Dose‑finding trial of a mannan‑conjugated Phleum pratense/Dactylis glomerata allergoid vaccine in patients with grass‑pollen allergic rhinitis or rhinoconjunctivitis

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What is this study about?

The study focuses on grass pollen induced allergic rhinitis or rhinoconjunctivitis, a condition that causes sneezing, a runny or blocked nose, and itchy, watery eyes when a person is exposed to grass pollen. The investigation will test a new allergy vaccine called polymerised mannan-conjugated allergoid Dactylis glomerata/Phleum pratense (code name EP-088_MG58) that is given subcutaneously – meaning the medicine is injected just under the skin. The main goal of the trial is to find which of two dose strengths provides the best relief of symptoms while remaining safe.

Participants will be randomly assigned to receive either a low‑dose, a high‑dose, or a placebo (a harmless substance that looks the same as the vaccine) in a series of injections spread over several weeks. After the dosing period, they will be followed throughout the grass pollen season and asked to note each day how severe their symptoms are and whether they need any allergy medication. The key result the study will look at is the average daily Combined Symptom and Medication Score (CSMS), a single number that combines the intensity of symptoms with the amount of rescue medicine used, to see how well the vaccine works compared with the placebo. Safety checks will be performed throughout the study.

1 randomization and first injection

after joining the trial you are assigned to one of two concentrations of the investigational product: 3000 mTU/mL or 9000 mTU/mL.

the product is given as a subcutaneous injection (injection under the skin) on the day of the first visit.

the exact amount of the injection follows the study protocol; the unit mTU (million therapeutic units) is used to describe the strength of the allergen preparation.

2 subsequent injections

you receive additional subcutaneous injections of the same concentration at the times defined by the study schedule.

each injection is administered by study staff during scheduled clinic visits.

the frequency and total number of injections are determined by the trial protocol and are the same for all participants in the same concentration group.

3 daily symptom and medication recording

during the peak grass pollen season in 2027 you record each day the severity of nasal and eye symptoms and any rescue medication you take.

the information is entered in a diary or electronic device provided by the study.

these records are used to calculate the combined symptom and medication score (CSMS), the primary outcome of the trial.

4 final assessment

after the pollen season you attend a final visit where study staff review your symptom diary and perform a clinical evaluation.

the data are analysed to compare the effectiveness and safety of the two concentrations.

you receive a summary of the study results and any follow‑up instructions.

Who Can Join the Study?

  • Age: You must be between 18 and 64 years old.
  • Kidney and liver health: Blood tests must show normal kidney and liver function. Small differences that are not serious (grade 2 or lower) are allowed, but larger problems mean you cannot join.
  • Allergy blood test (specific IgE): A blood test must show a certain level of antibodies (IgE) against grass pollen (Phleum pratense) – at least 0.7 kU/L. IgE are proteins that the immune system makes when you are allergic.
  • Pregnancy test for women who could become pregnant: A blood test (and later a urine test) must show that you are not pregnant.
  • Signed consent: You must sign and date an Informed Consent Form, confirming that you understand the study and agree to take part.
  • Overall health: You should be in good physical and mental health.
  • History of moderate or severe grass‑pollen allergy: You need a medical record showing that you have had moderate to severe allergic rhinitis (runny, itchy nose) or rhinoconjunctivitis (nose plus eye symptoms) caused by grass pollen for at least two past pollen seasons.
  • Previous allergy medication use: You must have used allergy medicines for at least two grass‑pollen seasons before joining the study.
  • Positive skin prick test: A doctor must perform a skin prick test that shows a small raised bump (wheal) at least 3 mm wide when grass pollen is applied, a similar reaction to a histamine control, and a tiny or no reaction (<2 mm) to a saline control. This test checks if your skin reacts to the allergen.
  • Contraception for women who could become pregnant: You must agree to use a highly effective birth‑control method (such as hormonal pills, implants, intrauterine device, tubal ligation, or a partner who has had a successful vasectomy) and have a negative urine pregnancy test.
  • Women who cannot become pregnant: If you are pre‑menarche (haven’t started periods), have had a hysterectomy, tubal ligation, or are post‑menopausal (no periods for 12 months), you are eligible.
  • Controlled allergic asthma: You must have a diagnosis of allergic (extrinsic) bronchial asthma that is well‑controlled according to the Global Initiative for Asthma (GINA) guidelines (steps 1‑3) and this must have been confirmed within the last four weeks and remain controlled during the trial.
  • Lung function criteria: If you have any breathing disorder such as asthma or COPD, your lung test results must show at least 80 % of the normal value for either forced expiratory volume in one second (FEV1) or peak expiratory flow (PEF). These tests measure how well you can breathe out air.
  • Allergy symptom score (CSMS): During a screening period, you must have a moderate to severe level of allergy symptoms measured by the Combined Symptom and Medication Score (CSMS), with a score between 1.3 and 5.5 on the worst 14‑day period out of 30 days.

