A Study to Evaluate Safety and Efficacy of Toreforant (JNJ-38518168) in Participants With Moderate to Severe Plaque-type Psoriasis

This is a randomized (study medication assigned to participants by chance), double-blind
(neither the researchers nor the participants know what treatment the participant is
receiving), parallel-group, placebo-controlled (an inactive substance; a pretend treatment
[with no drug in it] that is compared in a clinical trial with a drug to test if the drug has
a real effect) study. The study consists of Screening Phase (maximum of 42 days prior to Week
0), Treatment Phase (Week 0-12) and Follow-up Phase (up to Week 16). Participants will be
randomly assigned to receive JNJ-38518168 (3 milligram [mg] or 30 mg or 60 mg) or placebo
once daily. The initial group of the participants will be randomized to either JNJ-38518168
30 mg or placebo. The dose assignments for the subsequent participants will depend on the
results of up to 2 interim analyses. Efficacy will be primarily assessed by percentage of
participants who achieve a Psoriasis Area and Severity Index (PASI) 75 response at Week 12.
Participants' safety will be monitored throughout the study.

Inclusion Criteria:

- Participant must have a diagnosis of plaque-type psoriasis (with or without psoriatic
arthritis [PsA]) for at least 6 months before the first administration of study drug

- Participant must have a Psoriasis Area and Severity Index (PASI) Greater Than or equal
to (>=) 12 at screening and at baseline

- Participant must have an Investigator's Global Assessment (IGA) >=3 at screening and
at baseline

- A woman of childbearing potential must have a negative urine pregnancy test at
screening and at Week 0

- A man who is sexually active with a woman of childbearing potential and has not had a
vasectomy must agree to use a barrier method of birth control during the study and for
4 months after receiving the last administration of study drug. All men must also
agree to not donate sperm during the study and for 4 months after receiving the last
administration of study drug

Exclusion Criteria:

- Participant has a history or current signs or symptoms of severe, progressive, or
uncontrolled renal, hepatic, hematologic, gastrointestinal, endocrine, pulmonary,
cardiac, neurologic, cerebral, or psychiatric disease

- Participant has a current malignancy or history of malignancy within 5 years before
screening (with the exception of a nonmelanoma skin cancer that has been adequately
treated with no evidence of recurrence for at least 3 months before the first study
drug administration, or cervical carcinoma in situ that has been treated with no
evidence of recurrence for at least 1 year before the first study drug administration)

- Participant has a history of lymphoproliferative disease, including lymphoma; a
history of monoclonal gammopathy of undetermined significance (MGUS); or signs and
symptoms suggestive of possible lymphoproliferative disease, such as lymphadenopathy
or splenomegaly

- Participant has a history of chronic or recurrent infectious disease, including but
not limited to chronic renal infection, chronic chest infection (eg, bronchiectasis),
recurrent urinary tract infection (recurrent pyelonephritis or chronic nonremitting
cystitis), fungal infection (mucocutaneous candidiasis), or open, draining, or
infected skin wounds or ulcers

- Participant has a history of an infected joint prosthesis, or has received antibiotics
for a suspected infection of a joint prosthesis, if that prosthesis has not been
removed or replaced

- Participant has ever received any previous biologic therapy for psoriasis or psoriatic
arthritis