Relative Bioavailability of Dolutegravir (DTG) and Emtricitabine/Tenofovir Alafenamide Fumarate (F/TAF) Administered as Paediatric Tablet Formulations in Healthy Volunteers.

BACKGROUND AND OBJECTIVE: Within the UNIVERSAL project (RIA2019PD-2882) we aim to develop a paediatric dolutegravir (DTG)/emtricitabine (FTC or F)/tenofovir alafenamide (TAF) fixed-dose combination. To inform dosing of this study, we undertook a relative bioavailability (RBA) study in healthy volunteers to investigate a potential pharmacokinetic effect when paediatric formulations of DTG and F/TAF are taken together. METHODS: Participants received all of the following treatments as paediatric formulations in randomised order: a single dose of 180/22.5 mg F/TAF; a single dose of 30 mg DTG; a single dose of 180/22.5 mg F/TAF plus 30 mg DTG. Blood concentrations of DTG, FTC, TAF, and tenofovir (TFV) were measured over 48 h post-dose. If the 90% confidence intervals (CIs) of the geometric least squares mean (GLSM) ratios of area under the curve (AUC) and maximum concentration (Cmax) of each compound were within 0.70-1.43, we considered this as no clinically relevant PK interaction. RESULTS: A total of 15 healthy volunteers were included. We did not observe a clinically relevant PK interaction between the paediatric DTG and F/TAF formulations for the compounds DTG, FTC, and TFV. For TAF, the lower boundaries of the 90% CIs of the GLSM ratios of the AUC0-∞ and Cmax fell outside our acceptance criteria of 0.70-1.43. CONCLUSIONS: Although TAF AUC and Cmax 90% CIs fell outside the pre-defined criteria (0.62-1.11 and 0.65-1.01, respectively), no consistent effect on TAF PK was observed, likely due to high inter-subject variability. Moreover, there are several reasons to rely on TFV exposure as being more clinically relevant than TAF exposure. Therefore, we found no clinically relevant interactions in this study.

Quantification of the janus kinase 1 inhibitor upadacitinib in human plasma by LC-MS/MS.

Upadacitinib is a selective janus-kinase-1 inhibitor effective in the treatment of autoimmune related diseases like rheumatoid arthritis or psoriatic arthritis. Here, we described a LC-MS/MS method for the quantification of upadacitinib in human plasma applicable for therapeutic drug monitoring. Pexidartinib was used as internal standard. Plasma samples were prepared by acidic protein precipitation and the analytes were separated on a C-18 reversed phase column. Detection took place by tandem mass spectroscopy after ionization in the positive mode and collision induced fragmentation at m/z 381 â†’ 256, 213 for upadacitinib and m/z 418 â†’ 258, 165 for pexidartinib. The calibration function was linear in the range of 0.15 - 150 ng/mL. Precisions and accuracies were better than 10% in intra- as well as inter-day evaluations. The method was applied in therapeutic drug monitoring of patients undergoing treatment for rheumatoid arthritis with the standard dose of 15 mg upadacitinib extended release formulation once daily. At steady state, we found trough levels of 4.13 (3.51 - 11.0) ng/mL, which is comparable to values found in healthy volunteers receiving the same dose (2.8 ± 1.2 ng/mL).

Simultaneous measurement of upadacitinib and methotrexate by UPLC-MS/MS and its pharmacokinetic application in rats.

