Kymera Therapeutics Announces First Patient Dosed in BROADEN2 Phase 2b Atopic Dermatitis Clinical Trial of KT-621, a First-in-Class, Oral STAT6 Degrader

Rhea-AI Summary

Kymera Therapeutics (NASDAQ: KYMR) announced dosing has begun in the BROADEN2 Phase 2b trial of KT-621, an oral STAT6 degrader for moderate to severe atopic dermatitis (AD). The randomized, double-blind, placebo-controlled, dose-ranging study will enroll ~200 patients treated over 16 weeks with three dose arms and a primary endpoint of percent change in EASI score at Week 16.

The company expects BROADEN2 data by mid-2027, completed dosing in the Phase 1b BroADen trial with data due December 2025, and plans to initiate the BREADTH Phase 2b asthma trial in 1Q 2026. Patients may enter a 52-week open-label extension after the trial.

Positive

• Initiated dosing in BROADEN2 Phase 2b for KT-621
• BROADEN2 designed with ~200 patients and three dose arms over 16 weeks
• Company expects BROADEN2 readout by mid-2027
• BREADTH Phase 2b asthma trial on track to start in 1Q 2026
• Completed dosing in Phase 1b BroADen with data due December 2025

Negative

• No efficacy or safety readouts yet; primary BROADEN2 readout expected mid-2027
• Phase 2b BROADEN2 enrollment ~200 patients may limit power for rare events

Insights

Clinical Development Strategist

Kymera advanced KT-621 into a randomized Phase 2b AD trial and plans parallel Phase 2b asthma initiation, with readouts phased through mid-2027.

The trial design enrolls ~200 patients in a randomized, double-blind, placebo-controlled, dose-ranging study over 16 weeks, with a clear primary endpoint of percent change in EASI at Week 16 and common secondary outcomes including EASI-50, EASI-75, vIGA 0–1, and a ≥4‑point Peak Pruritus NRS improvement. The company also completed Phase 1b dosing with data due in December 2025, and plans a parallel Phase 2b in asthma targeted to start in Q1 2026, which can inform dose selection for planned registrational studies.

Key dependencies and risks include demonstration of meaningful efficacy on the prespecified EASI endpoint at Week 16 and an acceptable safety/tolerability profile across doses; without reported results, clinical and regulatory risk remain. Watch for the Phase 1b data in December 2025 for early human pharmacology and safety signals, the BREADTH trial initiation in Q1 2026, and the BROADEN2 topline readout by mid-2027 as critical milestones for program de‑risking within an 18–30 month horizon.

Data from the KT-621 BROADEN2 Phase 2b AD patient trial expected to be reported by mid-2027

KT-621 BREADTH Phase 2b trial in asthma on track to initiate in 1Q26

Completed dosing in KT-621 BroADen Phase 1b AD trial with data to be reported in December 2025

WATERTOWN, Mass., Nov. 25, 2025 (GLOBE NEWSWIRE) -- Kymera Therapeutics, Inc. (NASDAQ: KYMR), a clinical-stage biopharmaceutical company advancing a new class of oral small molecule degrader medicines for immunological diseases, today announced that it recently initiated dosing in its BROADEN2 Phase 2b clinical trial evaluating KT-621, an oral, highly selective, potent degrader of STAT6, in patients with moderate to severe atopic dermatitis (AD). The Company expects to report data from the BROADEN2 trial by mid-2027. Additionally, the Company previously announced it completed dosing in the KT-621 BroADen Phase 1b trial in AD, with data to be reported in December 2025.

“The initiation of dosing in the BROADEN2 trial represents a major step in the advancement of our first-in-industry STAT6 degrader program and reflects the continued progress of our translational strategy, building a robust foundation for future development across multiple Type 2 diseases,” Jared Gollob, MD, Chief Medical Officer, Kymera Therapeutics. “With additional key clinical milestones on the horizon – including the BroADen Phase 1b data in December and BREADTH Phase 2b asthma trial launch in the first quarter of 2026 – we remain focused on realizing the promise of KT-621 as a potential first-in-class oral treatment option for millions of patients living with chronic immunological diseases.”

The KT-621 BROADEN2 Phase 2b trial is a randomized, double-blind, placebo-controlled, multicenter, dose-ranging study evaluating the efficacy, safety and tolerability of three doses of KT-621 in approximately 200 patients with moderate to severe AD over 16 weeks. Baseline eligibility criteria include an Eczema Area and Severity Index (EASI) score of at least 16, at least 10% of body surface area affected, and an average weekly Pruritis Numerical Rating Scale (NRS) score of at least 4. Patients from the study have the opportunity to participate in a 52-week open label extension period after completion of the trial. The primary endpoint is the percent change from baseline in EASI score at Week 16. Secondary endpoints will evaluate a range of additional safety and efficacy measures, including the proportion of patients achieving EASI-50, EASI-75, a validated Investigator Global Assessment (vIGA) score of 0 to 1, and at least a 4-point improvement in Peak Pruritus NRS. More information on the BROADEN2 study can be found on clinicaltrials.gov (NCT07217015).

The Company is on track to initiate BREADTH, a Phase 2b trial in moderate to severe asthma patients, in the first quarter of 2026. The parallel Phase 2b studies in AD and asthma are expected to accelerate KT-621 development and enable dose selection for subsequent parallel Phase 3 registrational studies across multiple Type 2 dermatology, gastroenterology and respiratory indications.

