Obesity Drug Wegovy Shows Unexpected Benefit: Clearer Skin in Psoriasis Patients

Clinical results show that GLP-1 class obesity treatments combined with existing psoriasis medications produce more significant improvements in skin symptoms.

Eli Lilly recently announced results from a Phase 3b open-label clinical trial involving adults with moderate-to-severe plaque psoriasis who also had obesity or were overweight.

The study compared a group receiving both the autoimmune disease treatment Taltz (ixekizumab) and the obesity drug Zepbound (tirzepatide) against a group receiving Taltz alone. Zepbound contains tirzepatide, the same active ingredient as the diabetes treatment Mounjaro.

After 36 weeks of treatment, the combination therapy group met both skin improvement and weight loss targets. Among patients receiving combination therapy, 27.1% achieved both PASI 100 (complete skin clearance) and at least 10% weight loss simultaneously. This significantly exceeded the 5.8% rate in the Taltz-only group.

Secondary endpoints also showed notable differences. The PASI 100 achievement rate was 40.6% in the combination group, approximately 40% higher than the 29.0% in the monotherapy group. Given previous research showing that higher body weight correlates with lower chances of complete skin clearance, experts consider these figures meaningful.

The trial included patients with severe obesity, averaging BMI above 39 kg/m². This is approximately 9-10 kg/m² higher than average BMI levels in previous Phase 3 trials for psoriasis biologics. Most participants had extensive skin lesions, with an average of about one-quarter of their body surface affected. Ninety-seven percent had lesions in areas significantly impacting quality of life, including the face, scalp, and genitals.

The company noted that approximately 61% of psoriasis patients in the United States also have obesity or are overweight with at least one weight-related comorbidity. Both conditions are chronic inflammatory diseases, underscoring the need for simultaneous treatment strategies.

"Psoriasis and obesity are chronic inflammatory conditions that affect every aspect of a patient's life," said Adrienne Brown, President of Lilly Immunology. "The PASI 100 results from treating both conditions simultaneously demonstrate therapeutic potential."

Adverse events were generally mild to moderate. Events occurring in 5% or more of the combination group included nausea, diarrhea, constipation, injection site reactions, medication errors, vomiting, and dizziness. The monotherapy group reported injection site reactions, medication errors, and nasopharyngitis.

"Psoriasis and obesity share common inflammatory pathways but have traditionally been treated separately in clinical practice," said Dr. Mark Lebwohl, Professor of Dermatology at Mount Sinai's Icahn School of Medicine and lead investigator of the trial. "The PASI 100 results are particularly significant in patients with high BMI who are typically difficult to treat."

Zepbound is an FDA-approved obesity treatment based on dual GIP (glucose-dependent insulinotropic polypeptide) and GLP-1 receptor agonist technology. The company plans to publish the clinical results in an academic journal and discuss them with regulatory authorities.