Study of GS-0272 in Participants With Rheumatoid Arthritis or Systemic Lupus Erythematosus (MARASLE)

Key Inclusion Criteria: Part A (Rheumatoid Arthritis (RA) Cohorts)-Specific Inclusion Criteria: Diagnosis of RA at least 3 months prior to screening fulfilling the 2010 American College of Rheumatology (ACR)/European League Against Rheumatism (EULAR) classification criteria. Ongoing treatment with 1 or 2 conventional synthetic disease-modifying antirheumatic drugs (csDMARDs) for at least 12 weeks prior to the first dose of study drug, with a stable dose for at least 4 weeks prior to the first dose of study drug, as follows: Individuals must not be on a biologic disease-modifying antirheumatic drugs (bDMARD)/targeted synthetic disease-modifying antirheumatic drug (tsDMARD) at Day 1 or during the study and must discontinue b/tsDMARD use for at least 4 weeks (with the exception of rituximab, which must be discontinued for at least 16 weeks) prior to the first dose of study drug. Part B (Systemic Lupus Erythematosus (SLE) Cohort)-Specific Inclusion Criteria: Fulfill EULAR/ACR 2019 classification criteria for SLE at least 24 weeks prior to the first dose of study drug. Individuals using protocol-permitted nonbiologic immunosuppressive/immunomodulatory agents (antimalarials, methotrexate (MTX), azathioprine, cyclosporine, leflunomide, minocycline, mycophenolate mofetil, mycophenolic acid, dapsone, and oral [not topical] tacrolimus) for the treatment of SLE must maintain stable dose(s) for at least 4 weeks prior to the first dose of study drug and through the end of study. Key Exclusion Criteria: Meet any of the protocol-specified infection criteria (hepatitis C, Hepatitis B, HIV, tuberculosis, others). Highly active SLE (including but not limited to lupus nephritis (with significant increases in urine protein/creatinine ratio over clinical baseline, recent worsening or creatinine clearance, and/or pyuria/hematuria), neuropsychiatric SLE, and/or vasculitis) that could put the individual at risk per investigator's judgment. Exposure to cyclophosphamide or any biologic lupus therapy within 8 weeks prior to the first dose of study drug. Note: Other protocol defined Inclusion/Exclusion criteria may apply.