Effect of peramivir on respiratory symptom improvement in patients with influenza virus infection and pre‐existing chronic respiratory disease: Findings of a randomized, open‐label study

BACKGROUND: The efficacy of neuraminidase inhibitors on improvement of respiratory symptoms triggered by influenza in patients with pre‐existing chronic respiratory diseases is unknown. METHODS: This 2‐week, randomized, open‐label study evaluated intravenous peramivir 600 mg on two consecutive days (peramivir‐repeat), peramivir 300 mg single dose (peramivir‐single), and oral oseltamivir 75 mg twice daily for 5 days in patients with confirmed influenza and chronic respiratory diseases. Patients recorded symptom scores daily. The primary endpoint of cumulative area of time vs symptoms (CATVS) was expressed as an index value of area under the curve vs time of the total score of cough, sore throat, and nasal congestion from baseline to 2 weeks. RESULTS: Of 214 randomized patients, 209 (56% female, 77% aged <65 years, 94% outpatients, 91% bronchial asthma, 62% influenza A) received ≥1 dose of study drug. Mean (standard deviation) CATVS was similar for peramivir‐repeat (782.78 [487.17]) vs peramivir‐single (717.35 [347.55]; P = .4371), and for peramivir‐repeat vs oseltamivir (856.34 [404.99]; P = 1.00). However, CATVS was significantly shorter for peramivir‐single vs oseltamivir, with an estimated treatment difference (TD) of −145.07 (95% confidence interval: −284.57, −5.56; P = .0416). In subgroup analyses, CATVS was significantly shorter for peramivir‐single vs oseltamivir among patients with influenza A (TD: −206.31 [−383.86, −28.76]; P = .0231), bronchial asthma (TD: −156.57 [−300.22, −12.92]; P = .0328), baseline respiratory severity score <5 (TD: −265.32 [−470.42, −60.21]; P = .0120), and age <65 (TD: −184.30 [−345.08, −23.52]; P = .0249). CONCLUSIONS: In patients with chronic respiratory diseases, peramivir‐single was not significantly different from peramivir‐repeat and was more effective than oseltamivir at alleviating respiratory symptoms.