516. A Systematic Literature Review Evaluating Real-World Use of Nirmatrelvir-Ritonavir for the Prevention of COVID-19-Related Hospitalization and Death

BACKGROUND: Nirmatrelvir-ritonavir (NMV-r) is an oral antiviral medication used for the treatment of mild-to-moderate COVID-19 in patients aged 12 years or older at high risk of progression to severe disease and hospitalization. Following real-world utilization beginning in late 2021, millions of patients worldwide have been treated with NMV-r and many studies have described outcomes following treatment. This systematic literature review (SLR) was conducted to summarize the real-world clinical impact of NMV-r to inform healthcare decision-making. METHODS: Real-world studies of NMV-r use available in English, with ≥5 subjects, and reporting on hospitalization and/or mortality outcomes were identified from Embase, PubMed, and relevant congress abstracts. Studies were evaluated for eligibility using population, intervention, comparison, outcome, study design criteria and time period (Dec 2021-Nov 2022) (Table 1). Dual-independent screening was used at the title, abstract and full-text levels with third reviewer consensus; data were extracted by a single reviewer with validation by a second reviewer prior to a quality rating assessment. [Figure: see text] RESULTS: The SLR identified 28 eligible studies (Figure 1) representing 74,386 subjects that received NMV-r. The majority of studies reported on use in the United States (n=13) and patient vaccination status (n=25). Of the 16 studies that reported variant or sub-lineage data, all included patients treated during the Omicron period. Despite differences in baseline patient characteristics, treatment with NMV-r was consistently associated with a reduction in relative risk for hospitalization alone (n=5) or hospitalization and mortality (n=20). Studies that measured 30-day all-cause hospitalization (n=3) reported odds ratios (ORs) ranging from 0.43 to 0.54 (NMV-r vs. no NMV-r). Three studies measured 28-day all-cause mortality and reported ORs ranging from 0.05 to 0.23 (NMV-r vs. no NMV-r). [Figure: see text] CONCLUSION: Real-world studies show that NMV-r provides effective protection against hospitalization and death during the Omicron era among high-risk individuals. Outcomes following use of NMV-r in the real-world should be continually monitored as new studies are published and as the natural history of COVID-19 and treatment landscape continue to evolve. DISCLOSURES: Ashley S. Cha-Silva, PharmD, MS, Pfizer Inc.: Employee|Pfizer Inc.: Stocks/Bonds Meghan B. Gavaghan, MPH, Pfizer: Advisor/Consultant Jennifer L. Nguyen, ScD, MPH, MHCI, pfizer: employee Ronika Alexander-Parrish, RN, MAEd, Pfizer, Inc.: Employee|Pfizer, Inc.: Stocks/Bonds Jingyan Yang, MHS, DrPH, Pfizer Inc.: Stocks/Bonds Jaymin Patel, PharmD, Pfizer: Advisor/Consultant Denise A. Garner, PharmD, Pfizer: Advisor/Consultant Richard Stanford, PharmD, MS, Pfizer: Advisor/Consultant Genevieve Meier, PharmD, MSc, PhD, Pfizer: Advisor/Consultant