Pegylated liposome encapsulating docetaxel using microfluidic mixing technique: Process optimization and results in breast cancer models

The development of nanoparticles could help to improve the efficacy/toxicity balance of drugs. This project aimed to develop liposomes and immunoliposomes using microfluidic mixing technology.Various formulation tests were carried out to obtain liposomes that met the established specifications. The liposomes were then characterized in terms of size, polydispersity index (PDI), docetaxel encapsulation rate and lamellarity. Antiproliferative activity was tested in human breast cancer models ranging from near-negative (MDA-MB-231), positive (MDA-MB-453) to HER2 positive. Pharmacokinetic studies were performed in C57BL/6 mice.Numerous batches of liposomes were synthesised using identical molar ratios and by varying the microfluidic parameters TFR, FRR and buffer. All synthesized liposomes have a size < 200 nm, but only Lipo-1, Lipo-6, Lipo-7, Lipo-8 have a PDI < 0.2, which meets our initial requirements. The size of the liposomes was correlated with the total FRR, for a 1:1 FRR the size is 122.2 ± 12.3 nm, whereas for a 1:3 FRR the size obtained is 163.4 ± 34.0 nm (p = 0.019. Three batches of liposomes were obtained with high docetaxel encapsulation rates > 80 %. Furthermore, in vitro studies on breast cancer cell lines demonstrated the efficacy of liposomes obtained by microfluidic mixing technique. These liposomes also showed improved pharmacokinetics compared to free docetaxel, with a longer half-life and higher AUC (3-fold and 3.5-fold increase for the immunoliposome, respectively).This suggests that switching to the microfluidic process will produce batches of liposomes with the same characteristics in terms of in vitro properties and efficacy, as well as the ability to release the encapsulated drug over time in vivo. This time-efficiency of the microfluidic technique is critical, especially in the early stages of development.

Conditional generation of free radicals by selective activation of alkoxyamines: towards more effective and less toxic targeting of brain tumors

Brain tumors are an important cause of suffering and death. Glioblastoma are the most frequent primary tumors of the central nervous system in adults. They are associated with a very poor prognosis, since only 10% of GBM patients survive 5 years after diagnosis. Medulloblastoma are the most frequent brain malignancies in childhood; they affect the cerebellum in children under 10 years of age in 75% of cases. The current multimodal treatment comes at the expense of serious and often long-lasting side effects. Herein, we propose the synthesis of a library of novel alkoxyamines as anticancer drug candidates. The most efficient molecule, ALK4, was selected based on its ability to inhibit both survival and migration of GBM and MB cells in 2D cultures and in 3D tumor spheroids. A fluorescent derivative was used to show the early cytosolic accumulation of ALK4 in tumor cells. Spontaneous homolysis of ALK4 led to the release of alkyl radicals, which triggered the generation of reactive oxygen species, fragmentation of the mitochondrial network and ultimately apoptosis. To control its homolytic process, the selected alkoxyamine was bioconjugated to a peptide selectively recognized by matrix metalloproteases. This bioconjugate, named ALK4-MMPp, successfully inhibited survival, proliferation, and invasion of GBM and MB tumor micromasses. We further developed innovative brain and cerebellum organotypic models to monitor treatment response over time. It confirmed that ALK4-MMPp significantly impaired tumor progression, while no significant damage was observed on normal brain tissue. Lastly, we showed that ALK4-MMPp was well-tolerated in vivo by zebrafish embryos. This study provides a new strategy to control the activation of alkoxyamines, and revealed the bioconjugate ALK4-MMPp bioconjugate as a good anticancer drug candidate.

Tumor growth monitoring in breast cancer xenografts: A good technique for a strong ethic

Purpose

Although recent regulations improved conditions of laboratory animals, their use remains essential in cancer research to determine treatment efficacy. In most cases, such experiments are performed on xenografted animals for which tumor volume is mostly estimated from caliper measurements. However, many formulas have been employed for this estimation and no standardization is available yet.

Methods

Using previous animal studies, we compared all formulas used by the scientific community in 2019. Data were collected from 93 mice orthotopically xenografted with human breast cancer cells. All formulas were evaluated and ranked based on correlation and lower mean relative error. They were then used in a Gompertz quantitative model of tumor growth.

Results

Seven formulas for tumor volume estimation were identified and a statistically significant difference was observed among them (ANOVA test, p < 2.10⁻¹⁶), with the ellipsoid formula (1/6 π × L × W × (L + W)/2) being the most accurate (mean relative error = 0.272 ± 0.201). This was confirmed by the mathematical modeling analysis where this formula resulted in the smallest estimated residual variability. Interestingly, such result was no longer valid for tumors over 1968 ± 425 mg, for which a cubic formula (L x W x H) should be preferred.

Main findings

When considering that tumor volume remains under 1500mm³, to limit animal stress, improve tumor growth monitoring and go toward mathematic models, the following formula 1/6 π × L × W x (L + W)/2 should be preferred.

HCV cure: an appropriate moment to reduce cannabis use in people living with HIV? (ANRS CO13 HEPAVIH data)

BACKGROUND

Thanks to direct-acting antivirals, hepatitis C virus (HCV) infection can be cured, with similar rates in HCV-infected and HIV-HCV co-infected patients. HCV cure is likely to foster behavioral changes in psychoactive substance use, which is highly prevalent in people living with HIV (PLWH). Cannabis is one substance that is very commonly used by PLWH, sometimes for therapeutic purposes. We aimed to identify correlates of cannabis use reduction following HCV cure in HIV-HCV co-infected cannabis users and to characterize persons who reduced their use.

