Celldex Presents Positive Data from Phase 2 Chronic Spontaneous Urticaria and Phase 2 Cold Urticaria and Symptomatic Dermographism Studies Demonstrating Rapid, Profound and Durable Improvements in Patient Quality of Life at AAD 2026

Rhea-AI Summary

Celldex (NASDAQ:CLDX) presented Phase 2 data at AAD 2026 showing barzolvolimab produced rapid, profound and durable quality-of-life improvements in chronic spontaneous urticaria (CSU), cold urticaria (ColdU) and symptomatic dermographism (SD).

Key results: up to 51% complete response at Week 12 (CSU), 71% at Week 52, 41% maintained response seven months off therapy; ColdU/SD complete responses reached up to 66% and 49% at Week 20. DLQI domain scores improved across all six domains with many patients achieving DLQI 0/1.

Positive

• CSU complete response up to 71% at Week 52
• Off-treatment durability: 41% complete response seven months post-dose
• DLQI 0/1 in 94% of week-52 well controlled CSU patients
• ColdU clinical response up to 66% at Week 20
• Rapid QoL gains evident by Week 4 (300 mg Q8W)

Negative

• SD response declined from 58% at Week 12 to 49% at Week 20
• Phase 2 status — results require confirmation in pivotal trials
• Key QoL analysis was post hoc, limiting prospective strength

Key Figures

CSU complete response at 52 weeks: 71% of patients CSU off-treatment complete response: 41% of patients CSU DLQI 0/1 at Week 52: 94% of patients +5 more

8 metrics

CSU complete response at 52 weeks 71% of patients Phase 2 CSU study, active therapy at Week 52

CSU off-treatment complete response 41% of patients Seven months after last barzolvolimab dose

CSU DLQI 0/1 at Week 52 94% of patients Patients with well controlled disease at Week 52

CSU DLQI ≤5 at Week 76 76% of patients Well controlled at Week 52 with QoL follow-up

ColdU complete response Week 12 53% of patients Phase 2 ColdU study, primary endpoint

SD complete response Week 12 58% of patients Phase 2 symptomatic dermographism study, primary endpoint

ColdU complete response Week 20 66% of patients Phase 2 ColdU study extended treatment

SD complete response Week 20 49% of patients Phase 2 symptomatic dermographism study extended treatment

Market Reality Check

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Technical Trading above 200-day MA of $25.15 and about 8.02% below the 52-week high of $34.52.

Peers on Argus

CLDX is up 0.22% with key biotech peers also positive today, including COGT (3.3...

CLDX is up 0.22% with key biotech peers also positive today, including COGT (3.31%), AUPH (3.18%), VERA (2.03%) and ARDX (2.99%), indicating broader sector strength alongside the company-specific clinical update.

Previous Clinical trial Reports

5 past events · Latest: Feb 27 (Positive)

Same Type Pattern 5 events

Date	Event	Sentiment	Move	Catalyst
Feb 27	Phase 2 QoL data	Positive	-1.8%	Additional Phase 2 barzolvolimab data with durable responses and large Phase 3 enrollment.
Feb 25	Phase 3 enrollment	Positive	+24.1%	Completed global Phase 3 CSU enrollment of 1,939 patients ahead of guidance.
Dec 09	Phase 3 initiation	Positive	-5.7%	Initiated global registrational Phase 3 program in ColdU and SD after strong Phase 2 data.
Nov 06	Phase 2 CSU data	Positive	-2.0%	Reported rapid, profound and durable CSU control with strong UCT7 improvements.
Nov 06	Phase 2 ColdU/SD	Positive	-2.0%	Phase 2 ColdU/SD results with high complete response rates and favorable safety.

Pattern Detected

Recent clinical trial announcements have often seen weak or negative next-day moves despite positive data, with one strong upside reaction tied to Phase 3 enrollment progress.

Recent Company History

Over the past months, Celldex has repeatedly highlighted barzolvolimab’s profile in chronic urticarias. Prior clinical updates showed up to 71% complete response in CSU and robust ColdU/SD efficacy, while Phase 3 CSU enrollment of 1,939 patients was completed six months early with topline data guided for Q4 2026 and a planned 2027 BLA. Earlier Phase 3 initiations in ColdU/SD and extensive Phase 2 data established rapid, durable control. Today’s AAD data focus on sustained, off-treatment quality-of-life gains, reinforcing the same efficacy narrative.

