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Effectiveness of REGEN-COV Antibody Combination in Preventing Severe COVID-19 Outcomes – A Retrospective Cohort Study ​

17 Pages Posted: 24 Jan 2022

See all articles by Samah Hayek

Samah Hayek

Clalit Health Services

Yatir Ben Shlomo

Clalit Health Services

Noa Dagan

Clalit Health Services

Ben Y. Reis

Harvard University - Harvard Medical School

Noam Barda

Clalit Health Services

Eldad Kepten

Clalit Health Services

Alina Roitman

Clalit Health Services

Shachar Shapira

Israel Defense Forces (IDF)

Shlomit Yaron

Clalit Health Services - Community Medical Services Division

Ran Balicer

Ben Gurion University of the Negev

Doron Netzer

Clalit Health Services - Community Medical Services Division

Alon Peretz

Clalit Health Services - Community Medical Services Division

More...

Abstract

Background: REGEN-COV has been approved as a treatment for high-risk patients infected with SARS-CoV-2 within 5 days of their diagnosis. We aim to determine the real-world effectiveness of REGEN-COV treatment against COVID-19-related hospitalization, severe illness and death.

Methods: A cohort study was performed using the data repositories of Israel’s largest healthcare organization. Patients diagnosed with COVID-19 between September 19, 2021 and December 8, 2021 who were treated with REGEN-COV were matched to patients diagnosed with COVID-19 between July 1, 2021 and December 8, 2021 who were not treated with REGEN-COV. Patients were followed until the occurrence of the outcome (i.e. severe COVID-19 illness, hospitalization, and death due to COVID-19) or until 28-days from the index date. Analysis was performed using Cox regression, with estimated treatment effectiveness defined as one minus the hazard ratio.

Findings: 289 patients treated with REGEN-COV were matched with 1,294 untreated patients. The estimated effectiveness of REGEN-COV in the first 28- days after treatment was 55.2% (95% CI: 21.5-74.5%) in preventing COVID-19-related hospitalization, 59.4% (95% CI: 20.2-79.4%) in preventing severe COVID-19 illness, and 93.8% (95% CI: 54.4-99.2%) in preventing COVID-19-related death. A secondary analysis indicated that REGEN-COV was more effective in preventing COVID-19-related hospitalization among individuals younger than 60 compared to individuals aged 60 years or older.

Interpretation: REGEN-COV was effective in reducing the risk of deterioration in high-risk COVID-19 patients. With many individuals remaining unvaccinated, and breakthrough infections occurring among the vaccinated, effective treatment for COVID-19 remains vital.

Funding Information: None.

Declaration of Interests: The authors has no conflict of interest to declare.

Ethics Approval Statement: This study was approved by the CHS Institutional Review Board.

Keywords: COVID-19 infection, SARS-CoV-2, REGEN-COV treatment, COVID-19 treatment, observational studies, treatment effectiveness, two SARS-CoV-2 antibodies (Casirivimab and Imdevimab)

Suggested Citation

Hayek, Samah and Ben Shlomo, Yatir and Dagan, Noa and Reis, Ben Y. and Barda, Noam and Kepten, Eldad and Roitman, Alina and Shapira, Shachar and Yaron, Shlomit and Balicer, Ran and Netzer, Doron and Peretz, Alon, Effectiveness of REGEN-COV Antibody Combination in Preventing Severe COVID-19 Outcomes – A Retrospective Cohort Study ​. Available at SSRN: https://ssrn.com/abstract=4016543 or http://dx.doi.org/10.2139/ssrn.4016543

Samah Hayek (Contact Author)

Clalit Health Services ( email )

Israel

Yatir Ben Shlomo

Clalit Health Services ( email )

Israel

Noa Dagan

Clalit Health Services ( email )

Israel

Ben Y. Reis

Harvard University - Harvard Medical School ( email )

25 Shattuck St
Boston, MA 02115
United States

Noam Barda

Clalit Health Services ( email )

Israel

Eldad Kepten

Clalit Health Services ( email )

Israel

Alina Roitman

Clalit Health Services ( email )

Israel

Shachar Shapira

Israel Defense Forces (IDF) ( email )

Israel

Shlomit Yaron

Clalit Health Services - Community Medical Services Division ( email )

Tel Aviv
Israel

Ran Balicer

Ben Gurion University of the Negev ( email )

Beersheba
Israel

Doron Netzer

Clalit Health Services - Community Medical Services Division ( email )

Tel Aviv
Israel

Alon Peretz

Clalit Health Services - Community Medical Services Division ( email )

Tel Aviv
Israel