Study to Evaluate Safety, Tolerability, and Efficacy of GS-5718 in Participants With Active Rheumatoid Arthritis Who Have an Inadequate Response to Disease-modifying Antirheumatic Drug(s) (bDMARDs) Treatment

Key Inclusion Criteria:

* Diagnosis of rheumatoid arthritis (RA) ≥ 3 months prior to screening fulfilling the 2010 American College of Rheumatology (ACR)/European League Against Rheumatism (EULAR) classification criteria for RA
* Rheumatoid factor (RF) and/or anti-citrullinated protein antibodies (ACPA) positivity
* Individual fulfills all of the following minimum disease activity criteria:

* ≥ 6 swollen joints (from a swollen joint count based on 66 joints \[SJC66\]) provided this would also fulfill ≥ 4 swollen joints (from a swollen joint count based on 28 joints \[SJC28\]) at screening and Day 1, and
* ≥ 6 tender joints (from a tender joint count based on 68 joints \[TJC68\]), provided this would also fulfill ≥ 4 tender joints (from a tender joint count based on 28 joints \[TJC28\]) at screening and Day 1, and
* hsCRP \> upper limit of normal at screening
* Received at least one bDMARD for the treatment of RA to which there is a lack of efficacy and/or intolerance.

Key Exclusion Criteria:

* Individuals who do not qualify per the tofacitinib label and/or local guidelines should not be enrolled.
* Prior exposure to any Janus kinase inhibitor

Note: Other protocol defined Inclusion/Exclusion criteria may apply.