KT-621 Oral STAT6 Degrader Success: Kymera's New Atopic Dermatitis Drug Poses Dupixent Challenge
- Dec 9
- 2 min read
Kymera Therapeutics recently announced highly positive results from its Phase 1b BroADen clinical trial of KT-621, a groundbreaking, first-in-class oral small molecule intended to treat moderate to severe Atopic Dermatitis (AD). The results, released on December 8, 2025, show a level of clinical activity and biomarker modulation that positions KT-621 as a serious Dupixent Challenge, potentially transforming treatment paradigms for Type 2 inflammatory diseases.
KT-621 is unique because it is an Oral STAT6 Degrader, targeting the specific transcription factor (STAT6) responsible for IL-4/IL-13 signaling, which centrally drives Type 2 inflammation. Instead of merely blocking cytokines or their receptors, this oral drug uses targeted protein degradation to remove STAT6 itself from both the blood and skin, aiming to shut down all related signaling pathways. This mechanism allows the drug to potentially deliver the depth of pathway suppression normally associated only with injectable biologics.
The 22-patient BroADen trial successfully demonstrated profound STAT6 degradation, achieving median reductions of 94% in skin and 98% in blood across the tested dose groups. This resulted in robust clinical activity after just four weeks (28 days) of once-daily dosing. Crucially, the mean Eczema Area and Severity Index (EASI) score reduction reached 63% across all patients, demonstrating a rapid onset of action. Furthermore, patients saw meaningful relief from itching, with a mean 40% reduction in peak pruritus.
Company CEO Nello Mainolfi noted that these results were "in line with, or in some cases numerically exceeded," published data for dupilumab (marketed as Dupixent) at the four-week mark. The drug also strongly reduced disease-relevant Type 2 biomarkers, including a median 74% reduction in TARC levels in patients comparable to those in dupilumab studies, and achieved significant suppression of IL-31, a cytokine linked to pruritus.
A particularly noteworthy element of the data is the drug’s potential breadth and favorable safety profile. KT-621 was well-tolerated, with no serious adverse events, no treatment-related adverse events, and no reported cases of conjunctivitis. For patients with comorbid asthma, a median 56% reduction in fractional exhaled nitric oxide (FeNO), a Type 2 lung inflammation biomarker, was observed, supporting the drug’s systemic mechanism and potential utility across Type 2-driven diseases. Additionally, patients with allergic rhinitis also experienced meaningful symptom and quality-of-life benefits.
As Kymera Therapeutics progresses, the results validate the need for new oral therapies that offer convenience while addressing the underlying biology of AD. The company is currently advancing the BROADEN2 Phase 2b trial in moderate to severe AD, with data anticipated by mid-2027, and plans to start the BREADTH Phase 2b trial in asthma in early 2026. These next steps aim to accelerate the development of this promising Oral STAT6 Degrader and solidify its role as a potential front-line oral agent in the Type 2 inflammatory disease space.
🔖 Sources
Keywords: Kymera's New Atopic Dermatitis Drug
Kymera's New Atopic Dermatitis Drug
Four years ago, my husband was diagnosed with IPF (Idiopathic Pulmonary Fibrosis), a moment that changed our lives significantly. For more than two years, he followed his prescribed medications and attended regular medical checkups. Despite this, his symptoms persisted, and we remained concerned about his overall health. He struggled with low energy, frequent discomfort, and the emotional stress that came with ongoing uncertainty.In search of additional support, we decided last year to explore a herbal treatment program offered by NaturePath Herbal Clinic. We approached it cautiously and without high expectations. Over time, however, we began to notice encouraging changes. His tiredness eased, his digestion became more stable, and he appeared stronger and more at ease overall. Little by little, his…