zEli Lilly has announced positive results from the landmark Phase IIIb TOGETHER-PsO trial evaluating the combination of its GLP-1/GIP receptor agonist Zepbound (tirzepatide) with the IL-17A inhibitor Taltz (ixekizumab) for the treatment of moderate-to-severe plaque psoriasis in adults with obesity or overweight. The study met its primary endpoint, with 27.1% of patients in the combination arm achieving complete skin clearance (PASI 100) and at least 10% weight loss at 36 weeks, compared to 5.8% in the ixekizumab monotherapy arm.
The trial enrolled a difficult-to-treat population with a high disease burden and a mean body mass index (BMI) exceeding 39 kg/m². The combination also met all key secondary endpoints, demonstrating superior skin clearance compared to ixekizumab alone. Adverse events were generally mild to moderate and consistent with the known safety profiles of each drug. This study represents a significant advance in addressing the interrelated burdens of psoriasis and obesity, conditions that frequently co-occur. The data will be submitted for publication and discussed with regulatory authorities.

According to PharmCube's NextBiopharm® database, Lilly is developing tirzepatide as a combination therapy in other autoimmune conditions such as psoriatic arthritis, ulcerative colitis and Crohn's disease. Click here to request a free trial for NextBiopharm®.