Historical Comparison

+2.5% avg move · Past clinical trial news for CLDX moved on average 2.51%. Today’s modest 0.22% gain on additional Ph...

clinical trial

+2.5%

Average Historical Move clinical trial

Past clinical trial news for CLDX moved on average 2.51%. Today’s modest 0.22% gain on additional Phase 2 QoL data fits within the historical range but on the low side versus some larger Phase 3 milestones.

Clinical news shows a steady progression from positive Phase 2 CSU and ColdU/SD efficacy, into initiation and full enrollment of global Phase 3 programs across chronic urticarias.

Market Pulse Summary

This announcement adds detail on barzolvolimab’s impact on quality of life, with high complete respo...

Analysis

This announcement adds detail on barzolvolimab’s impact on quality of life, with high complete response rates and a large proportion of patients achieving DLQI scores indicating no impact on daily living. It builds on earlier Phase 2 CSU and ColdU/SD efficacy data and the now-enrolled global Phase 3 programs. Investors may focus on how these QoL findings support a differentiated, potentially disease-modifying profile ahead of planned Phase 3 readouts and a future BLA.

Key Terms

chronic spontaneous urticaria, cold urticaria, symptomatic dermographism, monoclonal antibody, +4 more

8 terms

chronic spontaneous urticaria medical

"Phase 2 clinical trials of barzolvolimab in chronic spontaneous urticaria (CSU)"

A long-term condition that causes recurring, itchy hives and sometimes swelling that appear without a clear trigger, like an alarm that goes off unpredictably on its own. It matters to investors because its chronic nature creates ongoing demand for treatments, diagnostics and follow-on care, influencing pharmaceutical research priorities, drug market size, regulatory review timelines and healthcare cost projections.

cold urticaria medical

"Phase 2 clinical trials of barzolvolimab in chronic spontaneous urticaria (CSU) and cold urticaria (ColdU)"

An allergic reaction in which exposure to cold — from air, water, or a cold object — causes red, itchy welts, swelling, or in severe cases whole-body symptoms. It matters to investors because its prevalence, treatment options, and safety profile can affect demand for therapies, the design and outcome of clinical trials, regulatory decisions, and potential workplace or product-liability costs; think of it like a sensitive smoke alarm that trips whenever the room gets cold.

symptomatic dermographism medical

"Phase 2 clinical trials of barzolvolimab in ... cold urticaria (ColdU) and symptomatic dermographism (SD)"

A form of physical urticaria where light pressure or stroking of the skin produces red, raised, itchy lines or welts—like someone “writing” on your skin with a finger. It matters to investors because it can influence clinical trial outcomes, product labeling, safety signals and market demand for dermatology or allergy treatments: a common, visible side effect can affect regulatory reviews, prescribing patterns and commercial uptake of therapies.

monoclonal antibody medical

"Barzolvolimab is a humanized monoclonal antibody with a completely novel mechanism of action"

A monoclonal antibody is a laboratory-made protein designed to recognize and attach to a specific target in the body, such as a disease-causing substance or cell. It functions like a highly precise lock-and-key tool, helping to treat or detect illnesses. For investors, companies developing monoclonal antibodies can represent promising opportunities in the healthcare sector, especially as these treatments often address unmet medical needs.

mast cell medical

"mechanism of action that uniquely targets the root cause ... —the mast cell."

A mast cell is a type of immune cell that sits in tissues like skin and the lining of the lungs and gut and releases chemical signals—such as histamine—when it detects danger. Think of it as a neighborhood alarm that calls in inflammation or allergy responses; its actions can drive allergic reactions, chronic inflammation, or disease. Investors pay attention because mast cells are common targets for new drugs, diagnostics, and safety issues that can affect a therapy’s market potential and regulatory path.

Dermatology Life Quality Index medical

"The Dermatology Life Quality Index2 (DLQI) measures impact of skin disease on quality of life"

A Dermatology Life Quality Index (DLQI) is a short, patient-completed questionnaire that measures how much a skin condition affects a person’s daily life, similar to a customer satisfaction score for health. Investors watch DLQI results because they show whether a treatment meaningfully improves patients’ day-to-day well-being, which can influence regulatory decisions, market demand, pricing, and insurance coverage — all drivers of a therapy’s commercial value.

DLQI medical

"DLQI mean baseline score of 15.6"

The Dermatology Life Quality Index (DLQI) is a brief, patient-completed questionnaire that measures how much a skin condition affects everyday activities, emotions, work and social life. As a widely used patient-reported outcome in clinical studies and regulatory reviews, DLQI scores act like a customer satisfaction rating for treatments — they help show whether a therapy meaningfully improves patients’ lives, which can influence regulatory decisions, adoption and commercial value.

