Multiple Ascending Doses of AMG 139 in Healthy and Crohn's Disease Subjects

Inclusion Criteria: Part A - Healthy Subjects: * Healthy male or female of non-reproductive potential subjects between 18 to 45 years-of-age * Body mass index (BMI) between 18 and 32 kg/m2 * Normal or clinically acceptable physical examination, clinical laboratory values, and ECG * Additional inclusion criteria apply Part B - Crohn's Subjects: * Male or female subjects with CD between 18 to 55 years-of-age * Body mass index (BMI) between 18 and 32 kg/m2 * Normal or clinically acceptable physical examination (PE), clinical laboratory values, and ECG; clinically acceptable PE includes evidence of mild to severe CD * Diagnosis of ileal or ileo-colonic CD for a minimum of 6 months * Mild to severe CD defined by a Crohn's Disease Activity Index (CDAI) score equal to or greater than 180 and equal to or less than 450 * Elevated fecal calprotectin and CRP * Additional inclusion criteria apply Exclusion Criteria: Parts A - Healthy Subjects: * History or evidence of a clinically significant disorder (including psychiatric), condition or disease that would pose a risk to subject safety or interfere with the study evaluation, procedures or completion; * Recent or on-going infection(s) * Underlying condition(s) that predisposes the subject to infections * History of malignancy of any type * Additional exclusion criteria apply Part B only - Crohn's Subjects: * History or evidence of a clinically significant disorder (including psychiatric), condition or disease that would pose a risk to subject safety or interfere with the study evaluation, procedures or completion; * Recent or on-going infection(s) * Underlying condition(s) that predisposes the subject to infections * History of malignancy of any type * Additional exclusion criteria apply