Eli Lilly said new 52-week data show that combining its psoriasis drug Taltz (ixekizumab) with obesity medicine Zepbound (tirzepatide) produced sustained or further improvements in adults with psoriatic disease and obesity.

 

The results, from two Phase 3b trials known as TOGETHER-PsO and TOGETHER-PsA, build on statistically superior outcomes reported at Week 36, when the combination outperformed Taltz alone on key disease and metabolic measures.

 

At one year, the benefits continued — including improvements in skin clearance, psoriatic arthritis activity, weight loss and markers of systemic inflammation. Lilly said no new safety concerns were identified.

 

"The primary results from these first-of-their-kind studies were already remarkable, showing that Taltz and Zepbound used together improved outcomes for patients with psoriatic disease and obesity. What's especially exciting now is seeing those improvements further deepened or sustained at one year, across disease activity, inflammation and metabolic outcomes," said Mark Genovese, senior vice president of Lilly Immunology development. 

 

"People living with the cumulative burden of psoriatic disease and obesity are too often treated with separate, disconnected approaches. These data showing durable results across multiple measures support a comprehensive approach that can potentially address immunometabolic health for patients living with these chronic diseases."

 

In the psoriasis trial, 30.6% of patients receiving Taltz plus Zepbound achieved both complete skin clearance, measured by PASI 100, and at least 10% weight loss at Week 52, compared with 4.4% receiving Taltz alone.

 

In the psoriatic arthritis trial, 39.2% of patients on the combination achieved at least a 50% reduction in disease activity, measured by ACR50, along with at least 10% weight loss. Only 1.7% of patients receiving Taltz alone reached both targets.

 

Complete skin clearance was maintained in the psoriasis study, with 40.5% of patients receiving the combination achieving PASI 100 at Week 52, compared with 29.1% on Taltz alone.

 

The psoriatic arthritis results also strengthened over time. At Week 52, 43.7% of patients receiving Taltz and Zepbound achieved ACR50, versus 15.7% receiving Taltz alone.

 

Lilly said the ACR50 benefit emerged as early as Week 4, before clinically meaningful weight loss was observed.

 

"Psoriatic disease is often accompanied by obesity or overweight, which can make treatment goals related to the skin and joints harder to reach," said Joseph F. Merola, President of the Rheumatology-Dermatology Society. 

 

"In psoriatic arthritis, the greater improvements in disease activity seen with Taltz and Zepbound in the first month, before clinically meaningful weight loss occurred, continued through one year. In psoriasis, the durability of complete skin clearance at one year represents real, lasting progress for patients. Paired with continued metabolic improvements, these findings show what may be possible when treating psoriatic disease and obesity concurrently."

 

Beyond skin, joint and weight outcomes, the combination was associated with deeper improvements in systemic inflammation over the course of the trials, as measured by high-sensitivity C-reactive protein.

 

Measures including body mass index, blood pressure, glucose, HbA1c, triglycerides and total cholesterol were also sustained or further improved with Taltz and Zepbound compared with Taltz alone.

 

The findings come as researchers increasingly examine the overlap between immune-driven diseases and metabolic dysfunction. Lilly said approximately 61% of people with psoriasis and 65% of people with psoriatic arthritis in the U.S. also have obesity or overweight with at least one weight-related comorbidity.

 

The trials enrolled patients with a BMI of at least 30 kg/m², or between 27 and less than 30 kg/m² with at least one weight-related comorbidity.

 

Two trials, 545 patients.

 

TOGETHER-PsO enrolled 274 adults with moderate-to-severe plaque psoriasis, while TOGETHER-PsA enrolled 271 adults with active psoriatic arthritis.

 

Participants were randomly assigned to receive either Taltz alone or Taltz together with Zepbound. Both treatments were administered by injection, alongside counseling on a reduced-calorie diet and increased physical activity.

 

The Week 52 analyses were pre-specified exploratory objectives and were not controlled for multiplicity, meaning comparisons between timepoints are descriptive rather than statistically tested for multiple comparisons.

 

Adverse events in patients receiving both medicines were generally mild to moderate and consistent with the known safety profiles of the individual drugs. Reported adverse events occurring in at least 5% of participants included nausea, diarrhea, constipation, injection-site reactions, vomiting, dizziness and headache.

 

Lilly said detailed 52-week results will be presented at future medical meetings and published in peer-reviewed journals.

 

The company describes the studies as first-of-their-kind investigations into the potential of simultaneously targeting psoriatic disease and obesity — an approach it says could broaden the focus from treating individual conditions to addressing interconnected aspects of immunometabolic health.