RecruitingPhase 1Biological interventionA Clinical Study of MK-1045 in People With Lupus or Rheumatoid Arthritis (MK-1045-004)This study looks at a study medicine called MK-1045 in people with lupus and rheumatoid arthritis (RA). The main goal of the study is to learn about the safety of MK-1045 and if people tolerate it when they receive it at different dose levels (amounts).