Upadacitinib, as a selective and reversible Janus kinase (JAK) inhibitor, has been widely used in the treatment of atopic dermatitis, ulcerative colitis and other inflammatory bowel diseases and other immune-mediated diseases. The combination of methotrexate and upadacitinib is a common clinical treatment strategy for rheumatoid arthritis (RA) in recent years. In this study, we established an ultra performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) assay for quantitative measurement of upadacitinib and methotrexate, by which we successfully determined pharmacokinetic parameters of them in rat plasma. In order to pretreat the samples, we used acetonitrile as the precipitant, and for the internal standard (IS), we chose tofacitinib. The Acquity BEHC18 (2.1 mm × 50 mm, 1.7 µm) column, with acetonitrile and 0.1% formic acid aqueous solution composed mobile phases, was used to separate upadacitinib, methotrexate and tofacitinib. A Xevo TQ-S triple quadrupole tandem mass spectrometer was used as the detecting instrument in the positive ion mode. For upadacitinib, excellent linearity was shown of this assay in the calibration range with 0.1-200 ng/mL, and as for methotrexate, the range was 0.05-100 ng/mL. As the results indicated, the lower limit of quantification (LLOQ) was respectively 0.1 and 0.05 ng/mL for upadacitinib and methotrexate, the intra- and inter-day precision were ≤ 13.3%, and the accuracy of all the analytes ranged from -4.1% to 12.7%. The recovery of each analyte was > 80.2% in this experiment, and matrix effects we observed were unobvious. The establishment of this method and its successful application in rat plasma can provide a theoretical and technical support for the deeper study of pharmacodynamics and the clinical medication strategies.

Detection of subcellular nitric oxide in mitochondria using a pyrylium probe: assays in cell cultures and peripheral blood.

Fluorescent probes for the detection of intracellular nitric oxide (NO) are abundant, but those targeted to the mitochondria are scarce. Among those molecules targeting mitochondrial NO (mNO), the majority use a triphenylphosphonium (TPP) cation as a vector to reach such organelles. Here we describe a simple molecule (mtNOpy) based on the pyrylium structure, made in a few synthetic steps, capable of detecting selectively NO (aerated medium) over other reactive species. The calculated detection limit for mtNOpy is 88 nM. The main novelty of this probe is that it has a simple molecular architecture and can act both as a fluorogenic and as a mitochondriotropic agent, without using TPP. mtNOpy has been tested in two different scenarios: (a) in a controlled environment of cell line cultures (human colon carcinoma HT-29 cells and mouse macrophage RAW 264.7 cells), using confocal laser scanning microscopy, and (b) on a much more complex sample of peripheral blood, using flow cytometry. In the first context, mtNOpy has been found to be responsive (turn-on fluorescence) to exogenous and endogenous NO stimuli (via SNAP donor and LPS stimulation, respectively). In the second area, mtNOpy has been able to discriminate between NO-generating phagocytes (neutrophils and monocytes) from other leukocytes (NK, B and T cells).

Brief Report: Pharmacokinetics of Bictegravir and Tenofovir in Combination With Darunavir/Cobicistat in Treatment-Experienced Persons With HIV.

BACKGROUND: Bictegravir coformulated with emtricitabine and tenofovir alafenamide as a fixed-dose combination (BIC/FTC/TAF 50/200/25 mg) is recommended as an initial regimen in patients who are antiretroviral (ARV)-naïve or virologically suppressed on a stable ARV regimen. However, no real-world pharmacokinetic (PK) data are available in treatment-experienced patients with antiretroviral resistance receiving BIC/FTC/TAF plus a boosted protease inhibitor. SETTING/METHODS: This prospective, single-center, nonrandomized pharmacokinetic study enrolled adult treatment-experienced persons with HIV and creatinine clearance >30 mL/min receiving BIC/FTC/TAF + DRV/c as part of routine clinical care. Steady-state PK profiles of BIC, TAF, tenofovir (TFV), and DRV after daily dosing of BIC/FTC/TAF + darunavir/cobicistat (DRV/c) were obtained with samples at predose and 0.5, 1, 2, and 4 hours postdose. The AUC0-24 at steady state was extrapolated by imputing C0 for C24 for each participant (AUC0-tau,exp). RESULTS: Nine participants were enrolled with a median age of 59 years (range 54-67) and median number of years on ART of 19 (range 5.8-30). The median (interquartile range [IQR]) BIC AUC0-tau,exp and Cmax values were 128.9 µg*h/mL (78.1-159.5) and 6.9 µg/mL (5.1-9.8), respectively. The median (IQR) TAF AUC0-tau,exp and Cmax values were 0.376 µg*h/mL (0.199-0.430) and 0.276 µg/mL (0.149-0.543), respectively. Predose concentrations of TFV and DRV were comparable with historical data. CONCLUSION: Treatment-experienced persons with HIV receiving BIC/FTC/TAF + darunavir/cobicistat (DRV/c) had BIC exposures (AUC0-tau) that were increased by approximately 26% compared with historical PK data. Although TAF exposures were substantially increased, plasma TFV was only modestly higher. These results suggest that BIC/TAF/FTC + DRV/c is a viable antiviral regimen option for treatment-experienced persons.

