Efficacy and Safety of BMS-986165 Compared With Placebo in Participants With Active Psoriatic Arthritis (PsA)

The study is intended to evaluate the safety and efficacy of BMS-986165 Dose A or B once
daily (QD) compared with placebo in adults with active PsA. The primary endpoint is american
college of rheumatology (ACR) 20 response at Week 16 (Part A).

Inclusion Criteria:

- Diagnosed with PsA for at least 6 months before screening, and who meet the
Classification Criteria for Psoriatic Arthritis (CASPAR) at screening

- Participants either (i) cannot have prior exposure to biologics (biologic-naïve) or
(ii) have failed or been intolerant to 1 tumor necrosis factor -inhibitor (TNFi)
(TNFi-experienced). Failure is defined as lack of response or loss of response with at
least 3 months of therapy with an approved dose of a TNFi, as judged by the
investigator. Failure must have occurred at least 2 months prior to Day 1

- Participants have at least 1 confirmed greater than or equal to (>=) 2 centimeter (cm)
lesion of plaque psoriasis at screening

- Participants have active arthritis as shown by a minimum of >= 3 swollen joints and >=
3 tender joints (66/68 joint counts) at screening and Day 1

- High sensitivity C-reactive protein (hsCRP) >= 3milligram per liter (mg/L) at
screening

- Women of Childbearing Potential (WOCBP) must have a negative serum or urine pregnancy
test within 24 hours prior to the start of study treatment

Exclusion Criteria:

- Has non-plaque psoriasis (that is (i.e.), guttate, inverse, pustular, erythrodermic or
drug-induced psoriasis) at screening or Day 1

- Has any other autoimmune condition such as rheumatoid arthritis, etc. There are
exceptions for inflammatory bowel disease or uveitis as follows: currently active
disease is excluded but, a history of no longer active disease for at least 12 months
(including not being on medication) is allowed

- Has active (i.e. currently symptomatic) fibromyalgia

- History or evidence of active infection and/or febrile illness within 7 days prior to
Day 1 (example, bronchopulmonary, urinary, gastrointestinal, etc.)

- History of recent serious bacterial, fungal, or viral infections requiring
hospitalization and intravenous (IV) antimicrobial treatment within 90 days prior to
screening, or any infection requiring antimicrobial treatment within 15 days prior to
Day 1

- History of active tuberculosis (TB) prior to screening visit, regardless of completion
of adequate treatment