COVID-19 Evidence Alerts
from McMaster PLUSTM

Current best evidence for clinical care (more info)

COVID-19 Evidence Alerts needs your support. If our service is of value to you, please consider donating to keep it going. Learn more Donate now

Treatment Gottlieb RL, Nirula A, Chen P, et al. Effect of Bamlanivimab as Monotherapy or in Combination With Etesevimab on Viral Load in Patients With Mild to Moderate COVID-19: A Randomized Clinical Trial. JAMA. 2021 Feb 16;325(7):632-644. doi: 10.1001/jama.2021.0202.

Importance: Coronavirus disease 2019 (COVID-19) continues to spread rapidly worldwide. Neutralizing antibodies are a potential treatment for COVID-19.

Objective: To determine the effect of bamlanivimab monotherapy and combination therapy with bamlanivimab and etesevimab on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) viral load in mild to moderate COVID-19.

Design, Setting, and Participants: The BLAZE-1 study is a randomized phase 2/3 trial at 49 US centers including ambulatory patients (N = 613) who tested positive for SARS-CoV-2 infection and had 1 or more mild to moderate symptoms. Patients who received bamlanivimab monotherapy or placebo were enrolled first (June 17-August 21, 2020) followed by patients who received bamlanivimab and etesevimab or placebo (August 22-September 3). These are the final analyses and represent findings through October 6, 2020.

Interventions: Patients were randomized to receive a single infusion of bamlanivimab (700 mg [n = 101], 2800 mg [n = 107], or 7000 mg [n = 101]), the combination treatment (2800 mg of bamlanivimab and 2800 mg of etesevimab [n = 112]), or placebo (n = 156).

Main Outcomes and Measures: The primary end point was change in SARS-CoV-2 log viral load at day 11 (±4 days). Nine prespecified secondary outcome measures were evaluated with comparisons between each treatment group and placebo, and included 3 other measures of viral load, 5 on symptoms, and 1 measure of clinical outcome (the proportion of patients with a COVID-19-related hospitalization, an emergency department [ED] visit, or death at day 29).

Results: Among the 577 patients who were randomized and received an infusion (mean age, 44.7 [SD, 15.7] years; 315 [54.6%] women), 533 (92.4%) completed the efficacy evaluation period (day 29). The change in log viral load from baseline at day 11 was -3.72 for 700 mg, -4.08 for 2800 mg, -3.49 for 7000 mg, -4.37 for combination treatment, and -3.80 for placebo. Compared with placebo, the differences in the change in log viral load at day 11 were 0.09 (95% CI, -0.35 to 0.52; P = .69) for 700 mg, -0.27 (95% CI, -0.71 to 0.16; P = .21) for 2800 mg, 0.31 (95% CI, -0.13 to 0.76; P = .16) for 7000 mg, and -0.57 (95% CI, -1.00 to -0.14; P = .01) for combination treatment. Among the secondary outcome measures, differences between each treatment group vs the placebo group were statistically significant for 10 of 84 end points. The proportion of patients with COVID-19-related hospitalizations or ED visits was 5.8% (9 events) for placebo, 1.0% (1 event) for 700 mg, 1.9% (2 events) for 2800 mg, 2.0% (2 events) for 7000 mg, and 0.9% (1 event) for combination treatment. Immediate hypersensitivity reactions were reported in 9 patients (6 bamlanivimab, 2 combination treatment, and 1 placebo). No deaths occurred during the study treatment.

Conclusions and Relevance: Among nonhospitalized patients with mild to moderate COVID-19 illness, treatment with bamlanivimab and etesevimab, compared with placebo, was associated with a statistically significant reduction in SARS-CoV-2 viral load at day 11; no significant difference in viral load reduction was observed for bamlanivimab monotherapy. Further ongoing clinical trials will focus on assessing the clinical benefit of antispike neutralizing antibodies in patients with COVID-19 as a primary end point.

Trial Registration: Identifier: NCT04427501.

Discipline / Specialty Area Score
Infectious Disease
Hospital Doctor/Hospitalists
Internal Medicine
Family Medicine (FM)/General Practice (GP)
General Internal Medicine-Primary Care(US)
Comments from MORE raters

Family Medicine (FM)/General Practice (GP) rater

The results of this very interesting study are preliminary and not immediately applicable in primary care. “The proportion of patients with COVID-19–related hospitalizations or emergency department visits was numerically lower for the monotherapy groups and the combination therapy group compared with the placebo group, but the difference was only significant for the combination group".

Family Medicine (FM)/General Practice (GP) rater

These are viral load reductions at 11 days, not change in meaningful clinical outcomes, so these are very preliminary data and not something that will change immediately available therapy.

Hospital Doctor/Hospitalists rater

As a hospitalist, this is of great interest. This well conducted study in mild to moderate covid-19 found the combination therapy reduced viral load. While this surrogate marker is of little interest to the practicing hospitalist, the promise of reductions in subsequent need for hospitalization warrants further study.

Infectious Disease rater

This randomized trial compared different doses of monotherapy with an anti-spike monoclonal antibody bamlanivimab versus a combination of bamlanivimab with another monoclonal antibody etesevimab versus placebo in ambulatory patients with mild to moderate symptoms of covid-19. Only the combination achieved significant reduction in viral load from baseline at day 11. There appears to have been a reduction in the need for hospitalization in the combination group but this end point was only exploratory. These are promising results but need to be confirmed in larger trials with a primary clinical endpoint.