Biological Standardization of Lepidoglyphus Destructor Allergen Extract for Allergic Patients Using Skin-Prick Test with Histamine Dihydrochloride and Sodium Chloride Controls

The primary objective of this study is the **biological standardization** of the allergenic extract of **Lepidoglyphus destructor**. This is clinically relevant as it aims to ensure the consistency and efficacy of the allergen extract used in the diagnosis and management of **allergies**. The standardization process is crucial for maintaining the quality and safety of the allergenic product, which is used in skin-prick tests to identify allergic sensitivities in patients. The study does not list any secondary objectives.

The clinical trial focuses on the **biological standardization** of the allergenic extract of Lepidoglyphus destructor, targeting individuals diagnosed with IgE-mediated **allergies** to this specific allergen. The study population comprises both male and female participants aged between 18 and 50 years. Participants are required to reside in geographic areas where Lepidoglyphus destructor is prevalent. The trial does not include a vulnerable population. Participants must have a positive skin prick test and specific IgE test results, indicating an allergy to the allergen. The sponsor has not provided information regarding the total number of participants. Lifestyle considerations such as diet and physical activity are not specified. Key inclusion criteria include a wheal diameter of at least 3 mm larger than the negative control in the skin prick test and a positive specific IgE test of class 1 or higher. Participants must also demonstrate a wheal diameter of at least 4 mm when exposed to a histamine dihydrochloride solution. The ability to understand the study's purpose and scope and the signing of informed consent are also required.

The clinical trial is designed to evaluate the **biological standardization** of the allergenic extract of **Lepidoglyphus destructor**. This is a Phase IV, randomized, double-blind, controlled study aimed at determining the concentration of the study extracts that elicit a wheal of a size equivalent to that produced by a solution of **histamine dihydrochloride** at 10 mg/ml. The trial is expected to commence on July 14, 2025, and conclude by December 15, 2025. Participants will be involved in the study for a maximum of one day, as the **skin-prick test** is conducted in a single visit.

The sequence of study visits includes an initial screening visit to confirm eligibility based on specific inclusion criteria, such as residing in a geographic area where **Lepidoglyphus destructor** is prevalent, being aged between 18 and 50 years, and having a confirmed **IgE-mediated allergy** to the allergen. The screening will also involve a **skin-prick test** to ensure a wheal diameter of at least 3 mm larger than the negative control and a positive specific IgE test. The primary endpoint is the area of the wheal (mm²) that occurs at the cutaneous level after administration of the extracts, with a secondary endpoint focusing on the safety assessment through descriptive analysis of adverse reactions.

Participants will be required to attend a single study visit where the **skin-prick test** will be administered using solutions of varying concentrations of the allergenic extract, alongside positive and negative controls. The positive control will be a solution of **histamine dihydrochloride**, and the negative control will be **sodium chloride**. The trial will involve intraepidermal use of the allergenic extract and subcutaneous use of the controls. Conditions that may lead to early termination from the study include the occurrence of significant adverse reactions or withdrawal of consent by the participant. The trial is not a low-intervention study and is categorized under trial category 2, with a justification for the trial category being the in vivo determination of the concentration of the study extracts.

The clinical trial involves the use of several **experimental medications** and control substances for the purpose of in vivo biological standardization of the **Lepidoglyphus destructor** allergen extract. The primary experimental medication is the "Diagnóstico prick Lepidoglyphus destructor," which is a **solution for skin-prick test** containing the active substance **Lepidoglyphus destructor**. This allergenic extract is available in three different concentrations: 10,000 PNU/ml, 2,000 PNU/ml, and 30,000 PNU/ml. The solution is administered via **intraepidermal use**. The maximum daily dose and total dose for each concentration is 10 mg/ml, with a maximum treatment period of one day. The solution is not a pediatric formulation and is not classified as an orphan drug.

In addition to the experimental allergen extracts, the study utilizes a negative control, "Diagnóstico prick control negativo," which is a **solution for skin-prick test** containing **sodium chloride**. This solution serves as a physiological serum and is administered via **subcutaneous use**. The maximum daily and total dose is 10 mg/ml, with a treatment period of one day. This solution is also not a pediatric formulation and is not classified as an orphan drug.

The positive control used in the study is "Diagnóstico prick control positivo," a **solution for skin-prick test** containing **histamine dihydrochloride**. This solution is used to ensure the skin's reactivity and is administered via **subcutaneous use**. The maximum daily and total dose is 10 mg/ml, with a treatment period of one day. Similar to the other solutions, it is not a pediatric formulation and is not classified as an orphan drug.

Participant compliance with the dosing schedule is monitored throughout the trial to ensure accurate and reliable results. The trial is conducted under the auspices of ASAC Pharmaceutical Inmunology, which is responsible for the production and supply of all test and control solutions used in the study.

The efficacy of the clinical trial will be assessed through the primary endpoint, which involves measuring the area of the wheal (mm²) that occurs at the cutaneous level after the administration of the allergenic extracts in the skin-prick test. This measurement will be used to calculate the primary endpoint, which includes the estimation of the dose/response relationship in each patient through regression analysis of area values versus concentration in PNU/ml. Additionally, the determination of the theoretical concentration of extract that produces a papule equivalent to that produced by a solution of **histamine dihydrochloride** at 10 mg/ml will be conducted.

Secondary endpoints will focus on the safety assessment through a descriptive analysis of adverse reactions that may occur during the study. The trial is designed to standardize biologically the allergenic extract of **Lepidoglyphus destructor**. The trial will involve the use of solutions for skin-prick tests, including allergenic extracts at various concentrations and control solutions, to evaluate the response in patients diagnosed with IgE-mediated allergy to **Lepidoglyphus destructor**. The trial is set to be conducted over a period with an estimated end date of December 15, 2025.