METHODS

We used data collected on HCV-cured cannabis users in a cross-sectional survey nested in the ANRS CO13 HEPAVIH cohort of HIV-HCV co-infected patients, to perform logistic regression, with post-HCV cure cannabis reduction as the outcome, and socio-behavioral characteristics as potential correlates. We also characterized the study sample by comparing post-cure substance use behaviors between those who reduced their cannabis use and those who did not.

RESULTS

Among 140 HIV-infected cannabis users, 50 and 5 had reduced and increased their use, respectively, while 85 had not changed their use since HCV cure. Cannabis use reduction was significantly associated with tobacco use reduction, a decrease in fatigue level, paying more attention to one's dietary habits since HCV cure, and pre-HCV cure alcohol abstinence (p = 0.063 for alcohol use reduction).

CONCLUSIONS

Among PLWH using cannabis, post-HCV cure cannabis reduction was associated with tobacco use reduction, improved well-being, and adoption of healthy behaviors. The management of addictive behaviors should therefore be encouraged during HCV treatment.

Influence of HLA-C environment on the spontaneous clearance of hepatitis C in European HIV-HCV co-infected individuals

Natural killer (NK) cell functions are regulated by diverse inhibitory and activating receptors, including killer cell immunoglobulin-like receptors (KIR), which interact with human leukocyte antigen (HLA) class I molecules. Some KIR/HLA genetic combinations were reported associated with spontaneous clearance (SC) of hepatitis C virus (HCV) but with discordant results, possibly reflecting KIR and/or HLA gene polymorphism according to populations. KIR/HLA genetic combinations associated with both an exhaustive NK and T cell repertoire were investigated in a cohort of HIV-HCV co-infected individuals with either SC (n = 68) or chronic infection (CI, n = 163) compared to uninfected blood donors [controls (Ctrl), n = 100]. Multivariate analysis showed that the HLA C2C2 environment was associated with SC only in European HIV-HCV co-infected individuals [odds ratio (OR) = 4·30, 95% confidence interval = 1·57-12·25, P = 0·005]. KIR2D⁺ NK cell repertoire and potential of degranulation of KIR2DL1/S1⁺ NK cells were similar in the SC European cohort compared to uninfected individuals. In contrast, decreased frequencies of KIR2DS1⁺ and KIR2DL2⁺ NK cells were detected in the CI group of Europeans compared to SC and a decreased frequency of KIR2DL1/S1⁺ NK cells compared to controls. Regarding T cells, higher frequencies of DNAX accessory molecule-1 (DNAM-1)⁺ and CD57⁺ T cells were observed in SC in comparison to controls. Interestingly, SC subjects emphasized increased frequencies of KIR2DL2/L3/S2⁺ T cells compared to CI subjects. Our study underlines that the C2 environment may activate efficient KIR2DL1⁺ NK cells in a viral context and maintain a KIR2DL2/L3/S2⁺ mature T cell response in the absence of KIR2DL2 engagement with its cognate ligands in SC group of HCV-HIV co-infected European patients.

Microelimination or Not? The Changing Epidemiology of Human Immunodeficiency Virus-Hepatitis C Virus Coinfection in France 2012–2018

Background

The arrival of highly effective, well-tolerated, direct-acting antiviral agents (DAA) led to a dramatic decrease in hepatitis C virus (HCV) prevalence. Human immunodeficiency virus (HIV)-HCV–coinfected patients are deemed a priority population for HCV elimination, while a rise in recently acquired HCV infections in men who have sex with men (MSM) has been described. We describe the variations in HIV-HCV epidemiology in the French Dat’AIDS cohort.

Methods

This was a retrospective analysis of a prospective cohort of persons living with HIV (PLWH) from 2012 to 2018. We determined HCV prevalence, HCV incidence, proportion of viremic patients, treatment uptake, and mortality rate in the full cohort and by HIV risk factors.

Results

From 2012 to 2018, 50 861 PLWH with a known HCV status were followed up. During the period, HCV prevalence decreased from 15.4% to 13.5%. HCV prevalence among new HIV cases increased from 1.9% to 3.5% in MSM but remained stable in other groups. Recently acquired HCV incidence increased from 0.36/100 person-years to 1.25/100 person-years in MSM. The proportion of viremic patients decreased from 67.0% to 8.9%. MSM became the first group of viremic patients in 2018 (37.9%). Recently acquired hepatitis represented 59.2% of viremic MSM in 2018. DAA treatment uptake increased from 11.4% to 61.5%. More treatments were initiated in MSM in 2018 (41.2%) than in intravenous drug users (35.6%). In MSM, treatment at the acute phase represented 30.0% of treatments in 2018.

Conclusions

A major shift in HCV epidemiology was observed in PLWH in France from 2012 to 2018, leading to a unique situation in which the major group of HCV transmission in 2018 was MSM.

Clinical Trials Registration. NCT02898987.

Abstract 5493: Mathematical modeling of antibody nanoconjugates transport quantifies the impact of the tumor microenvironment on drug penetration

One of the major challenges in breast cancer treatment is the high toxicity associated with cytotoxic agents. To overcome this issue, we developed nanoparticles conjugated with cancer cell specific antibodies (trastuzumab) to improve drug delivery to the tumor, while sparing healthy tissues. These antibody nano-conjugates (ANCs) consist in docetaxel-encapsulated liposomes engrafted with trastuzumab on the surface. Intra-tumor penetration properties of these ANCs are not fully understood and could be improved. To this end, mathematical modeling can provide quantitative tools to obtain a description of the ANCs transport inside a tumor. Few models in literature characterize the nanoparticle penetration in tumors. We derived a multi-scale model to obtain a description of the fluid flow and nanoparticle transport in the tumor interstitium and vessels. Moreover, there is a lack of studies that integrate spatial data to theoretical models. Here, we aim at filling this gap.

