The efficacy of tixagevimab/cilgavimab (Evusheld) in prophylaxis and treatment of COVID-19 in immunocompromised patients: a systematic review and meta-analysis.

Background: During the COVID-19 pandemic, some populations, including immunocompromised patients, could not tolerate COVID-19 vaccination or had low responses. Evusheld is a combined neutralizing monoclonal antibody containing tixagevimab and cilgavimab. The World Health Organization (WHO) has approved this combination as pre-exposure prophylaxis (PrEP) and treatment for immunocompromised patients. With the new variant, the (WHO) recommended an increase in dose from 300 to 600 mg with a booster dose after 6 months. The target of this review was to compare the efficacy of the two doses, 300 mg and 600 mg of tixagevimab/cilgavimab (Evusheld) as prophylaxis for higher-risk individuals to reveal if there is a significant difference in efficacy between those two doses of the drug.

Methods: In this study, electronic databases (PubMed, Web of Science core collection, Scopus, and Cochran) were investigated for articles up to 31/12/2022 in English using a well-established search strategy. We included studies conducted in immunocompromised patients (aged ≥ 12 years) (WHO) received Evusheld as prophylaxis or treatment for COVID-19. After excluding studies inconsistent with the selection criteria, 24 were involved, 22 of which were included in the meta-analysis. We analyzed the data by using RevMan 5.4 program software.

Results: In the double-arm subgroup analysis, Evusheld 600 mg, administered as prophylaxis, showed no significant difference in the COVID-19 infection rate, mortality rate, or needed hospitalization rate compared with the dose of 300 mg (p = 0.13, p = 0.29, and p = 0.25, respectively). In the single-arm subgroup analysis, Evusheld 600 mg, administered as prophylaxis, showed a significant decrease in the COVID-19 infection rate and the hospitalization rate compared with the dose of 300 mg (p = 0.0001, p = 0.007, respectively). As a treatment, Evusheld showed a significant decrease in the mortality rate over the placebo group (p = 0.01) in COVID-19 patients.

Conclusion: This result indicated that Evusheld was an effective prophylactic and therapeutic drug for COVID-19 infection, especially for immunocompromised patients, but there was no considerable variation between the high and low doses. Further prospective and randomized controlled trials (RCTs) with increased population sizes are necessary to show the valuable benefit of the high dose of Evusheld in COVID-19 prevention and treatment and to compare the difference between the two doses within adverse events.