Lenacapavir: A Novel Long-Acting Capsid Inhibitor for HIV

Effective management of multidrug-resistant HIV with lenacapavir and fostemsavir: A case study

Resistance to antiretroviral therapy is an increasing challenge in the management of HIV. We present the case of a woman living with HIV, with a history of multiple treatment regimens and resistances to antiretrovirals, who has been successfully treated with a combination of lenacapavir and fostemsavir for the past year, obtaining an undetectable viral load within one month of starting therapy and reporting no serious side effects. This case is amongst the first to document the combined use of lenacapivir and fostemsavir in treating multidrug-resistant HIV. It supports the potential of these novel agents in managing complex cases of HIV resistance.

Oral pre-exposure prophylaxis implementation in South Africa: a case study of USAID-supported programs

Since the introduction of oral pre-exposure prophylaxis (PrEP) in 2016, countries have successfully scaled-up PrEP to populations at risk of HIV acquisition, including key populations, serodiscordant couples and pregnant women. Between 2016 and 2023, there were over 5.6 million oral PrEP initiations globally. Of these, over 1.2 million occurred in South Africa, with nearly 700,000 implemented through USAID/South Africa's PEPFAR program. This case study uses WHO's Building Blocks for Health Systems Strengthening to describe USAID's oral PrEP program in South Africa, reporting experiences and lessons learned in 14 districts across 7 provinces. Key lessons include: (i) Substantial donor financial investment was critical for expanding oral PrEP in South Africa, but sustained leadership and investment from government stakeholders, such as the Department of Health and the National Treasury, have been essential for sustainability. Despite fluctuations in USAID funding, annual PrEP initiations have continued to increase in USAID-supported districts largely due to local leadership. (ii) Health information and supply chain systems required agility to monitor oral PrEP introduction and scale-up. When systems lacked agility, temporary solutions like the development of interim reporting tools were necessary. (iii) Integrating community-based and facility-based service delivery supported client-centered care. Nurses and lay health workers contributed to over 80% of the full-time equivalents supporting PrEP under USAID's human resources for health portfolio. (iv) Integrating sexual and reproductive health services with oral PrEP service delivery provided clients with comprehensive, client-centered care. (v) Other client-centered care included differentiated service delivery options, such as mobile and gazebo modalities, and expanded PrEP choice through implementation science activities for new PrEP products. (vi) USAID-supported PrEP initiations have been highest among females of reproductive age in the general population and men who have sex with men among key populations, priority populations in South Africa. As done in this case study, sharing best practices and lessons learned from USAID/South Africa's oral PrEP program can strengthen the implementation evidence base and inform more efficient PrEP service delivery, particularly as new PrEP products become available.

State of the ART (antiretroviral therapy): Long-acting HIV-1 therapeutics

Human immunodeficiency virus (HIV) impacts millions of individuals worldwide, and well over 2/3 of those living with HIV are accessing antiviral therapies that are successfully repressing viral replication. Most often, HIV treatments and prevention are administered in the form of daily pills as combinations of multiple drugs. An emergent and effective strategy for suppressing viral replication is the application of long-acting antiretroviral therapy (LAART), or antivirals that require less-frequent, non-daily doses. Thus far, the repertoire of LAARTs includes the widely used antiviral classes of non-nucleoside reverse transcriptase inhibitors (NNRTIs) and integrase strand transfer inhibitors (INSTIs) and has recently expanded to include a capsid-targeting antiviral. Possible future additions are nucleoside reverse transcriptase inhibitors (NRTIs) and nucleoside reverse transcriptase translocation inhibitors (NRTTIs). Here, we discuss the different strategies of using long-acting compounds to treat or prevent HIV-1 infection by targeting reverse transcriptase, integrase, and capsid.

Lack of Resistance Mutations to the Novel HIV-1 Capsid Inhibitor Lenacapavir Among People Living with HIV in Guangdong, China

Background

The capsid inhibitor (CAI) lenacapavir (LEN) was approved for use in 2022, yet there are few reports about its drug resistance mutations (DRMs) and sensitivity.

Purpose

To delineate the prevalence of CAI DRMs and drug susceptibility among HIV-1 infected individuals living in Guangdong, China.

Patients and Methods

A total of 1035 individuals with HIV-1 infection, including 660 highly Active Anti-Retroviral Therapy (HAART) naive individuals and 375 hAART experienced individuals whose protease (PR)/ reverse transcriptase (RT) fragments were amplified successfully during drug resistance surveillance between October 2021 and December 2023, were randomly included in this study. The entire HIV-1 gag gene was amplified from plasma in LEN-naive individuals with or without antiretroviral therapy. The epidemiological and demographic information of the enrolled individuals were collected. The Stanford HIV Drug Resistance Database HIVdb program for Capsid was used to interpret the CAI DRMs and the LEN susceptibility.

Results

Among 1035 samples, 805 gag sequences were amplified, sequenced and assembled successfully from 518 hAART drugs naive individuals and 287 hAART drugs experienced individuals. Among them, 0.50% (4/805) carried at least one CAI DRM, of which 0.19% (1/518) from HAART naive individuals and 1.05% (3/287) from HAART experienced individuals. Among the individuals with CAI DRMs, two patients carried CAI major mutations (Q67H) conferring intermediate resistance to LEN and two patients carried CAI accessory mutation (T107A) conferring low level resistance to LEN.

Conclusion

Extremely low prevalence of CAI DRMs was detected among people living with HIV (PLWH) in Guangdong, China. Our observations indicate that LEN application may be promising when used in clinical practice in China. Before the administration of LEN, there is no need to consider detecting CAI mutations in PLWH through DRM examination for the time being.

