Recludix Pharma Achieves Biologic-Comparable Efficacy with Oral STAT6 Inhibitor REX-8756 in Atopic Dermatitis Preclinical Model

Preclinical data presented by Recludix Pharma at the Society for Investigative Dermatology Annual Meeting position REX-8756 as a potential oral alternative to injectable biologics in Type 2 inflammatory disease — a shift that carries downstream implications for formulation strategy, manufacturing complexity, and the competitive landscape for small-molecule development programs.

In a Th2-mediated atopic dermatitis mouse model, orally administered REX-8756 attenuated skin inflammation at an efficacy level comparable to monoclonal antibodies targeting the IL-4/IL-13 signaling pathway, while also reducing Th2 cytokines IL-13 and IL-5 within the immune compartment. The compound is described as the first known orthosteric STAT6 SH2 domain inhibitor to enter the clinic, binding the active site directly to block physiological protein function rather than operating through allosteric modulation or protein degradation.

The safety differentiation from JAK inhibitors is a central claim in the dataset. Unlike JAK inhibitors, REX-8756 does not impair growth factor signaling involved in hematologic homeostasis and is not broadly immunosuppressive — a profile that, if confirmed in clinical studies, would address a known regulatory scrutiny point for that drug class. The compound is currently in a placebo-controlled Phase 1 study enrolling approximately 100 healthy volunteers across multiple cohorts, evaluating safety, tolerability, pharmacokinetics, and pharmacodynamics.

For formulation and process development teams, the oral small-molecule route introduces a manufacturing profile substantially less complex than the cold-chain, sterile fill-finish requirements of biologic comparators. STAT6 inhibition via an orthosteric mechanism also presents a defined, reversible pharmacology that may simplify the benefit-risk documentation required under evolving regulatory expectations for first-in-class mechanisms entering Phase 2 and beyond.

REX-8756, also designated SAR448755, is being developed under a strategic partnership with Sanofi, which includes an option for Recludix to participate in an equal U.S. profit-and-loss share. Recludix is also advancing a BTK SH2 domain inhibitor targeting B cell and mast cell-driven inflammation, extending the SH2 domain inhibitor platform beyond STAT6.

Readout from the ongoing Phase 1 study, including pharmacokinetic and pharmacodynamic data in healthy volunteers, will be the next measurable checkpoint for assessing whether the preclinical safety and efficacy profile translates to the clinical setting.

Source: Recludix Pharma, Inc. via GlobeNewswire, May 15, 2026.