Observational Study to Estimate the Effectiveness of Biologics When Treating Plaque Psoriasis

Plaque psoriasis is a chronic skin disease affecting 1-3% of US and European populations and
severely impairs quality of life. Four biologics are authorized in Europe and the US for
treatment of patients with moderate to severe psoriasis. Because complete skin clearance is
rare with these agents, the treatment goal adopted by regulatory and reimbursement agencies
is the proportion of patients achieving at least a 75% reduction from the subject's baseline
PASI (Psoriasis Area and Severity Index) score or similarly, a sPGA [static Physician's
Global Assessment) score of 0 or 1. Specifically, this study will provide information on the
effectiveness of approved biologics as they are used in clinical practice. This information
is currently not consistently available from other sources, including existing psoriasis
patient registries.

Study Hypothesis: This study will estimate in each country the proportion of biologic
treatment-naïve and biologic treatment-switching psoriasis subjects in the real-world having
total clearance at 6 months after initiating a biologic.

The study population will include up to approximately 300 adults in each of up to 6
participating countries who have been diagnosed by their physicians with moderate to severe
plaque psoriasis, and are initiating biologic therapy(biologic treatment-naïve or biologic
treatment-switching) for plaque psoriasis.

Summary of Subject Eligibility Criteria: aged 18 or over; diagnosed with moderate to severe
plaque psoriasis; initiating a biologic approved for psoriasis at study entry; able to fill
out questionnaires; provided written informed consent; and not participating in a clinical
trial utilizing an investigational agent in the 3 months prior to the first biologic dose.

Assessments: Skin clearance is the primary indicator of treatment effectiveness, and will be
measured using the physician-reported PASI and sPGA. Other assessments will be by the
following patient questionnaires: psoriasis symptom inventory (PSI), the dermatology life
quality index (DLQI), the static patient's global assessment ( sPtGA), treatment satisfaction
and global health status.

All subjects will be initiating biologic therapy at study entry. Therapy discontinuations,
switches, and dosing changes during follow-up will be reported by the site and summarized.

Follow-up continues for approximately 12 months after first dose or until the subject is lost
to follow-up or withdraws from the study (for any reason including death), whichever comes
first. Where appropriate, data will be obtained for each subject during mandatory visits at 6
months (± 6 weeks) and 12 months (± 6 weeks) after first biologic dose, and at routine visits
that occur during the follow-up period. To the extent possible data will also be collected at
other usual care visits that occur during follow-up.

Inclusion Criteria:

- subjects who are greater than or equal to 18 YO diagnosed with moderate to severe
plaque psoriasis

- subjects who will be initiating therapy with a biologic approved for moderate to
severe psoriasis either for the first time (biologic treatment naive) or in course of
switching to a different biologic agent

- subject who is able to complete questionnaires

- subject able to provide written informed consent

Exclusion Criteria:

- subjects who are participating in a clinical trial utilizing an investigational agent in
the 3 months prior to the first biologic dose on study