Background: Mannan‐conjugated allergoids represent an effective option for treating allergic diseases. This study evaluated the clinical impact of the mannan‐conjugated, polymerised birch pollen allergoid EP‐088_T502 in patients with birch pollen‐induced allergic rhinoconjunctivitis over 3 years. Methods: Following up to a double‐blind, placebo‐controlled dose‐finding study, in this open, long‐term extension study, 154 birch pollen‐allergic patients were enrolled in Germany. Patients were treated with a cumulative dose of 48,000 mTU EP‐088_T502 administered subcutaneously over five pre‐seasonal visits in each of the two treatment years (2021, 2022) with a subsequent follow‐up year in 2023. The primary efficacy endpoint was the combined symptom and medication score (CSMS) during the peak birch pollen season, which was compared with the CSMS of the placebo group during the peak pollen season of 2020. Safety, tolerability, and immunogenicity were also analysed. Results: Compared to the placebo group of the preceding study, median CSMS during the peak birch pollen seasons showed reductions of 47.5% in 2021 ( p < 0.001), 51.8% in 2022 ( p < 0.001), and 36.5% in 2023 ( p < 0.001). Median daily symptom scores were reduced by 40.7% in 2021 ( p < 0.001), 40.7% in 2022 ( p < 0.001), and 25.6% in 2023 ( p < 0.010). Median daily medication scores reached 0.07 in 2021 and 0.04 in 2022 ( p < 0.001) and were reduced by 65.9% in 2023 ( p < 0.003). Immunological responses showed a 4.82‐fold increase in Bet v1 sIgG4 ( p = 0.001) and a marked decrease (−65.5%, p = 0.001) in the sIgE/sIgG4 ratio after the first treatment phase. EP‐088_T502 demonstrated good safety and tolerability, with only six mild to moderate systemic allergic reactions (Grade I/II). No epinephrine was used. Conclusion: In this open‐label study, two consecutive years of pre‐seasonal short‐course allergen immunotherapy (AIT) with EP‐088_T502 markedly reduced symptoms and medication need in patients with birch pollen‐induced rhinoconjunctivitis. Persistent therapeutic effects observed during the follow‐up year, although limited by attrition of the study population, suggest sustained clinical improvement and indicate the potential disease‐modifying impact of this treatment regimen.

Background/Objectives: The guideline on allergen-specific immunotherapy of the European Academy of Allergy and Clinical Immunology recommends subcutaneous allergen-specific immunotherapy for the treatment of allergic rhinitis in children and adults with moderate to severe symptoms. The five years cohort study described below was designed in 2020 to demonstrate non-inferiority in terms of safety, tolerability and efficacy in a paediatric population compared with adult patients treated with microcrystalline tyrosine-adsorbed allergoids for their tree and grass pollen allergy in a perennial setting. Here, we present the preliminary findings from the first year. Methods: The Combined Symptom and Medication Score was chosen as the primary endpoint of this therapy. Secondary endpoints include the Rhinoconjunctivitis Quality of Life Questionnaire, the retrospective Rhinoconjunctivitis score, the Asthma Control Test and the Rhinitis Control Test, as well as an analysis of adverse drug reactions. Results: A total number of 320 patients were enrolled into this study, with 129 of these patients in the age group between 5 and 17 years and 191 patients in the adult age group. Mean Combined Symptom and Medication Score values did not differ significantly between minors and adults in the first pollen season after treatment induction. The retrospective score showed a strong and significant reduction in rhinoconjunctivitis and asthma symptoms. Treatment was well tolerated, with more than 80% of patients reporting no adverse drug reactions. Conclusions: The validity of this study approach of a cohort study has been confirmed by this first interim analysis for the initial course of therapy in the first year.