Saliva as a potential matrix for evaluating pharmacologically active dolutegravir concentration in plasma.

Therapeutic drug monitoring (TDM) is used in certain clinically selected cases and in research settings to optimize the response to antiretroviral therapy. Plasma of blood is commonly used for TDM, but blood sampling is invasive and at risk for transmission of infectious agents. On the other hand, saliva sampling is noninvasive, safe, cheap, and easily performed compared to blood. Dolutegravir (DTG) is now widely prescribed as a key component of antiretroviral therapy for HIV infection. In this study, we examined the relationship between DTG concentrations in plasma and saliva of treated patients to explore the possibility of using saliva as an alternative body fluid of TDM. A total of 17 pairs of blood and saliva samples were obtained from 15 consented HIV-1-infected subjects treated with DTG containing regimens for more than one month. Both blood and saliva samples were collected within 1 h of each other. Drug concentrations were determined by liquid chromatography-tandem mass spectrometry using DTG-d5 as an internal standard. The LLOQ was 0.5 ng/mL. The calibration curves were prepared with pooled plasma or saliva containing DTG in a range of 0.5-100 ng/mL with precision of <14.4% and accuracy within ±14.7%. The DTG concentrations in the plasma and saliva were significantly correlated (Pearson's correlation coefficient r = 0.76, p < 0.001). The median ratio of the drug concentration in saliva to those in plasma was 0.0056, which is close to the rate of non-protein-bound DTG in plasma (0.70%), suggesting that only free DTG in plasma is transported to the salivary glands and secreted into saliva. The present study demonstrates that DTG concentration in saliva reflects the pharmacologically active drug concentration in plasma and may provide an easily accessible alternative for monitoring effective antiretroviral treatment.

Multivalent cation and polycation polymer preparations influence pharmacokinetics of dolutegravir via chelation-type drug interactions.

Dolutegravir (DTG) is an integrase inhibitor, whose gastrointestinal absorption is impaired by the formation of chelates with multivalent metal cation preparations. However, little is known regarding the interactions of DTG with preparations containing other multivalent metal cations or with polycation polymer preparations. This study examined how the pharmacokinetics of DTG are affected by co-administration with Al(OH)3, LaCO3, and the polycation polymers bixalomer (Bxl) and sevelamer (Svl). Prior to oral administration of DTG (5 mg/kg), rats were orally administered Al(OH)3 (150 or 300 mg/kg), LaCO3 (50 or 75 mg/kg), Bxl (250 or 500 mg/kg), or Svl (300 or 600 mg/kg). Serum concentrations of DTG were then measured over the next 24 h. Compared to the administration of DTG alone, its co-administration with Al(OH)3, LaCO3, Bxl, and Svl led to reduced serum concentration of DTG, and consequently, a significantly reduced area under the curve. These comparisons also revealed a considerable reduction in the maximum concentration, suggesting that the interactions of these agents with DTG in the intestinal tract inhibit absorption of DTG. The above results demonstrate that Al(OH)3, LaCO3, Bxl, and Svl affect the pharmacokinetics of DTG and indicate the need for caution when combining any of the above preparations with DTG.

Older Age is Associated with Higher Dolutegravir Exposure in Plasma and Cerebrospinal Fluid of People Living with HIV.

