcare professionals. The summary is generated by AI from the published abstract, and the evidence level is assigned automatically from the study design on the Oxford CEBM hierarchy. Neither is medical advice. Read the full paper before changing practice.