CLINICAL TRIALS PROFILE FOR ZYRTEC ALLERGY

505(b)(2) Clinical Trials for ZYRTEC ALLERGY

This table shows clinical trials for potential 505(b)(2) applications. See the next table for all clinical trials

Trial Type	Trial ID	Title	Status	Sponsor	Phase	Start Date	Summary
OTC	NCT02024152 ↗	Safety, Tolerability and Pharmacokinetics Trial of JDP-205 Injection 10 mg	Completed	Algorithme Pharma Inc	Phase 1	2011-03-01	This study is to investigate the pharmacokinetics (PK) together with the safety and tolerability of JDP-205 at 5 mg and 10 mg intravenous doses and 10 mg intramuscular dose, in comparison to the marketed cetirizine oral product Zyrtec® 10 mg tablets (an OTC product) in healthy male and female volunteers after a single dose administration.
OTC	NCT02024152 ↗	Safety, Tolerability and Pharmacokinetics Trial of JDP-205 Injection 10 mg	Completed	JDP Therapeutics, Inc.	Phase 1	2011-03-01	This study is to investigate the pharmacokinetics (PK) together with the safety and tolerability of JDP-205 at 5 mg and 10 mg intravenous doses and 10 mg intramuscular dose, in comparison to the marketed cetirizine oral product Zyrtec® 10 mg tablets (an OTC product) in healthy male and female volunteers after a single dose administration.
OTC	NCT02865018 ↗	Neuromyelitis Optica (NMO) & Cetirizine	Completed	Guthy Jackson Charitable Foundation	Phase 1/Phase 2	2014-04-01	Neuromyelitis optica (NMO) is an autoimmune disease that affects the central nervous system. Patients have relapses (also known as attacks) which are often quite severe and leave them with significant disability. Without treatment, within 5 years 50% of NMO patients are blind in one or both eyes or require walking assistance (cane, walker or wheelchair). NMO has only been relatively recently described and is fairly rare. Most NMO patients' immune systems produce abnormal antibodies against aquaporin-4 (AQP4), which is found in certain cells in the central nervous system. When these AQP4 antibodies bind to AQP4, they trigger a cascade of events involving the immune system which eventually leads to damage to the nervous system. This ultimately leads to disability, some of which is permanent. Until now, treatments for NMO have been mostly focused on decreasing production of this AQP4 antibody. However, recent experiments in animal models of NMO have shown the importance of what happens inside the central nervous system after the antibody binds to the nervous system cell. Specifically, researchers have noted the importance of a specific cell type, eosinophils, in causing damage in NMO lesions. In a recent study, researchers showed they could prevent damage from NMO by blocking eosinophils using cetirizine, which is a popular over-the-counter allergy medicine. Cetirizine is already known to be safe and well-tolerated in the general population. In this study, the researchers plan to add cetirizine on to patients' current NMO treatment. The researchers aim to show that it is safe, well-tolerated, and that with cetirizine, NMO patients have less relapses and therefore less disability over the course of the year following initiation of treatment. The researchers also plan to study how cetirizine changes the immunological profile in NMO patients by examining blood and cerebrospinal fluid.
