Last reviewed 2026-05-30 · How we verify

Grazax + Aerius

ALK-Abelló A/S · Phase 3 active Small molecule Under review Quality 0/100

Grazax + Aerius is a Allergen immunotherapy + Antihistamine Small molecule drug developed by ALK-Abelló A/S. It is currently in Phase 3 development for Grass pollen-induced allergic rhinitis and/or allergic asthma.

Grazax is a sublingual immunotherapy tablet that desensitizes the immune system to grass pollen allergens, while Aerius (desloratadine) is an antihistamine that blocks histamine receptors to reduce allergic symptoms.

Grazax is a treatment for seasonal grass pollen-induced allergic rhinoconjunctivitis, and it is used in combination with Aerius, a histamine H1 receptor antagonist. Aerius is a small molecule that works by blocking the histamine H1 receptor.

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 name	Grazax + Aerius
Sponsor	ALK-Abelló A/S
Drug class	Allergen immunotherapy + Antihistamine
Target	Grass pollen allergens (Poa p 5) / H1 histamine receptor
Modality	Small molecule
Therapeutic area	Immunology / Allergy
Phase	Phase 3

Mechanism of action

Grazax works through allergen immunotherapy by gradually exposing the patient to increasing doses of grass pollen extract under the tongue, inducing immune tolerance and reducing allergic responses. Aerius is a selective H1-receptor antagonist that provides symptomatic relief by blocking histamine-mediated allergic reactions. The combination addresses both the underlying immune dysregulation and acute allergic symptoms.

Approved indications

Grass pollen-induced allergic rhinitis and/or allergic asthma

Common side effects

Oral pruritus
Throat irritation
Ear pruritus
Mouth edema
Somnolence (from Aerius)

Key clinical trials

A Trial Evaluating Tolerability of Grazax Treatment in Combination With Antihistamine (PHASE3)

Primary sources

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

Source	Used for
ClinicalTrials.gov	Trial 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:

Grazax + Aerius CI brief — competitive landscape report
Grazax + Aerius updates RSS · CI watch RSS
ALK-Abelló A/S portfolio CI

Frequently asked questions about Grazax + Aerius

What is Grazax + Aerius?

Grazax + Aerius is a Allergen immunotherapy + Antihistamine drug developed by ALK-Abelló A/S, indicated for Grass pollen-induced allergic rhinitis and/or allergic asthma.

How does Grazax + Aerius work?

What is Grazax + Aerius used for?

Grazax + Aerius is indicated for Grass pollen-induced allergic rhinitis and/or allergic asthma.

Who makes Grazax + Aerius?

Grazax + Aerius is developed by ALK-Abelló A/S (see full ALK-Abelló A/S pipeline at /company/alk-abell-a-s).

What drug class is Grazax + Aerius in?

Grazax + Aerius belongs to the Allergen immunotherapy + Antihistamine class. See all Allergen immunotherapy + Antihistamine drugs at /class/allergen-immunotherapy-antihistamine.

What development phase is Grazax + Aerius in?

Grazax + Aerius is in Phase 3.

What are the side effects of Grazax + Aerius?

Common side effects of Grazax + Aerius include Oral pruritus, Throat irritation, Ear pruritus, Mouth edema, Somnolence (from Aerius).

What does Grazax + Aerius target?

Grazax + Aerius targets Grass pollen allergens (Poa p 5) / H1 histamine receptor and is a Allergen immunotherapy + Antihistamine.

Drug class: All Allergen immunotherapy + Antihistamine drugs
Target: All drugs targeting Grass pollen allergens (Poa p 5) / H1 histamine receptor
Manufacturer: ALK-Abelló A/S — full pipeline
Therapeutic area: All drugs in Immunology / Allergy
Indication: Drugs for Grass pollen-induced allergic rhinitis and/or allergic asthma

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