KT-621 in Atopic Dermatitis: What Early EASI and Pruritus Data Show

"Our hope is if we have an oral drug that eventually is able to show substantial activity and safety potentially comparable to dupilumab, but now it's an oral drug, this could make the drug available to many more patients,” said Jared Gollob, MD, in a recent interview.

Gollob, chief medical officer at Kymera Therapeutics, described KT-621’s early signs of activity from initial dosing, the rationale and structure of the ongoing BroADen2 phase 2b study (NCT07217015), and how an effective oral option could expand systemic therapy uptake in a population currently underserved by injectable biologics.

Results of the phase 1b BroADen study (NCT06945458) were presented at the recent 2026 Society for Investigative Dermatology Annual Meeting. KT-621 targets STAT6, an intracellular transcription factor required for IL-4 and IL-13 signaling.^1,2

In a previous interview, Gollob described how KT-621 achieved effects on itch and skin lesion burden comparable to dupilumab (Dupixent; Sanofi and Regeneron) in the phase 1b BroADen study.

Early Target Degradation and Clinical Response

Gollob described rapid target engagement as a key feature of KT-621, noting full degradation of STAT6 in blood is observed within 4 to 8 hours of even the first dose. Improvements in EASI score and pruritus were detectable as early as 1 week after treatment initiation.

"We know when we give a dose of our drug, even after the first dose, within 4 to 8 hours after that dose, we get full degradation of our target in the blood," Gollob said. "To then be able to show on top of that we're seeing effects on itch and on skin lesion burden as early as 1 to 2 weeks following the initiation of therapy just tells us patients can start to see and feel improvement relatively soon after treatment."

He also noted responses did not plateau over the initial 4-week observation window, with deepening efficacy from week 1 through week 4, suggesting continued improvement with longer treatment duration.

Phase 2b Study Design and Objectives

The ongoing phase 2b study is a 16-week, randomized, double-blind, placebo-controlled dose range-finding trial evaluating 3 dose levels of KT-621 against placebo. Primary end points include EASI score and its variants, pruritus, disease severity, quality of life, and sleep. Gollob said the study aims to identify 1 dose to carry into subsequent phase 3 registration studies.

"What's important for us is number 1, to show our drug has a significant impact compared to placebo, and number 2, looking across these different doses and looking at safety and efficacy to ultimately choose 1 dose among those 3 to bring into our subsequent phase 3 study," Gollob said.

An open-label extension study will follow participants for an additional year beyond the 16-week treatment period.

Oral Administration as a Path to Broader Systemic Therapy Use

Gollob pointed to a significant gap in current AD care: only approximately 15% of patients with moderate to severe AD who are eligible for biologics such as dupilumab actually receive them, with reluctance around injectable therapy cited as a contributing factor. He framed an effective oral agent as a potential solution to low systemic therapy uptake.

"There are millions of such patients who are not taking systemic therapy just because they're hesitant to go on injectables,” Gollob said.

He said the broader goal is to reach patients who are deterred by injectables but stand to benefit meaningfully from a therapy targeting the root cause of their inflammation.

References

1. Kymera Therapeutics announces presentations on KT-621, a first-in-class, oral STAT6 degrader, at the Society for Investigative Dermatology and American Thoracic Society Congresses. News release. Kymera Therapeutics. May 15, 2026. Accessed June 11, 2026. https://investors.kymeratx.com/news-releases/news-release-details/kymera-therapeutics-announces-presentations-kt-621-first-class
2. Kymera Therapeutics presents KT-621 BroADen data in late-breaking research session at the American Academy of Dermatology (AAD) Annual Meeting. News release. Kymera Therapeutics. March 28, 2026. Accessed June 11, 2026. https://investors.kymeratx.com/news-releases/news-release-details/kymera-therapeutics-presents-kt-621-broaden-data-late-breaking