Baloxavir

Baloxavir is a first-in-class cap-dependent endonuclease inhibitor that has established a new mechanism of action for influenza treatment. As a polymerase acidic endonuclease inhibitor, Baloxavir targets the influenza virus at a critical step in the viral replication cycle—the cap-snatching process essential for viral mRNA transcription. The unique bicyclic structure of Baloxavir, featuring a difluorinated benzothiepine ring fused to a triazatricyclic dione scaffold, enables potent and selective inhibition of the influenza endonuclease with a single-dose treatment regimen. In pharmaceutical manufacturing, Baloxavir requires stringent quality control to ensure batch-to-batch consistency and therapeutic efficacy. The synthetic route to Baloxavir involves construction of the complex bicyclic scaffold with precise stereochemical control at multiple chiral centers. For generic manufacturers and research institutions, Baloxavir represents both a high-value therapeutic API and a compound of significant interest for antiviral drug discovery. As the first cap-dependent endonuclease inhibitor approved for influenza, Baloxavir offers a novel treatment option with a convenient single-dose administration.

 

Product Parameters

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Parameter	Specification
Product Name	Baloxavir
CAS Number	1985605-59-1
Molecular Formula	C₂₄H₁₉F₂N₃O₄S
Molecular Weight	483.49 g/mol
Density	1.63 ± 0.1 g/cm³
Boiling Point	644.7 ± 65.0 °C
pKa	4.50±1.00
Storage Condition	Store at -20 °C

 

New Rapid-acting Influenza Medication

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Baloxavir marboxil is a third-generation antinfluenza chemical drug originally developed by Shionogi Pharmaceutical Co., Ltd. of Japan and subsequently co-developed globally with Roche. It was approved for marketing in Japan in February 2018 and represents the first innovative anti-influenza drug with a novel mechanism of action approved by the U.S. FDA in nearly two decades. As a first-in-class single-dose oral medication, it exhibits a unique anti-influenza mechanism targeting both influenza A and B viruses, including resistant strains of oseltamivir (Tamil) and avian influenza strains (H7N9, H5N1). Studies have demonstrated that this drug requires only a single oral dose to achieve therapeutic efficacy in acute influenza patients aged ≥12 years with symptoms lasting no more than 48 hours.

 

Mechanism Of Action

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Baloxavir (brand name Xofluza) exerts its therapeutic effect by inhibiting the cap-dependent endonuclease present in influenza viruses. The genetic material of influenza viruses is packaged within RNA, and the primary function of this cap-dependent endonuclease is to facilitate genomic replication, enabling the virus to produce progeny. As an inhibitor of cap-dependent endonuclease, Xofluza blocks enzymatic reactions, preventing viral genome replication and thereby halting viral proliferation upon entry into cells. By employing this biological mechanism, Xofluza intervenes early in the viral lifecycle, effectively "killing the virus in its infancy," thereby achieving rapid influenza cure.

 

Indication

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In October 2019, Genentech, a subsidiary of Roche, announced that the FDA had approved an expanded indication application for its novel influenza treatment Xofluza (baloxavir marboxil). Xofluza is indicated for patients aged 12 years and older at high risk of influenza complications. It is intended for use in acute influenza patients who have been infected for no more than 48 hours without developing complications. Baloxavir is a "first-in-class" single-dose oral medication that exhibits efficacy against both oseltamivir-resistant virus strains and avian influenza viruses (H7N9, H5N1). The approval of this expanded indication was based on positive results from the Phase III trial CA Chemoprostone-2, which aimed to evaluate the efficacy and safety of Xofluza compared to oseltamivir or placebo in patients aged 12 years and older at high risk of influenza complications. The trial results demonstrated that Xofluza significantly delayed the median time to onset of influenza symptoms in these patients (102 hours versus 73 hours). Other key findings included: comparable efficacy of Xofluza versus oseltamivir in reducing symptom duration (54 hours versus 54 hours); and faster improvement in influenza symptoms with Xofluza compared to placebo for type B influenza viruses (75 hours versus 101 hours). Furthermore, Xofluza has demonstrated excellent tolerability and safety profiles.

 

Contact Us

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For Baloxavir with the quality, documentation, and reliability your antiviral program requires, Cosperpharm is your partner of choice.