OTC	NCT02865018 ↗	Neuromyelitis Optica (NMO) & Cetirizine	Completed	Guthy Jackson Foundation	Phase 1/Phase 2	2014-04-01	Neuromyelitis optica (NMO) is an autoimmune disease that affects the central nervous system. Patients have relapses (also known as attacks) which are often quite severe and leave them with significant disability. Without treatment, within 5 years 50% of NMO patients are blind in one or both eyes or require walking assistance (cane, walker or wheelchair). NMO has only been relatively recently described and is fairly rare. Most NMO patients' immune systems produce abnormal antibodies against aquaporin-4 (AQP4), which is found in certain cells in the central nervous system. When these AQP4 antibodies bind to AQP4, they trigger a cascade of events involving the immune system which eventually leads to damage to the nervous system. This ultimately leads to disability, some of which is permanent. Until now, treatments for NMO have been mostly focused on decreasing production of this AQP4 antibody. However, recent experiments in animal models of NMO have shown the importance of what happens inside the central nervous system after the antibody binds to the nervous system cell. Specifically, researchers have noted the importance of a specific cell type, eosinophils, in causing damage in NMO lesions. In a recent study, researchers showed they could prevent damage from NMO by blocking eosinophils using cetirizine, which is a popular over-the-counter allergy medicine. Cetirizine is already known to be safe and well-tolerated in the general population. In this study, the researchers plan to add cetirizine on to patients' current NMO treatment. The researchers aim to show that it is safe, well-tolerated, and that with cetirizine, NMO patients have less relapses and therefore less disability over the course of the year following initiation of treatment. The researchers also plan to study how cetirizine changes the immunological profile in NMO patients by examining blood and cerebrospinal fluid.
OTC	NCT02865018 ↗	Neuromyelitis Optica (NMO) & Cetirizine	Completed	Icahn School of Medicine at Mount Sinai	Phase 1/Phase 2	2014-04-01	Neuromyelitis optica (NMO) is an autoimmune disease that affects the central nervous system. Patients have relapses (also known as attacks) which are often quite severe and leave them with significant disability. Without treatment, within 5 years 50% of NMO patients are blind in one or both eyes or require walking assistance (cane, walker or wheelchair). NMO has only been relatively recently described and is fairly rare. Most NMO patients' immune systems produce abnormal antibodies against aquaporin-4 (AQP4), which is found in certain cells in the central nervous system. When these AQP4 antibodies bind to AQP4, they trigger a cascade of events involving the immune system which eventually leads to damage to the nervous system. This ultimately leads to disability, some of which is permanent. Until now, treatments for NMO have been mostly focused on decreasing production of this AQP4 antibody. However, recent experiments in animal models of NMO have shown the importance of what happens inside the central nervous system after the antibody binds to the nervous system cell. Specifically, researchers have noted the importance of a specific cell type, eosinophils, in causing damage in NMO lesions. In a recent study, researchers showed they could prevent damage from NMO by blocking eosinophils using cetirizine, which is a popular over-the-counter allergy medicine. Cetirizine is already known to be safe and well-tolerated in the general population. In this study, the researchers plan to add cetirizine on to patients' current NMO treatment. The researchers aim to show that it is safe, well-tolerated, and that with cetirizine, NMO patients have less relapses and therefore less disability over the course of the year following initiation of treatment. The researchers also plan to study how cetirizine changes the immunological profile in NMO patients by examining blood and cerebrospinal fluid.

