Celldex Therapeutics Inc. (NASDAQ:CLDX) has dosed the first patient with CDX-0159 its an open-label clinical study in symptomatic dermographism and cold contact urticaria, the most common chronic inducible urticaria (CIndU) forms.
Celldex developing CDX-0159 as a KIT receptor monoclonal antibody
CDX-0159 is Celldex’s human monoclonal antibody that is under development which binds the KIT receptor with high specificity thus strongly inhibiting its activity. Various cells such as mast cells express KIT receptor tyrosine kinase which mediates inflammatory responses such as allergic reactions and hypersensitivity. Most importantly KIT controls tissue recruitment, differentiation, activity, and survival of mast cells.
The company had previously presented results that showed a favorable safety profile of CDX-0159 as well as durable and profound plasma tryptase reductions. This is indicative of mast cell ablation in the phase 1a single-dose healthy participants study. Celldex commences the phase 1b study in October in chronic spontaneous urticaria.
Diane C Young, the company’s SVP and Chief Medical Officer said the initiation of the second urticaria study lays a good foundation for the CDX-0159 program. Young said that the CIndU study will offer a quick clinical proof of concept in a mast cell driven disease setting. Also, it will help the company to continue assessing CDX-0159’s safety and clinical benefit. She said that they expect to confirm the impact of CDX-01599 on mast cells by collecting and analyzing serial skin biopsies to help address the question about the mechanism of action of CDX-0159.
Phase 1b to assess single CDX-0159 dose
The company has designed the phase 1b study to assess a single CDX-0159 dose in around 20 patients with symptomatic dermographism (n=10) and cold contact urticaria (n=10-) that are refractory to antihistamines. Celldex will induce patient symptoms through provocation testing mirroring real-life triggering circumstances. The study’s secondary explorative objective will be pharmacodynamics and pharmacokinetic assessment includes baseline provocation thresholds changes, stem cell levels, and tryptase measurement as well as clinical activity outcomes. Participants will receive CDX-0159 intravenously in addition to H1-antihistamine. Initial study results will be available in Q1 2021.