In short
Poa pratensis pollen, depigmented polymerized extract is an investigational allergy immunotherapy being studied for allergic rhinoconjunctivitis with or without asthma caused by grass and olive pollen. Two Phase 3 trials are currently authorised, together planning to enrol 667 participants. The substance is given by subcutaneous injection as part of fixed-combination products developed by LETI Pharma, S.L.U.
Key points
- Poa pratensis pollen, depigmented polymerized extract is an investigational allergy immunotherapy, not yet authorised as a medicine.
- It is being studied in two Phase 3 trials for allergic rhinoconjunctivitis with or without asthma.
- The trials together plan to enrol 667 participants (343 and 324 respectively).
- The substance is given as a subcutaneous injection, in strengths of 1000 DPP/ml and 3000 DPP/ml.
- The main measure is the combined symptom and medication score (cSMS, 0-6) during peak pollen season.
- Both trials are currently authorised, meaning they are approved to begin or are ongoing.
What is Poa pratensis pollen, depigmented polymerized extract?
Poa pratensis pollen, depigmented polymerized extract is an investigational active substance used in allergen immunotherapy products. Its full registry name is Phleum pratense pollen, depigmented polymerized extract, Festuca elatior pollen, depigmented polymerized extract, Dactylis glomerata pollen, depigmented polymerized extract, Poa pratensis pollen, depigmented polymerized extract, Lolium perenne pollen, depigmented polymerized extract; Olea europaea pollen, depigmented polymerized extract. The substance is a mixture of depigmented, polymerized pollen extracts from several grass species and olive tree pollen. It is being developed by LETI Pharma, S.L.U. and has no marketing authorisation in the product records, meaning it is an investigational substance. The product names under study are Depigoid DUO Grass-Mix/Olea (1000 DPP/ml + 1000 DPP/ml), Depigoid Grass-Mix (1000 DPP/ml) and Depigoid FORTE Grass-Mix (3000 DPP/ml).
How does Poa pratensis pollen, depigmented polymerized extract work?
The substance is a depigmented and polymerized allergen extract. Depigmentation removes the colour-giving components of the pollen, and polymerization groups allergen molecules into larger structures. This approach is intended to reduce the risk of allergic reactions while keeping the ability to train the immune system to tolerate grass and olive pollen. The clinical data provided do not describe the exact molecular target or the precise immune mechanism in further detail. The trials measure clinical effect through a combined symptom and medication score during pollen season, rather than through laboratory markers of immune response.
Which conditions is it used or studied for?
- Allergic rhinoconjunctivitis with or without asthma due to grass and olive pollen — a condition where grass and olive pollen trigger sneezing, runny nose, itchy eyes and sometimes asthma symptoms.
- Allergic rhinoconjunctivitis with or without controlled asthma — studied in the second trial, focusing on grass pollen allergy.
How is Poa pratensis pollen, depigmented polymerized extract given?
The substance is provided as a suspension for injection and is given by subcutaneous injection or subcutaneous use. The trials use a 0.5 ml injection volume. Two strengths are being studied: 1000 DPP/ml and 3000 DPP/ml, the latter under the name Depigoid FORTE Grass-Mix. The substance is part of fixed-combination products in the product records, meaning it is given together with other pollen extracts in the same injection.
What do the clinical trials show?
Two Phase 3 trials are authorised for this substance. The first, Grass/Olive Immunotherapy for Rhinitis and Asthma (GOES), is a Phase 3 interventional trial with 343 participants. It studies Depigoid DUO Grass-Mix/Olea (1000 DPP/ml + 1000 DPP/ml) against placebo in allergic rhinoconjunctivitis with or without asthma due to grass and olive pollen. The second, Grass Immunotherapy for Rhinitis and Asthma (GIRA), is also a Phase 3 interventional trial, with 324 participants. It studies Depigoid Grass-Mix (1000 DPP/ml) and Depigoid FORTE Grass-Mix (3000 DPP/ml) against placebo in allergic rhinoconjunctivitis with or without controlled asthma. Both trials are currently authorised, meaning they have received approval to proceed.
What are the trials measuring?
The main outcome in both trials is the mean combined symptom and medication score (cSMS, 0-6) during the peak grass and olive pollen season, comparing the active group with placebo after at least 8 injections. The medication score ranges from 0 (no medication) to 1.5 (intranasal corticoid), and the symptom score from 0 (none) to 3 (severe) for symptoms such as runny nose, sneezing, itchy nose, nasal congestion, itchy eyes and tearing. The score is collected through a mobile app. The GIRA trial also has an open-label phase measuring the change in the amount of allergen needed to produce a positive conjunctival provocation test after the pollen season compared with baseline.
Who can take part in these trials?
The trials enrol people with allergic rhinoconjunctivitis with or without asthma, caused by clinically relevant sensitisation to grass and olive pollen in the GOES trial, and to grass pollen in the GIRA trial. The registry records do not provide detailed inclusion or exclusion criteria such as age range or specific asthma severity cut-offs. The GIRA trial specifies that asthma must be controlled.
What side effects are known?
The clinical trial records provided do not include a list of known side effects for this substance. As an investigational product, its safety profile is still being established through the ongoing Phase 3 trials.