Introduction to HIV, and the Antiretroviral Therapy Capsid Inhibitor Lenacapavir
HIV (Human Immunodeficiency Virus) is a major worldwide health issue, producing substantial morbidity and mortality. According to the World Health Organization (WHO), at least 42.3 million [35.7-51.1 million] individuals have died [WHO, 2023] from the illness since June 1981, when the US Centers for Disease Control and Prevention (CDC) reported the first cases of Acquired Immune Deficiency Syndrome (AIDS).
HIV targets the immune system, primarily CD4+ T cells, depleting them and making the body susceptible to opportunistic infections and malignancies [Tolomeo, 2024]. If left untreated, HIV can proceed to AIDS, which is characterized by severe immunological weakness. According to UNAIDS, 39.9 million [36.1 million-44.6 million] individuals worldwide had HIV in 2023 [UNAIDS, 2024]. Of them, more than 31 million [27-31.9 million] were receiving antiretroviral medication (ART), which has converted HIV into a chronic, treatable disease.
While traditional ART is beneficial, concerns like as medication resistance, adherence issues, and adverse effects need ongoing innovation in treatment techniques [SeyedAlinaghi, 2023]. Lenacapavir, a new capsid inhibitor, is a promising treatment alternative that offers hope to those with multidrug-resistant HIV [Kumar, 2024].
On December 22, 2022, the US FDA authorized Sunlenca® (lenacapavir) for the treatment of HIV-1 infection in people who have been intensively treated (HTE) and have multi-drug resistant (MDR) HIV-1 infection [Ross, 2022].
HIV Overview
HIV is spread by contact with infected body fluids, such as blood, sperm, vaginal fluids, rectal fluid, and breast milk [Nambiar, 2020]. Without treatment, the virus eventually weakens the immune system and causes AIDS. The fundamental objective of HIV treatment is to reduce virus replication, maintain immune function, and prevent transmission.
ART, or antiretroviral therapy, is a mix of medications that target different phases of the viral lifecycle. While ART is very successful in terms of reducing viral load [Clay, 2018], rigorous adherence is required, since noncompliance can result in medication resistance and treatment failure [Nhlongolwane, 2023]. Long-term ART is also connected with negative effects including as metabolic abnormalities, cardiovascular problems, and bone density loss. These problems underscore the necessity for novel medications such as Lenacapavir [Jemal, 2024].
Lenacapavir: A Breakthrough in HIV Treatment
Lenacapavir is a long-acting capsid inhibitor that belongs to a novel family of antiretroviral medicines [Prather, 2023]. It acts by targeting the HIV capsid, which is a protein shell that contains the viral RNA and enzymes. The capsid is involved in several phases of the HIV lifecycle, including reverse transcription, nuclear import, and the assembly of new virions [Novikova 2019].
Lenacapavir decreases viral load and replication by inhibiting these pathways. This drug's unique mechanism of action sets it apart from other antiretroviral medications, making it effective against HIV strains resistant to conventional regimens. [DiPerri, 2023].
Mechanism of Action
Lenacapavir interacts with certain locations on the HIV capsid protein, hyperstabilising its structure. This artificial stability influences a number of important processes in the viral lifecycle [Faysal, 2024]:
1. Reverse Transcription Inhibition: By interfering with the integrity of the capsid, Lenacapavir prevents viral RNA from being reverse transcribed into DNA, a critical stage in viral reproduction.
2. Nuclear Import Blockade: The capsid aids in the transfer of viral DNA into the host cell nucleus. Lenacapavir inhibits this mechanism, preventing incorporation into the host DNA.
3. Maturation Impairment: Lenacapavir hinders the formation of new virions, lowering th...
(All Rights Reserved)