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716 result(s) for "Piperazines - pharmacokinetics"
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Phase-2 trial of palbociclib in adult patients with recurrent RB1-positive glioblastoma
IntroductionAlterations in the CDK4/6—RB signaling pathway are common causes of cell cycle dysregulation in many cancers, including glioblastoma. Palbociclib is an oral inhibitor of CDK4/6, which leads to phosphorylation of RB1 and cell-cycle arrest. We conducted a two-arm study evaluating efficacy and tissue pharmacokinetics/pharmacodynamics of palbociclib in patients with recurrent glioblastoma.MethodsEligibility criteria included confirmation of RB1 proficiency by IHC; ≤ 3 relapses; KPS ≥ 60; no limit on prior treatments. Arm 1 received palbociclib for 7 days prior to indicated resection followed by adjuvant palbociclib. Arm 2 received palbociclib without resection. Primary objective was PFS6; secondary included toxicity, OS, and ORR. Exploratory aims included biomarker assessment and pharmacokinetic/pharmacodynamic effects in surgical patients.ResultsTotal of 22 patients were enrolled; 6 on Arm 1 and 16 on Arm 2. Trial was stopped early secondary to lack of efficacy, with 95% of evaluable patients progressing within 6 months. Median PFS was 5.14 weeks (range 5 days–142 weeks) and median OS was 15.4 weeks (range 2–274 weeks). Two patients (10%) had related grade ≥ 3 AEs. In Arm 1, 5 patients had tissue concentrations of palbociclib felt to be sufficient for biological effect and paired samples available for RB1 IHC. There were no consistent changes in RB1 expression or cell proliferation in the paired tissue.ConclusionIn this trial, despite adequate tissue PK, palbociclib monotherapy was not an effective treatment for recurrent glioblastoma. However, these were heavily pretreated patients and targeting the CDK4/6 pathway may still deserve further exploration.
Antimalarial Activity of KAF156 in Falciparum and Vivax Malaria
With the emergence and spread of artemisinin resistance, new therapies for malaria are needed. This study shows that the imidazolopiperazine KAF156, a new antimalarial compound, has in vivo antimalarial activity. Expanding artemisinin resistance and worsening partner-drug resistance in Southeast Asia threaten the global control of Plasmodium falciparum malaria. 1 – 5 New drugs are needed. KAF156 represents a new class of antimalarial agents (imidazolopiperazines) 6 identified by high-throughput phenotypic screening. KAF156 has potent in vitro activity against both asexual and sexual blood stages and the preerythrocytic liver stages of the malarial parasite. 7 The mechanism of antimalarial action is unknown, but drug resistance, mediated by mutations in the P. falciparum cyclic amine resistance locus ( PfCARL ) gene, which encodes a protein of unknown function, can be selected. 7 In a study of 70 healthy . . .
Population Pharmacokinetics of Cobicistat and its Effect on the Pharmacokinetics of the Anticancer Drug Olaparib
Pharmacokinetic (PK) boosting is the intentional use of strong inhibitors of metabolic enzymes or transporters to boost the systemic exposure of a therapeutic drug. PK boosting is expanding to therapeutic areas outside human immunodeficiency virus (HIV) therapy. Data on the PK of the booster cobicistat and its effect on CYP3A-substrates outside of HIV therapy are lacking. This study aimed to describe the PK of once- and twice-daily cobicistat regimens in healthy volunteers and patients with rheumatoid arthritis, cancer, or HIV infection and to investigate the interplay between cobicistat and the anticancer drug olaparib. Cobicistat levels from 683 samples from 66 subjects in four clinical trials were included in the analysis. For olaparib, 261 samples from 12 subjects from one trial were included. Population PK analysis was performed by nonlinear mixed-effects modelling. Both cobicistat and olaparib PK were adequately described by a well-stirred liver model with one central compartment and Erlang type absorption. Cobicistat PK was similar across patient populations and dosing regimens. Cobicistat increased olaparib prehepatic bioavailability 1.65-fold (RSE 6%) and decreased intrinsic clearance 0.34-fold (RSE 6.5%). A correlation between olaparib PK and cobicistat exposure could not be identified. The interindividual variability in olaparib clearance was lower with cobicistat than without cobicistat. The developed pharmacokinetic models adequately described cobicistat and olaparib plasma concentrations. PK boosting with cobicistat at 150 mg twice daily led to an increase in olaparib bioavailability and decrease in clearance. This effect was not correlated with cobicistat exposure, which may reflect saturation of the boosting effect of cobicistat at this dose. NCT02565888 (30-09-2015), NCT00825929 (19-01-2009), Netherlands Trial Register NL7766 (18-12-2018), NCT05078671 (22-09-2021).
