International multicentre, open-label, phase IV clinical trial to evaluate the efficacy, safety and effect on quality of life of bilastine in children with allergic rhinoconjunctivitis

The primary objective of this study is to assess the efficacy of bilastine 10 mg orodispersible tablet in children aged 6 to less than 12 years with allergic rhinoconjunctivitis after 14 days of daily treatment. Efficacy is evaluated through the variation in symptom severity using a combined five symptoms score (mean change from baseline in the T5CSS), which includes sneezing, rhinorrhoea, nasal pruritus, tearing, and ocular pruritus. This objective is clinically relevant as it measures the therapeutic impact on the most characteristic and burdensome symptoms of allergic rhinoconjunctivitis in the pediatric population, providing evidence of symptom control over a standard treatment period.

The secondary objectives include:

• Assessment of the variation in quality of life in children with allergic rhinoconjunctivitis, measured by the mean change from baseline in PRQLQ after 14 days of treatment.
• Evaluation of the evolution of allergic rhinoconjunctivitis symptoms using variations in the T5CSS as daily change after 7 and 14 days of treatment, and as mean change from baseline after 7 days.
• Assessment of the variation of nasal symptoms (runny nose, nasal itching, nasal congestion, and sneezing) after 7 and 14 days compared to baseline using the TNSS.
• Evaluation of the variation of non-nasal symptoms (ocular itching, tearing, ocular redness, and itchy ears/palate) after 7 and 14 days compared to baseline using the TNNSS.
• Assessment of the variation of overall allergic rhinoconjunctivitis symptoms (sum of symptoms included in TNSS and TNNSS) after 7 and 14 days compared to baseline using the TSS.
• Determination of the correlation between symptom evolution (global and specific) and participants' quality of life after 14 days of treatment.
• Evaluation of the variation in disease assessment after 14 days versus baseline, as assessed by participants, parents, and investigators using the Global Disease Evaluation.
• Assessment of satisfaction with allergic rhinoconjunctivitis treatment from the perspective of participants and parents after 14 days using a satisfaction questionnaire.
• Assessment of treatment adherence during the 14-day treatment period.
• Assessment of the safety and tolerability of bilastine 10 mg orodispersible tablet during the 14-day treatment period.

The sponsor did not provide information regarding the total number of participants enrolled in this clinical trial. The study population consisted of **pediatric participants** aged **6 to less than 12 years** of **both male and female genders** with a minimum body weight of **15 kg**. All participants had a documented clinical history of at least one year of **allergic rhinoconjunctivitis** and presented **mild-to-moderate symptoms** at the time of enrollment. The trial population was selected based on the presence of a positive **skin prick test** (papule diameter of at least 3 mm) or specific **IgE levels** greater than 0.70 KUA/L to at least one allergen, documented within one year prior to inclusion. Participants were required to have a clinical history of positive response to **oral antihistamine treatment** and demonstrate a combined five symptoms score of at least 8 points out of 15 for instantaneous symptoms at screening. Additionally, participants needed to have normal **haematological** and **biochemical** values and a **12-lead ECG** without clinically relevant abnormalities prior to study entry.

This is an international, multicentre, open-label, **phase IV clinical trial** designed to evaluate the efficacy, safety, and effect on quality of life of **bilastine** in pediatric participants with **allergic rhinoconjunctivitis**. The investigational medicinal product is bilastine 10 mg administered as an **orodispersible tablet** via the **oral route**. The trial follows an open-label design, meaning that both investigators and participants are aware of the treatment being administered. The study involves a **14-day treatment period** during which participants receive a **maximum daily dose of 10 mg**, resulting in a **maximum total dose of 140 mg** over the entire treatment duration. The estimated recruitment start date is January 15, 2026, with an anticipated study completion date of June 30, 2026.

The primary objective is to assess the efficacy of bilastine 10 mg orodispersible tablet in children aged 6 to less than 12 years with allergic rhinoconjunctivitis after 14 days of daily treatment. Efficacy will be measured through the variation in allergic rhinoconjunctivitis symptoms using a combined five symptoms score (T5CSS), which includes sneezing, **rhinorrhoea**, nasal pruritus, tearing, and ocular pruritus. The mean change from baseline in the T5CSS will serve as the primary endpoint. Reflective allergic rhinoconjunctivitis symptoms will be collected daily by participants using an electronic diary, referring to the preceding 12 to 24 hours, and these scores will be utilized for efficacy assessment.

