Global pharma powerhouse Eli Lilly and Company has unveiled striking results from its TOGETHER-PsA Phase 3b trial, showing that combining Taltz (ixekizumab) with Zepbound (tirzepatide) outperformed Taltz alone in adults with active psoriatic arthritis (PsA) and obesity.
The findings were presented as a late-breaking study at the 2026 American Academy of Dermatology (AAD) Annual Meeting and published simultaneously in Arthritis & Rheumatology.
At 36 weeks, patients receiving the combination therapy met the primary endpoint and all key secondary endpoints, showing statistically significant superiority over Taltz monotherapy. “A greater reduction in PsA disease activity (ACR50) was seen as early as Week 4 in the Taltz and Zepbound treatment arm (as compared to Taltz alone), before clinically meaningful weight loss was observed,” the study reported.
The combination also drove a significant rise in patients achieving Minimal Disease Activity (MDA)—a high benchmark for PsA treatment success—while improving fatigue, physical function, mental health-related quality of life, cardiometabolic health, and inflammation.
Additional benefits included nominally significant improvements in BMI, body weight, systolic blood pressure, glucose, HbA1c, triglycerides, and total cholesterol versus Taltz alone.
“In TOGETHER-PsA, treating PsA and obesity concurrently with Taltz and Zepbound yielded meaningful, broad improvements in PsA disease activity, inflammation, and outcomes that can impact patients' daily lives, such as fatigue, disability and quality of life,” said Philip Mease, Director of Rheumatology Research at Swedish Medical Center and Clinical Professor at the University of Washington, Seattle.
“These two chronic inflammatory diseases are often intertwined, with patients managing a substantial disease burden that remains difficult to treat. This clinical evidence supports a potential transformation in how we approach treatment for this patient population.”
The trial targeted a patient population with a high disease burden: an average BMI of 37.6 kg/m², elevated PsA activity, impaired physical function, and over 60% having prior experience with advanced therapies. About 65% of adults with PsA in the US also have obesity or overweight with at least one additional weight-related comorbidity, highlighting the urgent need for integrated treatment strategies.
