BACKGROUND AND PURPOSE:

• Neutralizing monoclonal antibodies may reduce viral load, lessens symptoms of COVID-19, and reduce hospitalizations
• LY-CoV555 antibody binds with high affinity to the receptor-binding domain of SARS-CoV-2
• Chen et al. (NEJM, 2020) report early results on the efficacy and safety of LY-CoV555, a monoclonal antibody treatment for COVID-19

METHODS:

• Randomized, double-blind, placebo-controlled, single-dose trial
  • 41 centers in the US
  • Interim analysis of ongoing phase 2 trial
• Data source
  • Blocking Viral Attachment and Cell Entry with SARS-CoV-2 Neutralizing Antibodies (BLAZE-1) trial
• Participants
  • Mild or moderate COVID-19
  • Managed as outpatients
• Intervention
  • Antibody LY-CoV555: Single IV infusion in either a 700 mg, 2800 mg, or 7000 mg dose
  • Placebo
• Primary outcome
  • Change from baseline in viral load at day 11

RESULTS:

• 452 patients included in primary analysis
  • Antibody group: 309 patients
  • Placebo: 143 patients
• By day 11, most patients had progressed towards viral clearance, even those in the placebo group
• Among the intervention groups, patients who received the 2800-mg dose of LY-CoV555 had the greatest decrease in viral load compared to placebo
  • Mean decrease from baseline: −0.53 (95% CI, −0.98 to −0.08; P=0.02)
  • Viral load was lower by a factor of 3.4
• On days 2 to 6, the patients who received LY-CoV555 had a slightly lower severity of symptoms than those who received placebo
• Percentage of patients who had a Covid-19–related hospitalization or visit to an emergency department
  • Antibody group: 1.6%
  • Placebo group: 6.3%
• Safety profiles were similar between groups

CONCLUSION:

• A 2800-mg dose of neutralizing antibody LY-CoV555 in patients with mild to moderate COVID-19 seems to accelerate a reduction in viral load by day 11, compared to placebo
  • 11 days was not a meaningful endpoint as most patients in the placebo group also cleared the virus by day 11
• However, these results do indicate fewer hospitalizations and a lower symptom burden vs placebo
• The authors conclude that

If these results are confirmed in additional analyses in this trial, LY-CoV555 could become a useful treatment for emergency use in patients with recently diagnosed Covid-19

Learn More – Primary Sources:

SARS-CoV-2 Neutralizing Antibody LY-CoV555 in Outpatients with Covid-19

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