Islatravir is a novel nucleoside reverse transcriptase translocation inhibitor recently approved for the treatment of HIV-1 infection in virologically suppressed PLWH. While we previously documented high-level phenotypic resistance to islatravir (ISL) in HIV-1 subtype C variants harboring combinations of type 2 thymidine analogue mutations (TAM2) along with the M184V resistance-associated mutation, the primary contributor to the observed phenotype remains unclear. This report dissects the relative contribution of M184V to ISL resistance in the context of TAM2-containing variants through systematic reversion analysis. We show that reverting mutant 184V to wildtype M184 resulted in substantial sensitization to ISL, with fold-change reductions ranging from 8.1 to 13.4-fold across three TAM2 genetic backgrounds. Contrary to the well-documented antagonism between M184V and TAMs in zidovudine resistance, these two resistance pathways exhibit cooperative rather than antagonistic interactions in the context of ISL resistance. These findings provide critical evidence for refinement of genotypic resistance interpretation algorithms for ISL and have direct implications for the future clinical management of ISL-based antiretroviral therapy in people living with HIV. Importantly, elucidating the mechanistic basis of M184V-TAM2 cooperation would establish a more predictive framework for understanding how complex resistance mutation patterns impact ISL susceptibility and guide treatment decisions in virologically experienced individuals. Considering the diminished use of TAM2-seletive antiretroviral drugs in contemporary ART regimens, islatravir is likely to be an effective treatment option.

New ecological, sustainability and practicality analytical methodologies became constant in the modern pharmaceutical analysis. Likewise, a simple, rapid, stability-indicating high-performance liquid chromatography (HPLC) method was developed and validated for simultaneous determination of lamivudine (3TC), zidovudine (ZDV) and nevirapine (NVP) in pharmaceutical formulations. The HPLC method was carried out on a monolithic C18 column (100 mm × 4.6 mm i.d.), maintained at 30°C. The mobile-phase consisted of ammonium acetate (pH 4.5; 10 mM)-methanol-acetonitrile (65:28:7, v/v/v), run at a flow rate of 2.0 mL/min, using photodiode array (PDA) detection at 270 nm. Validation parameters such as the specificity, linearity, precision, accuracy and robustness were evaluated according to the International Council for Harmonisation (ICH) guidelines. From the results obtained, the developed HPLC method was successfully applied for the simultaneous quantitative analysis of 3TC, ZDV and NVP in tablet dosage forms. The chromatographic separation was obtained in less than 3 min and it was suitable for high-throughput analysis. In addition, the greenness assessment, the holistic overall evaluation and the practicality check using the novel Analytical GREEnness Metric Approach and Software (AGREE) calculator, the RGB-12 model and Blue Applicability Grade Index (BAGI), respectively, were performed. The results demonstrated the environmental friendliness (AGREE), practicality (BAGI) and holistic sustainability profile (RGB-12 model) of the proposed method.

In this study, we isolated and structurally characterized a diastereoisomer (1- R) of the betulonic acid-zidovudine (AZT) conjugates 1- S , a previously reported anticancer lead. The absolute configuration at the C-2 position was determined via 1D/2D nuclear magnetic resonance (NMR) and optical rotatory dispersion (ORD). Both diastereomers exhibited potent anticancer activity against a panel of human cancer cell lines, with particular efficacy against SMMC-7721 (hepatoma) and A549 (lung carcinoma) cells (IC50 = 3.38-4.09 μM). Mechanistic investigations revealed that 1- R induces cell death primarily through a caspase-dependent apoptotic pathway. Notably, the necroptosis inhibitor necrostatin-1 (Nec-1, an inhibitor of necroptosis) provided substantial protection, suggesting that necroptosis may play a more prominent role in 1- R compared to that of 1- S , although this requires direct comparative validation in future studies. The autophagy inhibitor 3-methyladenine (3-MA, an autophagy inhibitor) partially attenuated cell death, indicating a modulatory role for autophagy. These findings highlight 1- R as a promising anticancer agent. Despite its initial isolation as a low-yield byproduct (3.2%), the comparable activity of 1- R to 1- S , coupled with the conformational plasticity of the C-2 linker, simplifies synthetic requirements and supports its further optimization.

