Determination of Blomia Tropicalis Allergen Extract in Prick Test Units

NCT07195929 | Not Yet Recruiting

• 2 other identifiers: M608-STD-0672024-515169-33-00
• Study Type: interventional
• Target: 30
• Locations: 1 country
• Sites: 1

Brief Summary

The primary objective is to assess the concentration of Blomia tropicalis allergenic extract that induces a wheal of size equivalent to that produced by a 10 mg/mL histamine dihydrochloride solution, in order to be used as in-house reference preparation (IHRP).

Conditions

Allergic Reactions; Allergic Skin Reaction

Keywords

Allergy; In-House Reference Preparation (IHRP); Prick test; Blomia tropicalis

Outcome Measures

Primary Outcomes (1)

• Size of the induced papule on the skin

  Size of the induced papule on the skin when applying each of the concentrations of the allergenic extracts and the positive (histamine) and negative controls, using the prick test.

  15 minutes

Secondary Outcomes (1)

• Adverse reactions

  30 minutes

Study Arms (1)

Extract B. tropicalis + Positive control + Negative control

EXPERIMENTAL

There is only one treatment arm. In each subject, one drop of each of the three concentrations of both allergenic extracts, along with the positive (Histamine dihydrochloride 10 mg/mL) and negative (saline solution) controls, will be applied. Blomia tropicalis dilutions: 100 µg/mL and 20 µg/mL.

Other: Allergenic Extract

Interventions

Allergenic Extract OTHER

In each subject, a drop of each of the 3 concentrations of the allergenic extract, in addition to the positive control (histamine) and the negative control, will be applied. The application will be duplicated on the subject's anterior forearm, with a distance of approximately 4 cm between each application to avoid overlapping reactions and false-positives results.

Also known as: Allergenic Blomia tropicalis extract

Extract B. tropicalis + Positive control + Negative control

Eligibility Criteria

• Age: 18 Years - 64 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64)

You may qualify if:

• 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.

You may not qualify if:

• 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) (See Section 5.2).
• 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.

Sponsors & Collaborators

• Inmunotek S.L.: lead

Study Sites (1)

Hospital Universitario de Canarias

San Cristóbal de La Laguna, Santa Cruz De Tenerife, 38320, Spain

Location

Related Publications (3)

• Skin tests used in type I allergy testing Position paper. Sub-Committee on Skin Tests of the European Academy of Allergology and Clinical Immunology. Allergy. 1989;44(s10):11-59. No abstract available.

  PMID: 2683837 BACKGROUND

• Casanovas M, Maranon F, Bel I. Comparison of skin-prick test assay and reverse enzyme immunoassay competition (REINA-C) for biological activity of allergens. Clin Exp Allergy. 1994 Feb;24(2):134-9. doi: 10.1111/j.1365-2222.1994.tb00209.x.

  PMID: 8187028 BACKGROUND

• Pawankar R. Allergic diseases and asthma: a global public health concern and a call to action. World Allergy Organ J. 2014 May 19;7(1):12. doi: 10.1186/1939-4551-7-12. eCollection 2014. No abstract available.

  PMID: 24940476 BACKGROUND

MeSH Terms

Conditions

Hypersensitivity

Interventions

grass pollen extract, alum-adsorbed

Condition Hierarchy (Ancestors)

Immune System Diseases

Study Officials

• María Inmaculada Sánchez Machín

  Hospital Universitario de Canarias

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Miguel Casanovas

CONTACT

+34912908942; mcasanovas@inmunotek.com

Anuta Caballero

CONTACT

+34607600638; rcaballero@inmunotek.com

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NA
• Masking: NONE
• Purpose: OTHER
• Intervention Model: SINGLE GROUP
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Model Details: Phase II trial, open-label, prospective, non-randomized, without a control group of subjects.

Study Record Dates

• First Submitted: September 19, 2025
• First Posted: September 29, 2025
• Study Start: November 1, 2025
• Primary Completion: January 1, 2026
• Study Completion (Estimated): January 1, 2027
• Last Updated: October 2, 2025

Record last verified: 2025-09

Locations

ES (1)