BACKGROUND: People living with human immunodeficiency virus are ageing under combination antiretroviral treatments but data on drug exposure in serum and cerebrospinal fluid are limited. Dolutegravir is a widely used second-generation integrase strand transfer inhibitor: conflicting data suggest that neuropsychiatric side effects may present at a higher frequency in patients with higher dolutegravir serum concentrations. METHODS: We performed a retrospective analysis of our therapeutic drug monitoring registry identifying patients receiving once-daily dolutegravir without concomitant interacting drugs and significant clinical conditions. Data were analysed stratifying time after drug dose intake (maximum concentration 0.5-4 and trough concentration 21-27 h). Cerebrospinal fluid samples from patients enrolled in neurological studies and receiving dolutegravir were analysed for dolutegravir cerebrospinal fluid concentrations and cerebrospinal fluid-to-plasma ratios. Serum and cerebrospinal fluid concentrations were measured through validated chromatographic methods. RESULTS: We included 207 (providing 457 serum samples) and 41 patients (providing 41 cerebrospinal fluid samples). Participants were mostly male (68.2-72.8%) of median age of 50 years (50-53 years). Non-significant changes in dolutegravir maximum concentration and trough concentration were observed with age at Spearman's test (p values > 0.05); linear logistic regression showed a significant effect of age on dolutegravir trough concentration (p = 0.0013) (Fig. 1). Dolutegravir maximum concentration [3830 ng/mL (2311-5057) vs 4230 ng/mL (2919-5272), p = 0.311] and trough concentration [838 ng/mL (362-1587) vs 966 ng/mL (460-2085), p = 0.056] were non-significantly or borderline higher in patients aged > 50 years. Cerebrospinal dolutegravir concentrations were associated with plasma concentrations (ρ = 0.374, p = 0.016) and age (ρ = 0.537, p = 0.003); cerebrospinal fluid dolutegravir concentrations (13.8 vs 7.3 ng/mL, p = 0.015) and cerebrospinal fluid-to-plasma ratios (0.57 vs 0.32%, p = 0.017] were higher in participants aged > 50 years. CONCLUSIONS: We observed an increase in dolutegravir exposure in serum and in cerebrospinal fluid in older patients living with human immunodeficiency virus.

Pharmacokinetics of Gepotidacin in Renal Impairment.

Gepotidacin is a novel triazaacenaphthylene bacterial topoisomerase inhibitor. In this phase 1, nonrandomized, open-label, parallel-group, multicenter, multipart study, the pharmacokinetics, safety, and tolerability of a single intravenous (IV) dose of gepotidacin 750 mg over 2 hours were evaluated in subjects with normal renal function, in those with moderate and severe renal impairment, and in end-stage renal disease (ESRD) on and not on dialysis. Administration of IV gepotidacin 750 mg was safe and generally tolerated in the study subjects. Dosing in severe renal impairment with and without hemodialysis resulted in significant increases in plasma drug levels and decreases in clearance. The geometric mean elimination half-life (t½ ) was minimally impacted (range 9.45 to 11.5 hours) in all the renal-impairment groups relative to normal renal function. Regardless of renal function, urine gepotidacin concentrations remained considerably high over a 12-hour period. Saliva concentrations displayed a linear relationship with plasma concentrations. The t½ in saliva was not impacted in the moderate-impairment and ESRD subjects and was comparable to t½ in plasma. Over a 4-hour dialysis, approximately 6% of the gepotidacin dose was removed. Overall, subjects with severe renal impairment and ESRD with and without hemodialysis may require adjustment in dose or dosing frequency.

The effect of veno-arterial extracorporeal oxygenation and nasogastric tube administration on the pharmacokinetic profile of abacavir, lamivudine and dolutegravir: a case report.

