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Anti‐KIT monoclonal antibody CDX‐0159 induces profound and durable mast cell suppression in a healthy volunteer study
Author(s) -
Alvarado Diego,
Maurer Marcus,
Gedrich Richard,
Seibel Scott B.,
Murphy Michael B.,
Crew Linda,
Goldstein Joel,
Crocker Andrea,
Vitale Laura A.,
Morani Pamela A.,
Thomas Lawrence J.,
Hawthorne Thomas R.,
Keler Tibor,
Young Diane,
Crowley Elizabeth,
Kankam Martin,
HeathChiozzi Margo
Publication year - 2022
Publication title -
allergy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.363
H-Index - 173
eISSN - 1398-9995
pISSN - 0105-4538
DOI - 10.1111/all.15262
Subject(s) - medicine , tryptase , monoclonal antibody , antibody , omalizumab , immunology , mast cell , pharmacology , immunoglobulin e
Background Mast cells (MC) are powerful inflammatory immune sentinel cells that drive numerous allergic, inflammatory, and pruritic disorders when activated. MC‐targeted therapies are approved in several disorders, yet many patients have limited benefit suggesting the need for approaches that more broadly inhibit MC activity. MCs require the KIT receptor and its ligand stem cell factor (SCF) for differentiation, maturation, and survival. Here we describe CDX‐0159, an anti‐KIT monoclonal antibody that potently suppresses MCs in human healthy volunteers. Methods CDX‐0159‐mediated KIT inhibition was tested in vitro using KIT‐expressing immortalized cells and primary human mast cells. CDX‐0159 safety and pharmacokinetics were evaluated in a 13‐week good laboratory practice (GLP)‐compliant cynomolgus macaque study. A single ascending dose (0.3, 1, 3, and 9 mg/kg), double‐blinded placebo‐controlled phase 1a human healthy volunteer study ( n = 32) was conducted to evaluate the safety, pharmacokinetics, and pharmacodynamics of CDX‐0159. Results CDX‐0159 inhibits SCF‐dependent KIT activation in vitro . Fc modifications in CDX‐0159 led to elimination of effector function and reduced serum clearance. In cynomolgus macaques, multiple high doses were safely administered without a significant impact on hematology, a potential concern for KIT inhibitors. A single dose of CDX‐0159 in healthy human subjects was generally well tolerated and demonstrated long antibody exposure. Importantly, CDX‐0159 led to dose‐dependent, profound suppression of plasma tryptase, a MC‐specific protease associated with tissue MC burden, indicative of systemic MC suppression or ablation. Conclusion CDX‐0159 administration leads to systemic mast cell ablation and may represent a safe and novel approach to treat mast cell‐driven disorders.