Celldex Reports Positive Preclinical Data on CDX-622 at AAAAI 2025

Celldex Therapeutics, Inc., based in Hampton, NJ, has announced promising preclinical results for its innovative bispecific antibody, CDX-622, which targets inflammation and fibrosis. The antibody addresses two crucial pathways involved in these conditions: thymic stromal lymphopoietin (TSLP) and stem cell factor (SCF)-related mast cell depletion. These pathways are essential in the pathogenesis of various inflammatory and fibrotic ailments.

CDX-622 has shown efficacy in neutralizing both SCF and TSLP, leading to a reduction in tissue mast cells and inhibition of Type 2 inflammatory reactions. This dual action suggests that CDX-622 may be more effective than treatments targeting only one pathway, making it a potentially significant therapeutic option for patients suffering from inflammatory and fibrotic disorders.

The encouraging data were presented by Diego Alvarado, PhD, Celldex's Vice President of Research, at the American Academy of Allergy, Asthma & Immunology (AAAAI) Annual Meeting 2025. The presentation highlighted how CDX-622's mechanism could offer improved clinical outcomes by simultaneously addressing both mast cell activity and TSLP-driven inflammation.

Dr. Tibor Keler, Celldex's Executive Vice President and Chief Scientific Officer, expressed enthusiasm about the findings. He emphasized the potential benefits of CDX-622's dual neutralization strategy, which could offer substantial advantages for patients with diseases where mast cells and TSLP contribute to the pathology. In light of these preclinical results, Celldex initiated a Phase 1 trial in healthy volunteers last November, which is currently enrolling participants. The company plans to release preliminary data from this trial later in the year.

CDX-622 operates by targeting and neutralizing TSLP and starving mast cells of SCF, a crucial factor required for their survival and activation via the KIT receptor. This approach is expected to effectively decrease mast cell presence in tissues and mitigate Type 2 inflammatory responses, potentially enhancing treatment efficacy for inflammatory and fibrotic diseases.

The ongoing Phase 1 study is a randomized, double-blind, placebo-controlled trial designed to assess the safety, pharmacokinetics, and pharmacodynamics of CDX-622. The trial includes two parts: the first involves single ascending doses, and the second involves multiple ascending doses. Up to 56 healthy participants will be enrolled to evaluate the antibody's performance and safety profile.

Celldex Therapeutics, a clinical-stage biotechnology company, focuses on pioneering advancements in mast cell biology to develop transformative treatments. Their pipeline includes antibody-based therapeutics that interact with the human immune system or directly influence critical pathways, aiming to improve the lives of patients with severe inflammatory, allergic, autoimmune, and other serious diseases.

Overall, the development of CDX-622 represents a significant step forward in the treatment of complex inflammatory and fibrotic disorders. With its unique mechanism of targeting both SCF and TSLP, it holds promise for offering more effective treatment options and enhancing patient outcomes in conditions with limited current therapies. As Celldex continues its clinical evaluations, the potential impact of CDX-622 on the field of inflammatory disease treatment remains highly anticipated.