Experimental data - carried on human MDA-MB-231 xenografts - included ex-vivo microscopy images of tumor sections obtained from different regions of the tumor (central and peripheral) using fluorescence imaging. This data allowed to recover the tumor microstucture. Our multi-scale model consisted of two Darcy equations for the fluid flow and two convection-diffusion equations governing the ANCs penetration, including the porosity of the medium. Eventually, our model was calibrated with the ex-vivo imaging data.

Simulations confirmed that the tumor microsctructure influences the macroscale flow dynamics and ANC delivery in the tumor interstitium. The model also provides quantitative predictions of the impact of the tumor microenvironment (e.g., heterogeneity, vessel leakage and interstitium permeability) on the accumulation and penetration of ANCs. This methodology could be further applied to personalize the dose of injected nanoparticles according to a patient's specific tumor histology.

Citation Format: Cristina Vaghi, Anne Rodallec, Guillaume Sicard, Florian Correard, Raphaelle Fanciullino, Joseph Ciccolini, Clair Poignard, Sebastien Benzekry. Mathematical modeling of antibody nanoconjugates transport quantifies the impact of the tumor microenvironment on drug penetration [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 5493.

Abstract 6244: Turning poorly vascularized tumors into highly vascularized tumors with nanoparticles: Proof of concept and pharmacometric analysis

Combinatorial regimen are a mainstay in oncology. Taxanes and trastuzumab are both gold standards for HER2 positive breast cancer. To what extent they could reshape tumor micro-environment remains to be elucidated. The aim of this study was to compare in breast cancer mice models the antiproliferative efficacy and impact on tumor neo-angiogenesis of trastuzumab stealth immunoliposomes encapsulating docetaxel and stealth liposomal docetaxel associated with free trastuzumab. Nude mice bearing human MDA-MB-231 breast cancer tumors were treated by saline (control), docetaxel liposome (5mg/kg) associated with free trastuzumab (1.9 mg/kg) or trastuzumab immunoliposome (eq. 5 mg/kg docetaxel and 1.9 mg/kg trastuzumab) QW for 4 consecutive weeks. Tumor growth was monitored twice a week by volumetric measurement using a caliper. Blodd vessels density was evaluated in vivo by fluorescence imaging using Angiosense as a vascular probe plus ex-vivo using anti-CD31 antibodies and electronic microscopy at 2, 4 and 6 weeks. A specific algorithm was developed on MatLab for imaging analysis. No treatment-induced toxicities was observed. After 4 weeks of dosing, no difference in efficacy was seen between treatments (p=0.798) and Angiosense imaging did not show differences either (p=0.628). However electronic microscopy showed that both immunoliposomes and liposomes increased tumor vascular density as compared with control. In addition, a difference between treatments was evidenced because a marked increase in vascularization of central tumors VS. peripheral tumors was observed with trastuzumab immunoliposome as compared with standard docetaxel liposome (p=0.00023). A numerical model based on porous medium theory combined with multi-scale approaches has been derived to describe the spatial distribution of the drugs within tissues. Overall our data suggest that trastuzumab stealth immunoliposomes induce a normalization of tumor vessels with an increase in blood vessels density in central tumors. This could pave the way for sequencing combinatorial strategies so as to improve drug delivery into tumors of the associated treatments.

Citation Format: Guillaume Sicard, Anne Rodallec, Florian Correard, Cristina Vaghi, Clair Poignard, Joseph Ciccolini, Sébastien Benzekry, Arnauld Sergé, Raphaelle Fanciullino. Turning poorly vascularized tumors into highly vascularized tumors with nanoparticles: Proof of concept and pharmacometric analysis [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 6244.

Prototyping Trastuzumab Docetaxel Immunoliposomes with a New FCM-Based Method to Quantify Optimal Antibody Density on Nanoparticles

Developing targeted nanoparticles is a rising strategy to improve drug delivery in oncology. Antibodies are the most commonly used targeting agents. However, determination of their optimal number at the surface remains a challenging issue, mainly due to the difficulties in measuring precisely surface coating levels when prototyping nanoparticles. We developed an original quantitative assay to measure the exact number of coated antibodies per nanoparticle. Using flow cytometry optimized for submicron particle analysis and beads covered with known amounts of human IgG-kappa mimicking various amounts of antibodies, this new method was tested as part of the prototyping of docetaxel liposomes coated with trastuzumab against Her2+ breast cancer. This quantification method allowed to discriminate various batches of immunoliposomes depending on their trastuzumab density on nanoparticle surface (i.e., 330 (Immunoliposome-1), 480 (Immunoliposome-2) and 690 (Immunoliposome-3), p = 0.004, One-way ANOVA). Here we showed that optimal number of grafted antibodies on nanoparticles should be finely tuned and highest density of targeting agent is not necessarily associated with highest efficacy. Overall, this new method should help to better prototype third generation nanoparticles.

Population modeling of tumor growth curves and the reduced Gompertz model improve prediction of the age of experimental tumors

Tumor growth curves are classically modeled by means of ordinary differential equations. In analyzing the Gompertz model several studies have reported a striking correlation between the two parameters of the model, which could be used to reduce the dimensionality and improve predictive power. We analyzed tumor growth kinetics within the statistical framework of nonlinear mixed-effects (population approach). This allowed the simultaneous modeling of tumor dynamics and inter-animal variability. Experimental data comprised three animal models of breast and lung cancers, with 833 measurements in 94 animals. Candidate models of tumor growth included the exponential, logistic and Gompertz models. The exponential and-more notably-logistic models failed to describe the experimental data whereas the Gompertz model generated very good fits. The previously reported population-level correlation between the Gompertz parameters was further confirmed in our analysis (R2 > 0.92 in all groups). Combining this structural correlation with rigorous population parameter estimation, we propose a reduced Gompertz function consisting of a single individual parameter (and one population parameter). Leveraging the population approach using Bayesian inference, we estimated times of tumor initiation using three late measurement timepoints. The reduced Gompertz model was found to exhibit the best results, with drastic improvements when using Bayesian inference as compared to likelihood maximization alone, for both accuracy and precision. Specifically, mean accuracy (prediction error) was 12.2% versus 78% and mean precision (width of the 95% prediction interval) was 15.6 days versus 210 days, for the breast cancer cell line. These results demonstrate the superior predictive power of the reduced Gompertz model, especially when combined with Bayesian estimation. They offer possible clinical perspectives for personalized prediction of the age of a tumor from limited data at diagnosis. The code and data used in our analysis are publicly available at https://github.com/cristinavaghi/plumky.