Background/Objectives: Previous studies have demonstrated the safety of pre-seasonal treatment with the mannan-conjugated birch pollen allergoid EP-088-T502. However, the safety of a combined pre- and co-seasonal treatment regimen has not yet been investigated. As climate change is associated with earlier and less predictable onset of birch pollen seasons, planned pre-seasonal allergen immunotherapy may unintentionally overlap with natural pollen exposure. Therefore, evaluation of the safety of treatment administered during the pollen season is of increasing clinical relevance. This study aimed to compare, in a purely descriptive manner, the safety and tolerability of pre-seasonal versus pre- and co-seasonal treatment with EP-088-T502. Methods: In this prospective, open-label, phase III trial (T502-SIT-059) (EudraCT No.: 2022-004082-20), patients (N = 109) who had participated in a preceding pivotal phase III study were offered continuation treatment with active EP-088-T502 (10,000 mTU/mL) across five treatment visits. For the subgroup analysis, all patients who completed their last treatment visit before 9 April 2023 (and, thus, before the start of the birch pollen season in Germany) were assigned to the pre-seasonal group (N = 20). Those who performed the last treatment visit thereafter were assigned to the pre-/co-seasonal group (N = 83). Due to post hoc subgroup allocation and unequal subgroup sizes, all subgroup analyses were purely descriptive. Results: No deaths nor serious adverse events (SAEs) were reported during the study. No epinephrine administration was required. Systemic adverse drug reactions (SADRs, N = 3) occurred in two patients who had previously received placebo. No grade III or IV systemic reactions, according to the German AWMF classification, were observed. Patients receiving pre- and co-seasonal treatment developed smaller wheals (mean diameter) compared with the pre-seasonal group (immediate reactions: 0.6 vs. 0.7 cm; late-phase reactions: 0.3 vs. 0.4 cm at the last treatment visit). This was also reflected in the medians (immediate reactions: 0.2 cm vs. 0.4 cm; late-phase reactions: 0.2 vs. 0 cm at the last treatment visit). Of all AEs that were (possibly) related to EP-088-T502 (N = 89), 74 (83%) occurred at the first three treatment visits (before the birch pollen season). The frequency of AEs appeared descriptively similar between groups for the last two treatment visits. Patients who had received placebo in the previous trial experienced more treatment-related side effects compared to patients who had already received EP-088-T502 in the previous year. Conclusions: These data suggest that EP-088-T502 is safe and well-tolerated, even when administered during the birch pollen season, regardless of prior exposure to EP-088-T502.

Background/Objectives: Placebo responses can substantially influence patient-reported outcomes in clinical trials and are particularly relevant in allergen immunotherapy (AIT), where treatment efficacy is commonly assessed using symptom- and medication-based endpoints. We conducted an exploratory post hoc cross-study comparison of birch pollen-allergic participants who received pre-seasonal placebo injections in two randomised, double-blind, placebo-controlled AIT trials with participants from a third trial in whom the planned study injections were not administered before the corresponding birch pollen season. Methods: Data were pooled from three prospective clinical studies evaluating the mannan-conjugated birch pollen allergoid EP-088-T502: T502-SIT-020, T502-SIT-045, and T502-SIT-068. Placebo-injection cohorts from studies T502-SIT-020 and T502-SIT-045 were compared with the injection-free cohort from study T502-SIT-068. Clinical outcomes included the Combined Symptom and Medication Score (CSMS), daily Symptom Score (dSS), and daily Medication Score (dMS). Results: The three comparison cohorts comprised 321 participants: 161 in the injection-free cohort and 160 in the placebo-injection cohorts. Participants in the injection-free cohort had significantly higher symptom and medication scores during the secondary fixed 1–30 April analysis period than participants in the placebo-injection cohorts. Median CSMS was 1.97 in the injection-free cohort compared with 1.32 and 0.86 in the placebo-injection cohorts. Likewise, median dSS (1.08 vs. 0.79 and 0.59) and dMS (0.87 vs. 0.33 and 0.25) were higher in the injection-free cohort. Pairwise comparisons indicated statistically significant between-cohort differences. Conclusions: In this non-randomised, non-concurrent cross-study comparison, symptom and rescue-medication scores were lower in the placebo-injection cohorts than in the injection-free cohort. Because the cohorts were derived from separate studies conducted in different years, these findings are hypothesis-generating and do not establish a causal effect of placebo injections. Trial-related contextual factors and other cross-study differences should be considered when interpreting the results.

