Efficacy of Ustekinumab Followed by Abatacept for the Treatment of Psoriasis Vulgaris

Psoriasis is a chronic immune disease of the skin and joints that affects about 2% of the
population. The most common form of psoriasis is plaque psoriasis, also called psoriasis
vulgaris. A variety of drugs, including biologics, are available for treatment of moderate to
severe psoriasis. When biologic agents are stopped, psoriasis can return (relapse) and often
requires the biologic to be restarted and continued. No treatment program has been identified
to prevent relapse of psoriasis.

The study design has a lead-in period of weight-based ustekinumab treatment, with all
participants receiving either 45 mg ustekinumab (<= 100 kg) or 90 mg ustekinumab (> 100 kg)
administered subcutaneously at weeks 0 and 4. At week 12, participants will be assessed for a
Psoriasis Area and Severity Index (PASI) 75 response to ustekinumab. Participants who do not
achieve a PASI 75 score will be discontinued from the investigation and permitted to seek
standard therapy.

Inclusion Criteria:

- A diagnosis of plaque psoriasis for at least 6 months

- Baseline Psoriasis Area and Severity Index (PASI) score >= 12

- >=10% body surface area psoriasis involvement

- Willingness to forgo other available psoriasis therapies, live vaccines, and pregnancy
during the trial

- Ability and willingness to provide informed consent and comply with study requirements

Exclusion Criteria:

- Non-plaque forms of psoriasis

- Grade 2 or 3 moderate to severe psoriatic arthritis not adequately managed with
non-steroidal anti-inflammatory drugs (NSAIDs)

- Myocardial infarction, unstable angina, cerebrovascular accident, or other significant
cardiovascular event within the previous one year

- Chronic obstructive pulmonary disease (COPD)

- Comorbid condition that requires regular systemic corticosteroid treatment

- History of malignancy, except treated basal cell skin carcinoma

- Treated basal cell skin carcinoma within the previous 5 years

- Severe, progressive, or uncontrolled renal, hepatic, hematological, gastrointestinal,
pulmonary, cardiac, or neurological disease, or any other medical condition that, in
the investigator's opinion, places the participant at risk by participating in this
study

- History of recent or ongoing uncontrolled bacterial, viral, fungal, or other
opportunistic infections

- Evidence of infection with Hepatitis B Virus (HBV), Hepatitis C Virus (HCV), or Human
Immunodeficiency Virus (HIV)

- Positive QuantiFERON-TB Gold test. Purified Protein Derivative (PPD) tuberculin test
may be substituted for QuantiFERON-TB Gold test.

- Severe reaction or anaphylaxis to any human monoclonal antibody

- Any previous treatment with agents targeting Interleukin (IL)-12 or IL-23, including
ustekinumab

- Any previous treatment with abatacept

- Treatment with biologic agents within previous 3 months, including adalimumab,
etanercept, and infliximab

- Treatment with immunosuppressive medications, including methotrexate, cyclosporine,
oral retinoids, prednisone, or phototherapy within previous 4 weeks

- Topical psoriasis treatment within previous 2 weeks, including topical
corticosteroids, vitamin D analogues, retinoids, calcineurin inhibitors, salicylic
acid, and coal tar

- Investigational study medication within previous 6 months

- Liver function test (aspartate aminotransferase [AST], alanine aminotransferase [ALT],
or alkaline phosphatase) results that are >/= 2x the upper limit of normal (ULN).

- Serum creatinine >= 2x the ULN.

- Any of the following hematologic abnormalities, confirmed by repeat test at least 1
week apart:

1. White blood count <3,000/μL or >14,000/μL;

2. Lymphocyte count <1,000/μL;

3. Neutrophil count <1,500/μL;

4. Platelet count <150,000 /μL; or

5. Hemoglobin <10 g/dL.

- Females who are pregnant, lactating, planning on pregnancy during the study period, or
unwilling to use FDA-approved method of birth control

- Receipt of a live vaccine (e.g., varicella, measles, mumps, rubella, cold-attenuated
intranasal influenza vaccine, and smallpox) in the 6 weeks before enrollment

- BCG (Bacillus Calmette-Guérin) vaccine one year prior to enrollment