Search

Background: Pregnancy and polymorphisms in drug disposition genes alter the clearance of key antiretrovirals used as part of regimens for prevention of mother-to-child transmission of HIV (PMTCT). The clinical significance of these in women initiating therapy late in pregnancy has not been investigated. The primary objective of the Viral and Antiretroviral Dynamics in HIV Mother-To-Child Transmission Fluids (VADICT) study is to investigate viral and antiretroviral dynamics in matrices associated with mother-to-child transmission (MTCT) (plasma, genital fluid and breastmilk) in women (stratified by CYP2B6 genotypes) who initiate antiretroviral therapy (ART) before or early in pregnancy versus late in pregnancy or early postpartum. Methods: A cohort of HIV-1 infected women who initiated ART containing 600 mg efavirenz before or early in pregnancy (n = 120), during the third trimester (n = 60), or early postpartum (n = 60) will be studied.  Eligible patients will be recruited from four hospitals in Benue State, North Central Nigeria and followed until the end of breastfeeding. Procedures at follow up visits will include sample collection for drug quantification and HIV-1 RNA and DNA in plasma, genital fluid and breastmilk; adherence monitoring; and newborn and infant assessment. Using newborn exposure to maternal efavirenz at birth for validation, prenatal pharmacogenetics of efavirenz will be explored using physiologically-based pharmacokinetic modelling. Three integrated methods will be used to monitor patterns and correlates of adherence across pregnancy and the breastfeeding period. A population pharmacokinetic-pharmacodynamic model will be developed to describe the observed data and simulate what to expect in women initiating ART containing 400 mg efavirenz (recently approved for non-pregnant adults) late in pregnancy or early postpartum. Discussion: This study will help in understanding residual MTCT in women receiving ART and reasons for the rise in MTCT risk during the breastfeeding period. Trial registration: ClinicalTrials.gov: NCT03284645 (15/09/2017)

Information on the extent of drug exposure to mothers and infants during pregnancy and lactation normally becomes available years after regulatory approval of a drug. Clinicians face knowledge gaps on drug selection and dosing in pregnancy and infant exposure during breastfeeding. Physiological changes during pregnancy often result in lower drug exposures of antiretrovirals, and in some cases a risk of reduced virologic efficacy. The International Maternal Pediatric Adolescent AIDS Clinical Trials (IMPAACT) network and the World Health Organization (WHO)-convened Pediatric Antiretrovirals Working Group collaboratively organized a workshop of key stakeholders in June 2019 to define key standards to generate pharmacology data for antiretrovirals to be used among pregnant and lactating women; review the antiretroviral product pipeline; describe key gaps for use in low-income and middle-income countries; and identify opportunities to undertake optimal studies allowing for rapid implementation in the clinical field. We discussed ethical and regulatory principles, systemic approaches to obtaining data for pregnancy pharmacokinetic/pharmacodynamic (PK/PD) studies, control groups, optimal sampling times during pregnancy, and pharmacokinetic parameters to be considered as primary end points in pregnancy PK/PD studies. For lactation studies, the type of milk to collect, ascertainment of maternal adherence, and optimal PK methods to estimate exposure were discussed. Participants strongly recommended completion of preclinical reproductive toxicology studies prior to phase III, to allow study protocols to include pregnant women or to allow women who become pregnant after enrolment to continue in the trial. The meeting concluded by developing an algorithm for design and interpretation of results and noted that recruitment of pregnant and lactating women into clinical trials is critical.

Medication use during pregnancy in the absence of pharmacokinetic and safety data is common, particularly for antiretrovirals, as pregnant women are not usually included in clinical trials leading to drug licensure. To date, data are typically generated through opportunistic pregnancy studies performed in the postmarketing setting, leading to a substantial time-lag between initial regulatory approval of a drug and availability of essential pregnancy-specific pharmacokinetic and safety data. During this period, health care providers lack key information on human placental transfer, fetal exposure, optimal maternal dosing in pregnancy, and maternal and fetal drug toxicity, including teratogenicity risk. We discuss new approaches that could facilitate the acquisition of these critical data earlier in the drug development process, aiding clinicians and patients in making informed decisions on drug selection and dosing during pregnancy. An integrated approach utilizing multiple novel methodologies (in vitro, ex vivo, in silico and in vivo) is needed to accelerate the availability of pharmacology data in pregnancy and lactation.

Background: Pregnancy and polymorphisms in drug disposition genes alter the clearance of key antiretrovirals used as part of regimens for prevention of mother-to-child transmission of HIV (PMTCT). The clinical significance of these in women initiating therapy late in pregnancy has not been investigated. The primary objective of the Viral and Antiretroviral Dynamics in HIV Mother-To-Child Transmission Fluids (VADICT) study is to investigate viral and antiretroviral dynamics in matrices associated with mother-to-child transmission (MTCT) (plasma, genital fluid and breastmilk) in women (stratified by CYP2B6 genotypes) who initiate antiretroviral therapy (ART) before or early in pregnancy versus late in pregnancy or early postpartum. Methods: A cohort of HIV-1 infected women who initiated ART containing 600 mg efavirenz before or early in pregnancy (n = 120), during the third trimester (n = 60), or early postpartum (n = 60) will be studied.  Eligible patients will be recruited from four hospitals in Benue State, North Central Nigeria and followed until the end of breastfeeding. Procedures at follow up visits will include sample collection for drug quantification and HIV-1 RNA and DNA in plasma, genital fluid and breastmilk; adherence monitoring; and newborn and infant assessment. Using newborn exposure to maternal efavirenz at birth for validation, prenatal pharmacogenetics of efavirenz will be explored using physiologically-based pharmacokinetic modelling. Three integrated methods will be used to monitor patterns and correlates of adherence across pregnancy and the breastfeeding period. A population pharmacokinetic-pharmacodynamic model will be developed to describe the observed data and simulate what to expect in women initiating ART containing 400 mg efavirenz (recently approved for non-pregnant adults) late in pregnancy or early postpartum. Discussion: This study will help in understanding residual MTCT in women receiving ART and reasons for the rise in MTCT risk during the breastfeeding period. Trial registration: ClinicalTrials.gov: NCT03284645 (15/09/2017)

