Subcutaneous birch pollen allergen immunotherapy with a depigmented polymerized extract shows only sustained and long-term efficacy in a subgroup of monosensitized adults and adolescents with allergic rhinitis

A randomized, double-blind, placebo-controlled trial with mannan-conjugated birch pollen allergoids

BACKGROUND

There is still great need to develop new strategies to improve the efficacy of allergen immunotherapies with optimal safety standards for patients. A new promising approach is to couple allergoids to mannan. The objective of this phase IIa/IIb study was to identify the optimal dose of mannan-conjugated birch pollen allergoids for the short-course treatment of birch pollen-induced allergic rhinoconjunctivitis.

METHODS

For this prospective, randomized, double-blind, placebo-controlled, dose-finding study, 246 birch pollen-allergic adults received 0.5 mL placebo or 1000, 3000 or 10,000 mTU/mL of mannan-conjugated birch pollen allergoids at five pre-seasonal visits. Efficacy was assessed by comparing allergic rhinoconjunctivitis symptoms and use of anti-allergic medication during the peak of the birch pollen season 2020. Immunologic, tolerability and safety effects were also analysed.

RESULTS

The highest dose of mannan-conjugated birch pollen allergoids reduced the combined symptom and medication score during the peak birch pollen season by a median of 24.7% compared to placebo. The production of Bet v 1 specific IgG4 significantly increased in a dose-dependent manner (3.6- and 4.5-fold) in the 3000 and 10,000 mTU/mL groups. The Bet v 1 specific IgE/IgG4 ratio was also strongly reduced (up to -70%). No fatalities nor serious adverse events were reported, and no adrenaline was used. In total, four systemic reactions occurred (two grade I and two grade II).

CONCLUSION

All doses of mannan-conjugated birch pollen allergoids can be considered as safe. Since the application of 10,000 mTU/mL resulted in the highest efficacy, this dose qualifies for further investigation.

A high-dose, depigmented polymerized birch pollen extract for subcutaneous allergen immunotherapy has a favourable efficacy/safety ratio

BACKGROUND

Subcutaneous allergen immunotherapy (SCIT) with depigmented, polymerized (DPP) birch pollen extract has been marketed at doses of up to 1000 DPP units/mL since 2001. We sought to determine the dose-dependent efficacy of a DPP birch pollen extract formulation in patients suffering from birch-pollen-induced allergic rhinitis or rhinoconjunctivitis with or without intermittent asthma.

METHODS

A titrated conjunctival provocation test (CPT) was applied as a surrogate marker. This Phase II randomized, double-blind, parallel-group, dose-ranging clinical trial was performed at 39 centres in Germany, Lithuania and Poland. After randomization to four dose-level groups (100, 1000, 5000 and 10,000 DPP units/mL) and up-dosing, participants received maintenance SCIT with five monthly subcutaneous injections. The primary endpoint was the proportion of patients in whom a higher concentration of birch pollen (vs. baseline) was needed to elicit a positive CPT.

RESULTS

Three hundred forty-three patients were included (mean (range) age: 42.6 (19-70)). The highest CPT responder rates were seen in the higher dose-level groups. In the intention-to-treat analysis, the difference between the 100 and 10,000 groups was statistically significant (p = 0.0118). Although the proportion of patients with ≥1 treatment-emergent adverse events increased with the dose, almost all these events were mild (65.6%) or moderate (18.5%).

CONCLUSION

Judging by the results of a CPT, the efficacy/safety ratio in SCIT appears to be favourable for a high-dose-level preparation of a DPP birch pollen extract.

Short-course subcutaneous treatment with PQ Grass strongly improves symptom and medication scores in grass allergy

BACKGROUND

A modified grass allergen subcutaneous immunotherapy (SCIT) product with MicroCrystalline Tyrosine and monophosphoryl lipid-A as an adjuvant system (Grass MATA MPL [PQ Grass]) is being developed as short-course treatment of grass-pollen allergic rhinitis (SAR) and/or rhinoconjunctivitis. We sought to evaluate the combined symptom and medication score (CSMS) of the optimized cumulative dose of 27,600 standardized units (SU) PQ Grass in a field setting prior to embarking on a pivotal Phase III trial.

