D2.217 - Structured Follow-Up Intervals Enhance Adherence to Sublingual Immunotherapy in Patients with Allergic Rhinitis: Real-World Evidence from a Stepwise Approach

Sublingual immunotherapy (SLIT) represents a disease-modifying therapy for allergic rhinitis (AR), yet long-term efficacy is critically dependent on sustained adherence over a three-year treatment period. While randomized controlled trials report high compliance rates, real-world studies frequently demonstrate substantial pre-termination and low persistence, highlighting an urgent unmet need for adherence-enhancing strategies.

In this study, we evaluate the impact of a structured, step-by-step adherence plan, incorporating prespecified regular follow-up moments, on patients’ adherence to SLIT over a three-year treatment course in routine clinical practice.

We conducted a retrospective, single-center, observational study including 266 patients (16–65 years) with AR who fulfilled at least 3 years of SLIT (ACARIZAX®, GRAZAX®, or ITULAZAX®) or discontinued early. The adherence intervention consisted of scheduled patient contacts (clinic visits or telephone calls) at four intervals during year one and two intervals in each consecutive year (years two and three), tailored to the principal non-adherence drivers: adverse events, waning motivation, and perceived inefficacy. Each interaction was designed to proactively identify and address barriers, reinforce motivation, and provide clinical management of side effects.

After three years, treatment completion was achieved by 94% of patients. Product-specific adherence rates were 94% for GRAZAX®, and 93% for both ITULAZAX® and ACARIZAX®. Adverse events were the most frequently cited reason for early discontinuation across all tablets. Self-reported full compliance was observed in 85% of the assessments, with a few and several missed doses in 12% and 3%, respectively. The implementation of systematic, targeted follow-up moments was associated with significant improvements in overall adherence compared to adherence rates previously reported in the literature.

This real-world study demonstrates that a proactive, structured follow-up plan embedded in routine clinical care dramatically improves adherence to SLIT in patients with AR. Engagement through regular, personalized contact points enables healthcare professionals to identify and address adherence barriers in a timely manner, thereby supporting sustained treatment completion. Our findings advocate for the integration of scheduled follow-up interventions as a standard component of SLIT management pathways to optimize long-term adherence.