ALLEGRA+ALLERGY - 505(b)(2) development and clinical trial profile

All Clinical Trials for ALLEGRA ALLERGY

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Trial ID	Title	Status	Sponsor	Phase	Start Date	Summary
NCT00103012 ↗	Drug Interactions of Echinacea, Ginseng, and Ginkgo Biloba Taken With Lopinavir/Ritonavir in Healthy Volunteers	Completed	National Institutes of Health Clinical Center (CC)	Phase 4	2005-01-01	This study will examine the interaction of the HIV combination medication lopinavir/ritonavir with the herbal products echinacea, ginseng, and ginkgo biloba. Patients with HIV infection often take herbal products and dietary supplements in addition to their doctor-prescribed medicines to treat the disease, lessen the side effects of anti-viral drugs, and improve their overall well being. Alternative medicines such as these may, however, interfere with the elimination of lopinavir/ritonavir from the body, causing either higher or lower blood levels of these drugs than would be expected. This study will assess in healthy subjects any potential harms of taking echinacea, ginseng, or ginkgo biloba together with lopinavir/ritonavir. Healthy normal volunteers between 18 and 50 years of age may be eligible for this study. Candidates are screened with a history, physical examination, and blood tests, including an HIV test and a pregnancy test for women. Pregnant women are excluded from the study. Participants come to the NIH Clinical Center after fasting overnight for the following procedures: Visits 1 and 2: A catheter (plastic tube) is placed in an arm vein to collect blood samples. After the first sample is drawn, the subject takes 8 mg of midazolam syrup and two fexofenadine tablets. Midazolam is a sedative, and fexofenadine (Allegra) is a medicine used to treat allergies. Subjects are given breakfast an hour after taking the drugs. Blood samples are collected at 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 5, 6, 8 and 24 hours after taking the drugs to measure blood levels of fexofenadine. An extra sample is collected at the 4-hour mark to measure the midazolam level. The catheter is removed after the 8-hour blood draw and subjects are dismissed home. They return the following morning (visit 2) for the 24-hour blood draw. Visit 3: From 7 to 28 days after visit 1, subjects begin taking lopinavir/ritonavir capsules twice a day by mouth for a total of 29.5 days. On day 15 they return to the clinic for lopinavir/ritonavir blood levels as were done for fexofenadine, except that samples are collected once before breakfast and then at 0.5, 1, 2, 3, 4, 6, 8 and 12 hours after the lopinavir/ritonavir dose. An extra sample is collected for routine tests. The catheter is removed after the 12-hour draw and the subject is dismissed home. The next morning, subjects begin taking one of the following: echinacea 500 mg 3 times a day; ginkgo biloba 120 mg twice a day; or ginseng 500 mg 3 times a day for 28 days. Visit 4: On the last day of taking lopinavir/ritonavir, subjects return to the clinic again for blood level measurements of these drugs as on visit 3, except that the catheter is removed and the subject dismissed home after the 8-hour blood draw. Visits 5 and 6: On the last day of taking the herbal supplement, subjects return to the clinic for repeat measurement of fexofenadine and midazolam levels, as described in visits 1 and 2. At the final visit (visit 6) an additional blood sample is collected for repeat laboratory testing. ...
NCT00261079 ↗	Fexofenadine in Pruritic Skin Disease	Completed	Handok Inc.	Phase 4	2005-04-01	Primary objective: - To compare the efficacy and safety profile of Fexofenadine 180mg tablets plus prednicarbate(2.5mg/g) vs prednicarbate(2.5mg/g) alone in the treatment of pruritic skin disease Secondary objective: - To evaluate patient's satisfaction of Allegra treatment
NCT00261079 ↗	Fexofenadine in Pruritic Skin Disease	Completed	Handok Pharmaceuticals Co., Ltd.	Phase 4	2005-04-01	Primary objective: - To compare the efficacy and safety profile of Fexofenadine 180mg tablets plus prednicarbate(2.5mg/g) vs prednicarbate(2.5mg/g) alone in the treatment of pruritic skin disease Secondary objective: - To evaluate patient's satisfaction of Allegra treatment
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.
NCT00562120 ↗	A Study to Test a New Decongestant in Patients With Allergic Rhinitis Following a Nasal Allergen Challenge	Completed	Pfizer	Phase 2	2007-12-01	An H3 receptor antagonist should reduce the congestion associated with allergic rhinitis. A nasal allergen challenge will be given to patients to induce rhinitis symptoms and acoustic rhinometry will be used to measure the congestion.
NCT00636870 ↗	Fexofenadine (Allegra®) in Healthy Adults Who Have Been Identified as Slow Metabolizers for Desloratadine	Completed	Sanofi	Phase 4	2003-02-01	To evaluate the single-dose and steady-state pharmacokinetics of desloratadine and fexofenadine in desloratadine slow metabolizers. To evaluate the safety and tolerability of desloratadine compared to fexofenadine following single and multiple oral doses administered to desloratadine slow metabolizers.
>Trial ID	>Title	>Status	>Sponsor	>Phase	>Start Date	>Summary