Emerging resistance mutations in PI-naive patients failing an atazanavir-based regimen (ANRS multicentre observational study)

Background

Atazanavir is a PI widely used as a third agent in combination ART. We aimed to determine the prevalence and the patterns of resistance in PI-naive patients failing on an atazanavir-based regimen.

Methods

We analysed patients failing on an atazanavir-containing regimen used as a first line of PI therapy. We compared the sequences of reverse transcriptase and protease before the introduction of atazanavir and at failure [two consecutive viral loads (VLs) >50 copies/mL]. Resistance was defined according to the 2014 Agence Nationale de Recherche sur le SIDA et les Hépatites Virales (ANRS) algorithm.

Results

Among the 113 patients, atazanavir was used in the first regimen in 71 (62.8%) patients and in the first line of a PI-based regimen in 42 (37.2%). Atazanavir was boosted with ritonavir in 95 (84.1%) patients and combined with tenofovir/emtricitabine or lamivudine (n = 81) and abacavir/lamivudine or emtricitabine (n = 22). At failure, median VL was 3.05 log10 copies/mL and the median CD4+ T cell count was 436 cells/mm3. The median time on atazanavir was 21.2 months. At failure, viruses were considered resistant to atazanavir in four patients (3.5%) with the selection of the following major atazanavir-associated mutations: I50L (n = 1), I84V (n = 2) and N88S (n = 1). Other emergent PI mutations were L10V, G16E, K20I/R, L33F, M36I/L, M46I/L, G48V, F53L, I54L, D60E, I62V, A71T/V, V82I/T, L90M and I93L/M. Emergent NRTI substitutions were detected in 21 patients: M41L (n = 2), D67N (n = 3), K70R (n = 1), L74I/V (n = 3), M184V/I (n = 16), L210W (n = 1), T215Y/F (n = 3) and K219Q/E (n = 2).

Conclusions

Resistance to atazanavir is rare in patients failing the first line of an atazanavir-based regimen according to the ANRS. Emergent NRTI resistance-associated mutations were reported in 18% of patients.

Is There Any Room for Pharmacometrics With Immuno-Oncology Drugs? Input from the EORTC-PAMM Course on Preclinical and Early-phase Clinical Pharmacology

As part of the Pharmacology & Molecular Mechanisms (PAMM) Group, European Organization for Research and Treatment on Cancer (EORTC) 2019 winter Meeting Educational sessions, special focus has been placed on strategies to be undertaken to reduce the attrition rate when developing immune-oncology drugs. Immune checkpoint inhibitors have been game-changing drugs in several settings over the past decade such as melanoma and lung cancer. However, during the last years a rising number of studies failing to further improve clinical outcome in patients with cancer was recorded. Extensive pharmacometrics such as pharmacokinetics/pharmacodynamics modeling support should help to overcome the current glass ceiling that has apparently been reached with immuno-oncology drugs (IOD). In particular, it should help in the issue of setting up combinatorial regimen (i.e. combining immune checkpoint inhibitors with cytotoxics, anti-angiogenesis or targeted therapies) that can no longer be addressed when following standard trial-and-error approaches, but rather by using mathematical-derived algorithms as decision-making tools by investigators for rational design. In routine clinical setting, developing therapeutic drug monitoring of immune checkpoint inhibitors with adaptive dosing strategies has been a long-neglected strategy. Still, substantial improvements might be achieved using dedicated tools for precision medicine and personalized medicine in immunotherapy.

Abstract 3000: Impact of trastuzumab coating when prototyping immunoliposomes in breast cancer models: The more the merrier

Background: Improving drug delivery in oncology by developing antibodies targeted nanoparticles loaded with cytotoxics is a rising strategy in oncology. Determination of the optimal density of antibodies on nanoparticles surface remains an open question, mainly due to the difficulty in measuring accurately the actual level of coating. We have developed a stealth immunoliposome encapsulating docetaxel and harboring anti-Her2 trastuzumab. To better prototyping the nanoparticles, we have developed a method for the absolute quantitation of trastuzumab, so as to compare the performance of the immunoliposomes in terms of efficacy in breast cancer depending on the number of antibodies. Methods: Using flow cytometry we have developed a quick and quantitative assay to measure the amount of trastuzumab coated per docetaxel immunoliposome. Three batches of immunoliposomes exhibiting different densities of trastuzumab were synthesized using the standard thin-film method and a maleimide linker. Quality control was operated regarding size, docetaxel encapsulation and trastuzumab coating levels, including stability studies. In vitro and in vivo efficacy studies were performed on MDA-MB-453 used as a canonical model of Her-2+ human breast cancer cells. Results: The three batches of Immunoliposomes exhibited 330 ± 30 (batch1), 480 ± 110 (batch2) and 690 ± 80 (batch3) trastuzumab IgG molecules per liposome, respectively (p&lt;0.01, One-Way Anova). In 2D apoptosis induction experiments, no difference was observed between free drugs and immunoliposomes, regardless of trastuzumab density. When shifting to 3D spheroids, higher antiproliferative efficacy was observed with batch2 as compared with other immunoliposomes or free drugs (+76%) or reference T-DM1 (+85%). Next, batch2 was further tested in mice bearing MDA-MB-453 xenografts. Immunoliposomes achieved a tumor reduction of 89 % when compared to free drugs and 66% as compared with T-DM1 (p&lt;0.05, One-Way Anova). Conclusion: Our assay based on flow cytometry of submicron particles can accurately quantify the number of coated antibodies on single nanoparticles. In vitro studies demonstrated that maximal density of targeting agent on nanoparticles was not a prerequisite for maximal therapeutic effect. In vitro spheroids and in vivo studies in mice demonstrated higher efficacy of our immunoliposomes when compared to free trastuzumab docetaxel used in combo and antibody-drug conjugate T-DM1. Beyond the current project, this new quantitation method could be valuable when prototyping nanoparticles or conjugated drugs using monoclonal antibodies as targeting agent.