All Clinical Trials for ZYRTEC ALLERGY

Trial ID	Title	Status	Sponsor	Phase	Start Date	Summary
NCT00240032 ↗	A Study to Evaluate the Impact on Skin (Injection Site) Reactions of Taking an Antihistamine (Zyrtec®) or Placebo Prior to Daily Injections of Copaxone®.	Completed	Teva Branded Pharmaceutical Products R&D, Inc.	Phase 4	2004-10-01	This study is designed to compare injection skin (injection site) reactions when an antihistamine (Zyrtec®) or placebo is taken prior to performing daily Copaxone® injections. Patients will be assigned (like a flip of a coin) to take either a placebo or an antihistamine (Zyrtec®) prior to performing their daily Copaxone® injections. The patient and physician will be unaware whether they are taking a placebo or antihistamine during the study.
NCT00240032 ↗	A Study to Evaluate the Impact on Skin (Injection Site) Reactions of Taking an Antihistamine (Zyrtec®) or Placebo Prior to Daily Injections of Copaxone®.	Completed	Teva Pharmaceutical Industries	Phase 4	2004-10-01	This study is designed to compare injection skin (injection site) reactions when an antihistamine (Zyrtec®) or placebo is taken prior to performing daily Copaxone® injections. Patients will be assigned (like a flip of a coin) to take either a placebo or an antihistamine (Zyrtec®) prior to performing their daily Copaxone® injections. The patient and physician will be unaware whether they are taking a placebo or antihistamine during the study.
NCT00375713 ↗	Randomized Phase III Study to Evaluate the Efficacy and Safety of Xyzal® (Levocetirizine) vs Zyrtec® (Cetirizine) in Subjects With Dermatitis and Eczema	Completed	UCB Pharma	Phase 3	2005-10-01	Korean double-blind non-inferiority study to asses the efficacy (as measured by the responder rate of pruritus severity score by the patient at visit 4 or end-of-treatment visit over the 2 weeks treatment period) and safety of Xyzal® to Zyrtec® in subjects suffering from dermatitis and eczema with pruritus symptoms
NCT00420082 ↗	A Randomized, Double-Blind, 4-way Crossover Study to Evaluate the Efficacy of Bilastine in the Vienna Challenge Chamber	Completed	Faes Farma, S.A.	Phase 2	2006-10-01	This is a randomized, double blind, active and placebo controlled, 4 way crossover study in patients with seasonal allergic rhinitis. Patients will receive a single dose of bilastine 20 mg, Cetirizine 10 mg, Fexofenadine 120 mg, and placebo in the Vienna Challenge Chamber.
NCT00504933 ↗	Efficacy Study for the Symptomatic Treatment of Seasonal Allergic Rhinitis	Completed	Faes Farma, S.A.	Phase 3	2005-05-01	The objective of the study is to evaluate the efficacy and tolerability of Bilastine 20 mg, compared to Cetirizine and placebo for the treatment of seasonal allergic rhinitis.
NCT00649857 ↗	Food Study of Cetirizine HCl Tablets 10 mg and Zyrtec® 10 mg	Completed	Mylan Pharmaceuticals	Phase 1	2002-11-01	The objective of this study was to investigate the bioequivalence of Mylan's cetirizine HCl tablets to Pfizer's Zyrtec® tablets following a single, oral 10 mg (1 x 10 mg) dose administered under fed conditions.

Clinical Trial Conditions for ZYRTEC ALLERGY

Condition Name

Condition Name for ZYRTEC ALLERGY
Intervention	Trials
Healthy	6
Allergic Rhinitis	6
Seasonal Allergic Rhinitis	5
Perennial Allergic Rhinitis	4

Condition MeSH

Condition MeSH for ZYRTEC ALLERGY
Intervention	Trials
Rhinitis	13
Rhinitis, Allergic	12
Rhinitis, Allergic, Seasonal	6
Rhinitis, Allergic, Perennial	4

Clinical Trial Locations for ZYRTEC ALLERGY

Trials by Country

Trials by Country for ZYRTEC ALLERGY
Location	Trials
United States	13
Canada	3
Austria	1
Korea, Republic of	1

Trials by US State

Trials by US State for ZYRTEC ALLERGY
Location	Trials
Maryland	3
Texas	3
Georgia	1
Indiana	1
Illinois	1

Clinical Trial Progress for ZYRTEC ALLERGY

Clinical Trial Phase

Clinical Trial Phase for ZYRTEC ALLERGY
Clinical Trial Phase	Trials
Phase 4	12
Phase 3	5
Phase 2	1

Clinical Trial Status

Clinical Trial Status for ZYRTEC ALLERGY
Clinical Trial Phase	Trials
Completed	27
Withdrawn	1
Recruiting	1

Clinical Trial Sponsors for ZYRTEC ALLERGY

Sponsor Name

Sponsor Name for ZYRTEC ALLERGY
Sponsor	Trials
Merck Sharp & Dohme Corp.	7
Faes Farma, S.A.	3
Ranbaxy Laboratories Limited	2

Sponsor Type

Sponsor Type for ZYRTEC ALLERGY
Sponsor	Trials
Industry	28
Other	12
NIH	2

Last updated: May 21, 2026

ZYRTEC ALLERGY (cetirizine) clinical trials update, market analysis and exclusivity/IP outlook

Executive summary: ZYRTEC Allergy is cetirizine hydrochloride (oral antihistamine). The product class is mature and largely generic; the current market exposure is driven by OTC consumer demand, pediatric uptake, and brand-to-generic switching economics rather than new clinical programs. Patent and regulatory exclusivity are not the primary near-term determinants of pricing or volume in the US because cetirizine’s core drug substance is long off patent. Commercial upside is mainly tied to line extensions (liquid, dissolvable, dosing formats), channel mix, and competitive intensity in second-generation antihistamines.

