Lilly Combo Therapy Shows Promise as New Standard for Psoriatic Arthritis With Obesity

Eli Lilly’s weight-loss drug Zepbound (tirzepatide), when used alongside its IL-17 inhibitor Taltz (ixekizumab), has demonstrated superior efficacy over Taltz alone in patients with psoriatic arthritis (PsA) and obesity, according to results from a Phase IIIb trial.

In the TOGETHER-PsA study, 31.7% of patients treated with the Zepbound–Taltz combination achieved both a 50% improvement in PsA disease activity (ACR50) and at least 10% body weight reduction, compared with just 0.8% in the Taltz monotherapy arm. The combination also improved overall PsA outcomes, with more patients reaching ACR50 versus Taltz alone.

Safety findings were consistent with the known profiles of both drugs, with mostly mild gastrointestinal effects and injection-site reactions reported.

Given the high prevalence of obesity among PsA patients, the results suggest the combination could represent a new standard of care while also helping Lilly extend Taltz’s clinical relevance ahead of its upcoming patent expiry.

11-01-2026