Condition Name for ALLEGRA ALLERGY
Healthy	10
Seasonal Allergic Rhinitis	6
Allergic Rhinitis	5
Atopic Dermatitis	2
[disabled in preview]	1
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Condition MeSH for ALLEGRA ALLERGY
Rhinitis, Allergic	16
Rhinitis	16
Rhinitis, Allergic, Seasonal	8
Eczema	2
[disabled in preview]	1
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Trials by Country for ALLEGRA ALLERGY
United States	14
Canada	4
Japan	3
India	3
Austria	1
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Trials by US State for ALLEGRA ALLERGY
New Jersey	3
North Dakota	2
West Virginia	2
Kentucky	1
Nebraska	1
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Clinical Trial Phase for ALLEGRA ALLERGY
Phase 4	13
Phase 3	3
Phase 2/Phase 3	2
[disabled in preview]	16
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Clinical Trial Status for ALLEGRA ALLERGY
Completed	30
Not yet recruiting	2
Recruiting	2
[disabled in preview]	1
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Sponsor Name for ALLEGRA ALLERGY
Sanofi	8
Dr. Reddy's Laboratories Limited	5
Merck Sharp & Dohme Corp.	5
[disabled in preview]	6
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Sponsor Type for ALLEGRA ALLERGY
Industry	30
Other	8
NIH	1
[disabled in preview]	1
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Last updated: July 28, 2026

Allegra Allergy is a brand of fexofenadine (antihistamine, H1 receptor antagonist) used for seasonal allergic rhinitis and chronic idiopathic urticaria. Clinical development activity is now dominated by new formulations, pediatric studies, and lifecycle work rather than novel mechanisms. Near- and mid-term market growth is driven by generic penetration management, channel mix, and OTC-to-Rx conversion patterns, with revenue largely dependent on price-to-generic dynamics and brand share retention.

What is Allegra Allergy (fexofenadine) and what clinical trials are active or recently completed?

Answer: Recent activity around Allegra is concentrated in lifecycle and regulatory studies, including bioequivalence (BE), pediatric positioning, and formulation optimization. Standalone “new drug” phase programs for fexofenadine are limited because the active ingredient’s core clinical evidence is established.

Trial landscape: what kinds of studies still show up

Common contemporary trial categories for fexofenadine products include:

Pharmacokinetic/bioequivalence studies for tablet, orally disintegrating, liquid, and dose-strength changes.
Pediatric studies tied to labeling expansion.
Food-effect and formulation equivalence work for reformulated products.
Real-world/observational studies that support market access and label maintenance rather than core efficacy claims.

How to read the “clinical trials update” signal for fexofenadine

For brands like Allegra, “activity” is often less about Phase 2/3 outcomes and more about:

maintaining OTC suitability and label consistency
executing regulatory comparability when changing excipients or manufacturing sites
supporting new dosage forms that preserve differentiation in a generic market

Which patents protect Allegra Allergy (fexofenadine) and how strong is the patent estate?

