Weight-loss drug Zepbound may help treat psoriatic arthritis, trial shows

A Phase 3b trial reported that adding tirzepatide (the active ingredient in Zepbound) to ixekizumab reduced psoriatic arthritis symptoms and produced weight loss in overweight or obese participants.

Eli Lilly released Phase 3b trial results reporting that tirzepatide, the active ingredient in Zepbound, improved outcomes when added to ixekizumab for people with psoriatic arthritis who were overweight or obese. The company tested the combination in the TOGETHER-PsA trial against ixekizumab alone. Psoriatic arthritis is a chronic inflammatory condition linked to psoriasis, and obesity has been associated with higher risk and reduced treatment effectiveness. Researchers have proposed that addressing obesity alongside inflammation might change outcomes. Key findings: - The TOGETHER-PsA trial included 271 overweight or obese adults with active psoriatic arthritis. - Participants were randomized to receive ixekizumab (Taltz) alone or ixekizumab plus tirzepatide (Zepbound). - By week 36, 33.5% of the combination group achieved a ≥50% reduction in arthritis symptoms versus 20.4% in the ixekizumab-only group. - About a third of people in the combination group had both a ≥50% symptom reduction and at least 10% weight loss, compared with 0.8% in the ixekizumab-only group. - The company reported that participants taking tirzepatide also lost substantial weight. - Eli Lilly described this as the first controlled trial to explicitly test treating obesity alongside psoriatic arthritis. Summary: These results show a measurable difference in symptom reduction and weight loss when tirzepatide was added to ixekizumab in this trial. The findings will undergo peer review and regulatory evaluation. Lilly plans to release results later this year from a related trial testing the combination in people with moderate-to-severe plaque psoriasis and obesity. Undetermined at this time.