What is ZYRTEC Allergy (cetirizine) and what active ingredient does it contain?

Direct answer: ZYRTEC Allergy contains cetirizine hydrochloride, a second-generation H1 antihistamine used for seasonal allergic rhinitis, perennial allergic rhinitis, and chronic idiopathic urticaria.

What indications does ZYRTEC Allergy cover in the US

• Seasonal allergic rhinitis
• Perennial allergic rhinitis
• Chronic idiopathic urticaria
• Common OTC labeling also supports symptom control for runny nose, sneezing, itchy/watery eyes, and itching.

What formulations drive brand shelf presence

Common US OTC/brand formats include:

• Tablets/caplets
• Liquid solution (including pediatric dosing)
• Dissolving tablets or chewable formats (brand-dependent by period/channel)

What is the latest clinical trials update for cetirizine (ZYRTEC) allergy?

Direct answer: For cetirizine, the clinical evidence base is dominated by older randomized efficacy studies and postmarketing safety/real-world studies rather than active phase-3 “new-to-world” development, because cetirizine is off patent for the drug substance and the standard of care is well established.

What kinds of trials typically appear for mature cetirizine products

For older small molecules, the active trial pipeline tends to be:

• Bioequivalence studies for generic/authorized generic dosage forms
• Pediatric dosing studies and palatability/safety evaluations for liquid/dissolving presentations
• Comparative trials versus other second-generation antihistamines (symptom control, onset timing, sedation profile)
• Real-world outcomes studies using claims or electronic health records

What to expect from “clinical updates” in a mature OTC market

Clinical updates that materially affect revenue tend to be:

• New formulation approvals that improve dosing convenience
• Label refinements supported by postmarketing data
• Trial outcomes that influence payer or formulary preferences in non-OTC or managed-care contexts

What is the market size, growth rate, and demand drivers for ZYRTEC Allergy?

Direct answer: ZYRTEC Allergy participates in the large US OTC antihistamine market. Demand is driven by:

• Seasonal allergy incidence patterns (weather variability)
• OTC consumer switching and promotions
• Pediatric dosing convenience
• Brand trust and pharmacy channel execution

Key demand drivers

• Seasonality: spring/fall peaks for allergic rhinitis
• Pediatrics: liquid and pediatric-friendly presentations expand household adoption
• Chronic urticaria: continuous self-management keeps baseline demand
• Sedation differentiation: cetirizine is “moderately” sedating relative to some non-sedating alternatives, which shapes consumer preference during daytime use

Channel economics that matter most

• Pharmacy and mass retail promotions during peak allergy weeks
• Private label and generic shelf take-rate
• Package-size optimization and subscription/club-store distribution where offered

How does ZYRTEC (cetirizine) compare with other OTC allergy drugs in efficacy and sedation?

Direct answer: Cetirizine is generally perceived as effective for allergic symptoms with modest sedation risk. Competitors include loratadine (Claritin), fexofenadine (Allegra), and levocetirizine (Xyzal), plus intranasal steroids in allergic rhinitis.

Typical comparative positioning in the market

• Cetirizine: faster perceived onset versus some alternatives, more sedation than fexofenadine
• Loratadine: less sedation but sometimes slower perceived relief
• Fexofenadine: low sedation profile; often chosen for daytime
• Levocetirizine: marketed as similar efficacy to cetirizine with a “cleaner” sedation perception, depending on consumer

When does cetirizine (ZYRTEC) lose exclusivity in the US and why is it mostly generic now?

Direct answer: The drug substance cetirizine hydrochloride is long out of New Molecular Entity exclusivity windows, and the core product is not meaningfully constrained by remaining exclusivity in the US. As a result, market access is largely enabled by generic manufacturing and OTC switching.

Exclusivity drivers that are no longer binding

• Drug-substance composition protections
• New formulation exclusivities (if any) are typically limited and format-specific
• Orphan/exclusivity constructs do not apply to this established OTC drug class

What patents protect ZYRTEC Allergy (cetirizine) in 2026, and what is the effective patent estate?

Direct answer: For a mature OTC small molecule like cetirizine, the remaining protectable subject matter is usually narrow and format-specific, and the practical patent landscape is dominated by generic entries already on the market.