Answer: The patent estate for fexofenadine as an active ingredient is largely historically expired or near-expired, shifting the practical protection focus to formulation-specific, process-specific, and product-manufacturing patents for specific Allegra presentations.

Where protection tends to concentrate for an established OTC antihistamine

Controlled-release or modified-release formulations (if any are tied to specific SKUs)
Orally disintegrating or liquid formulation IP
Process patents for manufacturing robustness and stability
Trademarks and exclusivity are more important commercially than core composition patents

What this means for generic competition

Generics generally rely on bioequivalence to enter.
Brand differentiation is maintained through form factor, dosing experience, and channel strategy, not new IP barriers.

What is the FDA regulatory status of Allegra Allergy and what is listed in the Orange Book?

Answer: Allegra Allergy products are marketed under established FDA approvals for fexofenadine dosage forms. The regulatory status is mature, with extensive generic competition. Orange Book coverage is typically dominated by:

the innovator brand reference product(s)
multiple ANDA entries for therapeutically equivalent generic fexofenadine products

OTC vs Rx relevance

Many fexofenadine products are available OTC, which compresses brand pricing latitude and reduces exclusivity value beyond formulation differentiation.

When does Allegra Allergy lose exclusivity and when can generics fully enter?

Answer: Allegra’s market exclusivity for fexofenadine is already well past initial new-molecular-entity exclusivity. The practical timing now is tied to:

presentation-level changes (BE, manufacturing, formulation)
expiration of any product-specific patents listed for particular Allegra SKUs

Typical “post-original” exclusivity reality

For established small-molecule antihistamines:

new entries are usually not blocked by fresh exclusivity
launch risk is primarily about ANDA approvals and switch-back timing in payer and retail systems

What patent litigation affects fexofenadine (Allegra) and what Paragraph IV challenges exist?

Answer: Because fexofenadine has long-established presence and OTC scale, Paragraph IV litigation is not consistently a primary driver of market access in the modern window for most geographies. Where disputes occur, they are usually tied to specific formulation/device patents rather than the core molecule.

Litigation impact pathway

Even if litigation occurs, it usually targets narrow product attributes.
Settlement and consent decrees generally influence timing only for the specific disputed entries.

What formulations are protected by Allegra Allergy and how do they compare with generic dosage forms?

Answer: Allegra is marketed in multiple presentations, commonly including:

tablets (including different strengths)
orally disintegrating tablets (for some markets)
oral suspension/liquid (for pediatric convenience, depending on SKU and country)

Commercial comparability

Generic products typically match:

active ingredient and strength
dosing regimen
key excipients for BE purposes

Differentiation that can persist includes:

tablet feel, speed of disintegration (for OD tablets)
pediatric palatability for liquid
distribution and pharmacist familiarity

How does Allegra Allergy compare with Zyrtec (cetirizine) and Claritin (loratadine) on market and differentiation?

Answer: Allegra competes in the non-sedating or “less sedating” antihistamine class, where brand positioning, perceived drowsiness risk, and channel dominance drive share. Relative performance is shaped by:

retail shelf placement
OTC bundle promotions
seasonal demand cycles
pharmacist recommendation patterns

Competitive behavior in an OTC-heavy class

Generic availability constrains pricing for all incumbents.
Brand growth depends on retaining incremental consumers who value specific presentation or sensation profile.

Which companies market fexofenadine products that compete with Allegra and what launch risks exist for generics?

Answer: The competitor set includes:

multiple ANDA manufacturers supplying generic fexofenadine in tablets/OD tablets/suspension (where applicable)
branded alternatives in the same therapeutic space (cetirizine, loratadine)
PBM and retail label-management systems influencing switching

Launch risk mapping

High risk where patents tied to specific SKUs are weak or expired.
Medium risk only where formulation/device/process patents remain enforceable for specific presentations.

What is the market size for fexofenadine/Allegra and what are the revenue drivers?

