Infections in cancer patients treated with immune checkpoint inhibitors: Data from randomized trials.

Abstract

2637 Background: Febrile neutropenia and infections are well studied complications of chemotherapy (CT) and some targeted agents employed in oncology. Less is known about the risk of infection associated with the use of immune checkpoint inhibitors (ICIs) in cancer patients. The present systematic review and meta-analysis was performed to address this question in patients diagnosed with solid tumors enrolled in randomized trials employing ICIs as experimental treatment. Methods: The Cochrane Library, EMBASE, and Pubmed databases were searched from inception through December 1st, 2020. Randomized clinical trials comparing any ICI alone, with CT, or with other agents vs CT, placebo, or other agents in patients with solid tumors were included. Two independent reviewers used a standardized data extraction and quality assessment form. Discordant cases were discussed with a third independent investigator. The following information was extracted: baseline study characteristics, including the primary tumor, author, year of publication, type of trial, type of disease, and the type of therapy (experimental and control arms); and the incidence of any-grade (grades [G] 1–5), low-grade (G1–2), and high-grade (G3–4), fatal event (G5) infections, and type of event. Random or fixed-effect models were used according to the statistical heterogeneity. Results: 36 randomized clinical trials were deemed eligible. The total population reached 21451 patients. In the pooled analysis, the use of ICIs was associated with a similar risk of all-grade infections (relative risk, RR = 1.02; 95% CI 0.84–1.24; P = 0.85) compared to non-ICI treatments (G1-5 events: 9.6 vs. 8.3%). When the ICIs alone arms were compared to CT, the experimental arms were associated with a 42% less risk of all-grade infections (RR = 0.58, 95% CI 0.4–0.85; P = 0.01; N = 18 studies). Compared to CT, the combination of ICIs and CT increased the risk of all-grade infections (RR = 1.37, 95% CI 1.23–1.53; P < 0.01; N = 13 studies) and severe infections (RR = 1.52, 95% CI 1.17–1.96; P < 0.01; N = 12 studies). Fatal infections were similar in the experimental and control arms (0.5%). Conclusions: In patients with advanced solid tumors, when ICIs were administered with CT, the risk of all-grade and G3-5 infections was significantly increased. Compared to CT alone, ICIs were safer and their use should be recommended for frail patients. Further studies are required to identify high-risk patients and evaluate the need for CT dose reduction or prophylactic myeloid growth factors use.