Monoclonal Antibody for Patients with Covid-19

To the Editor: The ACTIV-3/TICO LY-CoV555 Study Group (Dec. 22)(1) hypothesized that low penetration of the antibody into the infected lungs might explain the lack of benefit of bamlanivimab (LY-CoV555) in hospitalized patients with coronavirus disease 2019 (Covid-19). However, we previously measured transudation of human immunodeficiency virus type 1 (HIV-1) monoclonal antibodies (VRC07-523 and PGT121) into tissues of 1-month-old rhesus macaques as part of a study to assess the effectiveness of monoclonal antibodies as postexposure prophylaxis.(2) We detected high concentrations of passively transferred antibodies in the lungs of the two macaques (250 ng per milliliter in one and 285 ng . . .

Automated summary

The study on rhesus macaques showed that monoclonal antibodies can penetrate infected tissues, suggesting that there may be other factors contributing to the lack of benefit of bamlanivimab in patients with Covid-19.