Answer: The market for OTC antihistamines is large and seasonal, with fexofenadine forming a meaningful segment within second-generation H1 antihistamines. Revenue drivers are:

season length and severity (pollen, weather patterns)
retail promotional intensity
share of shelf versus generics
price premium sustainability for Allegra where consumers remain brand-loyal
channel mix (mass retail vs pharmacy vs online)

Key sensitivities

A mild allergy season reduces unit volume.
Higher generic penetration reduces realized price and marketing ROI.
Increased co-pay constraints or retailer planogram changes drive switching.

How should sales projections for Allegra Allergy be modeled over the next 3–5 years?

Answer: A practical projection framework for Allegra is built on three components:

Unit volume trajectory from seasonal demand and market share
Net price trajectory shaped by generic mix and promotional intensity
Presentation mix shifting between tablets, OD tablets, and liquid

Baseline projection logic (structure, not speculative numbers)

Assume stable-to-slightly declining share versus generics as pricing equalizes.
Model unit growth as linked to seasonality variability and minor channel recovery.
Model price erosion as linked to generic substitution rate and OTC promotion cycles.
Include milestone effects for any new presentation rollouts or label expansions.

Scenario ranges (qualitative)

Bear case: steeper price erosion and weaker shelf differentiation; faster share migration to lower-cost equivalents.
Base case: modest share stability; continued price compression; seasonal volume variability smooths annual totals.
Bull case: improved OTC marketing efficiency and stronger OD-tablet or pediatric SKU performance, limiting share decline.

What to watch for in the projection window

retailer planograms and promotion intensity each spring
changes in BE requirements or manufacturing comparability that cause supply constraints
new OTC rules or state-level pharmacy practice affecting recommendations

Where do clinical development updates actually affect Allegra market outcomes?

Answer: For an established antihistamine, clinical updates matter mainly through:

enabling new or maintained labeling (pediatric dosing, symptom scope)
supporting formulation changes that keep the brand competitive on user experience
sustaining regulatory compliance that prevents supply gaps

Commercial translation mechanism

Label support and new dosage forms can reduce conversion friction for parents (pediatric liquid) and for convenience-seeking consumers (OD tablets).
Supply reliability can be a more immediate driver than new efficacy data.

How does Allegra’s risk profile compare with novel allergy biologics and other antihistamines?

Answer: Allegra’s risk profile is lower on clinical success but higher on pricing erosion and patent maturity. Novel agents face:

higher clinical/regulatory uncertainty
payer access constraints
long enrollment-to-revenue timelines

Allegra’s execution risk sits primarily in:

competitive pricing
OTC channel dynamics
lifecycle product execution rather than clinical innovation.

Key Takeaways

Allegra Allergy (fexofenadine) is a mature, high-penetration OTC antihistamine with clinical activity now skewing to lifecycle, BE, and regulatory/pediatric support rather than novel Phase 2/3 efficacy.
Patent protection is largely not a broad molecule-level barrier in the current period; practical protection tends to be SKU-specific.
Market outcomes are dominated by generic substitution, season severity, and retail promotional intensity rather than by fresh clinical trial breakthroughs.
Sales projection over 3–5 years should be modeled via units (seasonal demand and share) plus net price (generic mix and promotions) plus presentation mix shifts.

FAQs

What are the most common Allegra (fexofenadine) dosing forms sold in the US and how do generics mirror them?
Do Allegra’s pediatric label indications affect market share versus generic fexofenadine?
How does allergy season variability change annual fexofenadine unit sales and pricing?
Which OTC channels most influence Allegra brand retention in a generic-heavy market?
What formulation characteristics (OD vs tablets vs liquid) drive consumer switching or brand loyalty?

References (APA)

U.S. Food and Drug Administration. (n.d.). Drug Approval Reports and label information for fexofenadine-containing products. https://www.fda.gov/drugs
U.S. Food and Drug Administration. (n.d.). Drugs@FDA database. https://www.accessdata.fda.gov/scripts/cder/daf/
U.S. Food and Drug Administration. (n.d.). Orange Book: Approved Drug Products with Therapeutic Equivalence Evaluations. https://www.accessdata.fda.gov/scripts/cder/ob/

CLINICAL TRIALS PROFILE FOR ALLEGRA ALLERGY