Casirivimab–Imdevimab treatment is associated with reduced rates of hospitalization among high-risk patients with mild to moderate coronavirus disease-19
Razonable et al.
, Casirivimab–Imdevimab treatment is associated with reduced rates of hospitalization among high-risk patients..
, EClinicalMedicine, doi:10.1016/j.eclinm.2021.101102
Retrospective 696 patients treated with casirivimab/imdevimab, and 696 matched controls, showing lower hospitalization with treatment. Authors only included patients with documented followup, which is likely to disproportionately bias the control group towards patients with worse outcomes.Confounding by treatment propensity.
This study analyzes a population
where only a fraction of eligible patients received the treatment. Patients
receiving treatment may be more likely to follow other recommendations, more
likely to receive additional care, and more likely to receive adjuvant
treatments that are not tracked in the data (e.g., nasal/oral hygiene
[c19early.org, c19early.org (B)]
, vitamin D
, etc.) — either because the physician
recommending casirivimab/imdevimab also recommended them, or
because the patient seeking out casirivimab/imdevimab is more
likely to be familiar with the efficacy of additional treatments. Therefore,
these kind of studies may overestimate the efficacy of treatments.
.Efficacy is variant dependent. In Vitro research suggests a lack of efficacy for omicron [Liu, Sheward, Tatham, VanBlargan].
risk of death, 75.0% lower, RR 0.25, p = 0.37, treatment 1 of 696 (0.1%), control 4 of 696 (0.6%), NNT 232.
risk of ICU admission, 28.6% lower, RR 0.71, p = 0.77, treatment 5 of 696 (0.7%), control 7 of 696 (1.0%), NNT 348.
risk of hospitalization, 66.7% lower, RR 0.33, p = 0.001, treatment 11 of 696 (1.6%), control 33 of 696 (4.7%), NNT 32.
Effect extraction follows pre-specified rules prioritizing more serious outcomes. Submit updates
Razonable et al., 31 Oct 2021, retrospective, USA, peer-reviewed, 18 authors, study period 4 December, 2020 - 9 April, 2021.
Abstract: EClinicalMedicine 40 (2021) 101102
Contents lists available at ScienceDirect
journal homepage: https://www.journals.elsevier.com/eclinicalmedicine
CasirivimabImdevimab treatment is associated with reduced rates of
hospitalization among high-risk patients with mild to moderate
Raymund R. Razonablea,*, Colin Pawlowskib, John C. O’Horoa, Lori L. Arndtc, Richard Arndtc,
Dennis M. Bierlea, Molly Destro Borgena, Sara N. Hansond, Michelle C. Hedina,
Patrick Lenehanb, Arjun Puranikb, Maria T Sevillee, Leigh L. Speicherf,
Sidna M. Tulledge-Scheitela, AJ Venkatakrishnanb, Caroline G. Wilkerg, Andrew D. Badleya,
Mayo Clinic, Rochester, MN, United States
nFerence, Cambridge, MA, United States
Mayo Clinic Health System, Eau Claire, WI, United States
Mayo Clinic Health System, Mankato, MN, United States
Mayo Clinic in Arizona, Phoenix, United States
Mayo Clinic in Florida, Jacksonville, United States
Mayo Clinic Health System Franciscan Healthcare, La Crosse, WI, United States
A R T I C L E
I N F O
Received 5 July 2021
Revised 10 August 2021
Accepted 11 August 2021
Available online 30 August 2021
A B S T R A C T
Background: Real-world clinical data to support the use of casirivimabimdevimab for the treatment of outpatients with mild to moderate coronavirus disease-19 (COVID-19) is needed. This study aimed to assess the
outcomes of casirivimabimdevimab treatment of mild to moderate COVID-19.
Methods: A retrospective cohort of 696 patients who received casirivimabimdevimab between December 4,
2020 and April 9, 2021 was compared to a propensity-matched control of 696 untreated patients with mild
to moderate COVID-19 at Mayo Clinic sites in Arizona, Florida, Minnesota, and Wisconsin. Primary outcome
was rate of hospitalization at days 14, 21 and 28 after infusion.
Findings: The median age of the antibody-treated cohort was 63 years (interquartile range, 5271); 45¢5%
were 65 years old; 51.4% were female. High-risk characteristics were hypertension (52.4%), body mass
index 35 (31.0%), diabetes mellitus (24.6%), chronic lung disease (22.1%), chronic renal disease (11.4%),
congestive heart failure (6.6%), and compromised immune function (6.7%). Compared to the propensitymatched untreated control, patients who received casirivimabimdevimab had signiﬁcantly lower all-cause
hospitalization rates at day 14 (1.3% vs 3.3%; Absolute Difference: 2.0%; 95% conﬁdence interval (CI):
0.53.7%), day 21 (1.3% vs 4.2%; Absolute Difference: 2.9%; 95% CI: 1.24.7%), and day 28 (1.6% vs 4.8%; Absolute Difference: 3.2%; 95% CI: 1.45.1%). Rates of intensive care unit admission and mortality at days 14, 21
and 28 were similarly low for antibody-treated and untreated groups.
Interpretation: Among high-risk patients with mild to moderate COVID-19, casirivimabimdevimab treatment was associated with a signiﬁcantly lower rate of hospitalization.
Funding: Mayo Clinic.
© 2021 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license
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