Efficacy and Safety Study of SUNPG1623

Inclusion Criteria:

Subject has provided written informed consent
Subject is ≥ 18 years of age at time of Screening
Subject must be on stable dose of NSAID for ≥ 4 weeks prior to initiation of IMP
Subject has a negative evaluation for TB within 4 weeks before initiating IMP
Subject has a diagnosis of PsA (by the Classification of Psoriatic Arthritis [CASPAR] criteria) with symptoms present for at least 6 months.
Subject has ≥ 3 tender and ≥ 3 swollen joints at Screening and Baseline.

Exclusion Criteria:

Subject has a planned surgical intervention between Baseline and the Week 24 evaluation for a pretreatment condition
Subject has an active infection or history of infections
Subject has any concurrent medical condition or uncontrolled, clinically significant systemic disease
Subject has a known history of infection with hepatitis B, hepatitis C, or human immunodeficiency virus