Nitazoxanide use is limited by gastrointestinal side effects associated with increasing dose. In this drug repurposing study, we investigated the possibility of enhancing the exposure of its active metabolite, tizoxanide, through pharmacokinetic interaction with atazanavir/ritonavir. In this crossover drug–drug interaction study, 18 healthy participants received a single dose of 1000 mg of nitazoxanide alone and in combination with 300/100 mg atazanavir/ritonavir in period 1 and 2 respectively. On both days, blood samples for intensive pharmacokinetic analyses were collected at 0–12 h post-dose. To explore the utility of dried blood spots (DBS) as an alternative to plasma for tizoxanide quantification, 50 µL of blood from some participants was spotted on DBS cards and correlated with plasma concentrations. Pharmacokinetic parameters were derived by non-compartmental analysis and compared between both periods. Co-administration of nitazoxanide with atazanavir/ritonavir resulted in a significant increase in tizoxanide plasma exposure [GMR (90% CI) of AUC0–12h, Cmax and C12h being 1.872 (1.870–1.875), 2.029 (1.99–2.07) and 3.14 (2.268–4.352), respectively]. DBS concentration (%CV) was 46.3% (5.6%) lower than plasma concentrations, and there was strong correlation (R = 0.95, p < 0.001) between DBS-derived plasma concentration and plasma concentrations. Co-administration with atazanavir/ritonavir enhanced tizoxanide exposure with no report of adverse events in healthy volunteers. [ABSTRACT FROM AUTHOR]

Lack of predictive preclinical models is a key contributor to the steep attrition rate in drug development. Successful clinical translation may be higher for new chemical entities or existing approved drugs reformulated for long-acting (LA) administration if preclinical studies designed to identify any new uncertainties are predictive of human exposure and response. In this review, we present an overview of standard preclinical assessments deployed for LA formulations and delivery systems, using human immunodeficiency virus LA therapeutics preclinical development as a paradigm. Key progress in the preclinical development of novel LA antiretrovirals formulations and delivery systems are summarized, including bispecific broadly neutralizing monoclonal antibody and small molecule technologies for codelivery of multiple drugs with disparate solubility properties. There are new opportunities to take advantage of recent developments in tissue engineering and 3-dimensional in vitro modeling to advance preclinical modeling of anti-infective activity, developmental and reproductive toxicity assessment, and to apply quantitative modeling and simulation strategies. These developments are likely to drive the progression of more LA anti-infective drugs and multipurpose technologies into clinical development in the coming years. [ABSTRACT FROM AUTHOR]

Aims: Lopinavir (LPV) is not a first‐line regimen. According to recent WHO data, LPV usage in low‐ and middle‐income countries accounted for approximately 52% of the adult and 23% of the paediatric protease inhibitor market in 2017. Since LPV is a substrate for the SLCO1B1 (OATP1B1) transporter, the aim of this study was to assess the impact of SLCO1B1 polymorphisms (rs11045819, rs4149032 and rs4149056) on LPV trough plasma concentrations (Ctrough) in Serbian patients. Methods: Plasma samples from 104 HIV/AIDS Caucasians were collected. LPV Ctrough was quantified using liquid‐chromatography‐mass spectrometry. Genotyping was carried out using real‐time‐PCR‐based allelic discrimination. One‐way analysis of variance, t test and linear regression were used for data analysis. Results: The overall mean (SD) LPV Ctrough was 5885 ± 2755 ng/mL. Significant differences were between patients with different rs11045819 genotypes: CC (LPV median Ctrough = 6072 ng/mL, interquartile range (IQR) = 4318–7617 ng/mL), CA (LPV median Ctrough = 4987 ng/mL, IQR = 4300–6295 ng/mL) and AA (LPV median Ctrough = 3648 ng/mL, IQR = 1949–4072 ng/mL) (P =.005). Significant differences were also observed according to rs4149032 genotype: CC (LPV median Ctrough = 6027 ng/mL, IQR =4548–8250 ng/mL), CT (LPV median Ctrough = 5553 ng/mL, IQR = 4300–6888 ng/mL) and TT (LPV median Ctrough = 4408 ng/mL, IQR = 3361–5233 ng/mL) (P =.007). For rs4149056 a statistically significant difference between T‐homozygotes (LPV median Ctrough = 5434 ng/mL, IQR = 3855–6830 ng/mL), heterozygotes (LPV median Ctrough = 6707 ng/mL, IQR = 5088–8063 ng/mL) and C‐homozygotes (LPV median Ctrough = 13906 ng/mL, IQR = 12946–14866 ng/mL) was observed (P =.002). In multivariate regression analysis, only the SLCO1B1 rs4149056 polymorphism was independently associated with higher LPV Ctrough (β = 2834.5 [1442–4226.9] ng/mL [P =.001]). Conclusions: Our results demonstrate a statistically significant influence of the SLCO1B1 rs4149056 polymorphism on higher LPV Ctrough in Caucasian HIV/AIDS patients. [ABSTRACT FROM AUTHOR]