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Clemizole HCl

Epygenix · Phase 3 active Small molecule Under review

Clemizole HCl is a H1-receptor antagonist (antihistamine) Small molecule drug developed by Epygenix. It is currently in Phase 3 development for Allergic conditions and pruritus (investigational in Phase 3). Also known as: EPX-100, Clemizole.

Clemizole HCl is a histamine H1-receptor antagonist that blocks histamine-mediated immune and inflammatory responses.

Clemizole HCl is a small molecule used in clinical trials for various conditions, including Dravet Syndrome, Hepatocellular Carcinoma, Lennox Gastaut Syndrome, and Hepatitis C. It has been studied in a 20-week multicenter trial as EPX-100 (Clemizole Hydrochloride) in participants with Dravet Syndrome.

Likelihood of approval
59.3% vs 58.3% industry baseline
If approved by FDA: likely 2028–2030
Steps remaining: NDA/BLA submission
Confidence: High
Why this estimate
  • Baseline phase 3 → approval rate +58.3pp
    Industry-wide phase 3 drugs reach approval ~58.3% of the time (BIO/Informa 2023 industry benchmark across all therapeutic areas).
  • Immunology slight uplift +1.0pp
    Mature endpoint landscape (ACR, DAS28, PASI) makes immunology approvals slightly more predictable.
Predicted approval windows by jurisdiction (conditional on FDA approval)
Regulator Country Likely year Lag vs FDA
FDA US 2028–2030
EMA EU 2029–2031 +0.7 yr
MHRA GB 2029–2031 +0.7 yr
Health Canada CA 2029–2032 +0.9 yr
TGA AU 2029–2032 +1.2 yr
PMDA JP 2029–2032 +1.5 yr
NMPA CN 2030–2033 +2.3 yr
MFDS KR 2029–2032 +1.4 yr
CDSCO IN 2029–2033 +1.8 yr
ANVISA BR 2030–2033 +2.3 yr

Hover any row for the lag rationale. Lag estimates are reduced when the drug has FDA Breakthrough or EMA PRIME designation (sponsors file globally in parallel).

Estimate based on the BIO/Informa industry phase transition rates plus per-drug modifiers for therapeutic area, sponsor type, FDA designations, mechanism, and trial design. Per-jurisdiction lags from Tufts CSDD international approval studies. Not investment, clinical or regulatory advice. Methodology: /methodology#likelihood.

At a glance

Generic nameClemizole HCl
Also known asEPX-100, Clemizole
SponsorEpygenix
Drug classH1-receptor antagonist (antihistamine)
TargetHistamine H1 receptor
ModalitySmall molecule
Therapeutic areaImmunology / Allergy / Inflammation
PhasePhase 3

Mechanism of action

Clemizole is a first-generation antihistamine that crosses the blood-brain barrier and antagonizes H1 receptors on mast cells, basophils, and other immune cells. By blocking histamine signaling, it reduces allergic and inflammatory responses. The drug has also been investigated for potential immunomodulatory effects beyond classical antihistamine activity.

Approved indications

Common side effects

Key clinical trials

Primary sources

Every claim on this page is sourced from regulatory or scientific primary sources. See our editorial policy for full methodology.

SourceUsed for
ClinicalTrials.govTrial enrolment, design, endpoints, results

Competitive intelligence

For the full competitive landscape — auto-detected comparators, recent regulatory actions across the set, upcoming PDUFA, patent timeline, sponsor landscape:

Frequently asked questions about Clemizole HCl

What is Clemizole HCl?

Clemizole HCl is a H1-receptor antagonist (antihistamine) drug developed by Epygenix, indicated for Allergic conditions and pruritus (investigational in Phase 3).

How does Clemizole HCl work?

Clemizole HCl is a histamine H1-receptor antagonist that blocks histamine-mediated immune and inflammatory responses.

What is Clemizole HCl used for?

Clemizole HCl is indicated for Allergic conditions and pruritus (investigational in Phase 3).

Who makes Clemizole HCl?

Clemizole HCl is developed by Epygenix (see full Epygenix pipeline at /company/epygenix).

Is Clemizole HCl also known as anything else?

Clemizole HCl is also known as EPX-100, Clemizole.

What drug class is Clemizole HCl in?

Clemizole HCl belongs to the H1-receptor antagonist (antihistamine) class. See all H1-receptor antagonist (antihistamine) drugs at /class/h1-receptor-antagonist-antihistamine.

What development phase is Clemizole HCl in?

Clemizole HCl is in Phase 3.

What are the side effects of Clemizole HCl?

Common side effects of Clemizole HCl include Drowsiness / sedation, Dry mouth, Dizziness.

What does Clemizole HCl target?

Clemizole HCl targets Histamine H1 receptor and is a H1-receptor antagonist (antihistamine).

Related

Primary sources · FDA · ClinicalTrials.gov · EMA · SEC EDGAR · ChEMBL · Wikidata · full sourcing