Where residual IP typically exists

• Specific formulation compositions (excipients, controlled-release/dissolving technologies)
• Specific device-like dosing systems (if any)
• Method-of-use claims are usually limited by broad prior art and older clinical literature
• Packaging and brand trade dress are generally not a barrier to generic pharmacological substitution

Practical IP implication

For ZYRTEC Allergy, the effective IP estate is not a primary gating factor for additional generic or authorized generic entries. Competitive pressure is driven by OTC market dynamics rather than litigation risk.

What is the Orange Book status of cetirizine (ZYRTEC) and what does that mean for generic entry risk?

Direct answer: Cetirizine is represented in the FDA Orange Book largely through older listings with many generics. For an OTC switch, the key question is whether any specific dosage form has active unexpired patents. In practice, most cetirizine presentations have available generic manufacturing routes.

Generic entry risk profile

• If a dosage form has no unexpired listed patents, generic entry is lower-friction
• If a dosage form has listed patents, entry timing becomes product-form specific (tablet vs liquid vs dissolving)

How many manufacturers sell cetirizine allergy products, and what does that do to pricing?

Direct answer: The US market for cetirizine has multiple generic and authorized generic manufacturers, which compresses pricing versus branded-only models.

Pricing and margin mechanics

• Brand premium declines as generic share increases
• Promotions and pharmacy rebates dominate near-term price realization
• Shelf placement is a primary marketing lever

What competitive landscape risks exist for ZYRTEC Allergy versus loratadine and fexofenadine?

Direct answer: Key risks are:

• Continued private label expansion for second-generation antihistamines
• Consumer switching to lower-sedation options (fexofenadine) for daytime use
• Cross-category competition from intranasal steroid products for allergic rhinitis control

What changes consumer switching

• Onset expectations
• Sedation experiences
• Product format preference (liquid for children; dissolving for convenience)

What generic entry scenarios exist for cetirizine dosage forms (tablets, liquid, dissolving)?

Direct answer: For already-mature dosage forms, entry scenarios are generally:

• Immediate generic/authorized generic competition when no active patents are listed for that specific formulation
• Entry delay only if a particular presentation has remaining listed patents or format-specific formulation protections

Operational entry barriers

• Bioequivalence completion timelines for each strength/form
• Manufacturing scale and stability for liquid/rapid dissolving formats
• Quality system capacity and OTC compliance

What clinical evidence most influences formulary and consumer choice for cetirizine allergy?

Direct answer: In practice, consumer choice is shaped by:

• Symptom control (rhinitis and urticaria)
• Perceived onset
• Side effect profile (sedation)
• Convenience and dosing

What payers and healthcare providers look at

• Comparative tolerability and sedation
• Real-world persistence and breakthrough symptom rates
• Pediatric compliance characteristics for liquid/chewable forms

Key takeaways

• ZYRTEC Allergy is a mature cetirizine franchise with demand driven by seasonal patterns, pediatric dosing convenience, and channel execution rather than new clinical differentiation.
• Clinical “updates” for cetirizine are mostly formulation and bioequivalence-related or real-world evidence rather than late-stage efficacy pivots.
• US exclusivity is not a binding constraint for new generic competition; remaining IP (if any) is format- and claim-specific and rarely shifts market access at the drug-substance level.
• The competitive battleground is OTC switching versus loratadine/fexofenadine and intranasal steroid strategies, with sedation perception and onset timing the dominant differentiators.

FAQs

1. Does cetirizine have any active patent barriers for specific OTC formats in the US?
2. How does cetirizine’s sedation risk compare with fexofenadine for daytime allergy control?
3. What types of FDA submissions drive changes for OTC cetirizine products (new strengths vs new formulations)?
4. How do seasonality and weather patterns typically affect cetirizine sales volumes quarter to quarter?
5. What real-world outcomes are most commonly assessed for antihistamines like cetirizine (persistence, breakthrough symptoms, sleep effects)?

References

No sources were provided in the prompt, and no verifiable external data (Orange Book listings, trial registry entries, FDA approvals, or revenue figures) were included.