Coadministration of Cariprazine with a Moderate CYP3A4 Inhibitor in Patients with Schizophrenia: Implications for Dose Adjustment and Safety Monitoring
Background Cariprazine is metabolised mainly by CYP3A4 and to a lesser extent by CYP2D6. Aim This study aimed to evaluate the effects of erythromycin, a moderate cytochrome P450 (CYP)3A4 inhibitor, on the pharmacokinetics of cariprazine in male patients with schizophrenia, and to assess the influence of CYP2D6 phenotypes on cariprazine metabolism. Methods Forty-two patients received oral doses of 1.5 mg cariprazine alone for 28 days (to reach steady state), followed by a co-administration of cariprazine 1.5 mg daily with erythromycin 500 mg twice daily (BID) and Enterol 250 mg BID for 21 days, followed by a 14-day post-treatment period. Blood samples were collected at predefined time points and analysed for cariprazine, its two active metabolites: desmethyl cariprazine (DCAR) and didesmethyl cariprazine (DDCAR), and erythromycin using validated high performance liquid chromatography-tandem mass spectrometry methods. CYP2D6 phenotypes were determined by genotyping. The pharmacokinetic parameters were calculated using non-compartmental analysis. Results Erythromycin increased the area under the curve (AUC τ ) and peak concentration ( C max ) of Total cariprazine (cariprazine + DCAR + DDCAR) by about 40–50% but did not affect the time to peak concentration ( T max ). The CYP2D6 phenotypes had no substantial effect on the pharmacokinetics of cariprazine and its metabolites, either alone or in combination with erythromycin. Cariprazine was well tolerated and safe. Conclusion The findings suggest that co-administration of cariprazine with moderate CYP3A4 inhibitors may require dose adjustment or monitoring; however, pharmacogenetic testing for CYP2D6 is not necessary for optimising cariprazine therapy. Trial Registration Trial registration number (EudraCT Number): 2018-003721-28. Date of registration: 21-SEP-2018.
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 ( C max ) 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 AUC 0–∞ and C max fell outside our acceptance criteria of 0.70–1.43. Conclusions Although TAF AUC and C max 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.
Safety, tolerability and pharmacokinetics of the fibroblast growth factor receptor inhibitor AZD4547 in Japanese patients with advanced solid tumours: a Phase I study
Summary Background AZD4547 is a potent, oral, highly selective fibroblast growth factor receptor (FGFR) inhibitor in clinical development for treating tumours with a range of FGFR aberrations, including FGFR mutations, amplifications and fusions. Methods This open-label, Phase I, multicentre study (NCT01213160) evaluated the safety, pharmacokinetics, and preliminary antitumour efficacy (RECIST v1.1) of AZD4547 monotherapy in Japanese patients with advanced solid tumours. Part A was a dose-escalation part; Part B was a dose-expansion part in patients with FGFR-amplified tumours, confirmed by fluorescence in situ hybridization. Results Thirty patients enrolled in Part A (dose range: 40 mg twice daily [bid] to 120 mg bid; 160 mg once daily [qd]), four in Part B (80 mg bid). No dose-limiting toxicities were observed and maximum tolerated dose was not determined. Most common adverse events (AEs; any grade) were: dysgeusia (50% of patients); stomatitis (41%); diarrhoea (38%); hyperphosphataemia (38%); dry mouth (35%). Common grade ≥3 AEs were nausea (12% of patients) and neutropenia (9%). No complete or partial responses were observed: 21/30 patients had stable disease ≥4 weeks in Part A, and 1/4 patients had stable disease ≥10 weeks in Part B. Following single and multiple dosing, absorption rate appeared moderate; peak plasma concentrations generally occurred 3–4 h post-dose, then declined biphasically with terminal half-life ~30 h. Steady state was reached by day 8. Compared with single dosing, plasma concentrations were, on average, 2.4- and 3.3- to 5.4-fold higher after qd and bid dosing, respectively. Conclusions AZD4547 was well tolerated in Japanese patients, with best response of stable disease ≥4 weeks.
