One-year data confirm the Taltz plus Zepbound combination in psoriatic disease

New 52-week data from two Eli Lilly trials show that pairing the biologic drug Taltz (ixekizumab) with Zepbound (tirzepatide) kept working through one year in adults with psoriatic disease and obesity, building on results already reported at 36 weeks.^[1]

The two Phase 3b studies, called TOGETHER-PsO and TOGETHER-PsA, enrolled people with either moderate-to-severe plaque psoriasis or active psoriatic arthritis who also had obesity or overweight plus at least one weight-related health problem.^[1] TOGETHER-PsO enrolled 274 adults, and TOGETHER-PsA enrolled 271 adults. Participants were split evenly between Taltz alone and Taltz combined with Zepbound, and all received counseling on diet and exercise.^[1] At baseline, average body mass index was 39.2 in the psoriasis trial and 37.6 in the arthritis trial.^[1]

At 52 weeks, 30.6% of people on the combination in the psoriasis trial reached the study's main goal — complete skin clearance plus at least 10% weight loss — compared with 4.4% on Taltz alone.^[1] In the arthritis trial, 39.2% of people on the combination met the primary goal of a 50% improvement in disease activity plus at least 10% weight loss, versus 1.7% on Taltz alone.^[1] Complete skin clearance was seen in 40.5% of combination patients versus 29.1% on Taltz alone, and the deeper arthritis response (ACR50) climbed to 43.7% with the combination versus 15.7% with Taltz alone, an improvement that showed up as early as week four, before meaningful weight loss had occurred.^[1] Lilly also reported that markers of inflammation and metabolic measures — including blood pressure, glucose, HbA1c, triglycerides, and cholesterol — improved further or held steady through the year.^[1] These week-52 findings were pre-specified exploratory measures without statistical correction for multiple comparisons, so they are considered supportive rather than the trials' proven primary results, according to Lilly.^[1]

Side effects with the combination were mostly mild to moderate and matched what's already known about each drug separately, including nausea, diarrhea, constipation, injection site reactions, vomiting, dizziness, and headache reported in at least 5% of participants.^[1] No new safety signals turned up over the year of follow-up.^[1]

Why it matters for patients

Lilly says roughly 61% of people with psoriasis and 65% of people with psoriatic arthritis in the U.S. also have obesity or overweight with a related health condition, and that combination is often linked to worse treatment results.^[1] These trial results suggest that adding a weight-loss drug to an existing biologic could improve disease control beyond what the biologic achieves alone, and that the effect lasted through a full year rather than fading.^[1] Dr. Joseph Merola, a dermatologist and rheumatologist involved with patient advocacy groups, said the year-long durability of complete skin clearance represents