Background: The mannan-conjugated birch pollen polymerised allergoid EP-088_T502 has previously been shown to reduce allergic symptoms and anti-allergic medication use during the birch pollen season. This confirmatory phase III trial aimed to evaluate the efficacy, safety, tolerability, and immunologic effects of six pre-seasonal subcutaneous injections.Methods: In this DBPC trial, 278 participants with birch pollen–induced allergic rhinoconjunctivitis (ARC) received either placebo or a cumulative dose of 28,000 mTU EP-088_T502. The primary efficacy endpoint was the combined symptom and medication score (CSMS) during the peak birch pollen season. Safety, tolerability, health-related quality of life (QoL), and immunologic parameters were also assessed.Results: EP-088_T502 significantly reduced the CSMS during the peak birch pollen season compared with placebo (mean absolute difference [MAD] −0.31; p=0.016, FAS). In the PP and Complete Cases sets, MAD were -0.36 (p=0.012) and -0.51 (p=0.013), respectively. Health-related QoL improved by 20% in the EP-088_T502 group compared with placebo during the peak season (p<0.005). EP-088_T502 increased Bet v1-specific IgG4 levels after treatment compared with placebo (6.4-fold; p<0.0001). The Bet v1-specific IgE/IgG4 ratio was reduced by 73% from baseline and by 69% compared with placebo (both p<0.0001). Thirteen systemic allergic reactions occurred, including one grade III systemic reaction considered related to EP-088_T502.Conclusions: EP-088_T502 significantly improved symptom and medication scores in participants with birch pollen–induced ARC and induced a substantial Bet v1-specific IgG4 response. The higher cumulative dose was associated with enhanced immunologic effects and an acceptable safety and tolerability profile.

Background/Objectives: Previous studies have demonstrated the safety of pre-seasonal treatment with the mannan-conjugated birch pollen allergoid EP-088-T502. However, the safety of a combined pre- and co-seasonal treatment regi-men has not yet been investigated. This study aimed to compare the safety and tolera-bility of pre-seasonal versus pre- and co-seasonal treatment with EP-088-T502. Meth-ods: In this prospective, open-label, phase III trial (T502-SIT-059) (EudraCT No.:2022-004082-20), patients (N=109) who had participated in a preceding pivotal phase III study were offered continuation treatment with active EP-088-T502 (10.000 mTU/mL) across five treatment visits. For the subgroup analysis, all patients who completed their last treatment visit before 9 April 2023 (and thus before the start of the birch pollen season in Germany) were assigned to the pre-seasonal group (N=20). Those who performed the last treatment visit thereafter were assigned to the pre/co-seasonal group (N=83). Both groups were compared in terms of local and sys-temic immediate and late phase reactions and other EP-088-T502-related adverse events (AEs). Results: No deaths nor serious adverse events (SAEs) were reported during the study. No epinephrine administration was required. Systemic adverse drug reactions (SADRs, N=3) occurred in two patients who had previously received placebo. No grade III or IV systemic reactions according to the German AWMF classification were observed. Patients receiving pre- and co-seasonal treatment developed smaller wheals (mean diameter) compared with the pre-seasonal group (immediate reactions: 0.6 vs. 0.7 cm, late phase reactions: 0.3 vs. 0.4 cm at the last treatment visit). This was also reflected in the medians (immediate reactions: 0.2 cm vs. 0.4 cm, late-phase reac-tions: 0.2 vs. 0 cm at the last treatment visit). Of all AEs that were (possibly) related to EP-088-T502 (N=89), 74 (83%) occurred at the first three treatment visits (before the birch pollen season). The frequency of AEs was comparable between groups for the last two treatment visits. Patients who had received placebo in the previous trial experienced more treatment related side effects compared to patients who had already received EP-088-T502 in the previous year. Conclusions: These data suggest that EP-088-T502 is safe and well tolerated even when administered during the birch pollen season, regardless of prior exposure to EP-088-T502.