UAS7 medical

"complete response (UAS7=0; no itch/no hives) at 12 weeks"

UAS7 is a standardized clinical score that sums a patient’s daily ratings of hive number and itch severity over seven days to quantify how active chronic hives are. Investors care because it’s a widely accepted measure used in clinical trials to show whether a treatment meaningfully reduces symptoms; like a thermometer for patient improvement, stronger UAS7 results can influence regulatory approval chances and commercial prospects.

AI-generated analysis. Not financial advice.

- Improvements seen across all six DLQI Domains indicating broad, beneficial impact on quality of life -
- Data further demonstrates first-in-class and best-in-disease barzolvolimab profile -

HAMPTON, N.J., March 27, 2026 (GLOBE NEWSWIRE) -- Celldex (NASDAQ:CLDX) presented additional positive data from the completed Phase 2 clinical trials of barzolvolimab in chronic spontaneous urticaria (CSU) and cold urticaria (ColdU) and symptomatic dermographism (SD) demonstrating profound improvements in patient quality of life (QoL) across all measured domains: symptoms and feelings, daily activities, leisure, work and school, personal relationships and treatment. Barzolvolimab is a humanized monoclonal antibody with a completely novel mechanism of action that uniquely targets the root cause of CSU, ColdU and SD—the mast cell. The data were presented at the 2026 Americal Academy of Dermatology (AAD) Annual Meeting being held March 27 – 31, 2026 in Denver, CO.

“Chronic urticarias are devastating diseases of misery that cause immense physical and psychological suffering for patients across all aspects of their daily lives,” said Diane Young, MD, Senior Vice President and Chief Medical Officer of Celldex. “Patients are either directly dealing with intensely itchy, painful burning hives and swelling associated with angioedema or living in fear of their next outbreak. These diseases take an incredible toll on patient quality of life and, sadly, but not surprisingly, recent literature¹ shows increased mortality for individuals with CSU as well as increased suicidal ideations and suicide attempts. We are gratified to see barzolvolimab’s profound clinical efficacy also translate to dramatic improvements in patient quality of life—offering new hope for patients and their physicians and supporting barzolvolimab’s profile as a best-in-class, best-in-disease potential treatment option for chronic urticarias.”

Summary of Presentations:

Posters are available on the Celldex website. The Dermatology Life Quality Index² (DLQI) measures impact of skin disease on quality of life, with a score of 0/1 indicating no effect of the disease on a patient’s life.

Prolonged and Enhanced Quality of Life in Patients with Chronic Spontaneous Urticaria Treated with Barzolvolimab, M. Metz, et al

• As previously reported in the Phase 2 CSU study, up to 51% of patients on study experienced symptom free complete response (UAS7=0; no itch/no hives) at 12 weeks, which continued to deepen over 52 weeks of active therapy to up to 71% of patients. This profound clinical benefit continued even after patients were off therapy—up to 41% of patients reported complete response seven months after receiving their last dose of barzolvolimab.
• In the post hoc analysis presented at AAD, the impact of disease on QoL for the subset of patients who received 52 weeks of barzolvolimab therapy (150 mg Q4W or 300 mg Q8W) and completed treatment with at least well controlled disease (UAS7<6) at Week 52 and had DLQI data through Week 76 was explored. The vast majority of patients included in this analysis had substantial disease burden at baseline (68% had both severe disease and angioedema) and patients had CSU for a long time (6 years, mean). Patients reported that their CSU had a very large negative impact on their QoL (DLQI mean baseline score of 15.6).
  • At Week 52, 94% of patients with well controlled disease at Week 52 also had a DLQI of 0/1, indicating their disease had no impact on their QoL .
  • Barzolvolimab treatment led to prolonged, off-treatment enhanced QoL seven months after the last dose of barzolvolimab.
    • At baseline, patients reported their CSU significantly impacted their QoL across all 6 DLQI domains (symptoms and feelings, daily activities, leisure, work and school, personal relationships, and treatment). Profound improvements were observed across all 6 domains at both Weeks 52 and 76.
    • 76% of patients with well controlled disease at Week 52 also reported that the disease had small to no impact (DLQI score ≤ 5) on their QoL at Week 76.
    • The majority of patients with well controlled disease at Week 52 achieved DLQI domain scores of 0/1 (no impact on QoL) at Week 76.
  • This sustained off-treatment improvement in QoL was observed despite barzolvolimab clearance and normalization of tryptase (a measure of mast cell burden), suggesting disease modification and supports barzolvolimab’s significant potential to become a transformative treatment option for patients suffering from CSU.