Who Cannot Join the Study?

  • Participating in another clinical trial now or within 30 days, or not having a sufficient wash‑out period (at least 5 half‑lives) from a previous investigational drug.
  • Having a positive skin test (SPT) to other allergens such as Alternaria mold, house dust mites, cat or dog dander when those allergies are clinically important or you are exposed to them.
  • Having had a severe systemic allergic reaction (grade III/IV) or anaphylaxis to foods (e.g., peanuts, shellfish), bee/wasp stings, or medicines (e.g., penicillin).
  • Being allergic to any ingredient (excipients) in the study drug or placebo.
  • Having non‑allergic (intrinsic) asthma.
  • Having allergic asthma that is only partly controlled or uncontrolled, according to the GINA asthma guidelines, within 4 weeks before screening or during treatment.
  • Having allergic asthma, emphysema, or other lung problems with a forced expiratory volume in 1 second (FEV1) or peak expiratory flow (PEF) less than 80 % of the normal value.
  • Having a recent upper or lower respiratory infection (within the past 2 weeks) or a recent flare‑up of lung disease (within the past 4 weeks).
  • Having serious kidney disease or chronic liver disease.
  • Having an active cancer, or a history of cancer in the past five years.
  • Having a severe autoimmune disease.
  • Receiving allergy shots (immunotherapy) with grass pollen in the last 5 years.
  • Having immune system problems such as immunosuppression or immunopathies.
  • Receiving any vaccination during the treatment period, except flu or COVID‑19 vaccines.
  • Using systemic immunosuppressive medicines (e.g., oral steroids, methotrexate, cyclosporine A).
  • Having any other major inflammatory disease, either acute or chronic.
  • Having other serious chronic illnesses such as severe heart failure, heart insufficiency, active stomach ulcer, inflammatory bowel disease, uncontrolled diabetes, etc.
  • Taking antidepressant or antipsychotic drugs that have strong antihistamine effects (e.g., tricyclic antidepressants, mirtazapine, quetiapine).
  • Receiving or planning to receive biologic therapies (therapeutic antibodies), mast‑cell stabilizers, or anti‑leukotriene drugs.
  • Taking beta‑blocker or ACE‑inhibitor medications.
  • Having active tuberculosis.
  • Having any condition that makes the use of adrenaline unsafe (including an overactive thyroid).
  • Currently receiving allergy shots for grass pollen or any other allergen.
  • Testing positive for HIV, hepatitis B, or hepatitis C antibodies.
  • Being pregnant, breastfeeding, or able to become pregnant and not using a highly effective birth‑control method.
  • Using systemic or nasal steroids or antihistamine medicines within the required time before the trial (except routine asthma control medication).
  • Keeping a diary for fewer than 14 days during the 30‑day pre‑treatment observation period.
  • Having a skin‑test (CAP) class 2 or higher (IgE ≥ 0.7 kU/L) to Alternaria mold, or having laboratory values for kidney or liver function that are higher than grade 2 according to FDA guidance and remain abnormal after a repeat test.
  • Experiencing an acute allergic rhinitis or rhinoconjunctivitis caused by other environmental allergens during the observation period.
  • Having any personal or financial relationship with the sponsor, CRO, or investigator that could influence the study.
  • Being unable to understand the study instructions or documents.
  • Being judged by the investigator as unlikely to follow the study rules (e.g., known alcohol or drug abuse, serious psychiatric disorder, unwillingness to give consent or follow requirements).
  • Being under legal custody or institutional commitment by court or administrative order.
  • Not having access to a smartphone or tablet (iOS or Android) needed for the study diary (paper diary only allowed in rare technical cases).

Where you can join this trial?

