Phase III study of Phlai capsules in the treatment of allergic rhinitis: A randomized, double-blind, placebo-controlled trial

Abstract

BACKGROUND: Preclinical studies demonstrated anti-inflammatory effects of Zingiber montanum (J.König) Link ex Dietr.(Phlai). However, its clinical effect on allergic rhinitis (AR) is not evident. OBJECTIVE: We sought to assess the efficacy and safety of Phlai for treating AR. METHODS: A phase 3, randomized, double-blind, placebo-controlled study was conducted. Patients with AR were randomized into three groups and received Phlai 100 mg or Phlai 200 mg or placebo once a day for four weeks. The primary outcome was a change in the reflective total five symptom score (rT5SS). The secondary outcomes were the change in the instantaneous total five symptom score (iT5SS), the reflective individual symptom scores (rhinorrhea, nasal congestion, sneezing, itchy nose, itchy eyes), Rhinoconjunctivitis Quality of Life-36 Questionnaire (RCQ-36) score, peak nasal inspiratory flow (PNIF), and adverse events. RESULTS: Two hundred and sixty-two patients were enrolled. Compared with placebo, Phlai 100 mg improved rT5SS [adjusted mean difference (aMD) -0.62; 95%CI -1.22, -0.03; p = 0.039], rhinorrhea (aMD -0.19; 95%CI -0.37, 0.002; p = 0.048), itchy nose (aMD -0.24; 95%CI -0.43, -0.05; p = 0.011), and itchy eyes (aMD -0.19; 95%CI -0.36, -0.02; p = 0.033) at week 4. Nasal obstruction, sneezing, iT5SS, overall RCQ-36 score, PNIF did not reach statistical significance. Phlai 200 mg did not bring additional benefits compared to 100 mg. Adverse events were similar among groups. CONCLUSIONS: Phlai was safe. At four weeks, there were small improvements in rT5SS, together with the individual symptoms of rhinorrhea, itchy nose, and itchy eyes.