Citation Format: Anne Rodallec, Corentin Franco, Stéphane Robert, Guillaume Sicard, Sarah Giacometti, Ariel Savina, Fanny Bouquet, Bruno Lacarelle, Joseph Ciccolini, Philippe Poncelet, Raphaelle Fanciullino. Impact of trastuzumab coating when prototyping immunoliposomes in breast cancer models: The more the merrier [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3000.

Switching from abacavir/lamivudine plus nevirapine to abacavir/lamivudine/dolutegravir in virologically controlled HIV-infected adults (SWAD study)

INTRODUCTION

The metabolic pathways of dolutegravir suggest a potential predator effect of nevirapine on dolutegravir pharmacokinetics and switching from a nevirapine- to a dolutegravir-containing regimen could lead to a lower and suboptimal exposure to dolutegravir several weeks after the switch in case of persistent inducer effect.

PATIENTS AND METHOD

Prospective, pilot, single-arm, open-label, non-comparative, bicentric study to evaluate the pharmacokinetics, virologic outcomes, safety, and patient satisfaction of switching from abacavir/lamivudine and nevirapine to a single tablet of abacavir/lamivudine/dolutegravir. The primary endpoint was the maintenance of virologic suppression (HIV-1 RNA<50 copies/mL) at week 12. Secondary endpoints were virologic suppression at week 48, safety and tolerability, patient satisfaction, and pharmacokinetic interaction between nevirapine and dolutegravir. Fifty-three adults on stable abacavir/lamivudine and nevirapine regimen for a median duration of 6years and virologically suppressed for 9.6years were included.

RESULTS

Dolutegravir reached steady state by week 4/week 12 when expected by day 5/day 10. All subjects maintained plasma HIV-RNA˂50 copies/mL at week 12 and week 48. Abacavir/lamivudine/dolutegravir was well-tolerated, with two cases of serious adverse events deemed unrelated to study drugs (coronary syndrome in both cases), and one discontinuation for renal impairment at week 24 with a slight improvement after dolutegravir discontinuation. Level of treatment satisfaction remained high after the switch.

CONCLUSION

The transient predator effect of nevirapine on dolutegravir had no clinical consequences after switching from nevirapine to dolutegravir, neither on safety nor maintenance of virologic suppression. It also had no consequences on patient satisfaction.

Turning cold tumors into hot tumors: harnessing the potential of tumor immunity using nanoparticles

INTRODUCTION

Immune checkpoint inhibitors have considerably changed the landscape of oncology. However apart from world-acclaimed success stories limited to melanoma and lung cancer, many solid tumors failed to respond to immune checkpoint inhibitors due to limited immunogenicity, unfavorable tumor micro-environments (TME), lack of infiltrating T lymphocytes or increases in Tregs. Areas covered: Combinatorial strategies are foreseen as the future of immunotherapy and using cytotoxics or modulating agents is expected to boost the efficacy of immune checkpoint inhibitors. In this respect, nanoparticles displaying unique pharmacokinetic features such as tumor targeting properties, optimal payload delivery and long-lasting interferences with TME, are promising candidates for such combinations. This review covers the basis, expectancies, limits and pitfalls of future combination between nanoparticles and immune check point inhibitors. Expert opinion: Nanoparticles allow optimal delivery of variety of payloads in tumors while sparing healthy tissue, thus triggering immunogenic cell death. Depleting tumor stroma could further help immune cells and monoclonal antibodies to better circulate in the TME, plus immune-modulating properties of the charged cytotoxics. Finally, nanoparticles themselves present immunogenicity and antigenicity likely to boost immune response at the tumor level.

From 3D spheroids to tumor bearing mice: efficacy and distribution studies of trastuzumab-docetaxel immunoliposome in breast cancer

Purpose

Nanoparticles are of rising interest in cancer research, but in vitro canonical cell monolayer models are not suitable to evaluate their efficacy when prototyping candidates. Here, we developed three-dimensional (3D) spheroid models to test the efficacy of trastuzumab-docetaxel immunoliposomes in breast cancer prior to further testing them in vivo.

Materials and methods

Immunoliposomes were synthesized using the standard thin film method and maleimide linker. Two human breast cancer cell lines varying in Her2 expression were tested: Her2+ cells derived from metastatic site: mammary breast MDA-MB-453 and triple-negative MDA-MB-231 cells. 3D spheroids were developed and tested with fluorescence detection to evaluate viability. In vivo efficacy and biodistribution studies were performed on xenograft bearing nude mice using fluorescent and bioluminescent imaging.