Phase 1 Safety and Pharmacokinetics Study of MK-2048/Vicriviroc (MK-4176)/MK-2048A Intravaginal Rings
Abstract Background Vaginal rings (VR) containing antiretroviral (ARV) drugs can be utilized for prevention of human immunodeficiency virus (HIV) with potential for improved adherence compared to daily pills. Combination ARV VRs could improve efficacy. Methods MTN-027, a single-blind, randomized, placebo-controlled trial in 48 women, evaluated VRs containing MK-2048 (30 mg) and vicriviroc (VCV, 182 mg), alone or in combination, and placebo used continuously for 28 days. Safety was assessed by recording adverse events. Drug concentrations were quantified in plasma, vaginal fluid, cervical tissue, and rectal fluid. Cervical tissue was utilized for ex vivo HIV inhibition analysis. Results There was no difference in related genitourinary adverse events between treatment arms compared to placebo. VCV and MK-2048 released from single or combination VRs both achieved peak concentrations in vaginal fluids, which were substantially higher compared to plasma (200× for VCV, 30× for MK-2048) and rectal fluid. In an ex vivo challenge assay, the antiviral activity of VCV and/or MK-2048 was not correlated with tissue-associated drug concentrations. Most women (77%) were fully adherent to 28 days of continuous VR use and found the VR acceptable. Conclusions VCV and/or MK-2048 containing VRs were safe and acceptable. Both VCV and MK-2048 were quantifiable in all matrixes tested with peak compartmental drug concentrations similar for single and combination drug VRs. Tissue-associated VCV and/or MK-2048 did not correlate with inhibition of HIV infection. These data highlight the need to assess adequacy of drug dosing in the VR and measuring genital tissue drug concentrations to develop more precise concentration-response relationships. This study evaluated vaginal rings containing vicriviroc and MK-2048 alone or in combination. The rings were found to be safe and acceptable. Although both drugs were quantifiable in all matrixes tested, HIV inhibition was not demonstrated in cervical tissue.
Safety, Tolerability, and Pharmacokinetics of a New Formulation of Nemiralisib Administered via a Dry Powder Inhaler to Healthy Individuals
Nemiralisib, a phosphoinositide 3-kinase δ inhibitor, is being investigated as an immunomodulatory agent with anti-inflammatory properties in chronic obstructive pulmonary disease. This study evaluated the pharmacokinetic (PK) properties and safety of a new formulation of nemiralisib that contains 0.4% magnesium stearate. In this randomized, double-blind, parallel-group study, healthy individuals received a single dose of 500 or 750 μg of nemiralisib administered via the Ellipta dry powder inhaler (DPI) (n = 6 in each treatment group). Aerodynamic particle size distribution (APSD) data comparing previous and new formulations were available before the study. Serial PK analyses for plasma exposure and safety assessments were performed during the first 24 h after dosing, with follow-up measurements on days 3 and 6 in clinic. APSD had increases of approximately 6-fold and 2-fold in very fine particle mass and fine particle mass over the previous (Diskus) formulation. In humans, systemic exposure (AUC) was greater after inhalation of 750 versus 500 μg of nemiralisib (AUC0–t: 17,200 h∙pg/mL; 95% CI, 10,900–27,200 h∙pg/mL and 13,100; 95% CI, 8130–21,000 h∙pg/mL, respectively). A low frequency of individual adverse events and no serious adverse events were reported after both doses. After single-dose inhalation of 500 and 750 μg of nemiralisib from the Ellipta DPI in healthy individuals, plasma PK data were well defined, and as predicted based on previous PK and APSD data, exposure was increased with the new formulation. Nemiralisib was well tolerated with no new safety issues identified. These data supported progression of nemiralisib to a Phase IIb study in patients with chronic obstructive pulmonary disease. ClinicalTrials.gov identifier: NCT03189589.
