Celldex Begins Phase 1 Study of CDX-622 for Inflammatory Diseases

Celldex Therapeutics, Inc. has announced the commencement of its Phase 1a clinical trial for CDX-622, a bispecific antibody, in healthy volunteers. This milestone marks the first patient dosing in the study. CDX-622 targets two key pathways responsible for chronic inflammation by neutralizing the alarmin thymic stromal lymphopoietin (TSLP) and depleting mast cells through stem cell factor (SCF) starvation.

Anthony Marucci, Co-founder, President, and CEO of Celldex Therapeutics, highlighted the significance of CDX-622, stating that it represents the company's first bispecific candidate aimed at treating inflammatory diseases. He emphasized that CDX-622 combines mast cell depletion with inhibition of Type 2 inflammatory responses, offering potential applications in a broad range of respiratory and dermatological disorders. Marucci further noted that upon successful completion of the study in healthy volunteers, the company intends to initiate studies in asthma and expand its pipeline. He also mentioned that CDX-622 complements the company's barzolvolimab program, enhancing their existing pipeline, which targets five diseases.

TSLP is implicated in numerous respiratory and dermatological disorders, including asthma, chronic obstructive pulmonary disease, eosinophilic esophagitis, atopic dermatitis, and chronic spontaneous urticaria, as well as fibrotic diseases such as systemic sclerosis and idiopathic pulmonary fibrosis. In these conditions, TSLP is often upregulated and associated with disease severity. Mast cells also play a crucial role in allergic, inflammatory, autoimmune, and fibrotic disorders. CDX-622's unique SCF neutralizing function is expected to inhibit and deplete mast cells, thereby potentially offering enhanced therapeutic benefits by reducing tissue mast cells and inhibiting Type 2 inflammatory responses.

The Phase 1a clinical trial is designed as a two-part, randomized, double-blind, placebo-controlled dose escalation study. It aims to assess the safety, pharmacokinetics, and pharmacodynamics of single ascending doses (Part 1) and multiple ascending doses (Part 2) of CDX-622 in up to 56 healthy participants. In Part 1, a single dose of CDX-622 or placebo will be administered intravenously. In Part 2, CDX-622 or placebo will be administered every three weeks for up to six weeks, totaling three doses. Participants will be monitored for 12 weeks following the last dose in both parts of the study.

Celldex will also evaluate blood and skin biomarkers associated with SCF and TSLP signaling and other immune inflammatory pathways as exploratory endpoints in healthy participants. Additionally, a subcutaneous formulation of CDX-622 is currently being developed and is expected to be incorporated into the study in 2025.

Celldex Therapeutics is a clinical-stage biotechnology company focusing on developing antibody-based therapeutics that interact with the human immune system or directly affect critical pathways to improve the lives of patients with severe inflammatory, allergic, autoimmune, and other debilitating diseases. The company's pipeline includes various antibody-based therapeutics designed to tackle these conditions.