Verified and Recommended Sites

No sites found in this category

Verified Sites

Site Name City Country Status
Hautarztpraxis Dr. Mihaescu Augsburg Germany
Hautzentrum Friedrichshain Berlin Germany
Technische Universitaet Dresden Dresden Germany
Pneumologisches Studienzentrum München-West Munich Germany
HNO Praxis Dr. Sonja Runge Neuenhagen Germany
MVZ Dr. Kasche und Kollegen GmbH Hamburg Germany

Other Sites

Site Name City Country Status
Klinische Forschung Osnabrueck Osnabrück Germany
Pgrscb Drw Jmkk Wbqduap Pqeemyzjeufxgux Skafrrvrncvenn Leipzig Germany
Sumlbxzadddguf Dvq Cairxlvdf Scabyiksz Peine Germany
Pgsuybxklxwdocgeumfry Mhzxueh Marburg Germany
Sxcxhwledvuzrr Dmc Sykjgd Luntpzby Saalfeld Germany
Bosmxihxizmktwsugxstijcbatrk Blt Pgpp Dvd Mno Grpetvt Hnnpszxh Dxt Mdv Ayaeutf Bzstgf Gxl Leipzig Germany
Hbu Pplwdv Dptgwiar Dreieich Germany
Pjrihx fwr Her uou Ayixaiseuvhv Dys Yuul Ylwui Dresden Germany
Gyie Gkrykkoqzztk fijq Eyzojvdlpocixo uht Ksgalkrxy Akflleiactpxvxlcb msu Wiesbaden Germany
Pyfkiy Dex Tsjjee Ghssn Bonn Germany
Ecurqjuebaep Gxov Essen Germany
Pclbuffkddonlnqffj Rogowt &gttu Ppyrhwo Schorndorf Germany
Hdl Phvxio Djuxolw Dvv mnxv Uwq Sufmhxu Dresden Germany
Cestcswdtd Guoe Wuppertal Germany
Bdaxprmdfrmex Fkerebzr Wsfaiqi Neu-Isenburg Germany
Mhyjrhde Grhp Frankfurt Germany
Hyx rmxzufht Gtzp Itzehoe Germany
Htc Pwytdy Dgp Ttuznc Duisburg Germany
Kshdrowq Sqnmpsntyw Ksazvi fwo Dmesmhfsieam awe Avuwuwhyrqrwc Ababllnkhtctnosmph Axjiyjzd 3 Stuttgart Germany
Mjjvttreixf Evajs Bpzopqj Essen Germany

Want to learn more about this study or check if you can participate? Contact us.

Trial status

Country Status Recruitment Start
Germany Germany
Not recruiting
01.06.2026

Trial locations

Mometasone nasal spray is a steroid spray used in the nose to reduce inflammation and relieve symptoms of allergic rhinitis such as sneezing, runny nose, and congestion. In the trial it was allowed as a background medication for participants who needed ongoing nasal steroid therapy.

Budesonide nasal spray is another nasal steroid that helps calm inflamed nasal passages and eases allergy symptoms. Participants could continue using it during the study if it was part of their regular treatment.

Bilastine tablets are oral antihistamine pills that block the action of histamine, a chemical that causes itching, sneezing, and watery eyes in allergies. They were permitted as a background medication for people who required daily allergy relief.

Triamcinolone acetonide nasal spray is a steroid spray that reduces swelling in the nasal lining, helping to control nasal allergy symptoms. It could be used by participants as part of their usual care.

Grass pollen skin‑prick test solution (Phleum pratense) is a small amount of grass pollen extract applied to the skin to check if a person is allergic to grass pollen. It was used in the study to confirm participants’ allergy status.

Emedastine eye drops are eye‑drop medication that relieves itchy, red, and watery eyes caused by allergic reactions. Participants could continue using them if they already needed eye‑drop treatment.

Ebastine tablets are oral antihistamine pills that help control sneezing, itching, and runny nose by blocking histamine. They were allowed as background therapy for allergic symptoms.

Cetirizine tablets are commonly used oral antihistamines that reduce allergy signs such as sneezing and itching. They could be taken by participants during the trial.

Desloratadine tablets are non‑sedating antihistamine pills that help relieve nasal and eye allergy symptoms. Participants were permitted to use them as part of their regular allergy regimen.

Fexofenadine tablets are oral antihistamines that relieve allergy symptoms without causing drowsiness. They were allowed as background medication.