BACKGROUND: Pharmacokinetic (PK) changes can affect antiretroviral (ARV) systemic exposure for critically ill patients living with HIV (CI-PLWH). Studies to guide ARV adjustments in this population are limited. METHODS: A PK analysis was conducted in a 44-year-old CI-PLWH who presented for a heart and lung transplant on veno-arterial extracorporeal membrane oxygenation (VA ECMO). Home ARV therapy (ART) of co-formulated abacavir/lamivudine/dolutegravir (ABC/3TC/DTG) was continued. ARV serum concentrations were obtained during and after VA ECMO. Two blood levels were drawn at 1 h, for maximum serum concentration (Cmax) and a serum trough (Ct). ARVs were given as a single tablet crushed via nasogastric tube. RESULTS: Area under the concentration-time curve (AUC0-t) was calculated using non-compartmental analysis. Cmax and AUC0-t were higher during VA ECMO compared with post-decannulation. The Cmax of ABC was >2.5-fold higher than the mean in the reference. Cmax and Ct post VA ECMO were within range of referenced literature for all ARVs. Cmax and AUC0-t of DTG post VA ECMO was approximately four- to fivefold lower than referenced literature. HIV virological suppression was maintained throughout the hospitalization. CONCLUSIONS: ART adjustments would not be required for this patient. Additional studies are needed to assess effects of VA ECMO and crushed tube administration of ARVs in CI-PLWH.

Case Report of Increased Exposure to Antiretrovirals following Sleeve Gastrectomy.

Bariatric surgery is increasingly performed in morbidly obese HIV patients. Limited data exist regarding antiretroviral drug exposure after bariatric surgery. We report a case of a morbidly obese HIV patient who underwent sleeve gastrectomy. Abacavir, lamivudine, and dolutegravir therapeutic drug monitoring was performed at several time points pre- and postsurgery. Significantly increased levels were measured, particularly for abacavir, whose levels increased ∼12-fold. Several mechanistic explanations for these findings are discussed.

Exposure-Response Analyses of Upadacitinib Efficacy and Safety in Phase II and III Studies to Support Benefit-Risk Assessment in Rheumatoid Arthritis.

Exposure-response analyses of upadacitinib (UPA) key efficacy and safety end points (3,685 and 4,577 subjects for efficacy and safety, respectively) using data from phase II and phase III rheumatoid arthritis (RA) studies were conducted to support benefit-risk assessment. Percentage of subjects achieving American College of Rheumatology (ACR)20/50/70, disease activity score 28 (C-reactive protein) (DAS28-CRP) ≤ 3.2, and DAS28-CRP < 2.6 increased with increasing UPA plasma exposures. With the small number of observed safety events, no clear trends for exposure-response relationships were identified for pneumonia, herpes zoster infection, changes in platelet count, lymphopenia (Grade ≥ 4), or neutropenia (Grade ≥ 3) up to Week 26. Shallow exposure-response relationships were observed for > 2 g/dL decrease in hemoglobin, lymphopenia Grade ≥ 3 at Week 12/14, and serious infections at Week 24/26. Exposure-efficacy analyses demonstrate that UPA 15 mg q.d. (once daily) dose provided the optimal benefit-risk in RA through maximizing efficacy with only small incremental benefit with 30 mg q.d.; and with consistency across RA subpopulations and with UPA monotherapy or combination with conventional synthetic disease-modifying antirheumatic drugs.

Pharmacokinetics of Upadacitinib in Healthy Subjects and Subjects With Rheumatoid Arthritis, Crohn's Disease, Ulcerative Colitis, or Atopic Dermatitis: Population Analyses of Phase 1 and 2 Clinical Trials.