Results

In vitro, antiproliferative efficacy was dependent upon cell type, size of the spheroids, and treatment scheduling, resulting in subsequent changes between tested conditions and in vivo results. Immunoliposomes performed better than free docetaxel + free trastuzumab and ado-trastuzumab emtansine (T-DM1). On MDA-MB-453 and MDA-MB-231 cell growth was reduced by 76% and 25%, when compared to free docetaxel + free trastuzumab and by 85% and 70% when compared to T-DM1, respectively. In vivo studies showed tumor accumulation ranging from 3% up to 15% of the total administered dose in MDA-MB-453 and MDA-MB-231 bearing mice. When compared to free docetaxel + free trastuzumab, tumor growth was reduced by 89% (MDA-MB-453) and 25% (MDA-MB-231) and reduced by 66% (MDA-MB-453) and 29% (MDA-MB-231) when compared to T-DM1, an observation in line with data collected from 3D spheroids experiments.

Conclusion

We demonstrated the predictivity of 3D in vitro models when developing and testing nanoparticles in experimental oncology. In vitro and in vivo data showed efficient drug delivery with higher efficacy and prolonged survival with immunoliposomes when compared to current anti-Her2 breast cancer strategies.

Pharmacokinetics variability: Why nanoparticles are not just magic-bullets in oncology

Developing nanoparticles to improve the specificity of anticancer agents towards tumor tissue and to better control drug delivery is a rising strategy in oncology. An increasing number of forms (e.g., conjugated nanoparticles, liposomes, immunoliposomes…) are now available on the shelves and numerous other scaffolds (e.g., dendrimeres, nanospheres, squalenes …) are currently at various stages of development. However, as of today most nanoparticles made available remain lipidic carriers. Pharmacokinetic variability is a major, yet largely underestimated issue with liposomal nanoparticles. A wide variety of causes (e.g., tumor type and disease staging, comorbidities, patient's immune system) can explain this variability, which can in return negatively impact pharmacodynamic endpoints such as poor efficacy or severe toxicities. This review aims to cover the main causes for erratic pharmacokinetics observed with most nanoparticles, especially liposomes used in oncology. Should the main causes of such variability be identified, specific studies in non-clinical or clinical development stages could be undertaken using dedicated models (i.e., mechanistic or semi-mechanistic mathematical models such as PBPK approaches) to better describe nanoparticles pharmacokinetics and decipher PK/PD relationships. In addition, identifying relevant biomarkers or parameters likely to impact nanoparticles pharmacokinetics would allow for either the modification of their characteristics to reduce the influence of the expected variability during development phases or the development of biomarker-based adaptive dosing strategies to maintain an optimal efficacy/toxicity balance. Broadly, we call for the development of comprehensive distribution studies and state-of-the-art modeling support to better understand and anticipate nanoparticle pharmacokinetics in oncology.

Docetaxel-trastuzumab stealth immunoliposome: development and in vitro proof of concept studies in breast cancer

Background

Trastuzumab plus docetaxel is a mainstay to treat HER2-positive breast cancers. However, developing nanoparticles could help to improve the efficacy/toxicity balance of this doublet by improving drug trafficking and delivery to tumors. This project aimed to develop an immunoliposome in breast cancer, combining docetaxel encapsulated in a stealth liposome engrafted with trastuzumab, and comparing its performances on human breast cancer cell lines with standard combination of docetaxel plus trastuzumab.

Methods

Several strategies to engraft trastuzumab to pegylated liposomes were tested. Immunoliposomes made of natural (antibody nanoconjugate-1 [ANC-1]) and synthetic lipids (ANC-2) were synthesized using standard thin film method and compared in size, morphology, docetaxel encapsulation, trastuzumab engraftment rates and stability. Antiproliferative activity was tested on human breast cancer models ranging from almost negative (MDA-MB-231), positive (MDA-MB-453) to overexpressing (SKBR3) HER2. Finally, cell uptake of ANC-1 was studied by electronic microscopy.

Results

ANC-1 showed a greater docetaxel encapsulation rate (73%±6% vs 53%±4%) and longer stability (up to 1 week) as compared with ANC-2. Both ANC presented particle size ≤150 nm and showed similar or higher in vitro antiproliferative activities than standard treatment, ANC-1 performing better than ANC-2. The IC_50s for docetaxel combined to free trastuzumab were 8.7±4, 2±0.7 and 6±2 nM with MDA-MB-231, MDA-MB-453 and SKBR3, respectively. The IC_50s for ANC-1 were 2.5±1, 1.8±0.6 and 3.4±0.8 nM and for ANC-2 were 1.8±0.3 nM, 2.8±0.8 nM and 6.8±1.8 nM with MDA-MB-231, MDA-MB-453 and SKBR3, respectively. Cellular uptake appeared to depend on HER2 expression, the higher the expression, the higher the uptake.

Conclusion

In vitro results suggest that higher antiproliferative efficacy and efficient drug delivery can be achieved in breast cancer models using nanoparticles.

Seek and destroy: improving PK/PD profiles of anticancer agents with nanoparticles

INTRODUCTION

The Pharmacokinetics/pharmacodynamics (PK/PD) relationships with cytotoxics are usually based on a steepening concentration-effect relationship; the greater the drug amount, the greater the effect. The Maximum Tolerated Dose paradigm, finding the balance between efficacy, while keeping toxicities at their manageable level, has been the rule of thumb for the last 50-years. Developing nanodrugs is an appealing strategy to help broaden this therapeutic window. The fact that efficacy and toxicity with cytotoxics are intricately linked is primarily due to the complete lack of specificity toward the tumor tissue during their distribution phase. Because nanoparticles are expected to better target tumor tissue while sparing healthy cells, accumulating large amounts of cytotoxics in tumors could be achieved in a safer way. Areas covered: This review aims at presenting how nanodrugs present unique features leading to reconsidering PK/PD relationships of anticancer agents. Expert commentary: The constant interplay between carrier PK, interactions with cancer cells, payload release, payload PK, target expression and target engagement, makes picturing the exact PK/PD relationships of nanodrugs particularly challenging. However, those improved PK/PD relationships now make the once contradictory higher efficacy and lower toxicities requirement an achievable goal in cancer patients.

