In the field of human immunodeficiency virus (HIV) treatment, the development and application of fixed-dose combination therapies have significantly improved treatment convenience and patient adherence. Biktarvy® (generic name: bictegravir/emtricitabine/tenofovir alafenamide tablets) is a well-established triple-drug antiretroviral regimen that, since its approval, has become an important option for the treatment of HIV-1 infection due to its potent antiviral efficacy, favorable safety profile, and simplified dosing regimen.

DengyueMed will provide a comprehensive overview of Biktarvy, including its basic information, mechanism of action, clinical applications, safety, and precautions for use.

Basic Drug Overview

Biktarvy is a fixed-dose combination formulation developed by Gilead Sciences, with main components including three antiretroviral drugs: bictegravir (BIC), emtricitabine (FTC), and tenofovir alafenamide fumarate (TAF). The drug is an oral tablet, currently available in two specifications: one containing 50mg bictegravir, 200mg emtricitabine, and 25mg tenofovir alafenamide per tablet; the other containing 30mg bictegravir, 120mg emtricitabine, and 15mg tenofovir alafenamide per tablet, suitable for different body weight groups.

From the perspective of its marketing history, Biktarvy was first approved by the U.S. Food and Drug Administration (FDA) in July 2018, approved in the European Union in June of the same year, and officially entered the Chinese market in August 2019, approved by the National Medical Products Administration. As a prescription drug, Biktarvy has been included in China's Category B medical insurance directory, which to some extent reduces the economic burden of medication for patients.

Core Mechanism of Action: Triple Synergy, Blocking Virus Replication

The highly effective antiviral effect of Biktarvy stems from the synergistic action of its three components, which comprehensively inhibit virus replication and reduce viral load by blocking different key stages of the HIV-1 virus life cycle.

First, bictegravir belongs to the integrase strand transfer inhibitors (INSTIs). During HIV-1 virus replication, the virus needs to integrate its linear DNA into the host cell genome through integrase to form a provirus and complete proliferation. Bictegravir selectively inhibits the strand transfer activity of HIV-1 integrase, directly blocking the integration process of viral DNA with the host genome, preventing virus replication and the production of new viruses from the source, with efficient and sustained inhibitory effects.

Second, both emtricitabine and tenofovir alafenamide belong to nucleoside reverse transcriptase inhibitors (NRTIs). They mimic the natural nucleosides required for virus replication, incorporating into the newly synthesized viral DNA chain during viral reverse transcription, leading to premature termination of DNA chain synthesis, thereby blocking virus replication. Among them, tenofovir alafenamide is an improved prodrug of tenofovir. Compared to traditional tenofovir formulations, it releases more slowly in the body with stronger targeting, significantly reducing the risk of toxicity to the kidneys and bones, offering better safety.

The three components synergistically exert force through the dual mechanism of "integrase inhibition + reverse transcriptase inhibition," not only enhancing antiviral efficacy but also effectively reducing the emergence of viral drug resistance, providing strong assurance for treatment success.

Key Medication Precautions

1. Monitoring for Co-infections: Patients with HIV co-infected with hepatitis B virus (HBV) or hepatitis C virus (HCV) have an increased risk of severe liver adverse reactions when receiving antiretroviral therapy. Therefore, HBV infection status must be tested before starting treatment; patients with HIV/HBV co-infection may experience severe acute exacerbation of hepatitis after discontinuing Biktarvy, requiring close monitoring through at least several months of clinical and laboratory follow-up after discontinuation.
2. Risk of Lactic Acidosis: When nucleoside analogs are used alone or in combination with other antiretroviral drugs, lactic acidosis and severe hepatomegaly with steatosis may occur, even fatally. If patients show clinical or laboratory findings suggestive of lactic acidosis or significant hepatotoxicity, treatment should be suspended immediately.
3. Drug Interactions: Biktarvy is contraindicated with rifampin or St. John's wort; it is not recommended to be used with antacids containing magnesium/aluminum, iron supplements, sucralfate, rifabutin, rifapentine, atazanavir, boceprevir, etc. If calcium supplements are needed, they should be taken together.
4. Transmission Prevention: Although effective viral suppression can significantly reduce the risk of HIV transmission through sexual behavior, it cannot completely eliminate residual risks, and patients still need to take preventive measures to prevent virus transmission in accordance with national guidelines.
5. Monitoring for Special Populations: Pregnant women should follow the recommended dosage, with virologically suppressed pregnant women taking one tablet daily; patients driving or operating machinery should be cautious, as the drug may cause dizziness, requiring careful operation.

Summary

Biktarvy, as a triple combination antiretroviral drug, provides high-quality treatment options for adult patients with HIV-1 infection with its core advantages of "highly effective antiviral, simplified dosing regimen, and good safety." Its unique synergistic mechanism effectively reduces the risk of drug resistance, the once-daily dosing significantly improves patient adherence, and its inclusion in Category B medical insurance further enhances drug accessibility.

It should be noted that Biktarvy must be used under the guidance of physicians experienced in HIV disease management, strictly following medical advice during treatment, with regular relevant examinations, and close attention to adverse reactions and disease changes. With the continuous deepening of medical research, it is believed that Biktarvy will play a more important role in the field of HIV infection treatment, bringing hope for long-term survival and high-quality life to more patients.