Bamlanivimab

Bamlanivimab is the recombinant version of an antibody (monoclonal antibody) that received emergency approval by the Food and Drug Administration (FDA) in the US in November 2020 for the treatment of mild to moderate COVID-19 disease. Bamlanivimab is an antibody that was discovered in the blood of one of the first US COVID-19 patients at the beginning of the pandemic. The antibody was chosen from among 500 different antibodies from the patient because it recognizes the section of the spike protein that SARS-CoV-2 uses to dock with human cells. This blocks the virus from entering human cells. After isolating the B cells, the coding gene was incorporated into recombinant cells. This allows the antibody to be produced in cell cultures in unlimited quantities. It is administered by intravenous infusion.

After the antibody significantly reduced viral load in animal studies in primates and was shown to be safe in a phase 1 study in clinic patients with COVID-19, a phase 2 study in humans was conducted on June 17. In this study (BLAZE-1 trial), bamlanivimab significantly reduced the proportion of patients who were subsequently hospitalised from 6.3% to 1.6% in outpatients with a mean symptom onset of 4 days ago and who were only mildly ill. Bamlanivimab has not yet been shown to be effective in people who are already severely ill.

The results of the BLAZE-1 trial led to the approval of bamlanivimab in patients with mild to moderate disease in the US in November. The BLAZE-2 trial tested whether preventive treatment with bamlanivimab can protect residents and staff of nursing homes where initial infections have occurred. The results in 1,097 patients treated with bamlanivimab showed that a single intravenous dose of bamlanivimab reduced the incidence of symptomatic disease by 57% (odds ratio 0.43, p=0.00021). In the subgroup of nursing home residents, there was even a reduction of 80 % (odds ratio 0.20; p=0.00026). The study confirms previous experience according to which treatment with antibodies (or serum therapy) achieves the greatest effect if it is given as early as possible. The study shows for the first time that high-risk individuals can be protected by preventive treatment.

The FDA lists anaphylaxis and infusion-related reactions as possible side effects, as well as nausea, diarrhea, dizziness, headache, itching, and vomiting.

In non-hospitalized patients with mild-to-moderate COVID-19 disease, combined treatment with bamlanivimab and etesevimab was associated with a statistically significant reduction in SARS-CoV-2 viral load at day 11 compared to placebo; no significant difference in viral load reduction was observed for bamlanivimab monotherapy. Further ongoing clinical trials will focus on evaluating the clinical benefit of antispike neutralizing antibodies in patients with COVID-19 as the primary endpoint.