Antiviral efficacy of favipiravir against Ebola virus: A translational study in cynomolgus macaques

BACKGROUND

Despite repeated outbreaks, in particular the devastating 2014-2016 epidemic, there is no effective treatment validated for patients with Ebola virus disease (EVD). Among the drug candidates is the broad-spectrum polymerase inhibitor favipiravir, which showed a good tolerance profile in patients with EVD (JIKI trial) but did not demonstrate a strong antiviral efficacy. In order to gain new insights into the antiviral efficacy of favipiravir and improve preparedness and public health management of future outbreaks, we assess the efficacy achieved by ascending doses of favipiravir in Ebola-virus-infected nonhuman primates (NHPs).

METHODS AND FINDINGS

A total of 26 animals (Macaca fascicularis) were challenged intramuscularly at day 0 with 1,000 focus-forming units of Ebola virus Gabon 2001 strain and followed for 21 days (study termination). This included 13 animals left untreated and 13 treated with doses of 100, 150, and 180 mg/kg (N = 3, 5, and 5, respectively) favipiravir administered intravenously twice a day for 14 days, starting 2 days before infection. All animals left untreated or treated with 100 mg/kg died within 10 days post-infection, while animals receiving 150 and 180 mg/kg had extended survival (P < 0.001 and 0.001, respectively, compared to untreated animals), leading to a survival rate of 40% (2/5) and 60% (3/5), respectively, at day 21. Favipiravir inhibited viral replication (molecular and infectious viral loads) in a drug-concentration-dependent manner (P values < 0.001), and genomic deep sequencing analyses showed an increase in virus mutagenesis over time. These results allowed us to identify that plasma trough favipiravir concentrations greater than 70-80 μg/ml were associated with reduced viral loads, lower virus infectivity, and extended survival. These levels are higher than those found in the JIKI trial, where patients had median trough drug concentrations equal to 46 and 26 μg/ml at day 2 and day 4 post-treatment, respectively, and suggest that the dosing regimen in the JIKI trial was suboptimal. The environment of a biosafety level 4 laboratory introduces a number of limitations, in particular the difficulty of conducting blind studies and performing detailed pharmacological assessments. Further, the extrapolation of the results to patients with EVD is limited by the fact that the model is fully lethal and that treatment initiation in patients with EVD is most often initiated several days after infection, when symptoms and high levels of viral replication are already present.

CONCLUSIONS

Our results suggest that favipiravir may be an effective antiviral drug against Ebola virus that relies on RNA chain termination and possibly error catastrophe. These results, together with previous data collected on tolerance and pharmacokinetics in both NHPs and humans, support a potential role for high doses of favipiravir for future human interventions.

Interest of proviral HIV-1 DNA genotypic resistance testing in virologically suppressed patients candidate for maintenance therapy

Switch of antiretroviral therapy in virologically suppressed HIV-infected patients is frequent, to prevent toxicities, for simplification or convenience reasons. Pretherapeutic genotypic resistance testing on RNA can be lacking in some patients, which could enhance the risk of virologic failure, if resistance-associated mutations of the new regimen are not taken into account. Proviral DNA resistance testing in 69 virologically suppressed patients on antiretroviral treatment with no history of virological failure were pair-wised compared with pre-ART plasma RNA resistance testing. The median time between plasma (RNA testing) and whole blood (proviral DNA testing) was 47 months (IQR 29-63). A stop codon was evidenced in 23% (16/69) of proviral DNA sequences; these strains were considered as defective, non-replicative, and not taken into consideration. Within the non defective strains, concordance rate between plasma RNA and non-defective proviral DNA was high both on protease (194/220 concordant resistance-associated mutations=88%) and reverse transcriptase (28/37 concordant resistance-associated mutations=76%) genes. This study supports that proviral DNA testing might be an informative tool before switching antiretrovirals in virologically suppressed patients with no history of virological failure, but the interpretation should be restricted to non-defective viruses.

Direct-acting antiviral treatment against hepatitis C virus infection in HIV-Infected patients - "En route for eradication"?

OBJECTIVES

Direct-Acting Antivirals (DAAs) opened a new era in HCV treatment. We report the impact of HCV treatment in French HIV-HCV coinfected patients.

METHODS

All HIV-HCV patients from the Dat'AIDS cohort followed between 2012 and 2015 were included. HCV status was defined yearly as naive, spontaneous cure, sustained virological response (SVR12), failure or reinfection.

RESULTS

Among 32,945 HIV-infected patients, 15.2% were positive for anti-HCV antibodies. From 2012 to 2015, HCV incidence rate increased from 0.35%PY to 0.69%PY in MSM, while median incidence was 0.08%PY in other patients. Median reinfection rate was 2.56%PY in MSM and 0.22%PY in other patients. HCV treatment initiation rate rose from 8.2% in 2012 to 29.6% (48.0% in pre-treated patients vs 22.6% in naïve patients). SVR12 rate increased from 68.7% to 95.2%. By the end of 2015, 62.7% of the patients were cured either spontaneously or following SVR.

CONCLUSIONS

HCV treatment dramatically increased in HIV-HCV patients in France from 2012 to 2015 resulting in HCV cure in nearly two-thirds of the patients in this cohort. Combined with a declining HCV prevalence, the prevalence of active HCV infection among HIV patients will drastically decrease in the forthcoming years.