Upadacitinib (ABT-494) is a selective Janus kinase (JAK)1 inhibitor being developed for treatment of several inflammatory disorders. A population pharmacokinetic model was developed for upadacitinib using 11,658 plasma concentrations from 1145 subjects from 4 phase 1 and 5 phase 2 studies in healthy subjects and subjects with rheumatoid arthritis, Crohn's disease, ulcerative colitis, or atopic dermatitis. A 2-compartment model with first-order absorption and lag time for the immediate-release formulation and mixed zero- and first-order absorption with lag time for the extended-release formulation, and linear elimination adequately described upadacitinib plasma concentration-time profiles. The oral bioavailability of upadacitinib extended-release formulation was estimated to be approximately 80% relative to the immediate-release formulation. Covariates included in the final model were creatinine clearance, subject population (healthy subjects vs subjects with atopic dermatitis, ulcerative colitis, or Crohn's disease vs subjects with rheumatoid arthritis) and sex on apparent oral clearance and sex and body weight on apparent volume of distribution of the central compartment. Female subjects had 21% higher upadacitinib steady-state area under the plasma concentration-time curve (AUC) compared to male subjects. Compared to healthy subjects, subjects with atopic dermatitis, ulcerative colitis, or Crohn's disease had 21% higher upadacitinib steady-state AUC, while subjects with rheumatoid arthritis had 35% higher steady-state AUC. Subjects with mild or moderate renal impairment were estimated to have 10% or 22% higher AUC, respectively, compared to subjects with normal renal function. Based on final model parameter estimates, effects of the tested covariates are not expected to result in clinically relevant changes in upadacitinib steady-state exposures.

Development of In Vitro-In Vivo Correlation for Upadacitinib Extended-Release Tablet Formulation.

Upadacitinib is a selective Janus Kinase 1 inhibitor which is being developed for the treatment of several inflammatory diseases including rheumatoid arthritis. Upadacitinib was evaluated in Phase 3 studies as an oral extended-release (ER) formulation administered once daily. The purpose of this study was to develop a level A in vitro-in vivo correlation (IVIVC) for upadacitinib ER formulation. The pharmacokinetics of four upadacitinib extended-release formulations with different in vitro release characteristics and an immediate-release capsule formulation of upadacitinib were evaluated in 20 healthy subjects in a single-dose, randomized, crossover study. In vivo pharmacokinetic data and in vitro dissolution data (USP Dissolution Apparatus 1; pH 6.8; 100 rpm) were used to establish a level A IVIVC. Three formulations were used to establish the IVIVC, and the fourth formulation was used for external validation. A non-linear IVIVC best described the relationship between upadacitinib in vitro dissolution and in vivo absorption profiles. The absolute percent prediction errors (%PE) for upadacitinib Cmax and AUC were less than 10% for all three formulations used to establish the IVIVC, as well as for the %PE for the external validation formulation and the overall mean internal validation. Model was cross-validated using the leave-one-out approach; all evaluated cross-validation runs met the regulatory acceptance criteria. A level A IVIVC was successfully developed and validated for upadacitinib ER formulation, which meets the FDA and EMA regulatory validation criteria and can be used as surrogate for in vivo bioequivalence.

Low plasmatic concentration of intensified antiretroviral therapy in a pregnant woman: a case report.

BACKGROUND: Identifying the most appropriate antiretroviral regimen for pregnant women with Human Immunodeficiency Virus (HIV-1) infection can be challenging, mainly due to pregnancy-related physiological alterations which can significantly reduce maternal drug plasma concentration. We would like to report our experience as it consists of an unusual case of low plasmatic concentration of antiretroviral drugs despite regimen intensification in a HIV-positive pregnant woman. It also underlines the need for accurate monitoring and treatment adjustment in pregnant women with Human Immunodeficiency Virus (HIV). CASE PRESENTATION: A 26-year-old Brazilian woman with HIV-1 infection attending our out-patient clinic presented with low plasmatic concentration of antiretroviral drugs and persistent detectable viral load despite regimen intensification during pregnancy. Trough plasma concentrations of dolutegravir and darunavir were measured by validated liquid chromatography-mass spectrometry. At 23 weeks of gestation it showed a lower value than expected in non-pregnant adults, compared to a normal level of plasma concentration measured at 10 weeks after delivery. Our patient and the baby had no regimen-related adverse effects. CONCLUSIONS: Physiological changes during pregnancy can affect pharmacokinetics and reduce a mother's bioavailability of antiretroviral drugs, potentially altering their pharmacological activity. A personalized treatment and a careful follow-up are hence mandatory for this key population.

