Eli Lilly says Taltz with Zepbound improved psoriatic arthritis outcomes at one year

Eli Lilly on November 11, 2026, announced detailed 52-week results from the TOGETHER-PsA Phase 3b open-label trial. The trial compared Taltz (ixekizumab) used together with Zepbound (tirzepatide) against Taltz alone in adults with active psoriatic arthritis and obesity or overweight. The company said the combination maintained or further improved outcomes across disease activity, patient-reported and metabolic measures through Week 52.

The company said a greater proportion of patients on the combination achieved ACR50, a measure of at least a 50% reduction in psoriatic arthritis disease activity, as early as Week 4, before clinically meaningful weight loss was observed. Physical function and fatigue were maintained or further improved from Week 36 to Week 52. The company said the combination was associated with improvements in body weight, blood pressure, glucose, HbA1c, triglycerides and total cholesterol versus Taltz alone.

Eli Lilly said the treatment met the primary and all key secondary endpoints for statistically significant superiority to Taltz alone at Week 36. Mark Genovese, M.D., senior vice president of Lilly Immunology development, said the data continue to evolve understanding of immunometabolic health. Philip Mease, M.D., Director of Rheumatology Research at Swedish Medical Center and Clinical Professor at the University of Washington, Seattle, and a TOGETHER-PsA study author, said the combined disease burden of psoriatic arthritis and obesity matters when caring for patients with both conditions.

The company said adverse events were generally mild to moderate and consistent with the known safety profile of each medicine. The 52-week findings were presented at the American College of Rheumatology Convergence 2026 and published at the same time in Arthritis & Rheumatology.