Safety, Tolerability, Pharmacokinetics, Pharmacodynamics, and Clinical Effects of AMG 557 in Adults With Psoriasis

Inclusion Criteria:

Subjects must sign an Institutional Review Board (IRB)-approved informed consent form (ICF) before any study specific procedures.

Diagnosis of moderate to severe plaque PsO for at least 6 months prior to screening as defined by:

A minimum PASI score of ≥ 10 obtained at screening;
Psoriasis involving ≥ 10% of the Body Surface Area (BSA) at screening.
Received at least 1 previous phototherapy or systemic PsO therapy (but not within the 30 days before study drug administration), or has been a candidate to receive phototherapy or systemic PsO therapy in the opinion of the PI.
Stable treatment without topical or systemic steroids, topical or systemic retinoids, vitamin D analogues (Dovenex), Psoralen Ultraviolet A (PUVA) therapy, Ultraviolet A (UVA) therapy or Ultraviolet B (UVB) therapy, methotrexate, or cyclosporine for at least 60 days prior to IP administration. Stable treatment of PsO involving scalp, axillae, or groin with topical corticosteroids of moderate strength will be allowed.
Agrees to wear clothing that protects from sun exposure for the duration of the study.
Agrees to use sunscreen (SPF of at least 30) on sun-exposed skin for the duration of the study.
Male or female subjects between 18 and 55 years of age, inclusive at the time of screening.
Body mass index (BMI) between 18 and 35 kg/m2, inclusive, at screening, unless considered by the PI and the Amgen Medical Monitor to be at an appropriate value in the context of other measured safety parameters.
Able and willing to complete entire study (including skin biopsies) according to study schedule.
Additional criteria per protocol.

Exclusion Criteria:

Diagnosis of guttate, pustular, or other non plaque forms of PsO.
Evidence of skin conditions other than PsO (eg, eczema) during the screening period that would interfere with evaluations of the effect of IP on PsO.
Previous receipt of any approved or investigational biologic agent for PsO or other medical conditions.
Received PUVA therapy, UVA therapy or UVB therapy ≤ 30 days prior to IP administration.
Treatment with any other systemic PsO therapy or oral or parenteral corticosteroids ≤ 30 days prior to IP administration.
Use of high potency topical steroids, topical vitamin A or D analog preparations, or anthralin ≤ 30 days prior to IP administration (Note: stable doses > 30 days of low or moderate strength topical steroids are permitted only on the scalp, axillae, and groin according to the package insert).
Received topical cyclosporin or calcineurin inhibitors such as pimecrolimus (Elidel) and tacrolimus (Protopic) ≤ 30 days prior to IP administration.
Received IV or oral calcineurin inhibitors such as tacrolimus (Prograf) ≤ 30 days prior to IP administration.

Significant concurrent medical conditions at the time of screening or prior to randomization, including:

Uncontrolled hypertension (defined as screening systolic blood pressure measurement of greater than 140 mm Hg or a screening diastolic blood pressure of greater than 90 mm Hg) confirmed by 2 separate measurements during the screening visit;
Unstable angina pectoris;
Congestive heart failure;
Steroid or oxygen dependent chronic obstructive pulmonary disease;
Diagnosis of multiple sclerosis or any other demyelinating disease;
Open cutaneous ulcers;
Uncontrolled diabetes (HbA1c > 7%).
History of myocardial infarction.
Subjects with two or more cardiovascular risk factors (defined as BMI > 30, BP systolic > 140 mm Hg, diagnosis of diabetes, history of cardiovascular event).

Evidence of significant renal insufficiency during the screening period, defined by a glomerular filtration rate < 50 mL/min using the Cockcroft and Gault equation:

72 x Serum Creatinine (in mg/dL) / (140 - Age) x Body Weight (in kg) x [0.85 if female]

Evidence of any bacterial, viral, parasitic, or systemic fungal infections during the 30 days prior to study drug administration (eg, common cold, viral syndrome, flu like symptoms).
Evidence of a recent (within 6 months of randomization) infection requiring in patient hospitalization or intravenous antibiotics.
Positive test for HIV antibodies, hepatitis B surface antigen, or hepatitis C antibodies.
Underlying condition that predisposes the subject to infections (eg, history of splenectomy; history of immunodeficiency).
Evidence of past or active tuberculosis on chest x-ray performed during screening (or documented evidence on a chest x-ray performed within 6 months prior to planned dosing); known tuberculosis antecedents; known exposure (without adequate treatment) to a person with active tuberculosis; or positive protein purified derivative (PPD) Mantoux skin or serum quantiferon test at screening (without documented history of treatment). A positive result is defined as either induration greater than or equal to 5 mm 48-72 hours after administration (Mantoux) or a positive serum quantiferon test result.
History of malignancy.
Evidence of liver disease (eg, serum ALT and AST > 1.5 x the upper limit of normal) during screening period.
Donated blood (including blood products) or experienced loss of blood ≥ 500 mL within 2 months of screening.
Additional criteria per protocol.