In short
Dermatophagoides pteronyssinus, depigmented/polymerized extract is an investigational allergy immunotherapy derived from house dust mites. It is being studied in a phase 3 trial with 410 participants to evaluate its efficacy and safety in people with moderate to severe persistent allergic rhinoconjunctivitis, with or without controlled asthma, caused by Dermatophagoides pteronyssinus and Dermatophagoides farinae.
Key points
- Phase 3 trial investigating subcutaneous immunotherapy in allergic rhinoconjunctivitis
- 410 participants planned for enrollment in the authorised trial
- Compares two concentrations of Depigoid Mite-Mix against placebo
- Primary measure is the change in combined symptom and medication score (cSMS) after 12 doses
- Administered as a subcutaneous injection in suspension form
- Developed by LETI PHARMA, S.L.U. as an investigational product
What is Dermatophagoides pteronyssinus?
Dermatophagoides pteronyssinus, depigmented/polymerized extract is an allergenic extract prepared from house dust mites of the species Dermatophagoides pteronyssinus. In the product records of the clinical trial, the full registry name also includes a depigmented/polymerized extract of Dermatophagoides farinae, another common house dust mite species. The substance is classified under immune system diseases in the therapeutic area of the trial records. It is an investigational substance with no marketing authorisation in the product records, supplied by LETI PHARMA, S.L.U. The product names under which it appears in the registry are Depigoid Mite-Mix (50 DPP/ml + 50 DPP/ml) and Depigoid FORTE Mite-Mix (150 DPP/ml + 150 DPP/ml). The extract is part of a fixed combination in two product records.
How does Dermatophagoides pteronyssinus work?
The extract belongs to a class of treatments called allergen immunotherapies. These aim to modify the immune system's response to a specific allergen, in this case proteins from house dust mites. A review of Dermatophagoides pteronyssinus proteins describes them as key triggers in the diagnostics and management of house dust mite allergy, and discusses how allergenic components are used to understand and treat the condition. The depigmented and polymerized form used in the trial is designed to reduce the allergenicity of the extract while maintaining its ability to induce immunological tolerance.
Which conditions is it used or studied for?
- Allergic rhinoconjunctivitis to Dermatophagoides pteronyssinus and Dermatophagoides farinae — the phase 3 trial studies people with moderate to severe persistent allergic rhinoconjunctivitis, with or without controlled asthma, caused by these two house dust mite species.
- House dust mite allergy — a related product, a standardised allergen extract from the same two mite species, is authorised in Europe for adults with allergic rhinitis and/or allergic asthma caused by house dust mite sensitisation.
How is Dermatophagoides pteronyssinus given?
The investigational extract is formulated as a suspension for injection and is given by subcutaneous injection, meaning under the skin. In the phase 3 trial, two concentrations are being tested: Depigoid Mite-Mix at 50 DPP/ml + 50 DPP/ml and Depigoid FORTE Mite-Mix at 150 DPP/ml + 150 DPP/ml, each administered as a 0.5 ml subcutaneous dose. A different but related house dust mite product, the HDM SLIT-tablet, is given as a sublingual tablet, meaning it dissolves under the tongue, and is authorised for adults aged 18 to 65 years in Europe.
What do the clinical trials show?
One clinical trial is registered for this substance in the EU Clinical Trials Information System. It is a phase 3, interventional trial with a planned enrollment of 410 participants. The trial is authorised, meaning it has received regulatory approval to proceed.
What is the trial measuring?
The primary outcome is the clinical efficacy of both concentrations of subcutaneous immunotherapy (SCIT) individually, compared to placebo. This is evaluated through the change in the combined symptom and medication score (cSMS) from baseline to the timepoint after 12 SCIT doses have been administered. Data collection is carried out via an electronic diary installed on the patient's mobile device at the time of the first treatment administration.
Who can take part in the trial?
The trial includes patients with moderate to severe persistent allergic rhinoconjunctivitis, with or without controlled asthma, who are sensitised to Dermatophagoides pteronyssinus and Dermatophagoides farinae. The study also uses a range of rescue and control medications, including budesonide, desloratadine, montelukast, salbutamol, and levocabastine, which are listed as interventions in the registry record.
What side effects are known?
For allergenic extracts in general, including house dust mite extracts, severe systemic reactions may occur. In certain individuals, especially those with steroid-dependent or steroid-liable asthma, these reactions may be life-threatening or cause death. Patients receiving this type of product should be observed for at least 20 minutes following treatment, and emergency measures as well as personnel trained in their use should be immediately available in the event of a life-threatening reaction. Patients receiving beta-blocking drugs may be refractory to the usual dose of epinephrine if epinephrine is required to control an adverse allergic reaction. The product should never be injected intravenously.