Population Pharmacokinetics of Upadacitinib Using the Immediate-Release and Extended-Release Formulations in Healthy Subjects and Subjects with Rheumatoid Arthritis: Analyses of Phase I-III Clinical Trials.

BACKGROUND AND OBJECTIVES: Upadacitinib is a selective Janus kinase (JAK) 1 inhibitor being developed as an orally administered treatment for patients with moderate to severe rheumatoid arthritis (RA) and other autoimmune disorders. These analyses characterized the population pharmacokinetics of upadacitinib across phase I-III clinical trials using data for immediate-release (IR) and extended-release (ER) formulations. METHODS: Pharmacokinetic data from 4170 subjects taking IR doses of 1-48 mg and ER doses of 7.5-30 mg across 12 studies spanning phase I-III clinical trials, with a total of 29,372 upadacitinib plasma concentrations, were analyzed using non-linear mixed-effects modeling. The model was evaluated using bootstrap analyses and visual predictive checks. RESULTS: A two-compartment model with first-order absorption with lag time for the IR formulation, mixed zero- and first-order absorption with lag time for the ER formulation, and linear elimination, adequately described upadacitinib plasma concentration-time profiles. Population estimates of upadacitinib apparent oral clearance and steady-state volume of distribution in healthy volunteers for the ER formulation were 53.7 L/h and 294 L, respectively. The relative bioavailability of the ER formulation compared with the IR formulation was estimated to be 76.2%. Statistically significant covariates were patient population (RA subjects vs. healthy subjects), creatinine clearance, and baseline bodyweight on apparent clearance (CL/F) and bodyweight on volume of distribution of the central compartment (Vc/F). The intersubject variability for upadacitinib CL/F and Vc/F were estimated to be 21% and 24%, respectively, in the phase I studies, and 37% and 53%, respectively, in the phase II/III studies. Upadacitinib area under the concentration-time curve (AUC) was estimated to be only 5% higher or lower for RA patients who were < 60 or > 100 kg, respectively, relative to subjects with a bodyweight of 60-100 kg. RA subjects with mild or moderate renal impairment had 13% and 26% higher AUC, respectively, compared with RA subjects with normal renal function. Sex, race, concomitant use of pH-modifying drugs, moderate cytochrome P450 3A inhibitors, or methotrexate use had no effect on upadacitinib exposure. CONCLUSIONS: A robust population pharmacokinetic model was developed for upadacitinib using a large dataset from phase I-III clinical trials in healthy volunteers and subjects with RA. None of the identified covariates had a clinically meaningful effect on upadacitinib exposures. The model is appropriate to use for simulations and to evaluate the exposure-response relationship of upadacitinib.

Noninferiority of Simplified Dolutegravir Monotherapy Compared to Continued Combination Antiretroviral Therapy That Was Initiated During Primary Human Immunodeficiency Virus Infection: A Randomized, Controlled, Multisite, Open-label, Noninferiority Trial.

BACKGROUND: Patients who start combination antiretroviral therapy (cART) during primary human immunodeficiency virus type 1 (HIV-1) infection show a smaller HIV-1 latent reservoir, less immune activation, and less viral diversity compared to patients who start cART during chronic infection. We conducted a pilot study to determine whether these properties would allow sustained virological suppression after simplification of cART to dolutegravir monotherapy. METHODS: EARLY-SIMPLIFIED is a randomized, open-label, noninferiority trial. Patients who started cART <180 days after a documented primary HIV-1 infection and had an HIV-1 RNA <50 copies/mL plasma for at least 48 weeks were randomized (2:1) to monotherapy with dolutegravir 50 mg once daily or to continuation of cART. The primary efficacy endpoint was the proportion of patients with <50 HIV-1 RNA copies/mL on or before week 48; noninferiority margin 10%. RESULTS: Of the 101 patients randomized, 68 were assigned to simplification to dolutegravir monotherapy and 33 to continuation of cART. At week 48 in the per-protocol population, 67/67 (100%) had virological response in the dolutegravir monotherapy group vs 32/32 (100%) in the cART group (difference, 0.00%; 95% confidence interval, -100%, 4.76%). This showed noninferiority of the dolutegravir monotherapy at the prespecified level. CONCLUSION: In this pilot study consisting of patients who initiated cART during primary HIV-1 infection and had <50 HIV-1 RNA copies/mL for at least 48 weeks, monotherapy with once-daily dolutegravir was noninferior to cART. Our results suggest that future simplification studies should use a stratification according to time of HIV infection and start of first cART. CLINICAL TRIALS REGISTRATION: NCT02551523.

