Background: Polymerized allergens conjugated to non‐oxidized mannan (PM‐allergoids) are novel vaccines targeting dendritic cells (DCs). Previous experimental data indicate that PM‐allergoids are readily taken up by DCs and induce Treg cells. This first‐in‐human study was aimed to evaluate safety and to find the optimal dose of house dust mite PM‐allergoid (PM‐HDM) administered subcutaneously (SC) or sublingually (SL).Methods: In a randomized, double‐blind, double‐dummy, placebo‐controlled trial, 196 subjects received placebo or PM‐HDM at 500, 1000, 3000, or 5000 mannan‐conjugated therapeutic units (mTU)/mL in 9‐arm groups for 4 months. All subjects received 5 SC doses (0.5 ml each) every 30 days plus 0.2 ml SL daily. The primary efficacy outcome was the improvement of titrated nasal provocation tests (NPT) with D. pteronyssinus at baseline and at the end of the study. All adverse events and reactions were recorded and assessed. Secondary outcomes were the combination of symptom and medication scores (CSMS) and serological markers.Results: No moderate or severe adverse reactions were reported. Subjects improving the NPT after treatment ranged from 45% to 62% in active SC, 44% to 61% in active SL and 16% in placebo groups. Statistical differences between placebo and active groups were all significant above 500 mTU, being the highest with 3000 mTU SL (p = 0.004) and 5000 mTU SC (p = 0.011). CSMS improvement over placebo reached 70% (p < 0.001) in active 3000 mTU SC and 40% (p = 0.015) in 5000 mTU SL groups.Conclusions: PM‐HDM immunotherapy was safe and successful in achieving primary and secondary clinical outcomes in SC and SL at either 3000 or 5000 mTU/ml.

Background: Subcutaneous immunotherapy has emerged as an effective option for treating allergic diseases. Here, we assessed the clinical impact of the mannan‐conjugated birch pollen polymerized allergoid T502 in birch pollen‐induced allergic rhinoconjunctivitis. Methods: In this prospective, randomized, double‐blind placebo‐controlled phase III trial, 298 birch pollen–allergic adult patients were treated across 28 trial sites in Germany. Patients received either placebo or 23,000 mTU T502 subcutaneously over five pre‐seasonal visits. Efficacy was assessed by comparing the combined symptom and medication score (CSMS) between placebo and T502 during the peak birch pollen season 2022. Safety, tolerability and immunologic effects were also analyzed. Results: During the peak birch pollen season, the median CSMS of the T502 group was reduced by 33% ( p = 0.002) compared to placebo. The median daily symptom score and daily medication score were reduced by 30.4% ( p < 0.001) and 56.3% ( p = 0.045), respectively. Health related quality of life improved as reflected by reduction of RQLQ values by 31.5% ( p < 0.0001). Production of Bet v 1 sIgG4 and Bet v 1 sIgG increased up to 6.2‐fold and 3‐fold respectively in the T502 group ( p < 0.0001). The sIgE/sIgG4 ratio was strongly reduced in the T502 group at V7 (−62.9%, p < 0.0001). No fatalities nor serious adverse events were reported. In total, 16 systemic allergic reactions occurred (Grade I/II). Conclusions: Treatment with T502 significantly reduced symptoms and medication need in rhinoconjunctivitis patients. The treatment is well tolerated and safe.

Subcutaneous allergen immunotherapy (SCIT) is recognized as an effective and safe treatment for children and adults suffering from allergic respiratory diseases driven by house dust mites (HDM) in tropical regions. To assess the clinical effectiveness and safety of SCIT using glutaraldehyde-polymerized allergen extracts of Dermatophagoides pteronyssinus and D. farinae in Colombian pediatric patients. A retrospective, observational study including 49 children diagnosed with HDM-induced allergic rhinitis, with or without asthma, who were treated with SCIT for 1 year. Primary endpoints were measured using the Combined Symptom and Medication Score (CSMS). Secondary outcomes were asthma medication use and Asthma Control Test (ACT) scores. Significant improvement in CSMS (median reduction: −0.8; p = 0.015) and ACT scores (median increase: −1.3; p = 0.015) were observed within 3 months; 76% of patients had at least a 20% of reduction of the CSMS compared to baseline after 6 months with immunotherapy (IT). Medication use for asthma decreased significantly after 1 year (p = 0.035). SCIT using polymerized HDM extracts demonstrated to be effective and safe in allergic pediatric populations.

Background: Allergies to fungi, such as Alternaria alternata, are significant contributors to respiratory conditions like asthma and rhinitis. Immunotherapy with native A. alternata extracts often results in high rates of adverse reactions. This study evaluates the safety of immunotherapy using glutaraldehyde-polymerized A. alternata extracts in both pediatric and adult populations. Methods: This observational real-world study involved 738 patients (435 children and 303 adults) monosensitized to A. alternata or polysensitized together to other allergens. Patients received personalized immunotherapy containing polymerized A. alternata extract, either alone or in combination with other polymerized allergens. The concentration of each polymerized allergen in the therapeutic vaccine was 10,000 TU/mL. Side reactions were classified and recorded based on immediate and delayed onset, and their severity was graded according to the EAACI guidelines. Results: All side reactions were expected and related to the intrinsic properties of allergens. The number of injections administered was 7392, with 4137 to children and 3255 to adults. Thirteen relevant local reactions (0.24% in children, 0.09% in adults) and seven systemic reactions (0.09% overall) were observed. Systemic reactions included mild to moderate symptoms, such as mild bronchospasm and rhinitis. Severe reactions were not reported. Conclusion: Immunotherapy with glutaraldehyde-polymerized A. alternata, alone or in combination with other polymerized allergens, is safe and well-tolerated in both children and adults. The polymerized extracts allow for higher concentrations and faster administration schedules, providing an effective treatment option for patients with fungal allergies, including those polysensitized to multiple allergens.

Background/Objectives: Allergen immunotherapy (AIT) with chemically modified allergoids represents a promising approach for the treatment of allergic rhinoconjunctivitis. This post hoc analysis investigated the clinical efficacy of a mannan-conjugated birch pollen allergoid (T502) by comparing outcomes in patients who received placebo in one pollen season and active treatment in the following year. Methods: Data were derived from four randomized clinical trials (EudraCT Numbers: 2018-002522-23, 2020-004126-32, 2021-002252-36, and 2022-004082-20) conducted over four consecutive years. Two independent patient groups were analyzed, with each group receiving placebo in the first year and subcutaneous T502 (10,000 mTU/mL) in the subsequent year. Daily symptom score (dSS), daily medication score (dMS), and combined symptom and medication score (CSMS) were assessed during the birch pollen season in April of each year. Results: In the first comparison between placebo in 2020 and an early treatment start in January 2021, treatment with T502 led to a 43.79% reduction in dSS (p ≤ 0.0001), a 71.43% reduction in dMS (p ≤ 0.001), and a 42.1% reduction in CSMS (p ≤ 0.001), all statistically significant. In the second comparison between placebo in 2022 and a late treatment start in March 2023, the reduction in dMS was 74.47% (p ≤ 0.001), whereas reductions in dSS (1.47%, p = 0.898) and CSMS (20.3%, p = 0.057) were not statistically significant. Conclusions: Subcutaneous immunotherapy (SCIT) with T502 significantly reduces allergic symptoms and medication use, particularly when all injections are completed before the onset of the birch pollen season in April. These findings highlight both the clinical value of T502 and the importance of optimized treatment timing.

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.