METHODS

In this exploratory, randomized, double-blind, placebo-controlled trial subjects were enrolled across 14 sites (Germany and the United States of America). Six pre-seasonal subcutaneous injections of PQ Grass (using conventional or extended regimens) or placebo were administered to 119 subjects (aged 18-65 years) with moderate-to-severe SAR with or without asthma that was well-controlled. The primary efficacy endpoint was CSMS during peak grass pollen season (GPS). Secondary endpoints included Rhinoconjunctivitis Quality of Life Questionnaire standardized (RQLQ-S) and allergen-specific IgG4 response.

RESULTS

The mean CSMS compared to placebo was 33.1% (p = .0325) and 39.5% (p = .0112) for the conventional and extended regimens, respectively. An increase in IgG4 was shown for both regimens (p < .01) as well as an improvement in total RQLQ-S for the extended regimen (mean change -0.72, p = .02). Both regimens were well-tolerated.

CONCLUSIONS

This trial demonstrated a clinically relevant and statistically significant efficacy response to PQ Grass. Unprecedented effect sizes were reached for grass allergy of up to ≈40% compared to placebo for CSMS after only six PQ Grass injections. Both PQ Grass regimens were considered equally safe and well-tolerated. Based on enhanced efficacy profile extended regime will be progressed to the pivotal Phase III trial.

Clinical efficacy and safety of coseasonal initiation of Artemisia annua sublingual immunotherapy on patients with Artemisia-induced rhinoconjunctivitis

PURPOSE

Patients with seasonal allergic rhinoconjunctivitis (SARC) might seek evaluation and treatment when symptoms appear during the pollen season. It is unclear whether coseasonal-initiated sublingual immunotherapy (SLIT) would be effective and safe for SARC. This study aims to identify the feasibility of initiating Artemisia annua SLIT during the pollen season.

MATERIALS AND METHODS

Sixty patients with Artemisia-induced SARC were equally recruited into the SLIT and control groups during the pollen season in 2021. The SLIT group was treated with standardized Artemisia annua SLIT drops using a modified dosing schedule combined with pharmacotherapy, while the control group only received pharmacotherapy. Diary cards for clinical symptoms, rescue medication use, and adverse events (AEs) were recorded during the pollen seasons. Objective measures, including average daily combined scores of medication and rhinoconjunctivitis symptoms (CSMRS), total rhinoconjunctivitis symptom score (TRSS), total medication score (TMS), and the score of visual analog scale (VAS) were calculated to evaluate the efficacy of SLIT. Safety was assessed through the occurrence and severity of AEs.

RESULTS

In total, 80.0 % (24/30) patients in the SLIT group and 86.67 % (26/30) patients in the control group completed the study. The severity of SARC, which was assessed by objective measures including CSMRS, TRSS, TMS, and VAS of the SLIT group and the control group, was generally at the same level during the 2021 pollen season, except for the medical consumption, which the score of TMS was slightly higher in the SLIT group. After one year of treatment, the scores of CSMRS, TRSS, and VAS in the SLIT group were significantly improved compared with the control group (all P < 0.001), and the difference in the TMS between the two groups disappeared (P > 0.05). Moreover, clinical improvement of the four objective measures was also observed in the SLIT group compared with the baseline value (P < 0.001). Overall, 9/24 patients in the SLIT group experienced mild local AEs, and two patients experienced mild systemic AEs during the SLIT period.

CONCLUSIONS

This controlled preliminary study identified that coseasonal-initiated Artemisia annua SLIT treatment for one year was generally safe and effective in improving the symptoms of SARC patients induced by Artemisia annua pollen.

Mechanisms and biomarkers of successful allergen-specific immunotherapy

Allergen-specific immunotherapy (AIT) is considered the only curative treatment for allergic diseases mediated by immunoglobulin E (IgE). Currently, the route of administration depends both on the different types of causal allergens and on its effectiveness and safety profile. Several studies have reported the mechanisms and changes in humoral and cellular response underlying AIT; however, the full picture remains unknown. Knowledge of who can benefit from this type of treatment is urgently needed due to the patient safety risks and costs of AIT. In vivo or in vitro biomarkers have become a strategy to predict clinical outcomes in precision medicine. There are currently no standardized biomarkers that allow determining successful responses to AIT, however, some studies have found differences between responders and nonresponders. In addition, different candidates have been postulated that may have the potential to become biomarkers. In this review, we aim to summarize the findings to date related to biomarkers in different IgE-mediated allergic diseases (respiratory, food, and venom allergy) with the potential to define who will benefit from AIT.