Safety and Efficacy Study of GDC-0853 Compared With Placebo and Adalimumab in Participants With Rheumatoid Arthritis (RA)

Inclusion Criteria:

- Have a diagnosis of adult-onset RA as defined by the 2010 American College of
Rheumatology/European League Against Rheumatism Classification Criteria for RA

- RA disease activity by joint counts and laboratory markers of inflammation: greater
than or equal to (>=) 6 tender/painful joints on motion (68 joint count) and >= 6
swollen joints (66 joint count) at both screening and Day 1 (randomization)

- For MTX-inadequate response (IR) participants: must have had an inadequate response to
MTX

- For TNF-IR participants: must have had an inadequate response or intolerance to
previous treatment with at least 1 and no more than 2 biologic TNF-alpha inhibitors
and may have also been exposed to no more than one biologic non-TNF-alpha inhibitor

- High sensitivity C-reactive protein of >= 0.400 milligrams per deciliter (mg/dL) for
Cohort 1 and >= 0.650 mg/dL for Cohort 2 at screening

Exclusion Criteria:

- History of or current inflammatory joint disease other than RA or other systemic
autoimmune disorder

- For MTX-IR participants: History of treatment with any TNF inhibitor, including
biosimilar equivalents and history of treatment with biologic non-TNF-alpha inhibitor
for RA

- For all participants: Previous treatment with cell-depleting therapy including B
cell-depleting therapy (e.g., anti-cluster of differentiation 20-directed therapy such
as rituximab), tofacitinib, or other Janus kinase inhibitor(s), or alkylating agents

- Current treatment with medications that are well known to prolong the QT interval at
doses that have a clinically meaningful effect on QT

- History of non-gallstone-related pancreatitis or chronic pancreatitis

- Evidence of serious uncontrolled concomitant cardiac, neurologic, pulmonary, renal,
hepatic, endocrine, metabolic, or gastrointestinal disease

- Evidence of chronic and/or active hepatitis B or C

- Women who are pregnant, nursing (breast feeding), or intending to become pregnant
during the study or within 60 days after completion of the study