Efficacy and Safety of Pimodivir Combined with Standard-of-care in Hospitalized and Non-hospitalized High-risk Adolescents and Adults with Influenza A Infection

Background: An unmet need exists for effective antivirals to treat patients hospitalized with influenza. The results of 2 Phase 3 studies evaluating the efficacy and safety of pimodivir in combination with investigator-chosen standard-of-care (SoC) treatment are presented.

Methods: Hospitalized patients (hospital study; NCT03376321) and high-risk outpatients (outpatient study; NCT03381196) with laboratory-confirmed influenza A infection were randomized 1:1 to 600 mg pimodivir twice daily (BID) + SoC, or placebo BID + SoC for 5 days. For most patients SoC included oseltamivir. Primary endpoints were Hospital Recovery Scale (HRS) at Day 6 (hospital study) and median time to resolution (TTR) of influenza-related symptoms (outpatient study).

Results: Pimodivir + SoC (oseltamivir) treatment showed no clinical benefit over placebo + SoC on HRS at Day 6 (common odds ratio, 0.943 [95% CI, 0.609-1.462], P = .397; hospital study). A shorter median TTR of 7 symptoms was estimated with pimodivir + SoC versus placebo (92.6 hours [95% CI, 77.6-104.2] versus 105.1 hours [95% CI, 92.7-128.6], P = .0216; outpatient study).

Conclusion: Pimodivir + SoC showed no additional clinical benefit versus SoC treatment alone in hospitalized patients. Pimodivir + SoC demonstrated shorter TTR of influenza symptoms versus placebo + SoC in high-risk outpatients.