Azvudine is an antiviral medication used to combat a range of viral infections. This drug belongs to a class of compounds known as nucleoside analogues. It was developed to interfere with how viruses multiply within the human body.
How Azvudine Works
Azvudine primarily functions as a nucleoside reverse transcriptase inhibitor (NRTI). When taken, Azvudine first undergoes a change inside the body’s cells, becoming an active form called Azvudine triphosphate. This active form mimics natural building blocks viruses use to create their genetic material (DNA or RNA).
The drug incorporates into the growing viral DNA or RNA chain during replication. Lacking a 3′-hydroxyl group, Azvudine triphosphate prevents further additions to the chain, stopping viral genetic material from being fully built. This “chain termination” halts the virus’s ability to make copies, inhibiting its spread. Azvudine also exhibits a dual-target action, inhibiting both reverse transcriptase in viruses like HIV and RNA-dependent RNA polymerase (RdRp) in viruses such as SARS-CoV-2 and Hepatitis C virus (HCV).
Azvudine’s Applications in Viral Infections
Azvudine has been explored for its potential in treating several viral infections. It was initially developed for Hepatitis C. Its development expanded, showing effectiveness against other reverse transcriptase viruses like HIV.
The drug shows broad-spectrum antiviral activity against RNA viruses, including HIV, Hepatitis C virus (HCV), enterovirus 71 (EV71), and Hepatitis B virus (HBV). More recently, Azvudine has garnered attention for its use in treating COVID-19, the disease caused by the SARS-CoV-2 virus. Studies indicate that for COVID-19, Azvudine can reduce viral load and may improve symptoms more quickly than standard treatments.
Clinical Development and Safety Profile
Azvudine’s clinical development has involved various trials to assess its effectiveness and safety. For COVID-19, multiple Phase III trials investigated Azvudine’s efficacy and safety in adults with mild to moderate symptoms. These studies have generally reported that Azvudine appears safe with few side effects.
Some trials indicated Azvudine can shorten the time to negative viral nucleic acid tests and reduce viral load. While symptom improvement studies showed inconsistent results, a meta-analysis of over 10,000 patients suggested Azvudine could significantly reduce mortality risk in COVID-19 patients compared to standard care or other treatments like Paxlovid. Adverse events reported in trials have typically been mild to moderate, with serious adverse events being infrequent.
Current Status and Future Directions
Azvudine received conditional regulatory approval in China for certain indications. In July 2021, it gained conditional approval in China for treating high-viral-load HIV-1, used with other antiretroviral medications. Subsequently, in July 2022, Azvudine received emergency conditional approval for COVID-19 treatment in adults in China. It became the first domestically developed oral antiviral drug for COVID-19 in mainland China.
The drug is administered orally in tablet form. As of August 2022, it was included in China’s national COVID-19 guidelines for adult patients with moderate symptoms, with a recommended dosage of 5 mg per day for up to 14 days. Ongoing research continues to explore Azvudine’s full potential, including its ability to modulate P-glycoprotein expression, which may further enhance its therapeutic effects and safety profile.