Real-world clinical outcomes of treatment with casirivimab-imdevimab among patients with mild-to-moderate coronavirus disease 2019 during the Delta variant pandemic

Suzuki et al., medRxiv, doi:10.1101/2021.12.19.21268078, Dec 2021
Mortality -200% improvement lower risk ← → higher risk Mortality b 60% Progression 45% Progression b 50% Casirivimab/i..  Suzuki et al.  EARLY TREATMENT Is early treatment with casirivimab/imdevimab beneficial for COVID-19? Retrospective 949 patients in Japan (July - September 2021) Lower progression with casirivimab/imdevimab (p=0.021) c19early.org Suzuki et al., medRxiv, December 2021 0 0.5 1 1.5 2+ RR
18th treatment shown to reduce risk in March 2021, now with p = 0.000095 from 34 studies, recognized in 52 countries. Efficacy is variant dependent.
Lower risk for hospitalization, progression, recovery, cases, and viral clearance.
No treatment is 100% effective. Protocols combine treatments.
6,300+ studies for 210+ treatments. c19early.org
Meta Analysis
Retrospective 949 patients in Japan, 314 treated with casirivimab/imdevimab showing significantly lower risk of deterioration with treatment.
Efficacy is variant dependent. In Vitro research suggests a lack of efficacy for many omicron variants1-7.
Standard of Care (SOC) for COVID-19 in the study country, Japan, is very poor with very low average efficacy for approved treatments8. Only expensive, high-profit treatments were approved for early treatment. Low-cost treatments were excluded, reducing the probability of early treatment due to access and cost barriers, and eliminating complementary and synergistic benefits seen with many low-cost treatments.
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risk of death, 200.0% higher, RR 3.00, p = 1.00, treatment 1 of 222 (0.5%), control 0 of 222 (0.0%), continuity correction due to zero event (with reciprocal of the contrasting arm), propensity score matching.
risk of death, 59.6% lower, RR 0.40, p = 0.67, treatment 1 of 314 (0.3%), control 5 of 635 (0.8%), NNT 213, unadjusted.
risk of progression, 45.2% lower, RR 0.55, p = 0.02, treatment 17 of 222 (7.7%), control 31 of 222 (14.0%), NNT 16, propensity score matching.
risk of progression, 49.9% lower, RR 0.50, p = 0.002, treatment 34 of 314 (10.8%), control 70 of 365 (19.2%), NNT 12, odds ratio converted to relative risk, multivariate.
Effect extraction follows pre-specified rules prioritizing more serious outcomes. Submit updates
Suzuki et al., 21 Dec 2021, retrospective, Japan, preprint, 49 authors, study period 24 July, 2021 - 30 September, 2021. Contact: shibatay@fmu.ac.jp.
$0 $500 $1,000+ Efficacy vs. cost for COVID-19 treatment protocols c19early.org December 2025 Japan United Kingdom Russia USA Sudan Angola Colombia Kenya Mozambique Vietnam Peru Philippines China Uzbekistan Nepal Ethiopia Iran Ghana Mexico South Korea Germany Bangladesh Saudi Arabia Algeria Morocco Yemen Poland India DR Congo Madagascar Thailand Uganda Venezuela Nigeria Egypt Bolivia Taiwan Zambia Fiji Bosnia-Herzegovina Ukraine Côte d'Ivoire Bulgaria Greece Slovakia Singapore Iceland New Zealand Czechia Mongolia Israel Trinidad and Tobago Hong Kong North Macedonia Belarus Qatar Panama Serbia CAR Japan favored high-profit treatments.The average efficacy of treatments was very low.High-cost protocols reduce early treatment, andforgo complementary/synergistic benefits. More effective More expensive 75% 50% 25% ≤0%
$0 $500 $1,000+ Efficacy vs. cost for COVID-19treatment protocols worldwide c19early.org December 2025 Japan United Kingdom Russia USA Sudan Angola Colombia Kenya Mozambique Vietnam Peru Philippines China Uzbekistan Nepal Ethiopia Iran Ghana Mexico South Korea Germany Bangladesh Saudi Arabia Algeria Morocco Yemen Poland India DR Congo Madagascar Thailand Uganda Venezuela Nigeria Egypt Bolivia Taiwan Zambia Fiji Bosnia-Herzegovina Ukraine Côte d'Ivoire Eritrea Bulgaria Greece Slovakia Singapore New Zealand Malawi Czechia Mongolia Israel Trinidad and Tobago North Macedonia Belarus Qatar Panama Serbia Syria Japan favored high-profit treatments.The average efficacy was very low.High-cost protocols reduce early treatment,and forgo complementary/synergistic benefits. More effective More expensive 75% 50% 25% ≤0%
