Baloxavir Marboxil (DB13997): A Comprehensive Pharmacological and Clinical Monograph

Introduction and Drug Profile

Baloxavir marboxil, marketed under the brand name Xofluza®, represents a significant advancement in the therapeutic armamentarium against seasonal influenza. As the first antiviral agent with a novel mechanism of action to be approved in nearly two decades, it addresses the ongoing need for effective and convenient treatments for influenza A and B infections.[1] The drug's primary distinction lies in its single-dose oral regimen, a feature that fundamentally alters the clinical management of influenza by circumventing the adherence challenges associated with multi-day therapies, such as the five-day course required for oseltamivir.[4] This single-dose administration directly addresses a common point of failure in real-world antiviral therapy, where patients may prematurely discontinue treatment upon feeling better, potentially leading to suboptimal clinical outcomes and fostering the development of viral resistance.

Developed through a collaboration between Shionogi & Co., Ltd., which discovered the compound, and the Roche Group (including Genentech in the United States), baloxavir marboxil has been globally commercialized for both the treatment of acute, uncomplicated influenza and for post-exposure prophylaxis.[2] Its therapeutic profile is characterized by a broad spectrum of activity, demonstrating efficacy against both influenza A and B viruses, including strains that have developed resistance to older neuraminidase inhibitors and certain avian strains in non-clinical studies.[4] A hallmark of its clinical effect is the rapid and profound reduction in viral load, a pharmacodynamic property that distinguishes it from previous standards of care and contributes to its public health potential in reducing viral transmission.[4]

Table 1: Drug Identification and Key Properties