Eine Studie zur Bewertung der Auswirkungen eines PsA-Medikaments namens Apremilast auf die Ergebnisse von bildgebenden Verfahren, beurteilt anhand von Magnetresonanztomographie (MRT) bei Patienten mit Psoriasis-Arthritis (PsA, eine entzündliche Arthritis).

Drug: CC-10004

Inclusion Criteria:

Subjects must satisfy the following criteria to be enrolled in the study:

1. Males or females, aged = 18 years at time of consent

2. For all regions, the local Regulatory Label for treatment with apremilast must be
followed.

3. Must understand and voluntarily sign an informed consent document prior to any study
related assessments/procedures being conducted

4. Able to adhere to the study visit schedule and other protocol requirements

5. Have a documented diagnosis of PsA of = 3 months AND = 5 years in duration, meeting
the CASPAR criteria for PsA at the time of Screening Visit

6. Have = 3 swollen AND = 3 tender joints, with hand involvement (defined as = 1 swollen
joint or dactylitis [each clinically active joint of a dactylitic digit is counted as
one joint]).

7. Have at least 1 active enthesitis site (one of the SPARCC or LEI sites)

8. Must not have been treated previously with a TNF blocker or other biologic drug for
PsA treatment

9. Must not have been treated with more than 2 csDMARDs

10. Subjects taking csDMARDs, with the exception of MTX, cyclosporine, or LEF, do not
require a washout period. However, they must discontinue the csDMARD treatment at
least one day prior to their Baseline Visit (ie, Visit 2, Day 1)

11. Subjects who have been previously treated with MTX for < 6 months and who are not on
stable doses for at least 3 months will require a 28-day washout prior to the Baseline
Visit (ie, Visit 2, Day 1) to participate in the study

12. Subjects who have been previously treated with LEF will require a 12-week washout
prior to the Baseline Visit (ie, Visit 2, Day 1), or treatment with cholestyramine,
per LEF prescribing label (ie, 8 g cholestyramine 3 times daily for 11 days)

13. Subjects who have been previously treated with cyclosporine will require a 28-day
washout prior to the Baseline Visit (ie, Visit 2, Day 1) to participate in the study

14. If taking MTX (= 25 mg/week), continuity of treatment will be allowed if duration of
treatment is = 6 months and on a stable dose for at least 3 months prior to the
Baseline Visit (ie, Visit 2, Day 1)

15. If taking oral glucocorticoids, must be on a stable dose of prednisone = 10 mg/day or
equivalent for at least 4 weeks prior to the Baseline Visit (ie, Visit 2, Day 1)

16. If taking NSAIDs or narcotic analgesics, must be on stable dose for at least 4 weeks
prior to Baseline Visit (ie, Visit 2, Day 1)

17. A female of childbearing potential (FCBP)† must have a negative pregnancy test at
screening and baseline. While on IP and for at least 28 days after taking the last
dose of IP, a FCBP who engages in activity in which conception is possible must use
one of the approved contraceptive§ options described below:

Option 1: Any one of the following highly effective methods: hormonal contraception
(oral, injection, implant, transdermal patch, vaginal ring); intrauterine device;
tubal ligation; or partner's vasectomy; OR Option 2: Male or female condom (latex
condom or non-latex condom NOT made out of natural [animal] membrane [for example,
polyurethane]); PLUS one additional barrier method: (a) diaphragm with spermicide; (b)
cervical cap with spermicide; or (c) contraceptive sponge with spermicide.

† An FCBP is defined as a sexually mature female who 1) has not undergone a
hysterectomy (the surgical removal of the uterus) or bilateral oophorectomy (the
surgical removal of both ovaries) or 2) has not been postmenopausal for at least 24
consecutive months (that is, has had menses at any time during the preceding 24
consecutive months).

§ The female subject's chosen form of contraception must be effective by the time the
female subject is screened into the study (for example, hormonal contraception should
be initiated at least 28 days before screening).

18. Must be in general good health (except for PsA) as judged by the investigator, based
on medical history, physical examination, and clinical laboratories. (Note: The
definition of good health means a subject does not have uncontrolled significant
comorbid conditions).

Exclusion Criteria:

The presence of any of the following will exclude a subject from enrollment:

1. Contraindication to MRI examination including, but not limited to, intracranial metal
clips, heart pacemakers, insulin pumps, implanted hearing aids, neurostimulators,
metal hip replacements, profound claustrophobia or inability to lie in the MRI machine
in an appropriate position to obtain quality images, history of hypersensitivity to
gadolinium contrast agent

2. Severe renal impairment (creatinine clearance of less than 30 mL per minute estimated
by the Cockroft-Gault equation), which would prevent the use of gadolinium enhancement

3. History of clinically significant (as determined by the investigator) cardiac,
endocrine, pulmonary, neurologic, psychiatric, hepatic, renal, hematologic,
immunologic disease, or other major uncontrolled disease

4. Any condition, including the presence of laboratory abnormalities, which places the
subject at unacceptable risk if he/she were to participate in the study

5. Prior history of suicide attempt at any time in the subject's lifetime prior to
signing the informed consent, or major psychiatric illness requiring hospitalization
within the last 3 years prior to signing the informed consent.

6. Pregnant or breast feeding

7. Active substance abuse or a history of substance abuse within 6 months prior to
screening

8. History of allergy or hypersensitivity to any component of the IP

9. History of rare hereditary problems of galactose intolerance, lapp lactase deficiency
or glucose-galactose malabsorption

10. History of positive human immunodeficiency virus (HIV), or congenital or acquired
immunodeficiency (eg, Common Variable Immunodeficiency Disease)

11. Active tuberculosis or a history of incompletely treated tuberculosis

12. Bacterial infections requiring treatment with oral or injectable antibiotics, or
significant viral or fungal infections, within 4 weeks of screening. Any treatment for
such infections must have been completed and the infection cured, at least 4 weeks
prior to screening and no new or recurrent infections prior to the Baseline Visit

13. Malignancy or history of malignancy or myeloproliferative or lymphoproliferative
disease within the past 3 years, except for treated (ie, cured) basal cell or squamous
cell in situ skin carcinomas;

14. Major