Treatment with Barzolvolimab Improves DLQI Scores in All Domains in Patients with Chronic Inducible Urticaria, M. Metz, et al

• As previously reported in the Phase 2 ColdU and SD study, up to 53% of patients with ColdU and 58% with SD achieved complete response (negative provocation test) at Week 12 (primary endpoint analysis) and up to 66% of patients with ColdU and 49% with SD achieved complete response at Week 20.
• Barzolvolimab treatment improved the QoL of patients with ColdU and SD throughout the 20-week treatment period.
  • Mean DLQI improved from a very large effect of disease on QoL at baseline to a small effect of disease on QoL at Week 20.
  • Benefits on QoL were rapid and apparent by the first DLQI measurement at Week 4 (300 mg Q8W).
• Barzolvolimab treatment increased the rate of achieving no impact of disease on QoL (DLQI of 0/1) at Week 20 by up to 3.1-fold in patients with ColdU and 4.0-fold in patients with SD vs placebo.
• Barzolvolimab treatment resulted in improvements across all six DLQI domains, indicating broad, beneficial effects on QoL.
• This Phase 2 study is the first large randomized, placebo-controlled study to demonstrate clinical benefit in patients with CIndU.
  

References:
¹Kolkhir P, Bieber K, Hawro T, et al. Mortality in adult patients with chronic spontaneous urticaria: A real-world cohort study. Journal of Allergy and Clinical Immunology, 2024; 155:1290-1298.
²Dermatology Life Quality Index (DLQI) consists of ten questions (on a scale of 0–3, total 0–30) used to measure the impact of skin disease on patient quality of life related to symptoms and feelings, daily activities, leisure, work and school, personal relationships, and treatment. DLQI 0–1 indicates no effect on a patient’s life.

About Chronic Spontaneous Urticaria (CSU)
CSU is an underdiagnosed disease of misery marked by spontaneous hives, unbearable itch, and unpredictable episodes of disfiguring swelling (angioedema) that causes substantial mental health burden, profound impact on quality of life and is associated with a 1.7-fold increase in all cause mortality at 5 years. Mast cell activation plays a central role in the onset and progression of CSU. While the goal of CSU treatment is the complete absence of symptoms, the vast majority of patients today, even those receiving the most advanced approved and available therapies, continue to suffer from itch, hives, swelling, sleep disruption, and unrelenting anxiety about when the next flare up will occur.

In February, Celldex announced the completion of enrollment in the Company’s global Phase 3 program in CSU. The Program, which fully accrued six months ahead of guidance, consists of two trials—EMBARQ-CSU1 and EMBARQ-CSU2. 1,939 patients were enrolled—the largest program conducted in antihistamine refractory CSU, including patients with advanced therapy experienced/refractory CSU. The studies included 43 countries and over 500 sites. Topline data from the studies are expected in the fourth quarter of 2026.

About Chronic Inducible Urticaria (CIndU), Cold Urticaria (ColdU), Symptomatic Dermographism (SD)
CIndU is characterized by the occurrence of hives or wheals that have an attributable trigger associated with them. ColdU symptoms include itching, burning wheals/hives and angioedema when skin is exposed to cold temperatures. SD symptoms include the development of wheals in response to stroking, scratching or rubbing of the skin. For these diseases, mast cell activation leading to release of soluble mediators is thought to be the driving mechanism leading to the wheals and other symptoms. There are currently no approved therapies for chronic inducible urticarias other than antihistamines and patients attempt to manage symptoms associated with their disease through avoidance of triggers.

In December 2025, Celldex initiated a global Phase 3 study in cold urticaria (ColdU) and symptomatic dermographism (SD), EMBARQ-ColdU and -SD, and enrollment is ongoing.

About Barzolvolimab
Barzolvolimab is a humanized monoclonal antibody with a completely novel mechanism of action that targets mast cells by binding with high specificity to a unique part of the KIT receptor and potently inhibiting its activity. The KIT receptor is abundantly expressed by mast cells and critical for their function and survival. Mast cells are drivers of inflammatory responses such as hypersensitivity and allergic reactions and, in certain inflammatory diseases, such as chronic urticarias, mast cell activation plays a central role in the onset and progression of the disease. Based on data from robust, randomized, placebo controlled Phase 2 studies, barzolvolimab has significant potential as a first-in-class and best-in-disease treatment option for patients with chronic spontaneous urticaria (CSU), cold urticaria (ColdU) and symptomatic dermographism (SD). Barzolvolimab is currently being studied in Phase 3 studies in CSU and ColdU/SD and Phase 2 studies in prurigo nodularis (PN) and atopic dermatitis (AD), with additional indications planned for the future.

