Business Description

Overview Celldex Therapeutics, Inc., which we refer to as “Celldex,” “we,” “us,” “our” or the “Company,” is a biopharmaceutical company dedicated to exploring the science of mast cell biology and developing therapeutic antibodies which have the ability to engage the human immune system and/or directly affect critical pathways to improve the lives of patients with severe inflammatory, allergic, autoimmune and other devastating diseases. Our drug candidates include monoclonal and bispecific antibodies designed to address mast cell mediated diseases for which available treatments are inadequate. We are focusing our efforts and resources on the continued research and development of ● Barzolvolimab (also referred to as CDX-0159), a monoclonal antibody that specifically binds the KIT receptor and potently inhibits its activity, which is currently being studied across multiple mast cell driven diseases including - Chronic Spontaneous Urticaria (CSU): In February 2026, we announced that enrollment is complete in our Phase 3 studies in CSU and that topline data will be available in the fourth quarter of 2026. In November 2023, we announced that our Phase 2 study in CSU achieved the primary efficacy endpoint (statistically significant mean change from baseline to Week 12 of urticaria activity score compared to placebo) and was well tolerated. Patients on study continued to receive barzolvolimab and, in September 2024, we reported data from 52 weeks of treatment—demonstrating sustained and deepening disease efficacy and a well tolerated long term safety profile. In June 2025, Celldex presented longer term follow up data from the study. At 76 weeks, 7 months after the completion of dosing with barzolvolimab, over 40% of patients (150 mg Q4W) continued to experience profound, sustained complete response and improved quality of life; - Cold Urticaria (ColdU) and Symptomatic Dermographism (SD): We initiated a Phase 3 study in ColdU and SD in December 2025 and enrollment is ongoing. In July 2024, we announced that our Phase 2 study being conducted in two forms of chronic inducible urticaria (CIndU), ColdU and SD, achieved the primary efficacy endpoint (statistically significant difference between the percent of patients with a negative provocation test compared to placebo at Week 12) and was well tolerated. 12 week data from the CIndU study were presented in October of 2024 and all secondary endpoints across the study were also met and were highly statistically significant and clinically meaningful. Patients on study continued to receive barzolvolimab and, in November 2025, we reported data from 20 weeks of treatment—demonstrating sustained efficacy and a well tolerated safety profile over the longer treatment period; - Prurigo Nodularis (PN): In April 2024, we initiated a Phase 2 study in PN and enrollment was completed in December 2025. Topline data from the study is expected in summer 2026. Positive data from a Phase 1b study in PN was reported in November 2023; and - Atopic Dermatitis (AD): A Phase 2 study in AD was initiated in December 2024 and enrollment was completed in January 2026. Topline data from the study is expected in late 2026. ● Our next generation bispecific antibody platform to support pipeline expansion with additional candidates for inflammatory diseases. Targets are being selected based on new science as well as their compatibility to be used in bispecific antibody formats with our existing antibody programs. Development is focused on emerging, important pathways controlling inflammatory diseases. - CDX-622 (TSLP & SCF): Our first bispecific candidate for inflammatory diseases is CDX-622 which targets two complementary pathways that drive chronic inflammation, potently neutralizing the alarmin thymic stromal lymphopoietin (TSLP) and depleting mast cells via stem cell factor (SCF) starvation. In November 2024, a Phase 1a dose-escalation study in healthy volunteers was initiated and enrollment was completed in January 2026. Positive data from the single ascending dose portion of the study was presented in October 2025. Data from the multiple ascending dose portion of the study and subcutaneous administration are anticipated in the third quarter of 2026. In January 2026, we initiated an open-label, single-dose Phase 1 proof of mechanism study in adults with mild to moderate asthma. 1 Table of Contents More detail on these programs is provided in the Clinical Development Programs section.…