Kymera CEO Says 'We Probably Taught The Market Too Much' With KT621, So KT579 Details Stay Private
Kymera is holding back dose-response data on its lupus drug KT579 while reporting more than 90% IRF5 degradation in its top five dose cohorts.
Kymera Therapeutics, a clinical-stage biotech building oral drugs that destroy disease-causing proteins, is deliberately limiting what it shows on KT579, its lupus drug, CEO Nello Mainolfi said on the company's third-quarter earnings call Thursday. His reason: "We feel with KT621, we probably taught the market too much."
Why the dose data stays hidden
Asked by a Barclays analyst how biomarker response varied across dose cohorts, Mainolfi said Kymera wants to "retain some competitive advantage over the fierce competition that we've seen increasing over the past few years." He said he does not want to reveal the level of IRF5 degradation that produces the best biomarker changes.
Chief Medical Officer Terrence Rooney had flagged the approach in prepared remarks, saying that "primarily for competitive reasons" some slides carried only limited data. Kymera showed degradation only for the multiple-dose cohorts, which Rooney said most closely mirror intended clinical use.
Mainolfi added that some of the assays the team built in-house are not being shared because they are inventions the company wants to protect.
What the healthy-volunteer data showed
Rooney said the top five dose cohorts all reached median IRF5 degradation above 90%, with degradation saturating at dose level three, where blood degradation hit 94%. He said skin showed comparable reductions.
In the multiple-dose cohorts, TLR7/8-stimulated interferon beta fell by a median of 98%. Rooney said KT579 was well tolerated, with a safety profile comparable to placebo and no serious adverse events.
Asked which dose would move forward, Mainolfi said Kymera will "continue the mystery around the dose for now." He noted that preclinical work showed 85% degradation is enough to drive the biology, and every dose exceeded that.
Lupus study and cash runway
Kymera plans to begin a Phase 1b lupus study, LUMORA, by early next year. It will enroll about 30 patients with lupus, randomized 2 to 1 to KT579 or placebo for 16 weeks, and the company said the study is not powered for clinical endpoints.
Chief Financial Officer Bruce Jacobs said third-quarter R&D expense was $128.5 million and the company ended September with about $1.6 billion in cash and investments, a runway into 2029. There was no collaboration revenue in the quarter, and none is expected for the rest of 2026.
Separately, Kymera expects Phase 2b data for KT621 in atopic dermatitis by year-end and enters a quiet period next week.
Phase 2b atopic dermatitis data for KT621 are due by year-end, and Kymera will not comment on its STAT6 program until they arrive.
Sources
- Kymera Therapeutics to Announce KT-579 Phase 1 Healthy Volunteer Trial Results on October 29, 2026 — Yahoo Finance
- Kymera Therapeutics (KYMR) Nears Earnings With KT 621 In Focus, Is The Stock Still Cheap? — Yahoo Finance
- Kymera Therapeutics Announces Third Quarter 2026 Financial — rss.globenewswire.com
- Kymera Therapeutics to Announce KT-579 Phase 1 Healthy — globenewswire.com