Herein, we report the first Sc(OTf)3-catalyzed redox-neutral cascade [1,5]-hydride transfer/cyclization for the efficient synthesis of azepane-fused spiroindolenines. This structurally strained seven-membered-ring scaffold has long eluded efficient access. The reaction proceeds via Knoevenagel condensation, intramolecular hydride transfer, and cyclization, delivering the target products in good to excellent yields (up to 97%). Notably, this protocol eliminates the need for substrate pre-functionalization or external oxidants. The methodology is readily scalable to the gram scale and enables diverse downstream transformations, including late-stage coupling with zidovudine. Preliminary biological evaluation indicates that selected derivatives exhibit micromolar antiproliferative activity against ovarian cancer cells, warranting further investigation as potential anticancer agents.

Transmitted HIV drug resistance can compromise treatment outcomes in children with vertically acquired infection, particularly when baseline resistance testing is unavailable. This case report describes the longitudinal clinical, virological, immunological, and molecular course of a male child diagnosed with vertically acquired HIV-1 subtype C infection, most consistent with mother-to-child transmission. Clinical history, viral load, CD4/CD8 profiles, HIV-1 pol sequencing, phylogenetic analysis, and interpretation were performed using the Stanford HIV Drug Resistance Database (HIVdb). The baseline viral load was 240,993 copies/mL, with a CD4:CD8 ratio of 0.40. Genotypic analysis identified major protease inhibitor resistance mutations V82A and I84I/V, together with M184V. Stanford HIVdb predicted high-level resistance to lopinavir/ritonavir, atazanavir/ritonavir, lamivudine, and emtricitabine; low-level resistance to darunavir/ritonavir and abacavir; and preserved susceptibility to tenofovir, zidovudine, and the evaluated NNRTIs. Initial lopinavir/ritonavir-based regimens failed to achieve sustained virological suppression. Following treatment optimization with an integrase inhibitor-based regimen and subsequent transition to bictegravir/emtricitabine/tenofovir alafenamide (BIC/FTC/TAF), HIV-1 RNA became Target Not Detected (TND) from November 2024 onward. At the latest follow-up, the CD4 count was 877 cells/µL, the CD8 count was 722 cells/µL, and the CD4:CD8 ratio had improved to 1.21, indicating substantial immune recovery. This single-patient case highlights the clinical value of baseline genotypic resistance testing and individualized, genotype-guided antiretroviral therapy in achieving durable virological suppression in pediatric HIV.

The accurate prediction of clinical drug-drug interactions (DDIs) in modeling analysis relies on the fraction of metabolism and transport of the substrate drugs and on the inhibitory potency and plasma exposure of index inhibitors. Fluconazole is frequently used as a clinical index inhibitor of cytochrome P450 (CYP) 2C9 and CYP3A4 to assess DDI liabilities involving these CYP enzymes. It also inhibits uridine diphosphate glucuronosyltransferase (UGT) 2B7 and exhibits gender-dependent pharmacokinetics (PK). The currently available model profile of fluconazole does not account for these population-specific PK variations. Therefore, extrapolating from one fluconazole DDI dataset to another remains questionable when it is used as an index inhibitor. In the present study, a physiologically based pharmacokinetic (PBPK) model of fluconazole was developed using PK data from male and female subjects. A minimal PBPK model with advanced dissolution, absorption, and metabolism (ADAM) for fluconazole was built in the Simcyp Simulator (V22). The base model from the Simcyp compound library captured fluconazole plasma profiles following oral administration only in male subjects, but not in female subjects. The volume of distribution at steady state (Vss) of fluconazole is close to the total body water volume, which can contribute to differences in plasma profiles between male and female subjects. Therefore, Vss in female subjects was optimized by curve fitting. The total clearance (CL) value in female subjects was also adjusted to reflect the similar fluconazole elimination half-life (t1/2) between male and female subjects. The plasma profiles of fluconazole in the general population were captured well when the predicted mean Vss and total CL were calibrated by the proportion of female subjects. The developed model was further validated by simulating reported clinical DDI studies with fluconazole. Using the refined PBPK model, the inhibitory constants (Ki) for fluconazole against CYP2C9 and UGT2B7 were optimized. The final fluconazole model captured the precipitant DDIs with midazolam (CYP3A probe substrate), tolbutamide (CYP2C9 probe substrate), omeprazole (CYP2C19 probe substrate), and zidovudine (UGT2B7 probe substrate), indicating that the refined fluconazole PBPK model in the present study can accurately predict clinical DDIs across studies in different populations with diverse gender mixes.

