Psoriatic Arthritis Study of Izokibep

Inclusion Criteria:

General

• Subject has provided signed informed consent including consenting to comply with therequirements and restrictions listed in the informed consent form (ICF) and in thisprotocol.

• Subject must be ≥18 (or the legal age of consent in the jurisdiction in which thestudy is taking place) and ≤75 years of age, at the time of signing the informedconsent.

Type of Subject and Disease Characteristics

• Clinical diagnosis of psoriatic arthritis (PsA) with symptom onset at least 6 monthsprior to first dose of study drug and fulfillment of the ClASsification forPsoriatic ARthritis (CASPAR) criteria at Screening.

• Active PsA defined as ≥3 tender joints (based on 68 joint counts) and ≥3 swollenjoints (based on 66 joint counts) at Screening and Baseline Visits

• Rheumatoid factor (RF) and anti-cyclic citrullinated peptide (anti-CCP) negative atscreening.

• Subject must have had an inadequate response, intolerance, or contraindication to atleast one of the following:

1. nonsteroidal anti-inflammatory drug (NSAID)

2. conventional-synthetic disease-modifying anti-rheumatic drugs (csDMARD) (i.e.methotrexate, sulfasalazine, leflunomide, hydroxychloroquine, cyclosporine A)

3. tumor necrosis factor-alpha inhibitor(s) (TNFi) (e.g. adalimumab, infliximab,etanercept, golimumab, certolizumab).

• For subjects using methotrexate, leflunomide, sulfasalazine, hydroxychloroquine, orapremilast, treated for ≥3 months and a stable dose (not to exceed 25 mgmethotrexate per week, 20 mg leflunomide per day, sulfasalazine 3 g per day,hydroxychloroquine 400 mg per day, or apremilast 60 mg per day) for ≥4 weeks priorto first dose of study drug.

• For subjects using corticosteroids, must have been on a stable dose and regimen andnot to exceed 7.5 mg per day of prednisone (or other corticosteroid equivalent to 7.5 mg per day of prednisone) for ≥4 weeks prior to first dose of study drug.

• Subjects using NSAIDs, or low potency opioid medications (tramadol, paracetamol incombination with hydrocodone or with codeine) must have been on a stable dose andregimen for ≥2 weeks prior to first dose of study drug.

Other Inclusions

• No known history of active tuberculosis (TB).

• Subject has a negative TB test at screening

Exclusion Criteria:

Disease-related Medical Conditions

• Any history or current confirmed diagnosis of inflammatory bowel disease (IBD)

OR

• Any of the following symptoms (of unknown etiology) or any signs or symptoms withinthe last year that in the opinion of the Investigator may be suggestive of IBD, withfecal calprotectin ≥ 500 μg/g; OR if fecal calprotectin >150 to <500 μg/g withoutconfirmed approval from a GI consult that an IBD diagnosis is clinically unlikelywhen the following clinical signs and symptoms are present:

1. prolonged or recurrent diarrhea

2. prolonged or recurrent abdominal pain

3. blood in stool

• History of fibromyalgia, or any arthritis with onset prior to age 17 years orcurrent diagnosis of inflammatory joint disease other than psoriatic arthritis (PsA) (including, but not limited to rheumatoid arthritis, gout, connective tissuediseases). Prior history of axial spondyloarthritis or fibromyalgia is permitted ifdocumentation of change in diagnosis to PsA or documentation that the diagnosis wasmade incorrectly. Prior history of reactive arthritis or axial spondyloarthritis ispermitted if an additional diagnosis of PsA is made. Chronic osteoarthritis symptomsthat in the Investigator's opinion may interfere with study assessments.

• Uncontrolled, clinically significant system disease

• Malignancy within 5 years

• Severe, uncontrolled, medically unstable mood disorder, such as severe depression.

• History or evidence of any clinically significant disorder (including psychiatric),condition, or disease that, in the opinion of the investigator, may pose a risk tosubject safety or interfere with the study evaluation, procedures, or completion.

• Active infection or history of certain infections

• Candida infection requiring systemic treatment within 3 months prior to first doseof study drug.

• Tuberculosis or fungal infection seen on available chest x-ray taken within 3 monthsprior to first dose of study drug or at screening (Exception: documented evidence ofcompleted treatment and clinically resolved).

• Known history of human immunodeficiency virus (HIV) or positive HIV test atscreening.

Other protocol defined Inclusion/Exclusion criteria may apply