Real-world clinical outcomes of treatment with casirivimab-imdevimab among patients with mild-to-moderate coronavirus disease 2019 during the Delta variant pandemic
Yasuhito Suzuki, MD Yoko Shibata, Hiroyuki Minemura, Takefumi Nikaido, Yoshinori Tanino, Atsuro Fukuhara, Ryuzo Kanno, Hiroyuki Saito, Shuzo Suzuki, Taeko Ishii, Yayoi Inokoshi, Eiichiro Sando, Hirofumi Sakuma, Tatsuho Kobayashi, Hiroaki Kume, Masahiro Kamimoto, Hideko Aoki, Akira Takama, Takamichi Kamiyama, Masaru Nakayama, Kiyoshi Saito, Koichi Tanigawa, Masahiko Sato, Toshiyuki Kanbe, Norio Kanzaki, Teruhisa Azuma, Keiji Sakamoto, Yuichi Nakamura, Hiroshi Otani, Mitsuru Waragai, Shinsaku Maeda, Tokiya Ishida, Keishi Sugino, Yasuhiko Tsukada, Ryuki Yamada, Riko Sato, Takumi Omuna, Hikaru Tomita, Mikako Saito, Natsumi Watanabe, Mami Rikimaru, Takaya Kawamata, Takashi Umeda, Julia Morimoto, Ryuichi Togawa, Yuki Sato, Junpei Saito, Kenya Kanazawa, Ken Iseki
doi:10.1101/2021.12.19.21268078
This real-world retrospective study demonstrates the contribution of treatment with casirivimab-imdevimab to the prevention of deterioration in patients with mild-to-All rights reserved. No reuse allowed without permission. perpetuity.
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DOI record: { "DOI": "10.1101/2021.12.19.21268078", "URL": "http://dx.doi.org/10.1101/2021.12.19.21268078", "abstract": "<jats:p>Background: Mutations of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) may reduce the efficacy of neutralizing monoclonal antibody therapy against coronavirus disease 2019 (COVID-19). We here evaluated the efficacy of casirivimab-imdevimab in patients with mild-to-moderate COVID-19 during the Delta variant surge in Fukushima Prefecture, Japan.\nMethods: We enrolled 949 patients with mild-to-moderate COVID-19 who were admitted to hospital between July 24, 2021 and September 30, 2021. Clinical deterioration after admission was compared between casirivimab-imdevimab users (n = 314) and non-users (n = 635). \nResults: The casirivimab-imdevimab users were older (P &lt; 0.0001), had higher body temperature (≥ 38 degree) (P &lt; 0.0001) and greater rates of history of cigarette smoking (P = 0.0068), hypertension (P = 0.0004), obesity (P &lt; 0.0001), and dyslipidemia (P &lt; 0.0001) than the non-users. Multivariate logistic regression analysis demonstrated that receiving casirivimab-imdevimab was an independent factor for preventing deterioration (odds ratio 0.448; 95% confidence interval 0.263 to 0.763; P = 0.0023). Furthermore, in 222 patients who were selected from each group after matching on the propensity score, deterioration was significantly lower among those receiving casirivimab-imdevimab compared to those not receiving casirivimab-imdevimab (7.66% vs 14.0%; p = 0.021).\nConclusion: This real-world study demonstrates that casirivimab-imdevimab contributes to the prevention of deterioration in COVID-19 patients after hospitalization during a Delta variant surge.</jats:p>", "accepted": { "date-parts": [ [ 2021, 12, 21 ] ] }, "author": [ { "affiliation": [], "family": "Suzuki", "given": "Yasuhito", "sequence": "first" }, { "affiliation": [], "family": "Shibata", "given": "Yoko", "sequence": "additional" }, { "affiliation": [], "family": "Minemura", "given": "Hiroyuki", "sequence": "additional" }, { "affiliation": [], "family": "Nikaido", "given": "Takehumi", "sequence": "additional" }, { "affiliation": [], "family": "Tanino", "given": "Yoshinori", "sequence": "additional" }, { "affiliation": 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