New Therapies and Strategies to Curb HIV Infections with a Focus on Macrophages and Reservoirs

More than 80 million people worldwide have been infected with the human immunodeficiency virus (HIV). There are now approximately 39 million individuals living with HIV/acquired immunodeficiency syndrome (AIDS). Although treatments against HIV infection are available, AIDS remains a serious disease. Combination antiretroviral therapy (cART), also known as highly active antiretroviral therapy (HAART), consists of treatment with a combination of several antiretroviral drugs that block multiple stages in the virus replication cycle. However, the increasing usage of cART is inevitably associated with the emergence of HIV drug resistance. In addition, the development of persistent cellular reservoirs of latent HIV is a critical obstacle to viral eradication since viral rebound takes place once anti-retroviral therapy (ART) is interrupted. Thus, several efforts are being applied to new generations of drugs, vaccines and new types of cART. In this review, we summarize the antiviral therapies used for the treatment of HIV/AIDS, both as individual agents and as combination therapies, and highlight the role of both macrophages and HIV cellular reservoirs and the most recent clinical studies related to this disease.

Viral Factors in Modulation of Host Immune Response: A Route to Novel Antiviral Agents and New Therapeutic Approaches

Viruses utilize host cells at all stages of their life cycle, from the transcription of genes and translation of viral proteins to the release of viral copies. The human immune system counteracts viruses through a variety of complex mechanisms, including both innate and adaptive components. Viruses have an ability to evade different components of the immune system and affect them, leading to disruption. This review covers contemporary knowledge about the virus-induced complex interplay of molecular interactions, including regulation of transcription and translation in host cells resulting in the modulation of immune system functions. Thorough investigation of molecular mechanisms and signaling pathways that are involved in modulating of host immune response to viral infections can help to develop novel approaches for antiviral therapy. In this review, we consider new therapeutic approaches for antiviral treatment. Modern therapeutic strategies for the treatment and cure of human immunodeficiency virus (HIV) are considered in detail because HIV is a unique example of a virus that leads to host T lymphocyte deregulation and significant modulation of the host immune response. Furthermore, peculiarities of some promising novel agents for the treatment of various viral infections are described.

A Review of FDA-Approved Anti-HIV-1 Drugs, Anti-Gag Compounds, and Potential Strategies for HIV-1 Eradication

Acquired immunodeficiency syndrome (AIDS) is an enormous global health threat stemming from human immunodeficiency virus (HIV-1) infection. Up to now, the tremendous advances in combination antiretroviral therapy (cART) have shifted HIV-1 infection from a fatal illness into a manageable chronic disorder. However, the presence of latent reservoirs, the multifaceted nature of HIV-1, drug resistance, severe off-target effects, poor adherence, and high cost restrict the efficacy of current cART targeting the distinct stages of the virus life cycle. Therefore, there is an unmet need for the discovery of new therapeutics that not only bypass the limitations of the current therapy but also protect the body's health at the same time. The main goal for complete HIV-1 eradication is purging latently infected cells from patients' bodies. A potential strategy called "lock-in and apoptosis" targets the budding phase of the life cycle of the virus and leads to susceptibility to apoptosis of HIV-1 infected cells for the elimination of HIV-1 reservoirs and, ultimately, for complete eradication. The current work intends to present the main advantages and disadvantages of United States Food and Drug Administration (FDA)-approved anti-HIV-1 drugs as well as plausible strategies for the design and development of more anti-HIV-1 compounds with better potency, favorable pharmacokinetic profiles, and improved safety issues.

Preparation of a Key Intermediate En Route to the Anti-HIV Drug Lenacapavir

A very efficient four-step synthesis of the main fragment of Gilead's anti-HIV drug lenacapavir is described. The route showcases a 1,2-addition to an intermediate aldehyde using an organozinc halide derived from a commercially available difluorobenzyl Grignard reagent. This sets the stage for the oxidation of the resulting secondary alcohol to the desired ketone, which relies solely on catalytic amounts of TEMPO together with NaClO as the terminal oxidant, affording the targeted ketone in 67% overall yield.

Discovery, Crystallographic Studies, and Mechanistic Investigations of Novel Phenylalanine Derivatives Bearing a Quinazolin-4-one Scaffold as Potent HIV Capsid Modulators

Optimization of compound 11L led to the identification of novel HIV capsid modulators, quinazolin-4-one-bearing phenylalanine derivatives, displaying potent antiviral activities against both HIV-1 and HIV-2. Notably, derivatives 12a2 and 21a2 showed significant improvements, with 2.5-fold over 11L and 7.3-fold over PF74 for HIV-1, and approximately 40-fold over PF74 for HIV-2. The X-ray co-crystal structures confirmed the multiple pocket occupation of 12a2 and 21a2 in the binding site. Mechanistic studies revealed a dual-stage inhibition profile, where the compounds disrupted capsid-host factor interactions at the early stage and promoted capsid misassembly at the late stage. Remarkably, 12a2 and 21a2 significantly promoted capsid misassembly, outperforming 11L, PF74, and LEN. The substitution of easily metabolized amide bond with quinolin-4-one marginally enhanced the stability of 12a2 in human liver microsomes compared to controls. Overall, 12a2 and 21a2 highlight their potential as potent HIV capsid modulators, paving the way for future advancements in anti-HIV drug design.

Lenacapavir with Fostemsavir in a Multidrug-Resistant HIV-Infected Hemodialysis Patient

We report a hemodialysis MDR HIV-infected patient switched to fostemsavir with lenacapavir plus lamivudine for more than a year. She maintained a suppressed viral replication and did not present any clinical or biological drug-related side effects. The combination of lenacapavir plus fostemsavir looks promising in terms of safety and efficacy even in patients with end-stage renal disease awaiting renal transplant. Both drugs are first in class ARVs so that there is no cross resistance with previous drugs, maintaining their efficacy against MDR HIV.