Psoriatic Arthritis Research Collaborative: Biologic Sub-Study

Psoriatic arthritis (PsA) is a chronic inflammatory arthritis that can be associated with
devastating outcomes including irreversible joint damage. The management of a patient with
PsA is extremely challenging due to the high degree of phenotypic heterogeneity. The ultimate
goal of this proposal is to prepare pragmatic trials in PsA trials that will encompass all
relevant subgroups of patients. The aims of this study specifically focus on responses to
biologic therapy among patients with PsA and determining the optimal set of outcome measures
for PsA trials.

Inclusion Criteria:

- Age 18-89

- Active PsA (at least one swollen joint or enthesitis) -Meet CASPAR criteria (Table 2)
(103) -Initiation of TNFi (etanercept, adalimumab, infliximab, certolizumab,
golimumab) (At the time of the submission, TNFi biosimilars have been approved by the
FDA but are not available on the US market. Once available, patients starting TNFi
biosimilars will similarly be eligible for participation. Patients may have been on
the medication in the past but must have had greater than 2 months off the
medication.Patients may be taking other traditional DMARDs. A washout period is not
required.)

Exclusion Criteria:

- Unable to give informed consent

- Out of the age range

- Switching therapies for skin psoriasis in the setting of well controlled joint and
enthesis symptoms.

- Patients with only active PsA