About KT-621
KT-621 is an investigational, first-in-class, once daily, oral degrader of STAT6, the specific transcription factor responsible for IL-4/IL-13 signaling and the central driver of Type 2 inflammation. In the Phase 1 clinical study in healthy volunteers, KT-621 demonstrated complete STAT6 degradation in blood and skin following low daily oral doses, reductions of multiple disease relevant Type 2 biomarkers, and a safety profile undifferentiated from placebo. KT-621, the first STAT6-directed drug to enter clinical evaluation, has the potential to transform treatment paradigms for more than 130 million patients around the world, including children and adults, suffering from Type 2 diseases such as atopic dermatitis (AD), asthma, bullous pemphigoid (BP), chronic obstructive pulmonary disease (COPD), chronic rhinosinusitis with nasal polyps (CRSwNP), eosinophilic esophagitis (EoE), chronic spontaneous urticaria (CSU), and prurigo nodularis (PN), among others.

About Atopic Dermatitis
Atopic dermatitis (AD) is the most common form of eczema, a chronic inflammatory disease that causes the skin to become inflamed and irritated, making it extremely pruritic (itchy). AD occurs most frequently in children but also affects adults. It can affect a patient’s quality of life and lead to additional complications, such as infections and sleep loss. While there are currently available medicines for AD, such as topical therapies and injectable biologics, there remains a significant unmet need and opportunity to improve treatment options for millions of patients. Learn more about AD on Kymera’s website.

About Kymera Therapeutics
Kymera is a clinical-stage biotechnology company pioneering the field of targeted protein degradation (TPD) to develop medicines that address critical health problems and have the potential to dramatically improve patients’ lives. Kymera is deploying TPD to address disease targets and pathways inaccessible with conventional therapeutics. Having advanced the first degrader into the clinic for immunological diseases, Kymera is focused on building an industry-leading pipeline of oral small molecule degraders to provide a new generation of convenient, highly effective therapies for patients with these conditions. Founded in 2016, Kymera has been recognized as one of Boston’s top workplaces for the past several years. For more information about our science, pipeline and people, please visit www.kymeratx.com or follow us on X or LinkedIn.

Cautionary Note Regarding Forward-Looking Statements
This press release contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995, as amended, including, without limitation, implied and express statements about our expectations regarding strategy, business plans and objectives on the development of our clinical and preclinical pipeline, including the therapeutic potential, clinical benefits and safety thereof, including for the Phase 1b data readout of KT-621 in AD patients in December 2025, the Phase 2b data readout of KT-621 in AD patients by mid-2027 and the initiation of Phase 2b studies of KT-621 in patients with asthma in the first quarter of 2026. The words "may," "might," "will," "could," "would," "should," "expect," "plan," "anticipate," "intend," "believe," "expect," "estimate," "seek," "predict," "future," "project," "potential," "continue," "target," “upcoming” and similar words or expressions are intended to identify forward-looking statements, although not all forward-looking statements contain these identifying words. Any forward-looking statements in this press release are based on management's current expectations and beliefs and are subject to a number of risks, uncertainties and important factors that may cause actual events or results to differ materially from any forward-looking statements contained in this press release, including, without limitation, that the results from the Phase 1b KT-621 trial may differ from the Phase 1a KT-621 data, that preclinical and clinical data, including the results from the Phase 1a trial of KT-621, is not predictive of, may be inconsistent with, or more favorable than, data generated from future or ongoing clinical trials of the same product candidate, uncertainties inherent in the initiation, timing and design of future clinical trials, the availability and timing of data from ongoing and future clinical trials and the results of such trials, the ability to successfully demonstrate the safety and efficacy of drug candidates, the timing and outcome of planned interactions with and submissions to regulatory authorities, the availability of funding sufficient for our operating expenses and capital expenditure requirements, the unexpected emergence of adverse events or other undesirable side effects during preclinical and clinical development, whether Kymera will be able to fund development activities and achieve development goals, and other factors. These risks and uncertainties are described in greater detail in the section entitled "Risk Factors" in the most recent Quarterly Report on Form 10-Q and in subsequent filings with the SEC. In addition, any forward-looking statements represent our views only as of today and should not be relied upon as representing our views as of any subsequent date. We explicitly disclaim any obligation to update any forward-looking statements. No representations or warranties (expressed or implied) are made about the accuracy of any such forward-looking statements.

Investor and Media Contact: 

Justine Koenigsberg
Vice President, Investor Relations
investors@kymeratx.com
media@kymeratx.com
857-285-5300 

FAQ

What is Kymera announcing about KT-621 and atopic dermatitis (KYMR) on November 25, 2025?

Kymera announced dosing initiation in the BROADEN2 Phase 2b trial of KT-621 for moderate to severe AD and expects a BROADEN2 readout by mid-2027.

How large is the BROADEN2 Phase 2b trial for KT-621 (KYMR) and what is the primary endpoint?

BROADEN2 will enroll approximately 200 patients over 16 weeks and the primary endpoint is percent change from baseline in EASI score at Week 16.

When will Kymera report KT-621 Phase 1b BroADen data and how does it affect KYMR timelines?

Kymera expects to report BroADen Phase 1b data in December 2025, preceding the BROADEN2 mid-2027 readout.

Is Kymera planning other KT-621 trials that affect KYMR investors?

Yes; Kymera plans the BREADTH Phase 2b asthma trial to initiate in 1Q 2026, running in parallel with BROADEN2 to inform dose selection.

Will BROADEN2 trial participants have long-term access to KT-621 after Week 16?

Participants completing BROADEN2 have the opportunity to join a 52-week open-label extension.