A Study to Investigate the Effectiveness of Tirzepatide (LY3298176) Following Initiation of Ixekizumab (LY2439821) in Participants With Moderate-to-Severe Plaque PsO and Obesity or Overweight in Clinical Practice (TOGETHER AMPLIFY-PsO)

Inclusion Criteria:

• Have a diagnosis of moderate-to-severe plaque PsO, as defined by a dermatologist orother experienced clinician treated PsO (for example, allergologist, nursepractitioner or physician assistant)

• Have body mass index (BMI) of 30 kilograms per meter squared (kg/m²) or greater (obesity) or 27 kg/m² to <30 kg/m² (overweight) in the presence of at least 1weight-related comorbid condition (hypertension, dyslipidemia, type 2 diabetesmellitus, obstructive sleep apnea, or cardiovascular diseases).

• Must have initiated treatment with ixekizumab for approximately 3 months (± 1 month)prior to decision to add tirzepatide.

• Must be able to initiate tirzepatide (Day 0) within 30 days of treatment decision (baseline/screening).

Exclusion Criteria:

• Have currently received ixekizumab for more than 4 months or less than 2 months.

• Have had any exposure to tirzepatide or other glucagon-like peptide-1 receptoragonist (GLP-1 RAs), for example, dulaglutide, liraglutide, or semaglutide.

• Are currently enrolled in any other clinical study.

Other exclusions

• Have a known hypersensitivity to tirzepatide or to any of its component.

• Have a personal or family history of medullary thyroid cancer.

• Have multiple endocrine neoplasia type 2.

• Have type I diabetes mellitus.

• Have a history of chronic or acute pancreatitis at any time before screening (Visit 1).

• Have a history of proliferative diabetic retinopathy, diabetic maculopathy, ornonproliferative diabetic retinopathy that requires acute treatment.

• Have a history of ketoacidosis or hyperosmolar state/coma.

• Have a history of severe hypoglycemia and hypoglycemia unawareness within the 6months before screening.

• Have a history of severe gastrointestinal complications, including gastroparesis,gastroesophageal reflux disease, dyspepsia, chronic nausea/constipation/vomiting.