Usefulness of an HIV DNA resistance genotypic test in patients who are candidates for a switch to the rilpivirine/emtricitabine/tenofovir disoproxil fumarate combination

OBJECTIVES

In the context of a rilpivirine/emtricitabine/tenofovir disoproxil fumarate switch in HIV-1-infected patients with at least 1 year of virological success, we determined whether proviral DNA is an alternative to plasma HIV RNA for resistance genotyping.

METHODS

Resistance-associated mutations (RAMs) in DNA after at least 1 year of virological success [viral load (VL) <50 copies/mL] were compared with those identified in the last plasma RNA genotype available. Rilpivirine/emtricitabine/tenofovir disoproxil fumarate RAMs studied were K65R, L100I, K101E/P, E138A/G/K/R/Q, V179L, Y181C/I/V, M184V/I, Y188L, H221Y, F227C and M230I/L in the RT. We studied patients without virological failure (VF) and with at least 1 VF (two consecutive VLs >50 copies/mL). Kappa's coefficient was used to measure agreement between the DNA and RNA genotypes.

RESULTS

In patients without VF (n = 130) and with VF (n = 114), RNA and DNA showed resistance to at least one drug of the rilpivirine/emtricitabine/tenofovir disoproxil fumarate combination in 8% and 9% and in 60% and 45%, respectively. For rilpivirine RAMs, correlation between RNA and DNA was higher in patients without VF than in patients with VF (kappa = 0.60 versus 0.19, P = 0.026). Overall, the prevalence of RAMs was lower in DNA than in RNA.

CONCLUSIONS

Incomplete information provided by the DNA genotypic test is more notable in patients with VF, suggesting that all resistance mutations associated with prior VF have not been archived in the proviral DNA or decreased to a level below the threshold of detection. In the case where no historical plasma genotypic test is available, DNA testing might be useful to rule out switching to rilpivirine/emtricitabine/tenofovir disoproxil fumarate.

Beating the odds: efficacy and toxicity of dihydropyrimidine dehydrogenase-driven adaptive dosing of 5-FU in patients with digestive cancer

AIMS

5-FU is the backbone of most regimens in digestive oncology. Administration of standard 5-FU leads to 15-30% of severe side effects, and lethal toxicities are regularly reported with fluoropyrimidine drugs. Dihydropyrimidine dehydrogenase (DPD) deficiency is a pharmacogenetic syndrome responsible for most cases of life-threatening toxicities upon 5-FU intake, and pre-treatment checking for DPD status should help to reduce both incidence and severity of side effects through adaptive dosing strategies.

METHODS

We have used a simple method for rapidly establishing the DPD phenotype of patients with cancer and used it prospectively in 59 routine patients treated with 5-FU-based therapy for digestive cancers. No patient with total DPD deficiency was found but 23% of patients exhibited poor metabolizer phenotype, and one patient was phenotyped as profoundly deficient. Consequently, 5-FU doses in poor metabolizer patients were cut by an average 35% as compared with non deficient patients (2390 ± 1225 mg vs. 3653 ± 1371 mg, P < 0.003, t-test).

RESULTS

Despite this marked reduction in 5-FU dosing, similar efficacy was achieved in the two subsets (clinical benefit: 40 vs. 43%, stable disease: 40 vs. 37%, progressive disease: 20% in both subsets, P = 0.893, Pearson's chi-square). No difference in toxicities was observed (P = 0.104, Fisher's exact test). Overall, only 3% of early severe toxicities were recorded, a value markedly lower than the 15-30% ones usually reported with 5-FU.

CONCLUSIONS

This feasibility study shows how simplified DPD-based adaptive dosing of 5-FU can reduce sharply the incidence of treatment-related severe toxicities while maintaining efficacy as part of routine clinical practice in digestive oncology.

Computed tomography of the optic nerve: part I. Normal results

In vivo visualization of the optic nerve (ON) by computed tomography (CT) has important clinical applications, both realized and potential. An accurate CT analysis of the ON is, however, hampered by a number of technical limitations. Sinuosity and gaze-shift-related motility of the ON tend to increase the difficulties of demonstrating in a consistently satisfactory fashion this anatomical structure. Nevertheless, if rigid imaging criteria are followed, adequate visualization of the ON may be attained in the majority of patients. Simultaneous visualization of the ON and the eyeball permits establishment of a neuroocular index for clinical use.

Computed tomography of the optic nerve: part II. Size and shape modifications in papilledema

Increase in the caliber and course tortuosity of the optic nerve (ON) can be demonstrated by computed tomography (CT) in cases of papilledema due to intracranial tumors, hydrocephalus, pseudotumor cerebri, and other conditions causing increased intracranial pressure. The enlargement of the ON in these conditions is generally bilateral, although one of the nerves, usually of the side of the tumoral pathology, may be thicker. Enlargement on the ON may also be demonstrated by CT in papilledema due to optic neuritis. Occasionally, the thickened ON also display increased attenuation coefficient values.

[Action potential changes induced by a polyflavane on normal or hypoxic guinea pig myocardial strips]

On normal isolated or stimulated Guinea-Pig myocardial strips, a polyflavane extracted from Poterium spinosum (Rosaceae) increased the duration of the action potential plateau phase. Such a modification was also elicited on hypoxic strips; in this case it did not depend on the glucose concentration in the medium; it could be related to an effect on the slow calcium-sodium channel.

[Electrophysiological analysis of the effects of 4-amino-pyridine in the isolated heart ventricle of the guniea pig]

The effects of 4-aminopyridine (4-AP) on guinea pig myocardial ventricular isolated strips were studied by means of intracellular microelectrodes. 4-AP increased the maximal depolarization velocity and decreased the effects of quinidine. In contrast to adrenaline, 4-AP antagonized the effects of MnCl1, but was ineffective against the alterations induced by a sodium poor solution. These findings support the suggestion that 4-AP modifies the electrophysiological membrane properties probably by increasing the Na+ inward current.