Treating obesity improves psoriatic arthritis therapy

Obesity and psoriatic arthritis share a bidirectional and negative relationship. Obesity worsens psoriatic arthritis by increasing inflammation and reducing the effectiveness of treatments, while the inflammation itself can contribute to weight gain, creating a vicious cycle that raises cardiovascular and metabolic risks. A new clinical study has opened the door to a paradigm shift, demonstrating for the first time that addressing obesity along with joint inflammation significantly improves patient health. The pharmaceutical company Eli Lilly has announced the positive results of its Phase 3b trial, which evaluated the combined use of ixekizumab (Taltz) and tirzepatida (Mounjaro).

The research focused on adults with active psoriatic arthritis who also had obesity or overweight with associated complications. The results, obtained after 36 weeks of follow-up, reveal that the combined treatment offers superior efficacy compared to the use of the biologic in monotherapy.

31.7% of the patients who received the combined therapy achieved a 50% improvement in disease activity and, at the same time, a weight reduction of at least 10%. In contrast, only 0.8% of the patients treated only for arthritis achieved both goals. Beyond weight loss, the key data for rheumatologists is that treating obesity enhances the drug's effect against arthritis. The combined use resulted in a relative increase of 64% in the proportion of patients who improved their joint symptoms compared to monotherapy.

The relationship between both pathologies is close and concerning. It is estimated that in Spain, 71% of adults with psoriatic arthritis also have overweight or obesity. Dr. Rubén Queiro, a rheumatologist at the Central University Hospital of Asturias, explains that obesity is not just a consequence, but acts as a "chronic low-grade inflammatory state".

“The results reinforce the idea that treating excess weight is not an ancillary aspect, but a key component of the comprehensive approach,” says Dr. Queiro, emphasizing its relevance in patients where pain and inflammation make the physical activity needed to lose weight difficult. The trial included patients with a high disease burden and, moreover, more than 60% had already gone through other advanced therapies without success.