Lenacapavir: A Novel, Potent, and Selective First-in-Class Inhibitor of HIV-1 Capsid Function Exhibits Optimal Pharmacokinetic Properties for a Long-Acting Injectable Antiretroviral Agent

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.

Antiretroviral drugs from multiple classes induce loss of excitatory synapses between hippocampal neurons in culture

Introduction: Antiretroviral (ARV) drugs have improved prognoses for people living with HIV. However, HIV-associated neurocognitive disorders (HAND) persist despite undetectable viral loads. Some ARVs have been linked to neuropsychiatric effects that may contribute to HAND. Synapse loss correlates with cognitive decline in HAND and synaptic deficits may contribute to the neuropsychiatric effects of ARV drugs. Methods: Using an automated high content assay, rat hippocampal neurons in culture expressing PSD95-eGFP to label glutamatergic synapses and mCherry to fill neuronal structures were imaged before and after treatment with 25 clinically used ARVs. Results and Discussion: At a concentration of 10 μM the protease inhibitors nelfinavir and saquinavir, the non-nucleoside reverse transcriptase inhibitors etravirine and the 8-OH metabolite of efavirenz, the integrase inhibitor bictegravir, and the capsid inhibitor lenacapavir produced synaptic toxicity. Only lenacapavir produced synapse loss at the nanomolar concentrations estimated free in the plasma, although all 4 ARV drugs induced synapse loss at Cmax. Evaluation of combination therapies did not reveal synergistic synaptic toxicity. Synapse loss developed fully by 24 h and persisted for at least 3 days. Bictegravir-induced synapse loss required activation of voltage-gated Ca2+ channels and bictegravir, etravirine, and lenacapavir produced synapse loss by an excitotoxic mechanism. These results indicate that select ARV drugs might contribute to neuropsychiatric effects in combination with drugs that bind serum proteins or in disease states in which synaptic function is altered. The high content imaging assay used here provides an efficient means to evaluate new drugs and drug combinations for potential CNS toxicity.

Pharmacokinetics, Disposition, and Biotransformation of [14C]Lenacapavir, a Novel, First-in-Class, Selective Inhibitor of HIV-1 Capsid Function, in Healthy Participants Following a Single Intravenous Infusion

BACKGROUND AND OBJECTIVE

Lenacapavir (LEN) is a novel, first-in-class, multistage, selective inhibitor of human immunodeficiency virus type 1 (HIV-1) capsid function recently approved for the treatment of HIV-1 infection in heavily treatment-experienced adults with multidrug-resistant HIV-1 infection. The purpose of this multicohort study was to evaluate the pharmacokinetics, metabolism, excretion, safety, and tolerability of LEN following a single intravenous (IV) infusion of 10 mg LEN or 20 mg [14C]LEN in healthy participants.

METHODS

Twenty-one healthy adult participants were enrolled into the study and received either a single IV dose of 10 mg LEN (n = 8 active, n = 3 placebo; cohort 1) or a single IV dose of 20 mg [14C]LEN containing 200 µCi (n = 10; cohort 2). Blood, urine, and feces samples (when applicable) were collected after dosing, and radioactivity (cohort 2) was assessed using liquid scintillation counting in both plasma and excreta. LEN in plasma was quantified by liquid chromatography (LC) tandem mass spectroscopy (MS/MS) method bioanalysis. Metabolite profiling in plasma and excreta were performed using LC-fraction collect (FC)-high-resolution MS and LC-FC-accelerator mass spectrometry in plasma.

RESULTS

Between the 10 mg and 20 mg doses of LEN, the observed plasma exposure of LEN doubled, while the elimination half-life was similar. Following administration of 20 mg [14C]LEN (200 µCi), the mean cumulative recovery of [14C] radioactivity was 75.9% and 0.24% from feces and urine, respectively. The mean whole [14C] blood-to-plasma concentration ratio was 0.5-0.7, which showed a low distribution of LEN to red blood cells. Intact LEN was the predominant circulating species in plasma (representing 68.8% of circulating radioactivity), and no single metabolite contributed to > 10% of total radioactivity exposure through 1176 h postdose. Similarly, intact LEN was the most abundant component (32.9% of administered dose; 75.9% of recovered dose) measured in feces, with metabolites accounting for trace amounts. These results suggest metabolism of LEN is not a primary pathway of elimination. Of the metabolites observed in the feces, the three most abundant metabolites were direct phase 2 conjugates (glucuronide, hexose, and pentose conjugates), with additional metabolites formed to a lesser extent via other pathways. The administered LEN IV doses were generally safe and well-tolerated across participants in this study.

CONCLUSIONS

The results of this mass balance study indicated that LEN was majorly eliminated as intact LEN via the feces. The renal pathway played a minor role in LEN elimination (0.24%). In addition, no major circulating metabolites in plasma or feces were found, indicating minimal metabolism of LEN.