REGEN-COV Antibody Combination in Outpatients With COVID-19 – Phase 1/2 Results

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Abstract

Background

Continued SARS-CoV-2 infections and COVID-19-related hospitalizations highlight the need for effective anti-viral treatments in the outpatient setting. In a descriptive interim analysis of the phase 1/2 portion of a double-blind phase 1/2/3 trial in COVID-19 outpatients conducted between June 16, 2020 and September 4, 2020, REGEN-COV ® (casirivimab plus imdevimab) antibody combination reduced SARS-CoV-2 viral load versus placebo.

Methods

This final phase 1/2 analysis comprises 799 outpatients, including 275 from the previous descriptive analysis (group-1) and 524 from phase 2 (group-2). Patients were randomized (1:1:1) to placebo, REGEN-COV 2400mg, or REGEN-COV 8000mg. Prespecified hierarchical analyses of virologic endpoints were performed in group-2. The proportion of patients with ≥1 COVID-19–related medically attended visit (MAV) through day 29 was assessed in group-1+2. Efficacy was assessed in patients confirmed SARS-CoV-2–positive by baseline nasopharyngeal RT-qPCR. Safety was assessed in all treated patients.

Results

Data from 799 outpatients enrolled from June 16, 2020 to September 23, 2020 are reported. Time-weighted average daily reduction in viral load through day 7 was significantly greater in the REGEN-COV combined 2400mg+8000mg group versus placebo in patients with baseline viral load >10 7 copies/mL (prespecified primary endpoint): -0.68 log 10 copies/ml (95% CI, -0.94 to -0.41; P <.0001). This reduction was - 0.73 ( P <.0001) and -0.36 ( P =.0003) log 10 copies/mL in serum antibody–negative patients and in the overall population, respectively. REGEN-COV reduced the proportion of patients with ≥1 COVID-19–related MAV versus placebo (2.8% [12/434] REGEN-COV combined dose group versus 6.5% [15/231] placebo; P =.024; relative risk reduction [RRR]=57%); in patients with ≥1 risk factor for hospitalization, the treatment effect was more pronounced (RRR=71%). Adverse events were similar across groups.

Conclusions

In COVID-19 outpatients enrolled prior to the widespread circulation of delta and omicron variants, treatment with REGEN-COV significantly reduced viral load and COVID-19–related MAVs.

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  1. SciScore for 10.1101/2021.06.09.21257915: (What is this?)

    Please note, not all rigor criteria are appropriate for all manuscripts.

    Table 1: Rigor

    EthicsIRB: The local institutional review board or ethics committee at each study center oversaw trial conduct and documentation.
    Consent: All patients provided written informed consent before participating in the trial.
    Sex as a biological variablenot detected.
    RandomizationTRIAL DESIGN: This is an ongoing, adaptive, multicenter, randomized, double-blind, placebo-controlled, seamless phase 1/2/3 trial in Covid-19 outpatients (NCT04425629).
    BlindingThe investigators, site personnel, and Regeneron were unaware of the treatment-group assignments.
    Power Analysisnot detected.

    Table 2: Resources

    Antibodies
    SentencesResources
    15 All patients were assessed for the presence or absence of anti-SARS-CoV-2 antibodies: anti-spike [S1] IgA, anti-spike [S1] IgG, and anti-nucleocapsid IgG.
    antibodies
    suggested: None
    anti-spike
    suggested: None
    anti-nucleocapsid IgG
    suggested: None
    Software and Algorithms
    SentencesResources
    Statistical analyses were performed with SAS software, version 9.4 or higher (SAS Institute).
    SAS
    suggested: (SASqPCR, RRID:SCR_003056)
    SAS Institute
    suggested: (Statistical Analysis System, RRID:SCR_008567)

    Results from OddPub: We did not detect open data. We also did not detect open code. Researchers are encouraged to share open data when possible (see Nature blog).


    Results from LimitationRecognizer: An explicit section about the limitations of the techniques employed in this study was not found. We encourage authors to address study limitations.

    Results from TrialIdentifier: We found the following clinical trial numbers in your paper:

    IdentifierStatusTitle
    NCT04425629RecruitingSafety, Tolerability, and Efficacy of Anti-Spike (S) SARS-Co…


    Results from Barzooka: We did not find any issues relating to the usage of bar graphs.


    Results from JetFighter: We did not find any issues relating to colormaps.


    Results from rtransparent:
    • Thank you for including a conflict of interest statement. Authors are encouraged to include this statement when submitting to a journal.
    • Thank you for including a funding statement. Authors are encouraged to include this statement when submitting to a journal.
    • No protocol registration statement was detected.

    Results from scite Reference Check: We found no unreliable references.


    About SciScore

    SciScore is an automated tool that is designed to assist expert reviewers by finding and presenting formulaic information scattered throughout a paper in a standard, easy to digest format. SciScore checks for the presence and correctness of RRIDs (research resource identifiers), and for rigor criteria such as sex and investigator blinding. For details on the theoretical underpinning of rigor criteria and the tools shown here, including references cited, please follow this link.