Birch allergen challenges in allergic conjunctivitis using standard conjunctival allergen challenge and environmental exposure chamber

BACKGROUND

Environmental exposure chambers (EECs) have been used extensively to study allergic rhinoconjunctivitis. Few studies have been published using EECs in conjunctivitis only, and none have used conjunctival allergen challenge as a selection criterion. The present study validated ALYATEC EEC in allergic conjunctivitis to birch pollen.

METHODS

Sixteen patients with a positive conjunctival allergen challenge (CAC) were exposed to 60 ng/m3 of Bet v 1 in an EEC on two consecutive days for a maximum of 4 h to validate EEC exposure to birch. Reproducibility was tested among seven of the patients. A conjunctival positive scoring during the CAC and the EEC exposure was defined as a Total Ocular Symptom Score (TOSS) ≥ 5.

RESULTS

Fifty percent of patients had a conjunctival positive scoring during first exposure and 75% during second exposure. The mean time to a conjunctival response was 81.2 ± 33.9 min and 101.6 ± 57 (P > 0.05) during first and second exposure, respectively. No difference in TOSS occurred between the two exposures. The time necessary to obtain a positive response during the CAC was significantly shorter than with the EEC. The estimated quantity of Bet v 1 inducing a positive response was 0.07 ± 0.03 ng (exposure 1), 0.07 ± 0.07 ng (exposure 2), 980 ± 784 ng (CAC). Conjunctival positive scoring and quantity of Bet v 1 was reproducible in all six EEC exposures.

CONCLUSIONS

Early conjunctival responses induced by birch allergen exposures in EEC were different than from those identified with direct instillation during CAC. EEC appears to be closer to natural exposure than CAC.

Bepotastine besilate ophthalmic solution 1.5% for alleviating nasal symptoms in patients with allergic conjunctivitis

Background

Bepotastine besilate ophthalmic solution (BBOS) 1.5% is a topical antihistamine for the treatment of ocular itching associated with allergic conjunctivitis (AC). Allergic rhinitis and AC are common comorbid conditions. We explored the efficacy of BBOS 1.5% in alleviating nasal symptoms in an integrated analysis of two Phase III conjunctival allergen challenge (CAC) studies and a Phase IV environmental allergen study.

Methods

In the Phase III trials, a CAC was performed 15 minutes, 8 hours, and 16 hours following ocular instillation of BBOS 1.5% (n=78) or placebo (n=79), and subjects evaluated nasal symptoms. In the environmental study, subjects instilled BBOS 1.5% (n=123) or placebo (n=122) twice daily and nasal symptoms were evaluated over 2 weeks.

Results

In the Phase III trials, BBOS 1.5% had reduced CAC-induced nasal congestion and pruritus at 15 minutes and 8 hours postdosing and rhinorrhea and a non-ocular composite-symptom score (sum of nasal scores plus ear or palate pruritus) at all time points postdosing (all P≤0.01 vs placebo). In the Phase IV environmental study, BBOS 1.5% reduced sneezing and nasal pruritus over 2 weeks and median number of days to improvement of nasal pruritus and total nasal symptom score (sum for rhinorrhea, sneezing, nasal pruritus, and nasal congestion; P≤0.04 vs placebo). Additionally, investigator-reported improvement in overall ocular (pruritus, hyperemia, tearing) and nasal symptoms was greater with BBOS 1.5% vs placebo (P≤0.03).

Conclusion

Results of these exploratory analyses indicate that topical ocular BBOS 1.5% reduced nasal symptoms, supporting its use for alleviating rhinitis symptoms associated with AC.

Pooled analysis of two studies evaluating efficacy and safety of olopatadine hydrochloride 0.77% in patients with allergic conjunctivitis

Purpose

Two individual phase 3 conjunctival allergen challenge (CAC) studies of similar design have assessed the efficacy and safety of olopatadine hydrochloride (HCl) 0.77% for the treatment of allergic conjunctivitis. The purpose of this study is to evaluate the integrated efficacy and safety of olopatadine HCl 0.77% from a larger dataset by pooling data from the two individual CAC studies.

Methods

Data were pooled from two phase 3, randomized, multicenter, double-masked, active- and vehicle-controlled CAC studies. The primary comparison was on ocular itching scores between olopatadine HCl 0.77% versus vehicle (at onset and 24 hours) and olopatadine HCl 0.77% versus olopatadine 0.2% (at 24 hours). Additional end points included conjunctival redness, total redness, and proportion of itching responders at onset and 24-hour duration of CAC. For both primary and secondary analysis, mixed model repeated measures analysis was used, except for proportion of ocular itching responders. Sensitivity analyses were carried out using a two-sample t-test.

Results

This analysis included 448 patients. Olopatadine HCl 0.77% was superior to vehicle (P<0.0001) at onset and 24-hour duration of action (difference in means: −1.14 to −1.52) and to olopatadine 0.2% (P=0.0009) at 24-hour duration of action in relieving ocular itch. Additionally, olopatadine HCl 0.77% substantially reduced conjunctival redness and total redness over vehicle and olopatadine 0.2% at onset and 24-hour duration of action. At 24 hours CAC, there were a higher proportion of itching responders with olopatadine HCl 0.77% compared to vehicle or olopatadine 0.2% (difference in proportion of responders: 43.17%, P<0.0001, and 17.25%, P=0.0012, respectively). No safety concerns were identified.

Conclusion

This analysis confirms the findings from the individual studies. The rapid onset and prolonged duration of action (for 24 hours) of olopatadine HCl 0.77% supports once-daily dosing in the treatment of allergic conjunctivitis.

