Effects of a potent CYP3A inhibitor on the pharmacokinetics and safety of enzastaurin

2007 ◽  
Vol 25 (18_suppl) ◽  
pp. 2572-2572
Author(s):  
L. Musib ◽  
C. Darstein ◽  
J. Suico ◽  
J. Baldwin ◽  
P. Welch

2572 Background: Enzastaurin (ENZ) targets the PKCβ and PI3K/AKT pathways to induce tumor cell apoptosis, reduce proliferation, and suppress tumor-induced angiogenesis. ENZ is metabolized by CYP3A in vitro. This study examined the potential clinical effects of a potent CYP3A4 inhibitor, ketoconazole (KETO), on the pharmacokinetics and safety of ENZ. Methods: In this open-label, fixed-sequence, three-period, crossover study (duration = 6 weeks), healthy subjects received an oral, 200- mg, single dose of ENZ (period 1); 400-mg daily doses of KETO for 4 days to assess QT (period 2); and 400-mg daily doses of KETO for 14 days, with a 200-mg single dose of ENZ given on day 4 (period 3). Plasma samples for PK analysis were collected predose and after ENZ administration in periods 1 and 3 at scheduled intervals. Results: Of the 16 women enrolled, 13 completed the study. Changes in PK parameters of ENZ and its metabolite, LY326020, in the presence of KETO are summarized in the table . No serious adverse events (AEs) occurred. A similar number of AEs possibly related to enzastaurin occurred in period 1 (6) and period 3 (7). Headache (n=4) and nausea (n=3) were more frequent in period 3, but were also the most common AEs related to KETO. Three patients had hepatic transaminase elevations, but no consistent pattern with dosing period or ENZ exposures was observed. At 4 hours post-dose, QT intervals were prolonged by a mean 5.88 (95% CI: 1.767–10.00) msec after four daily doses of KETO and by a mean 9.29 (95% CI: 5.165–13.41) msec when coadministered with ENZ. Conclusion: In the presence of KETO, plasma concentrations of ENZ and its metabolites increased significantly. ENZ alone did not increase QT intervals. Ketoconazole plus ENZ caused a slightly greater increase in QT intervals compared to KETO alone, but this very small change may not be clinically significant. ENZ was generally well tolerated, alone or with KETO. [Table: see text] No significant financial relationships to disclose.

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Furong Qiu ◽  
Jian Jiang ◽  
Yueming Ma ◽  
Guangji Wang ◽  
Chenglu Gao ◽  
...  

The aim of this study was to investigate the effect of single- and multidose administration of the ethanol extract of danshen on in vivo CYP3A activity in healthy volunteers. A sequential, open-label, and three-period pharmacokinetic interaction study design was used based on 12 healthy male individuals. The plasma concentrations of midazolam and its metabolite 1-hydroxymidazolam were measured. Treatment with single dose of the extract caused the meanCmaxof midazolam to increase by 87% compared with control. After 10 days of the danshen extract intake, the mean AUC0–12,Cmax, andt1/2of midazolam were decreased by 79.9%, 66.6%, and 43.8%, respectively. The mean clearance of midazolam was increased by 501.6% compared with control. The in vitro study showed that dihydrotanshinone I in the extract could inhibit CYP3A, while tanshinone IIA and cryptotanshinone could induce CYP3A. In conclusion, a single-dose administration of the danshen extract can inhibit intestinal CYP3A, but multidose administration can induce intestinal and hepatic CYP3A.


2019 ◽  
Vol 2019 ◽  
pp. 1-6 ◽  
Author(s):  
Jung-Ryul Kim ◽  
Jin Ah Jung ◽  
Seokuee Kim ◽  
Wooseong Huh ◽  
Jong-Lyul Ghim ◽  
...  

