The purpose of this Phase 2 study is to find out whether bamlanivimab is able to stop COVID-19 from getting worse.

3000 participants with mild-to-moderate COVID-19 will receive bamlanivimab via an injection into a vein. These participants will be matched to similar COVID-19 patients who received other treatment at a local medical center.

All participants will be followed to learn how their disease responds. Participation could last about 3 months and includes two required visits to the study site, with the remainder of assessments performed by phone or by medical record review.