HIV infections among children have been on the decline since the introduction of infant HIV prophylaxis regimens including the HIV reverse transcriptase inhibitor, zidovudine (ZDV). This makes adherence to ZDV and other HIV medications paramount for the survival of young infants and children across the globe. However, the large dose volume and extremely bitter taste of ZDV often results in infants spitting up the medication, resulting in inaccurate dosing. Inclusion of ZDV into an oral thin film (OTF) would reduce the dose volume required, thus improving adherence to the medication regimen. To overcome the poor taste of ZDV, we created encapsulated ZDV (eZDV) formulations via spray-drying and evaluated polymer selection and ZDV particle size as potential avenues for effectively reducing the release of ZDV in simulated salivary fluid (SSF). The combined use of Eudragit E PO (EPO) and ethylcellulose (EC) was found to be the most effective polymer coating for reducing the release of ZDV. The optimal formulation ratio was determined to be 5:20:75 (EC:EPO:ZDV) to maintain high drug load while still reducing the dissolution of ZDV in SSF. Additionally, mortar-and-pestling ZDV prior to spray drying allowed for less variability and a more homogenous spread of eZDV throughout an OTF. These factors ultimately resulted in eZDV loaded OTFs that were able to successfully reduce the release of ZDV in SSF below its taste detection threshold.

Ritonavir-boosted atazanavir (atazanavir/r) is an effective once-daily option for pediatric subsequent-line antiretroviral therapy when used with two nucleoside reverse transcriptase inhibitors (NRTIs). Tuberculosis co-treatment complicates its use because rifampicin markedly induces atazanavir/r clearance. Although twice-daily atazanavir/r can overcome this interaction in adults, data in children are lacking. We aimed to characterize atazanavir population pharmacokinetics in children with HIV and simulate the effect of rifampicin co-treatment. Atazanavir concentration-time data in African children with HIV from CHAPAS-4 (ISRCTN22964075) and VirTUAL (NCT03923231) were analyzed by nonlinear mixed-effect modeling. We investigated the effect of weight, age, atazanavir formulation, ritonavir dose, and NRTI backbone (tenofovir alafenamide [TAF]-emtricitabine, abacavir-lamivudine, or zidovudine-lamivudine). Simulations were performed across weight bands to evaluate atazanavir/r exposures under standard conditions and, using adult-derived induction effects, predict exposures and possible dosing regimens during rifampicin co-treatment. Seventy children were included, with a median (range) age of 10.9 (3.2-17.7) years and weight of 29 (15-85) kg. A two-compartment model with sequential zero- and first-order absorption best described atazanavir disposition. The estimated typical value of atazanavir clearance was 4.8 L/h for a 27-kg individual. Atazanavir pharmacokinetics in children were unaffected by the NRTI backbone. Once-daily atazanavir/r with current dosing guidelines achieved adequate exposures across weight bands. When simulating pharmacokinetics during rifampicin co-treatment, twice-daily atazanavir/r is expected to restore exposures to levels comparable to once-daily dosing without rifampicin. These findings provide a framework for future clinical evaluation in children with HIV and tuberculosis.

Cytokines play crucial roles in regulating immune cell interactions, and in influencing innate and adaptive immune responses. People living with HIV (PLWH) on antiretroviral therapy (ART) show reduced inflammation and immune activation but with partial immune recovery. Interactions between HIV and human coronaviruses (hCoVs), with respect to immune modulation and ART impact on immune recovery, are not well understood. In this case-control cross-sectional study, we investigated cytokine profiles among three groups: PLWH co-infected with hCoVs (HIV+/hCoVs+), HIV mono-infected individuals (HIV+/hCoVs-), and HIV-negative without hCoVs control group (HIV-/hCoVs). A total of 300 PLWH were screened for hCoVs in three hospitals by subjecting their nasopharyngeal and oropharyngeal swabs to RNA extraction and PCR. Sixty-seven (67) PLWH with hCoVs were age- and sex-matched with HIV mono-infected and HIV negative control groups, and plasma samples were collected to assess cytokine levels using a Luminex multiplex bead-based immunoassay. Lower cytokine levels were observed among the HIV co-infected and mono-infected groups compared to HIV-negative control group. Granzyme B, TNF-α, IL-17 A, IL-3, IL-15 and VEGF were significantly reduced in the HIV co-infected group. Participants who had been on ART for less than a year had higher TNF-α levels than those who had been on ART for more than 5 years. The study demonstrates that HIV co-infection with hCoVs is associated with significantly reduced levels of key cytokines, which may be due to immune dysregulation and/or exhaustion associated with chronic HIV infections. The cytokine phenotype may be mitigated with long-term ART, which reduces inflammation and promote immunological recovery.