Safety and Immunogenicity of Cat-allergen Intralymphatic Immunotherapy in Patients With Cat Allergy With and Without Asthma

The goal of this clinical trial is to evaluate the safety and tolerability of intralymphatic immunotherapy (ILIT) with ALUTARD SQ Felis domesticus in patients with cat allergy-induced allergic rhinitis and asthma. The main questions it aims to answer are: Is ILIT with ALUTARD SQ Felis domesticus safe and well tolerated? What immunological responses play a role in ILIT? Researchers will compare the effects of ILIT to existing subcutaneous immunotherapy (SCIT) approaches to assess safety, tolerability, immunogenicity, and efficacy. Participants will: Receive 3-4 ILIT injections of ALUTARD SQ Felis domesticus into an inguinal lymph node, guided by ultrasound. Undergo safety monitoring, including WAO guidelines for systemic allergic reactions and tryptase measurement. Complete lung function tests, questionnaires, and a modified nasal provocation test to evaluate asthma effects and treatment efficacy. Provide blood samples for ImmunoCAP and basophil activation testing using CAST ELISA. Inclusion criteria: Adults aged 18-65 with cat-dander-induced allergic rhinitis and asthma. Exclusion criteria: Hypersensitivity to treatment components, systemic steroid use, uncontrolled asthma (FEV1 \< 70%), recent severe asthma exacerbations, or serious comorbidities. The study aims to generate data to inform future efficacy trials.