About Celldex
Celldex is pioneering new horizons in immunology to deliver life-changing therapies. We are relentless in our pursuit of novel antibody-based treatments that engage the human immune system and directly affect critical pathways to improve the lives of patients with allergic, inflammatory and autoimmune disorders.
Visit www.celldex.com.

Forward Looking Statement
This release contains "forward-looking statements" made pursuant to the safe harbor provisions of the Private Securities Litigation Reform Act of 1995. These statements are typically preceded by words such as "believes," "expects," "anticipates," "intends," "will," "may," "should," or similar expressions. These forward-looking statements reflect management's current knowledge, assumptions, judgment and expectations regarding future performance or events. Although management believes that the expectations reflected in such statements are reasonable, they give no assurance that such expectations will prove to be correct or that those goals will be achieved, and you should be aware that actual results could differ materially from those contained in the forward-looking statements. Forward-looking statements are subject to a number of risks and uncertainties, including, but not limited to, our ability to successfully complete research and further development and commercialization of Company drug candidates, including barzolvolimab (also referred to as CDX-0159) and CDX-622, in current or future indications; the uncertainties inherent in clinical testing and accruing patients for clinical trials; our limited experience in bringing programs through Phase 3 clinical trials; our ability to manage and successfully complete multiple clinical trials and the research and development efforts for our multiple products at varying stages of development; the availability, cost, delivery and quality of clinical materials produced by our own manufacturing facility or supplied by contract manufacturers, who may be our sole source of supply; the timing, cost and uncertainty of obtaining regulatory approvals; the failure of the market for the Company's programs to continue to develop; our ability to protect the Company's intellectual property; the loss of any executive officers or key personnel or consultants; competition; changes in the regulatory landscape or the imposition of regulations that affect the Company's products; our ability to continue to obtain capital to meet our long-term liquidity needs on acceptable terms, or at all, including the additional capital which will be necessary to complete the clinical trials that we have initiated or plan to initiate; and other factors listed under "Risk Factors" in our annual report on Form 10-K and quarterly reports on Form 10-Q.

All forward-looking statements are expressly qualified in their entirety by this cautionary notice. You are cautioned not to place undue reliance on any forward-looking statements, which speak only as of the date of this release. We have no obligation, and expressly disclaim any obligation, to update, revise or correct any of the forward-looking statements, whether as a result of new information, future events or otherwise.

Company Contact
Sarah Cavanaugh
Senior Vice President, Corporate Affairs & Administration
(508) 864-8337
scavanaugh@celldex.com

Patrick Till
Meru Advisors
(484) 788-8560
ptill@meruadvisors.com 

FAQ

What efficacy did Celldex (CLDX) report for barzolvolimab in CSU at AAD 2026?

Barzolvolimab achieved up to 51% complete response at Week 12 and 71% at Week 52. According to the company, durability was notable with 41% of patients maintaining complete response seven months after last dose.

How did barzolvolimab affect quality of life (DLQI) for CLDX patients in the Phase 2 results?

Treatment produced broad DLQI improvements across all six domains, with many patients reaching DLQI 0/1. According to the company, 94% of week-52 well controlled CSU patients had DLQI 0/1, sustained at Week 76 for most.

What were the ColdU and symptomatic dermographism (SD) response rates Celldex (CLDX) presented?

ColdU responses reached up to 53% at Week 12 and 66% at Week 20; SD responses were 58% at Week 12 and 49% at Week 20. According to the company, improvements translated into meaningful DLQI gains.

Did Celldex (CLDX) report durability of barzolvolimab benefits after stopping therapy?

Yes. Up to 41% of CSU patients reported complete response seven months after their last dose. According to the company, sustained DLQI improvements persisted despite drug clearance and tryptase normalization.

What limitations did Celldex (CLDX) note about the barzolvolimab Phase 2 findings at AAD 2026?

Key QoL analyses included post hoc subsets and Phase 2 sample sizes, which limit definitive conclusions. According to the company, these data support further confirmatory pivotal trials.

How quickly did patients report quality-of-life improvement with barzolvolimab (CLDX) in trials?

Patients showed QoL benefits by the first DLQI measurement at Week 4. According to the company, rapid onset was observed at the 300 mg Q8W dose with continued improvement through Week 20–52.