The trial involves a structured sequence of study visits. At the **screening visit** (V1), participants undergo initial assessment to determine eligibility for enrollment. Principal inclusion criteria include participants of either sex aged 6 to less than 12 years with a body weight of at least 15 kg, a documented clinical history of allergic rhinoconjunctivitis for at least one year, and presentation of mild to moderate clinical symptoms at inclusion. Participants must have a positive skin reaction or RAST test documented within one year prior to enrollment, defined as a positive prick test with a papule diameter of at least 3 mm or specific **IgE** greater than 0.70 KUA/L against at least one allergen. Additionally, participants must demonstrate a T5CSS score of at least 8 points out of 15 for instantaneous symptoms at the screening visit, have a clinical history of positive response to oral **antihistamine** treatment, possess at least one analytical determination including **haemogram** and biochemistry without clinically relevant abnormalities, and have a **12-lead ECG** without clinically relevant abnormalities. Written consent must be obtained from parents or legally authorized representatives, and a signed assent form may be obtained from participants if required.

Following the screening visit, participants enter the 14-day treatment phase during which they receive daily administration of bilastine 10 mg orodispersible tablet. Throughout this period, participants record their allergic rhinoconjunctivitis symptoms daily using an electronic diary. Follow-up assessments are conducted to monitor treatment response, safety, and tolerability. At the **end-of-study visit** (V3), which occurs after 14 days of treatment, final efficacy assessments are performed, including measurement of the T5CSS score to determine the mean change from baseline. Safety evaluations and quality of life assessments are also completed at this visit. The expected length of participant involvement spans approximately 14 days of active treatment, with additional time for screening and final assessments.

Conditions that may lead to early termination from the study include the occurrence of adverse events that compromise participant safety, withdrawal of consent by parents or legally authorized representatives, protocol violations, loss to follow-up, or investigator decision based on clinical judgment. Participants may also be discontinued if they fail to comply with study procedures or if they require concomitant medications that could interfere with study assessments. All reasons for early discontinuation will be documented and reported according to the study protocol.

The experimental medication under investigation in this clinical trial is bilastine, administered as an orodispersible tablet formulation marketed under the name Bilaxten Flas. Each tablet contains 10 mg of the active substance bilastine, which is of chemical origin. The pharmaceutical form consists of orodispersible tablets designed to disintegrate in the oral cavity without the need for water. The medication is administered via the oral route with a dosing regimen of 10 mg once daily. The maximum daily dose is 10 mg, and the maximum total dose over the treatment period is 140 mg. The treatment duration is 14 days, during which participants receive daily administration of the study medication. Bilastine is classified under the ATC code R06AX29, indicating its pharmacological classification as an antihistamine for systemic use.

The clinical trial is designed as an open-label study, meaning that no placebo or active comparator treatment is utilized. All enrolled participants receive the experimental medication bilastine 10 mg orodispersible tablets. The study focuses on evaluating the efficacy and safety of bilastine in children aged 6 to less than 12 years diagnosed with allergic rhinoconjunctivitis. Participant compliance is monitored through daily collection of reflective symptom scores, which refer to the preceding 12 to 24 hours. These scores assess five combined symptoms including sneezing, rhinorrhoea, nasal pruritus, tearing, and ocular pruritus, which serve as the primary efficacy assessment parameters throughout the 14-day treatment period.

Efficacy will be assessed through the evaluation of overall **allergic rhinoconjunctivitis** symptoms using a combined five symptoms score (T5CSS). The T5CSS includes five parameters: sneezing, rhinorrhoea, nasal pruritus, tearing, and ocular pruritus. The primary endpoint is the mean change in the T5CSS score from baseline (Visit 1) to after 14 days of treatment (Visit 3). Reflective allergic rhinoconjunctivitis symptoms will be collected daily by participants using an electronic diary, referring to the preceding 12-24 hours, and these scores will be used for the efficacy assessment. At the screening visit, participants must present a T5CSS score of at least 8 points out of 15 for instantaneous symptoms to be eligible for inclusion.