Taltz plus Zepbound shows broader biomarker effects in psoriasis and obesity study

Eli Lilly has reported new exploratory findings from the Phase IIIb TOGETHER-PsO study suggesting that combined treatment with Taltz and Zepbound produces broader biological changes than Taltz alone in adults living with plaque psoriasis and obesity or overweight.

The findings were presented at the 2026 Fall Clinical Dermatology Conference in Las Vegas.

TOGETHER-PsO is evaluating Taltz, also known as ixekizumab, together with Zepbound, or tirzepatide, in adults with moderate to severe plaque psoriasis and obesity or overweight with at least one additional weight related condition.

The latest prespecified analysis focused on circulating proteins and gene expression in blood to investigate potential links between immune and metabolic biology.

At week 36, biomarker changes seen in both treatment groups were consistent with the known biological effects of Taltz and Zepbound when used in their approved indications.

However, the combination produced broader changes across psoriasis related, immune and metabolic biomarkers compared with Taltz alone.

Differences were already apparent by week 12.

By week 36, treatment with Taltz and Zepbound was associated with changes in 482 differentially expressed proteins compared with 140 with Taltz monotherapy.

The combination also affected 467 differentially expressed genes compared with 16 genes in the Taltz only group.

Lilly said the combined treatment was also associated with greater reductions in inflammatory immune activity.

This included changes linked to neutrophils, immune cells involved in inflammatory processes.

A subset of neutrophil associated biomarkers was found to mediate part of the additional improvement in Psoriasis Area and Severity Index response observed with the combination compared with Taltz alone.

Mark Genovese, MD, Senior Vice President of Lilly Immunology Development, said psoriasis and obesity can create overlapping health burdens but are often treated separately.

He said the broader biomarker changes seen with the combination may help improve understanding of the relationship between metabolic and immune pathways in patients living with both conditions.

James G. Krueger, MD, PhD, Professor and Laboratory Head at The Rockefeller University, said the findings provide additional evidence of biological connections between psoriasis and obesity.

He said differences in inflammatory pathways among patients receiving the combination highlight immunometabolic health as an area for further research.

The biomarker findings build on previously reported clinical results from TOGETHER-PsO.

Earlier data showed that Taltz and Zepbound together produced greater skin clearance and clinically meaningful weight reduction at the week 36 primary endpoint compared with Taltz alone.

Those improvements were maintained or further increased through week 52.

Safety findings remained consistent with the established profiles of each medicine.

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Related Topics and Keywords

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