Effect of alcaftadine 0.25% on ocular itch associated with seasonal or perennial allergic conjunctivitis: a pooled analysis of two multicenter randomized clinical trials

PURPOSE

Seasonal and perennial allergic conjunctivitis represent the majority of cases of ocular allergy. This analysis was designed to evaluate the efficacy and safety of once-daily alcaftadine 0.25% in preventing ocular itching associated with seasonal or perennial allergic conjunctivitis.

SUBJECTS AND METHODS

Pooled data from two double-masked, multicenter, placebo-controlled studies using the conjunctival allergen challenge (CAC) model of allergic conjunctivitis were analyzed. Subjects randomized to receive treatment with alcaftadine 0.25% or placebo were challenged with seasonal (grass, ragweed, trees) or perennial (cat dander, cat hair, dog dander, dust mites, cockroach) allergens, 16 hours after treatment instillation. The primary efficacy measure was subject-evaluated mean ocular itching at 3 minutes post-CAC. Secondary measures included ocular itching at 5 and 7 minutes post-CAC. The proportion of subjects with minimal itch (itch score <1) and zero itch (itch score =0), and safety were also assessed.

RESULTS

A total of 189 subjects enrolled in the two studies were treated with alcaftadine or placebo. Overall, 129 subjects were challenged with seasonal allergens and 60 subjects were challenged with perennial allergens. Alcaftadine 0.25% achieved a statistically significant reduction in mean itch score at 3, 5, and 7 minutes post-CAC compared with placebo in subjects challenged with seasonal allergens (P<0.0001 at all time points) and those challenged with perennial allergens (P<0.0001 at all time points). A higher percentage of subjects treated with alcaftadine compared with placebo achieved minimal itch (P≤0.001 versus placebo at all time points) and zero itch (P<0.05 at all time points except 7 minutes for perennial) when challenged with either seasonal or perennial allergens. No treatment-related or serious adverse events were reported.

CONCLUSION

Once-daily alcaftadine 0.25% ophthalmic solution was well tolerated and demonstrated effective relief of ocular itching in subjects challenged with allergens classic for triggering either seasonal or perennial allergic conjunctivitis.

Exacerbation of signs and symptoms of allergic conjunctivitis by a controlled adverse environment challenge in subjects with a history of dry eye and ocular allergy

BACKGROUND

The goal of this study was to assess the effect of a controlled adverse environment (CAE) challenge on subjects with both allergic conjunctivitis and dry eye.

METHODS

Thirty-three subjects were screened and 17 completed this institutional review board-approved study. Subjects underwent baseline ocular assessments and conjunctival allergen challenge (CAC) on days 0 and 3. Those who met the ocular redness and itching criteria were randomized to receive either the controlled adverse environment (CAE) challenge (group A, n = 9) or no challenge (group B, n = 8) at day 6. Thirty minutes after CAE/no-CAE, subjects were challenged with allergen and their signs and symptoms graded. Exploratory confocal microscopy was carried out in a subset of subjects at hourly intervals for 5 hours post-CAC on days 3 and 6.

RESULTS

Seven minutes post-CAC, subjects exposed to the CAE had significantly greater itching (difference between groups, 0.55 ± 0.25, P = 0.028), conjunctival redness (0.59 ± 0.19, P = 0.002), episcleral redness (0.56 ± 0.19, P = 0.003) and mean overall redness (mean of conjunctival, episcleral, and ciliary redness, 0.59 ± 0.14, P < 0.001). The mean score at 7, 15, and 20 minutes post-CAC for conjunctival redness (0.43 ± 0.17, P = 0.012), episcleral redness (0.49 ± 0.15, P = 0.001), mean overall redness in all regions (0.43 ± 0.15, P = 0.005), and mean chemosis (0.20 ± 0.08, P = 0.017) were also all significantly greater in CAE-treated subjects. Confocal microscopic images of conjunctival vessels after CAC showed more inflammation in CAE-treated subjects.

CONCLUSION

In subjects with both dry eye and allergic conjunctivitis, exposure to adverse environmental conditions causes an ocular surface perturbation that can intensify allergic reactions.

Evaluation of alcaftadine 0.25% ophthalmic solution in acute allergic conjunctivitis at 15 minutes and 16 hours after instillation versus placebo and olopatadine 0.1%

PURPOSE

To evaluate the effectiveness of alcaftadine 0.05%, 0.1%, and 0.25% ophthalmic solutions in treating the signs and symptoms of allergic conjunctivitis when compared with olopatadine hydrochloride 0.1% and placebo using the conjunctival allergen challenge (CAC) model.

METHODS

One hundred and seventy subjects were randomized and 164 subjects completed all visits. CAC was performed to determine and confirm subjects' eligibility at visits 1 and 2, respectively. The CAC was repeated at visit 3 (day 0 ± 3), 16 hours after study medication instillation, and at visit 4 (day 14 ± 3), 15 minutes after instillation. Ocular itching and conjunctival redness were evaluated after an allergen challenge, along with several secondary endpoints.

RESULTS

Alcaftadine 0.25% and olopatadine 0.1% treatments exhibited significantly lower mean scores compared with placebo for ocular itching and conjunctival redness at visits 3 and 4. Most adverse events were self-limiting and mild in severity. No serious treatment-related adverse events occurred.

CONCLUSION

Treatment with alcaftadine 0.25% ophthalmic solution resulted in mean differences of >1 unit (ocular itching) and approximately >1 unit (conjunctival redness), which was significant (P < 0.001) compared with placebo treatment. All doses of alcaftadine were safe and well tolerated in the population studied.