Subcutaneous Dermatophagoides/Lepidoglyphus immunotherapy for moderate-to-severe allergic rhinitis/rhinoconjunctivitis with mild-to-moderate asthma: randomized placebo-controlled trial

The primary objective is to evaluate the clinical efficacy of the subcutaneous investigational allergen immunotherapy at 30,000/30,000 TU/mL compared with placebo in participants aged 12 to 65 years with moderate-to-severe persistent allergic rhinitis/rhinoconjunctivitis, with or without controlled mild-to-moderate asthma. This is clinically relevant because it assesses treatment effect in a population with confirmed sensitization to Dermatophagoides species and Lepidoglyphus destructor. The secondary objectives are to evaluate: clinical efficacy by mean daily rhinitis/conjunctivitis symptom scores adjusted for baseline; safety and clinical tolerability; overall clinical benefit across efficacy parameters versus placebo and baseline; effect on immunological status; impact on quality of life and symptom control; and effect on healthcare resource utilization related to the study conditions.

The sponsor did not provide the total number of participants. The trial population comprised male and female participants aged 12 to 65 years with moderate-to-severe persistent allergic rhinitis/rhinoconjunctivitis, with or without controlled mild-to-moderate asthma, and with confirmed sensitization to Dermatophagoides and Lepidoglyphus destructor. Participants were selected on the basis of a confirmed clinical history of inhalant allergy, positive skin prick testing, and specific IgE results consistent with the condition. Eligible participants were required to be able to comply with the dosing regimen and to record symptoms and medication use in an electronic or paper diary. Women of childbearing potential were required to have a negative urine pregnancy test and to use a highly effective contraceptive method throughout the study and for 1 month after treatment. Participants sensitized to other aeroallergens were included only under specified conditions related to animal dander exposure and pollen season timing. The sponsor did not provide information on lifestyle factors such as diet, physical activity, or habits.

The trial is a prospective, randomized, double-blind, placebo-controlled, multicenter clinical trial evaluating the efficacy and safety of subcutaneous immunotherapy with Dermatophagoides/L. destructor 30,000/30,000 TU/mL compared with placebo in participants aged 12 to 65 years with moderate-to-severe persistent rhinitis/rhinoconjunctivitis, with or without controlled mild-to-moderate asthma. The overall study duration is planned from 16 June 2026 to 16 December 2028. Study participation includes a screening visit to verify eligibility criteria, including clinical history, sensitization testing, symptom assessment, and pregnancy testing when applicable, followed by treatment and follow-up visits during which efficacy, safety, symptom scores, medication use, quality of life, asthma control, and immunological parameters are assessed. The primary outcome is the Rhinoconjunctivitis Combined Symptom and Medication Score recorded over 4 weeks after one year of treatment. The expected participant involvement extends through the treatment period and the final end-of-study visit after completion of assessments. Early termination may occur for screening failure, inability to comply with the dosing regimen or diary recording, failure to meet pollen-season timing requirements for participants sensitized to pollens, withdrawal of consent, or any other condition that prevents continued participation according to protocol requirements.

The investigational medicinal product was Dermatophagoides/L. destructor 30,000/30,000 TU/mL suspension for injection, containing Dermatophagoides farinae allergoid, glutaraldehyde-modified, Dermatophagoides pteronyssinus allergoid, glutaraldehyde-modified, and Lepidoglyphus destructor, polymerised extract. It was administered by the subcutaneous route at a dose of 0.5 mL.

The comparator was a placebo consisting of the same solution and presentation as the active treatment but without active ingredients. The trial was conducted in a prospective, randomised, double-blind, placebo-controlled design. No additional information on dosing schedule or compliance monitoring was provided in the source data.

Efficacy will be assessed by comparing the investigational medicinal product with placebo in participants with allergic rhinitis/rhinoconjunctivitis with or without mild-to-moderate asthma. The primary endpoint is the Rhinoconjunctivitis Combined Symptom and Medication Score assessed over 4 weeks after one year of treatment and recorded in the Participant’s Diary. Secondary efficacy assessments include the Rhinitis/Rhinoconjunctivitis Symptom Score, Rhinitis/Rhinoconjunctivitis Medication Score, Asthma-Combined Symptom and Medication Score, Asthma Symptom Score, Asthma Medication Score, Asthma and Rhinitis/Rhinoconjunctivitis Symptom Score, Asthma and Rhinitis/Rhinoconjunctivitis Medication Score, and Asthma and Rhinitis/Rhinoconjunctivitis Combined Symptom and Medication Score.

Additional efficacy assessments include asthma exacerbations, measured as time to first exacerbation and as number, duration, and severity; immunological parameters, including total IgE, specific IgE and IgG4, and the specific IgE/total IgE ratio; and allergen profiling by the ALEX technique. Quality of life and control outcomes are also assessed using the Asthma Quality of Life Questionnaire, Rhinoconjunctivitis Quality of Life Questionnaire, Asthma Control Questionnaire, and Visual Analogue Scale. Consumption of health resources is also evaluated.