Dive Brief:

• An experimental protein-degrading drug from Kymera Therapeutics appeared safe and able to affect its intended target in an early-stage clinical trial, leading shares in the biotechnology company to climb by nearly 50%.
• Data from a Phase 1 study in healthy volunteers showed that all dose levels of Kymera’s therapy, KT-621, either completely or nearly completely degraded a key protein in the blood and skin that’s linked to inflammation. The drug also had a safety profile “undifferentiated from placebo,” with no serious adverse events observed so far, Kymera said.  
• KT-621 is currently in a Phase 1b trial in patients with a moderate to severe form of eczema. Kymera expects to report results by the end of the year, and then begin mid-stage trials in atopic dermatitis and asthma.  

Dive Insight:

Kymera is built on a type of technology called targeted protein degradation, which uses cells’ internal trash disposal systems to destroy troublesome proteins. The approach is seen as a way to get after proteins tough to reach by traditional drugmaking methods, and Kymera aims to use it to develop oral medications with biologic-like potency.   

With KT-621, for instance, Kymera aims to develop a pill as powerful as Dupixent, which is approved to treat seven inflammatory conditions and is one of the world’s best-selling drugs. Dupixent is an injectible medicine that inhibits a pair of inflammatory cytokines called IL-4 and IL-13. Kymera’s drug, by comparison, degrades a transcription factor called STAT6 that’s in the same molecular signaling pathway.

STAT6 has long been pursued of drug companies, as it’s a central player in the so-called Type 2 inflammation implicated in many immune diseases. But it’s been difficult to develop a small molecule that can both latch onto STAT6 and block its activity, said Nello Mainolfi, Kymera’s CEO, in an interview. 

Kymera claims that targeted protein degradation may be a better solution. KT-621 is designed to grab STAT6 and drag it to the proteasome, the cell’s protein-shredder, for destruction. The results Monday suggest it’s working as intended, as STAT6 was completely degraded in all volunteers who received multiple doses. Markers of an effect on Type 2 inflammation were also “comparable or superior to” published results on Dupixent, the company said. 

“We’ve rendered STAT6 a drug target,” Mainolfi said.

In a research note, Leerink Partners analyst Faisal Khurshid called the findings a “best-case scenario” with “no red flags on safety.” The results provide “important validation for the target,” Khurshid wrote, though he cautioned that the “clinical relevance” of degrading STAT6 in the skin is unclear.

Kymera anticipates starting a Phase 2b trial in atopic dermatitis by the end of 2025 and following with a mid-stage study in asthma in the first quarter of 2026. The company is also working on a second drug that Mainolfi calls “complementary” to its STAT6 program and that’ll be tested on immune diseases like lupus and rheumatoid arthritis. An application to start clinical testing should come soon. 

Nurix Therapeutics, another biotech focused on protein degradation, is also developing a STAT6 drug. On Monday, Sanofi exercised an option to license it under an existing partnership. 

Kymera shares climbed 46%, to more than $43 apiece, in Monday trading.