Eli Lilly and Company has reported positive top line data from the TOGETHER-PsO Phase IIIb clinical trial, which evaluated the combination of Taltz (ixekizumab) and Zepbound (tirzepatide) versus Taltz alone in adults diagnosed with moderate to severe plaque psoriasis and obesity or who are overweight.
The study also included participants with at least one additional weight-related comorbidity.
The multi-centre, assessor-blinded, randomised, open-label, 52-week trial results demonstrated that the combination therapy achieved superior skin clearance and weight loss at 36 weeks compared to Taltz monotherapy.
It enrolled 274 adults who were assigned in equal numbers to receive either subcutaneous Taltz alone or in combination with Zepbound.
All participants received dietary advice and guidance on increasing physical activity. The primary endpoint was the proportion of subjects achieving both complete skin clearance - Psoriasis Area Severity Index (PASI) 100 and a minimum 10% weight reduction at week 36.
Results showed that 27.1% of patients treated with both Taltz and Zepbound achieved PASI 100 and at least 10% weight loss, compared to 5.8% for Taltz monotherapy.
For the key secondary endpoint, 40.6% of the combination arm reached PASI 100 compared to 29% using only Taltz, representing a 40% relative increase in complete skin clearance rate when both medicines were used.
Lilly executive vice-president and immunology president Adrienne Brown said: “Psoriasis and obesity can profoundly impact how people feel, how they are seen, and how they live.
"For people living at the intersection of these chronic inflammatory diseases, these PASI 100 results represent far more than a clinical milestone—they demonstrate what becomes possible when we address both simultaneously.
“Taltz has a decade of proven efficacy in psoriasis, and the superior outcomes achieved when Zepbound was used concomitantly for obesity signal a potential advance in treatment for patients who deserve nothing less.”
Adverse events were mainly mild to moderate for those receiving both treatments.
The most frequently reported events were diarrhoea, nausea, injection site reactions, constipation, vomiting, dosing error, and dizziness with combination therapy. Adverse events mainly associated with monotherapy included injection site reactions, dosing error, and nasopharyngitis.
Taltz is a monoclonal antibody targeting interleukin-17A (IL-17A) cytokine while Zepbound is a dual glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) receptor agonist for obesity management.
This month, Lilly’s oral targeted cancer therapy, Retevmo, demonstrated benefit as an adjunctive therapy in a Phase III trial in patients with early-stage (II-IIIA) rearranged during transfection (RET) fusion-positive non-small cell lung cancer (NSCLC).
