Systemic Lupus Erythematosus (SLE) Clinical Trials

The purpose of this study is to learn about the safety and effects of the study medicine (called PF-08065010) for possible treatment of rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE). This study is seeking participants who are: * male or female between 18 and 65 years of age * deemed to be healthy Participants in this study will receive PF-08065010 or placebo. A placebo does not have any medicine in it but looks just like the medicine being studied. PF-08065010 or placebo will be given as a shot (in the abdomen, thigh or back of the arms) or as an IV infusion in the arm (given directly into a vein) at the study clinic. In Part A, participants will take PF-08065010 or placebo only 1 time and will take part in this study for about 5 months. During this time, they will stay at the study clinic for about 9-10 days and will have about 6 more study visits at the study clinic. Participants in Part B of the study will take PF-08065010 or placebo once a month, for 3 months and will take part in this study for about 7 months. During this time, they will stay at the study clinic for about 4 days each month and will have about 6 more study visits at the study clinic. During study clinic stays and study visits, urine, blood samples, and physical exams will be done.