Effect of Combination Therapy on Symptoms of Allergic Rhinitis

Allergic Rhinitis and Its Treatment Options

An exaggerated immune response to an allergen causes allergic rhinitis (AR), which is characterized by symptoms such as nasal congestion, sneezing, rhinitis, and nasal itching. AR is one of the most common chronic conditions in both adult and pediatric populations. It negatively impacts quality of life, reduces productivity, disrupts sleep, and causes fatigue and depression.  

Most patients with AR try at least one treatment modality to control their symptoms. Several options are available: regimen measures, environmental control and adjustment, allergen immunotherapy, and pharmacological treatments. However, each of these has its drawbacks. Complete environmental control is impractical, immunotherapy requires long-term adherence, and medication (both over-the-counter and prescription) does not always sufficiently relieve symptoms and may even lose effectiveness over time. 

Combination Treatment in Nasal Spray GSP301

The nasal spray GSP301 contains a fixed dose combination of an antihistamine (olopatadine hydrochloride) and a corticosteroid (mometasone furoate). Individually, both ingredients are effective and well-tolerated modalities of intranasal AR therapy. Researchers investigated how their fixed combination could enhance treatment efficacy and clinical improvement. 

Study Methodology and Progress

This randomized double-blind study was conducted in 43 centers across the USA. Patients over 12 years old with seasonal allergic rhinitis during the autumn and cedar pollen season were enrolled. The study was divided into two phases: first, the placebo-run in phase (7−10 days from study entry to randomization), followed by the treatment phase (15−17 days from randomization to the final visit). During randomization, patients were divided into 4 treatment groups for 14 days (2 sprays in each nostril 2×a day): fixed combination GSP301 (olopatadine hydrochloride 665 μg + mometasone furoate 25 μg), monotherapy with olopatadine hydrochloride (665 μg), monotherapy with mometasone furoate (25 μg), placebo (GSP301 carrier without active ingredient). 

Study Population

A total of 1176 patients with at least 2 years of clinical AR history were enrolled, and 97.5% completed the study. Women and Caucasians with moderate to severe nasal and ocular symptoms predominated. The average age ranged between 39.2 and 39.9 years, with similar demographic and quality of life scores across groups. Inclusion criteria included a positive skin prick test (redness ≥ 5 mm compared to the negative control), average 12-hour morning and evening nasal symptom score (rTNSS) ≥ 8 (max. 12), and morning nasal congestion ≥ 2.   

Results 

After 14 days of treatment, the GSP301 group exhibited statistically significant and clinically meaningful improvement in 12-hour rTNSS compared to placebo (p < 0,001) and monotherapies (olopatadine, p = 0.03; mometasone, p = 0.02). Monotherapies also significantly improved compared to placebo (olopatadine p = 0,001; mometasone p = 0,002). Similar significant improvements were observed in iTNSS (instantaneous TNSS) in the GSP301 group (p < 0,05 for all).

GSP301 also significantly improved overall ocular symptoms (p = 0,001) and individual nasal symptoms (p < 0,001 for all) compared to placebo after 14 days of treatment. Monotherapies significantly improved individual nasal symptoms compared to placebo (p ≤ 0,05 for all) with the exception of olopatadine and nasal congestion, and mometasone and nasal itching. The onset of GSP301's effect was observed 15 minutes after application and persisted to subsequent measurement points. 

During the study, 15.6% of patients in the GSP301 group, 12.6% in the olopatadine group, 9.6% in the mometasone group, and 9.5% in the placebo group reported treatment-related adverse events. 

Conclusion

According to this study, GSP301 represents an effective and well-tolerated modality for the therapy of nasal and ocular symptoms of allergic rhinitis, with rapid onset of action observed 15 minutes after application. 

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Source: Gross G. N., Berman G., Amar N. J. et al. Efficacy and safety of olopatadine-mometasone combination nasal spray for the treatment of seasonal allergic rhinitis. Ann Allergy Asthma Immunol 2019; 122 (6): 630−638.e3, doi: 10.1016/j.anai.2019.03.017.