Comparison of CHS-1420 Versus Humira in Subjects With Chronic Plaque Psoriasis

This is a 55-week, randomized, double-blind, active-control, parallel group, multicenter,
global study in subjects with active, moderate to severe, chronic PsO.

The study will consist of 24 weeks of administration of blinded study drug, divided into
Treatment Period 1 and Treatment Period 2, then 23 weeks of administration of open-label
CHS-1420 and a Follow-up visit 8 weeks after the last dose. Subjects who meet
inclusion/exclusion criteria will be stratified by body mass index (BMI), and age and
randomized 1:1 to receive CHS-1420 or Humira in Treatment Period 1. Subjects assigned to
CHS-1420 will continue to receive CHS-1420 in Period 2. Subjects assigned to Humira in
Period 1 will be randomly assigned (1:1) to either continue with Humira in Treatment Period
2 or to switch to CHS-1420 in Treatment Period 2. All subjects will receive open label
CHS-1420 in Treatment Period 3.

Inclusion Criteria:

- Male or female adults

- PsO diagnosis for 6 months

- Active disease: PASI greater than or equal to 12, Physician's Static Global
Assessment (PSGA) score greater than or equal to 3 (based on a scale of 0-5),

- Body Surface Area (BSA) involved with PsO greater than or equal to 10%

Exclusion Criteria:

- Forms of psoriasis other than PsO

- Drug induced psoriasis

- Positive QuantiFERON-tuberculosis (TB) Gold Test

- Presence of significant comorbid conditions

- Chemistry and hematology values outside protocol specified range

- Major systemic infections