Characterization of the Effect of Renal Impairment on Upadacitinib Pharmacokinetics.

Upadacitinib is a novel selective Janus kinase 1 inhibitor developed for treatment of rheumatoid arthritis and other autoimmune diseases. The objective of this study was to assess the pharmacokinetics and safety of a single upadacitinib dose in subjects with normal renal function and in subjects with renal impairment. A total of 24 subjects between the ages of 18 and 75 years were assigned to 1 of 4 renal function groups based on estimated glomerular filtration rate (normal, mild, moderate, severe; N = 6/group). A single 15-mg dose of upadacitinib extended-release formulation was administered under fasting conditions. Serial plasma and urine samples were assayed to evaluate the effect of renal impairment on upadacitinib exposure through regression analysis and analysis of covariance. The primary analysis was the regression analysis of upadacitinib exposures versus estimated glomerular filtration rate. The point estimates for upadacitinib plasma exposure ratios (90% confidence interval [CI]) in subjects with mild, moderate, and severe renal impairment were 1.18 (90%CI, 1.06-1.32), 1.33 (90%CI, 1.11-1.59), and 1.44 (90%CI, 1.14-1.82) for area under the plasma concentration-time curve and 1.06 (90%CI, 0.92-1.23), 1.11 (90%CI, 0.88-1.40), and 1.14 (90%CI, 0.84-1.56) for maximum observed plasma concentration, respectively, relative to subjects with normal renal function based on the regression analysis. The analysis of covariance categorical analysis provided consistent results. Upadacitinib was well tolerated by all subjects, and no safety issues were identified in subjects with renal impairment. Renal impairment has a limited effect on upadacitinib pharmacokinetics. This is in agreement with the known limited role of urinary excretion in upadacitinib elimination. Based on the limited impact on exposure, no dose adjustment is necessary for upadacitinib in subjects with impaired renal function.

Development and validation of an UPLC-MS/MS bioanalytical method for simultaneous quantification of the antiretroviral drugs dolutegravir, elvitegravir, raltegravir, nevirapine and etravirine in human plasma.

Dolutegravir, elvitegravir, raltegravir, nevirapine and etravirine are antiretroviral drugs used as part of combined antiretroviral treatment for HIV-infection. For quantification of these drugs in human K2EDTA plasma samples an ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) bioanalytical method was developed and validated. Stable isotope labeled internal standards were used for each analyte. Simple protein precipitation with methanol was implemented to prepare plasma samples of at least 50 µL. The method was validated for dolutegravir, elvitegravir, raltegravir, nevirapine and etravirine over the ranges 9.7-9700, 52-10,470, 9.7-9730, 73-14,680 and 15-3010 ng/mL, respectively. Within-run and between-run accuracy and precision were within ±15% of the nominal concentration for quality controls at high, medium and low concentrations, and within ±20% at the lower limit of quantification for all analytes. Recovery was ≥76% and reproducible. Long-term stability of patient plasma samples was demonstrated for at least 12 months at -40 °C (4 months for etravirine). Currently, this robust method with a run time of 10 min is used in clinical research and for therapeutic drug monitoring of these frequently used antiretroviral drugs.