TLDR
- Taltz + Zepbound combo proves effective for psoriasis, obesity, but Eli Lilly stock drops.
- Eli Lilly’s psoriasis-obesity combo therapy shows promise; stock falls.
- Taltz + Zepbound combo hits psoriasis + obesity targets, but stock dips.
- Eli Lilly’s psoriasis treatment combo shows results; stock sees decline.
- Psoriasis & obesity trial success, yet Eli Lilly stock drops post-results.
Eli Lilly and Company (LLY) shares fell to $1,018.92, down $17.13 or 1.65%, as of 11:19 AM EST. The decline followed the announcement of Phase 3b TOGETHER-PsO trial results. The trial tested Taltz and Zepbound combination versus Taltz alone in patients with psoriasis and obesity.
Eli Lilly and Company, LLY
The study enrolled 274 adults with moderate-to-severe plaque psoriasis and overweight or obesity with at least one weight-related comorbidity. Patients received Taltz plus Zepbound or Taltz monotherapy over 36 weeks. The trial aimed to assess skin clearance and weight loss outcomes simultaneously.
The combination therapy met the primary endpoint, showing a significant advantage over Taltz alone. About 27.1% of participants achieved complete skin clearance and at least 10% weight loss. Taltz alone delivered the same outcome in only 5.8% of patients.
Combination Therapy Shows Significant Clinical Benefits
Taltz plus Zepbound also achieved a 40% higher PASI 100 response compared with Taltz alone. The secondary endpoints demonstrated meaningful improvement in skin symptoms and weight management. These results indicate that treating obesity alongside psoriasis enhances therapeutic outcomes.
The study population had an average BMI of over 39 kg/m², higher than previous psoriasis trials. Most participants had extensive skin involvement, affecting roughly 25% of their body surface area. Nearly all patients had psoriasis in high-impact areas such as the face, scalp, or genitals.
Adverse events were generally mild to moderate, consistent with known drug safety profiles. Common side effects included nausea, diarrhea, constipation, vomiting, dizziness, and injection site reactions. Taltz monotherapy mostly caused injection site reactions, dosing errors, and nasopharyngitis.
Market Context and Drug Significance
Psoriasis affects millions globally, with about 61% of U.S. patients also overweight or obese. The trial highlights the need for integrated treatment approaches targeting both skin and metabolic conditions. Eli Lilly’s Taltz and Zepbound combination offers the first evidence-based therapy for this dual burden.
Zepbound is a dual GIP and GLP-1 receptor agonist approved for obesity management. Taltz, a selective IL-17A inhibitor, has over a decade of proven efficacy in psoriasis treatment. Together, the drugs provide a comprehensive option for patients with overlapping inflammatory and metabolic conditions.
The TOGETHER-PsO findings reinforce the importance of addressing comorbid obesity in psoriasis care. Positive results may influence clinical practice and treatment guidelines moving forward. Despite the trial success, Eli Lilly stock experienced a short-term decline, reflecting market volatility.





