{"doi":"10.1093/ofid/ofab331","title":"Real-world Effectiveness and Tolerability of Monoclonal Antibody Therapy for Ambulatory Patients With Early COVID-19","abstract":"BACKGROUND: Neutralizing monoclonal antibodies (MAbs) are a promising therapy for early coronavirus disease 2019 (COVID-19), but their effectiveness has not been confirmed in a real-world setting. METHODS: In this quasi-experimental pre-/postimplementation study, we estimated the effectiveness of MAb treatment within 7 days of symptom onset in high-risk ambulatory adults with COVID-19. The primary outcome was a composite of emergency department visits or hospitalizations within 14 days of positive test. Secondary outcomes included adverse events and 14-day mortality. The average treatment effect in the treated for MAb therapy was estimated using inverse probability of treatment weighting and the impact of MAb implementation using propensity-weighted interrupted time series analysis. RESULTS: Pre-implementation (July-November 2020), 7404 qualifying patients were identified. Postimplementation (December 2020-January 2021), 594 patients received MAb treatment and 5536 did not. The primary outcome occurred in 75 (12.6%) MAb recipients, 1018 (18.4%) contemporaneous controls, and 1525 (20.6%) historical controls. MAb treatment was associated with decreased likelihood of emergency care or hospitalization (odds ratio, 0.69; 95% CI, 0.60-0.79). After implementation, the weighted probability that a given patient would require an emergency department visit or hospitalization decreased significantly (0.7% per day; 95% CI, 0.03%-0.10%). Mortality was 0.2% (n = 1) in the MAb group compared with 1.0% (n = 71) and 1.0% (n = 57) in pre- and postimplementation controls, respectively. Adverse events occurred in 7 (1.2%); 2 (0.3%) were considered serious. CONCLUSIONS: MAb treatment of high-risk ambulatory patients with early COVID-19 was well tolerated and likely effective at preventing the need for subsequent emergency department or hospital care.","journal":"Open Forum Infectious Diseases","year":2021,"id":154701,"datarank":0.0,"base_score":0.0,"endowment":0.0,"self_citation_contribution":0.0,"citation_network_contribution":0.0,"self_endowment_contribution":0.0,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":62,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.9436,"is_data_producer":false,"deposit_databanks":null,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2021-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":234864,"name":"Whitney R. Buckel","orcid":"0000-0001-9505-2572","position":1,"is_corresponding":false},{"id":655330,"name":"Todd J. Vento","orcid":"0000-0001-9834-5426","position":2,"is_corresponding":false},{"id":655331,"name":"Allison Butler","orcid":"0000-0003-1388-1612","position":3,"is_corresponding":false},{"id":238527,"name":"Nancy Grisel","orcid":null,"position":4,"is_corresponding":false},{"id":105995,"name":"Samuel M. Brown","orcid":"0000-0003-1206-6261","position":5,"is_corresponding":false},{"id":105996,"name":"Ithan D. Peltan","orcid":"0000-0003-1730-234X","position":6,"is_corresponding":false},{"id":567179,"name":"Emily S Spivak","orcid":"0000-0002-4314-9644","position":7,"is_corresponding":false},{"id":655332,"name":"Mark Shah","orcid":"0009-0002-4877-7815","position":8,"is_corresponding":false},{"id":656141,"name":"Theadora Sakata","orcid":null,"position":9,"is_corresponding":false},{"id":656142,"name":"Anthony Wallin","orcid":null,"position":10,"is_corresponding":false},{"id":238529,"name":"Eddie Stenehjem","orcid":null,"position":11,"is_corresponding":false},{"id":656143,"name":"Greg Poulsen","orcid":null,"position":12,"is_corresponding":false},{"id":250230,"name":"Joseph Bledsoe","orcid":"0000-0002-3005-2878","position":13,"is_corresponding":false},{"id":234860,"name":"Brandon Webb","orcid":"0000-0002-1799-3315","position":0,"is_corresponding":true}],"reference_count":16,"raw_metadata":null,"created_at":"2026-07-18T23:43:54.469024Z","pmid":"34327256","pmcid":null,"fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":null,"license":null,"views":0,"total_file_size_bytes":0,"version_count":0,"fair_f":null,"fair_a":null,"fair_i":null,"fair_r":null,"fair_zscore":null,"fair_rationale":null,"fair_model":null,"fair_agent_version":null,"fair_fulltext_source":null,"fair_has_llm":null,"fair_computed_at":null,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}