Objective This report presents tenofovir alafenamide (TAF) and elvitegravir (EVG) fabricated into nanoparticles (NPs) for subcutaneous (SubQ) delivery as prevention strategy. Design Prospective prevention study in hu-BLT mice. Methods Using an oil-in-water emulsion solvent evaporation technique, TAF+EVG drugs were entrapped together into NPs containing poly(lactic-co-glycolic acid) (PLGA). In vitro prophylaxis studies (IC90) compared NPs to drugs in solution. Humanized-BLT (n=5/group) mice were given 200 mg/kg SubQ, and vaginally challenged with HIV-1 (5×105 TCID50) 4 and 14 days (d) post-NP administration (PI). Control mice (n=5) were challenged at 4 d. Weekly plasma viral load (pVL) was performed using RT-PCR. Hu-BLT mice were sacrificed and lymph nodes were harvested for HIV-1 viral RNA detection by in situ hybridization (ISH). In parallel, CD34+ humanized mice (3/time point) compared tenofovir (TFV) and EVG drug levels in vaginal tissues from NPs and solution. TFV and EVG were analyzed from tissue using LC-MS/MS. Results TAF+EVG NPs were < 200 nm in size. In-vitro prophylaxis indicates TAF+EVG NPs IC90 was 0.002 μg/mL and TAF+EVG solution was 0.78 μg/mL. TAF+EVG NPs demonstrated detectable drugs for 14 days and 72 h for solution, respectively. All Hu-BLT control mice became infected within 14 d after HIV-1 challenge. In contrast, hu-BLT mice that received NPs and challenged at 4 d PI, 100% were uninfected, and 60% challenged at 14 d PI were uninfected (p = 0.007; Mantel-Cox test). ISH confirmed these results. Conclusions This proof-of-concept study demonstrated sustained protection for TAF+EVG NPs in a hu-BLT mouse model of HIV vaginal transmission.

Use of NRTIs will continue to be critical for successful treatment and prevention of HIV-1.

Daily oral antiretroviral (ARV) drugs for pre-exposure prophylaxis (PrEP) has proven efficacy for diverse groups of high-risk individuals. However, daily dosing regimen has augmented nonadherence. These experiments comparatively investigated the long-acting (LA) PrEP potency of subcutaneous (SubQ) administrated tenofovir alafenamide (TAF) and emtricitabine (FTC) loaded nanoparticles (NPs) to solution in humanized (hu) mice. TAF+FTC NPs and TAF+FTC solution (each drug at 200 mg/kg) were administered to hu-CD34-NSG mice (n=3/time point) for plasma and tissue pharmacokinetic parameter estimation using LC-MS/MS. NP enhanced tissue ARV assimilation compared to plasma. The same dose was administered for PrEP efficacy in HIV-1 challenged hu-BLT mice (n=5/group). The hu-BLT mice were vaginally challenged with a transmission-founder (T/F) virus at 5 × 10 5 TCID 50 inoculation, on day 4, 7 and 14 post-SubQ treatments (PT) and were compared to infected-untreated-control hu-BLT mice. By 21 days PT, 100% TAF+FTC solution-treated and control-untreated mice were infected. However, TAF+FTC NPs resulted in significant (p=0.0002) protection from HIV-1 (day 4: 80%, day 7 and 14: 60%, respectively) compared to control mice. This proof-of-concept study demonstrated detectable TAF/FTC vaginal levels among TAF+FTC NP-treated hu-BLT mice correlating with prolonged PrEP efficacy, thus establishing long-acting TAF+FTC NPs as a potential PrEP modality.

Combination antiretroviral (cARV) treatment is more common in human immunodeficiency virus (HIV) infection. In many instances, treatment regimen includes two or more combination of drugs from six different classes. Some of the antiretroviral combination medications are under study at preclinical and clinical stages. A precise method is required to quantify the drug concentration in biological matrices to study pharmacokinetic behavior and tissue distribution profile in animals and/or humans. We have developed and validated a sensitive and precise liquid chromatography-tandem mass spectrometry method for simultaneous quantification of selected antiretroviral drugs, tenofovir (TNF), emtricitabine (FTC), rilpivirine (RPV), dolutegravir (DTG) and elvitegravir (EVG) in mouse biological matrices. This method involves a solid phase extraction, simple isocratic chromatographic separation using Restek Pinnacle DB BiPh column (50mm × 2.1mm, 5 μm) and mass spectrometric detection by an API 3200 Q Trap instrument. The total run time for each sample was 6 min. The method was validated in the concentration range of 5 to 2000 ng/mL for FTC, RPV, DTG, EVG and 10 to 4000 ng/mL for TNF respectively with correlation coefficients (r2) higher than 0.9976. The results of intra and inter-run assay precision and accuracy were within acceptance limits for all the five analytes. This method was used to support the study of pharmacokinetics and tissue distribution profile of nanoformulated antiretroviral drugs in mice.

Nontuberculous mycobacteria (NTM) pathogens particularly infect patients with structural lung disorders. We previously reported novel indole-2-carboxamides (ICs) that are active against a wide panel of NTM pathogens. This study discloses in vivo data for two lead molecules (compounds 5 and 25) that were advanced for efficacy studies in Mycobacterium abscessus-infected mouse models. Oral administration of the lead molecules showed a statistically significant reduction in the bacterial loads in lung and spleen of M. abscessus-infected mice.