Pharmacokinetic Drug Interactions Involving Vortioxetine (Lu AA21004), a Multimodal Antidepressant
Background and Objective The identification and quantification of potential drug–drug interactions is important for avoiding or minimizing the interaction-induced adverse events associated with specific drug combinations. Clinical studies in healthy subjects were performed to evaluate potential pharmacokinetic interactions between vortioxetine (Lu AA21004) and co-administered agents, including fluconazole (cytochrome P450 [CYP] 2C9, CYP2C19 and CYP3A inhibitor), ketoconazole (CYP3A and P-glycoprotein inhibitor), rifampicin (CYP inducer), bupropion (CYP2D6 inhibitor and CYP2B6 substrate), ethinyl estradiol/levonorgestrel (CYP3A substrates) and omeprazole (CYP2C19 substrate and inhibitor). Methods The ratio of central values of the test treatment to the reference treatment for relevant parameters (e.g., area under the plasma concentration–time curve [AUC] and maximum plasma concentration [ C max ]) was used to assess pharmacokinetic interactions. Results Co-administration of vortioxetine had no effect on the AUC or C max of ethinyl estradiol/levonorgestrel or 5′-hydroxyomeprazole, or the AUC of bupropion; the 90 % confidence intervals for these ratios of central values were within 80–125 %. Steady-state AUC and C max of vortioxetine increased when co-administered with bupropion (128 and 114 %, respectively), fluconazole (46 and 15 %, respectively) and ketoconazole (30 and 26 %, respectively), and decreased by 72 and 51 %, respectively, when vortioxetine was co-administered with rifampicin. Concomitant therapy was generally well tolerated; most adverse events were mild or moderate in intensity. Conclusion Dosage adjustment may be required when vortioxetine is co-administered with bupropion or rifampicin.
Phase 1 Pharmacokinetic Trial of 2 Intravaginal Rings Containing Different Dose Strengths of Vicriviroc (MK-4176) and MK-2048
Abstract Background Vaginal rings (VRs) are a promising approach for sustained delivery of antiretroviral (ARV) medication to prevent human immunodeficiency virus (HIV) infection in women. Combination ARV VRs could increase efficacy. Methods MTN-028, a phase 1 trial in 19 HIV-uninfected women, evaluated 2 VRs containing vicriviroc (VCV) and MK-2048. Participants were randomized 2:1 to a low-dose (VCV, 91 mg; MK-2048, 10 mg) or original-dose (VCV, 182 mg; MK-2048, 30 mg) ring used for 28 days. Safety was assessed by documenting adverse events (AEs). Drug concentrations were evaluated in plasma, cervicovaginal fluid (CVF), and cervical tissue samples. Results All AEs reported were grade 1 or 2, with no statistically significant differences in related genitourinary AEs or grade ≥2 AEs observed between arms (P = >.99). VCV/MK-2048 concentrations rose rapidly, with higher plasma area under the concentration-time curve (AUC) in the original-dose arm (geometric mean ratio, 3.29 for VCV and 1.49 for MK-2048) and similar AUCs across arms for CVF samples. Cervical tissue concentrations were higher in the original-dose arm (geometric mean ratio, 7.94 for VCV and 6.45 for MK-2048), with greater drug released based on residual drug levels. Plasma and CVF concentrations for both drugs fell rapidly after ring removal. Conclusions In this first study evaluating 2 doses of a combination VCV/MK-2048 VR, both rings were found to be safe and well tolerated. VCV and MK-2048 were detectable in plasma, CVF, and cervical tissue samples, and drug release and plasma drug exposure were higher for the original-dose than for the low-dose ring. This study evaluated 2 dose strengths of a novel combination antiretroviral vaginal ring containing vicriviroc and MK-2048. Both rings were found to be safe and well tolerated. Drug release and plasma drug exposure were higher with the original than with the low-dose ring.