September 03, 2026 – INDIANAPOLIS -- Eli Lilly and Company reported that combining Taltz (ixekizumab) with Zepbound (tirzepatide) sustained or deepened efficacy at 52 weeks in patients with psoriatic disease and obesity, building on statistically superior results already seen at Week 36 versus Taltz alone.
Combination therapy nearly triples complete skin clearance response rates
In the TOGETHER-PsO trial, 30.6% of patients on the combination achieved PASI 100 plus at least 10% weight loss at Week 52, compared with 4.4% on Taltz monotherapy. Complete skin clearance alone (PASI 100) was maintained by 40.5% of combination patients versus 29.1% on monotherapy.
Psoriatic arthritis responders reach 43.7% on combined regimen
In TOGETHER-PsA, the primary outcome of ACR50 plus at least 10% weight loss was met by 39.2% of combination-arm patients versus 1.7% on Taltz alone. ACR50 response alone rose to 43.7% at Week 52 with the combination, up from 15.7% on monotherapy, with joint-disease improvements first appearing at Week 4 before meaningful weight loss occurred.
Trials enrolled nearly 550 patients with severe obesity comorbidity
TOGETHER-PsO enrolled 274 adults with moderate-to-severe plaque psoriasis and a mean baseline BMI of 39.2; TOGETHER-PsA enrolled 271 adults with active psoriatic arthritis and a mean baseline BMI of 37.6. Both Phase 3b, open-label studies randomized participants 1:1 to Taltz alone or Taltz plus Zepbound, alongside diet and exercise counseling.
Systemic inflammation markers and metabolic profiles continue to improve
High-sensitivity C-reactive protein, a marker of systemic inflammation, showed deeper reductions over time with the combination in both trials. Improvements in BMI, blood pressure, glucose, HbA1c, triglycerides and total cholesterol were sustained or further improved compared with Taltz monotherapy, though Lilly notes these were pre-specified exploratory endpoints without multiplicity control.
Safety profile remains consistent with no new signals at one year
Adverse events in the combination arm were generally mild to moderate and consistent with each drug's known profile. Events reported in at least 5% of participants across both trials included nausea, diarrhea, constipation, injection site reactions, vomiting, dizziness and headache.
Market context: roughly two-thirds of psoriatic disease patients also carry obesity
Lilly cites data showing approximately 61% of U.S. psoriasis patients and 65% of psoriatic arthritis patients also have obesity or overweight with at least one weight-related comorbidity, a population the company says is often treated through disconnected care pathways. Detailed 52-week results will be presented at future medical meetings and submitted for peer-reviewed publication.