Assessment of Blomia tropicalis Allergen Extract Concentration in Skin Prick Test for Patients with Blomia tropicalis Allergy Using Histamine Dihydrochloride Control
- Trial ID
- 2024-515169-33-00
- Protocol
- M608-STD-067
- Sponsor
- Inmunotek S.L.
Trial statistics
Diseases & Conditions
Objectives
The primary objective is to determine the concentration of Blomia tropicalis allergenic extract required to induce a wheal size equivalent to that produced by a 10 mg/mL histamine dihydrochloride solution. This assessment is relevant for the standardization of allergen extracts used in skin prick tests. The secondary objective involves evaluating the safety and tolerability of the extract. 1: Diagnosis; 4: Safety; 9: Dose response.
Participants
The sponsor did not provide information regarding the total number of participants. The study population consists of male and female patients between the ages of 18 and 64 years. Participants are selected based on a positive medical history of inhalant allergy, including rhinitis, rhinoconjunctivitis, or asthma, specifically related to Blomia tropicalis. Inclusion requires a positive skin prick test or the presence of specific IgE against the allergen. Furthermore, the population must reside in a geographical area where this allergen is relevant. For women of childbearing age, a negative pregnancy test and the use of highly effective contraception are required.
Plans and Procedures
This Phase II clinical trial is designed to determine the Blomia tropicalis allergenic extract concentration required to induce a wheal size equivalent to a 10 mg/mL histamine dihydrochloride solution. The study involves a skin prick test to measure the area of induced wheals resulting from three concentrations of the allergen extract, as well as a positive control and a negative control using sodium chloride. The primary efficacy endpoint is the measurement of the wheal area in mm² for each substance applied via cutaneous use. Secondary endpoints include the assessment of adverse events, administration site reactions, and systemic reactions. The study protocol includes a screening process to verify inhalant allergy history, specific IgE presence, and appropriate control responses. The estimated duration of the study spans from September 2025 to January 2026.
Treatment
The experimental substance is a Blomia tropicalis extract provided as a solution for skin-prick test. Administration is via cutaneous use at a dose of 2 units per application.
The positive control consists of histamine dihydrochloride in a solution for skin-prick test. This substance is administered via cutaneous use at a dose of 2 drops.
The negative control consists of sodium chloride in a solution for skin-prick test. This substance is administered via cutaneous use at a dose of 2 drops.
Efficacy
The primary efficacy endpoint is the measurement of the wheal area, expressed in mm2, induced upon the skin following the application of three distinct concentrations of Blomia tropicalis extract. This assessment is performed using a skin prick test and includes comparisons against a histamine dihydrochloride positive control and a sodium chloride negative control. The objective is to determine the in vivo histamine equivalent units.
Secondary endpoints involve the evaluation of adverse events, specifically analyzing the overall rate, seriousness, and ratio per administration and subject. Further assessments include the monitoring of administration site reactions, systemic reactions, and any medication required for the treatment of an adverse reaction.
Inclusion and Exclusion Criteria
Inclusion Criteria
- Female or male aged 18 to 64 years, both included.
- Subjects who have signed and dated the informed consent form.
- Subjects must reside in a geographical area where allergic problems caused by Blomia tropicalis are relevant.
- Positive medical history of inhalant allergy (rhinitis and/or rhinoconjunctivitis and/or asthma) to Blomia tropicalis
- A positive prick-test (mean wheal diameter ≥ 3 mm) with an extract of the same allergen and/or presence of specific IgE against complete extract or any molecular component to the allergenic source.
- The area of the wheal obtained with 10 mg/mL histamine dihydrochloride should be ≥ 7 mm², which corresponds to a mean wheal diameter ≥ 3 mm.
- The area of the wheal obtained with negative control should be < 7 mm², which corresponds to a mean wheal diameter < 3 mm.
- Women of childbearing age (i.e following menarche and until postmenopause, defined as no menses for 12 months without an alternative medical cause, or non-subject to permanent sterilization methods, such as hysterectomy, bilateral salpingectomy and bilateral oophorectomy) must present a negative urine pregnancy test at the time of enrollment in the trial, as well as a confirmed menstrual period.
- Women of childbearing age must commit to using a highly effective and adequate contraception method during the trial and up to 72 hours after the end of treatment with the investigational medicinal product. Such methods include combined (estrogen and progestogen containing) hormonal; contraception associated with inhibition of ovulation (oral, intravaginal or transdermal), progestogen-only hormonal contraception associated with inhibition of ovulation (oral, injectable or implantable), intrauterine device (IUD), intrauterine hormone-releasing system (IUS), bilateral tubal occlusion, vasectomized partner or sexual abstinence.
Exclusion Criteria
- Subjects outside the age range.
- Subjects who have previously received immunotherapy within the last 5 years for the treatment of asthma or allergic rhinoconjunctivitis induced by allergens that may interfere with Blomia tropicalis extract.
- Subjects with significant symptoms of rhinoconjunctivitis and/or bronchial asthma in whom discontinuation of systemic antihistamine treatment is contraindicated.
- Subjects who have previously exhibited a severe adverse reaction during diagnostic skin prick tests.
- Subjects on treatment with ß-blockers.
- Use of drugs that could interfere with skin prick test reactions (e.g., antihistamines).
- Clinically unstable subjects (acute asthma, febrile, etc.).
- Subjects with active urticaria lesions, severe active dermographism, severe atopic dermatitis, sunburn, eczema, psoriasis lesions in the area where the prick test is performed (risk of false positives).
- Subjects with active herpes simplex viral infection, or herpes varicella zoster in the area where the prick test is performed.
- Subjects with any pathology in which the administration of adrenaline is contraindicated (hyperthyroidism, hypertension, heart disease, etc.).
- States in which the subject is unable to offer cooperation and severe psychiatric disorders.
- Pregnant or potentially pregnant women and breastfeeding women.
- Subjects with known phenol allergy.
Trial Status by Country
| Country | Status | Start of Recruitment | Planned Patients |
|---|---|---|---|
 Spain | Not Recruiting | 01 Sept 2025 | 30 |
Sites & Investigators
Research sites
Investigators
Investigational Products
Details about the medicinal products being studied in this clinical trial.
| Product Name | Role in Trial | Formulation | Administration | Max Daily Dose | Treatment Duration | EU MP Number |
|---|---|---|---|---|---|---|
Skin Prick Test Negative control | Other | SOLUTION FOR SKIN-PRICK TEST | CUTANEOUS USE | 2 | 1 | PRD11276451 |
Prick test of Blomia tropicalis extract | Test | SOLUTION FOR SKIN-PRICK TEST | CUTANEOUS USE | 2 | 1 | PRD12365053 |
Skin Prick Test Positive control | Other | SOLUTION FOR SKIN-PRICK TEST | CUTANEOUS USE | 2 | 1 | PRD11269985 |