Fluticasone furoate nasal spray is a steroid spray that reduces nasal inflammation and congestion associated with allergies. Participants could keep using it if it was part of their normal treatment.

Bilastine eye drops are eye‑drop antihistamines that help relieve itchy and watery eyes caused by allergies. They could be used by participants who needed eye‑drop therapy.

Cat epithelia skin‑prick test solution contains proteins from cat skin and is used to test for cat allergy by a small skin prick. It helped confirm participants’ sensitivity to cat allergens.

Olopatadine eye drops are antihistamine eye drops that reduce itching, redness, and tearing caused by allergic eye reactions. Participants could continue using them if prescribed.

Mannan‑conjugated allergoid vaccine (grass pollen) is the investigational product being tested. It is a specially processed mixture of grass pollen proteins (from Phleum pratense and Dactylis glomerata) linked to a harmless sugar molecule (mannan) to reduce allergic reactions while stimulating the immune system. It was given by subcutaneous injection at two different concentrations to see which works best for treating grass‑pollen allergic rhinitis.

Histamine dihydrochloride positive control solution is a tiny amount of histamine used during skin‑prick testing to show that the skin reacts normally. It served as a reference point for the allergy skin tests in the study.

Rupatadine tablets are oral antihistamines that also have anti‑inflammatory effects, helping to control nasal and eye allergy symptoms. They could be used by participants as part of their usual care.

Dog epithelia skin‑prick test solution contains proteins from dog skin and is used to test for dog allergy through a small skin prick. It helped identify participants with dog‑related allergic sensitivity.

Histamine dihydrochloride positive control (alternative preparation) is another form of the histamine reference solution used during skin‑prick testing to confirm proper skin reactivity.

Alternaria alternata skin‑prick test solution contains mold spores from the fungus Alternaria and is used to test for mold allergy. It was part of the allergy testing panel.

Azelastine eye drops are antihistamine eye drops that quickly relieve itchy, red, and watery eyes caused by allergies. Participants could keep using them if needed.

Grass pollen mixture skin‑prick test solution combines extracts from many common grass species to test for broad grass‑pollen allergy. It helped verify participants’ sensitivity to a range of grass pollens.

Levocetirizine tablets are a newer, non‑sedating antihistamine that reduces sneezing, itching, and runny nose. They were allowed as background therapy.

Dermatophagoides pteronyssinus skin‑prick test solution contains dust‑mite allergen and is used to test for house‑dust‑mite allergy by a small skin prick. It helped confirm participants’ allergic status.

Levocabastine eye drops are antihistamine eye drops that relieve allergic eye symptoms such as itching and tearing. They could be used by participants during the trial.

Loratadine tablets are oral antihistamines that help control nasal and eye allergy symptoms without causing strong drowsiness. They were permitted as background medication.

Negative control solution (water for injection) is a harmless saline solution used in skin‑prick testing to show what a non‑reactive result looks like. It served as a baseline for the allergy tests.

Negative control solution (phenol) is another non‑reactive solution used in skin‑prick testing to ensure the skin’s response is specific to allergens. It acted as a negative control.

Ciclesonide inhalation solution is an inhaled steroid used for asthma and can also reduce airway inflammation. Participants with asthma could continue using it as part of their regular treatment.

Fluticasone propionate nasal spray is a steroid nasal spray that decreases swelling in the nose to improve breathing and reduce allergy symptoms. It was allowed as a background medication.

Allergic rhinitis – It is an inflammation of the nasal lining caused by an allergic reaction to airborne substances such as grass pollen. Symptoms start with sneezing, a runny or blocked nose, and itching. With continued exposure, the nasal lining becomes more swollen and mucus production increases. The condition often worsens during the pollen season and improves when the allergen is removed. Repeated seasonal exposure can make the symptoms return each year.

Allergic rhinoconjunctivitis – This condition combines the nasal symptoms of allergic rhinitis with eye irritation caused by the same allergen. After inhaling grass pollen, the eyes become red, itchy, and watery. Ongoing exposure leads to increased swelling of the eye surface and more discharge. Symptoms typically peak during the height of the pollen season and lessen when pollen levels drop. Repeated seasonal episodes can make the eyes more sensitive over time.

Trial ID:
2025-524580-21-00
Protocol code:
MG58-SIT-084
Trial Phase:
Therapeutic use (Phase IV)

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