Purpose. We evaluated potential drug-drug interactions between cilostazol and simvastatin, both CYP3A substrates, in healthy subjects. Methods. An open-label, two-period, fixed-sequence clinical study was conducted. Seventeen subjects were given a single oral dose of simvastatin 40 mg on day 1 and multiple oral doses of cilostazol 100 mg twice daily on days 2 to 5 followed by a single dose of cilostazol and simvastatin on day 6. Plasma concentrations of simvastatin and its active metabolite, simvastatin acid, were measured using liquid chromatography-tandem mass spectrometry for pharmacokinetic assessment. Moreover, serum lipid profiles under fasting conditions were determined. Results. The geometric mean ratios of the area under the plasma concentration-time curve from time zero to time infinity of simvastatin combined with cilostazol to that of simvastatin alone were 1.64 (90% CI, 1.38-1.95) for simvastatin and 1.31 (1.04-1.66) for simvastatin acid. In addition, coadministration with cilostazol significantly increased the maximum concentration of simvastatin and simvastatin acid, up to 1.8-fold and 1.6-fold, respectively. However, the effects of a single dose of simvastatin on serum lipid profiles were not affected notably when simvastatin was coadministered with cilostazol. Conclusions. Multiple doses of cilostazol increased the systemic exposure of simvastatin and simvastatin acid following a single dose of simvastatin.


2013 ◽  
Vol 31 (6_suppl) ◽  
pp. 126-126 ◽  
Author(s):  
Olivier Rixe ◽  
John Sarantopoulos ◽  
Chung-Tsen Hsueh ◽  
A. Craig Lockhart ◽  
Sharona Ross ◽  
...  

126 Background: Cabazitaxel (Cbz) is approved in combination with prednisone/prednisolone for the treatment of men with hormone-refractory metastatic prostate cancer previously treated with a docetaxel-containing treatment regimen. In vitro studies showed that Cbz is mainly metabolized through CYP3A, resulting in inhibition of this family of enzymes. Midazolam (Mdz) is primarily metabolized by CYP3A4. We aimed to determine the effect of Cbz on CYP3A activity by comparing the pharmacokinetic (PK) properties of Mdz when administered alone and following co-administration with Cbz. Methods: An ongoing safety and PK study of Cbz in patients with metastatic or locally advanced solid tumors and varying degrees of hepatic impairment (NCT01140607) included a cohort with normal hepatic function to assess the effect of a single Cbz dose on the PK profile of a single dose of Mdz. This was an open-label, two-period, fixed-sequence study in patients aged between 45 and 60 years with advanced solid tumors and normal hepatic function. A single dose of Mdz (2 mg) was administered orally alone (Day –1) and at the end of a 1-hour infusion of Cbz (25 mg/m2) (Day 1), with a 24-hour interval between the two administrations of Mdz. Endpoints included AUC and AUClastof Mdz with and without Cbz administration, and safety evaluations. Results: Of the 13 patients enrolled and treated in the cohort, 11 patients were included in the PK analysis. Exposure (AUC and AUClast) and other PK parameters after a single administration of Mdz alone and in combination with Cbz (Day 1) were similar. The AUC ratio for Mdz administered alone or with Cbz was 0.97 (90% CI: 0.76–1.23). The AUClast ratio for Mdz administered alone or with Cbz was 1.04 (90% CI: 0.81–1.34). All 13 patients had ≥1 adverse event (AE), 11 (84.6%) experienced a Grade 3–4 AE, and 4 (30.8%) experienced a serious AE. The majority of Grade 3–4 AEs were haematological and no new or unexpected safety findings were observed. Conclusions: In this study, Cbz did not increase the plasma exposure of Mdz. This indicates that Cbz is not a CYP3A inhibitor in the clinical setting and can be administered in combination with drugs metabolized by CYP3A. Clinical trial information: NCT01140607.


2016 ◽  
Vol 61 (2) ◽  
Author(s):  
Sauzanne Khalilieh ◽  
Ka Lai Yee ◽  
Rosa I. Sanchez ◽  
Ilias Triantafyllou ◽  
Li Fan ◽  
...  

ABSTRACT Doravirine is a novel, highly potent, nonnucleoside reverse transcriptase inhibitor that is administered once daily and that is in development for the treatment of HIV-1 infection. In vitro and clinical data suggest that doravirine is unlikely to cause significant drug-drug interactions via major drug-metabolizing enzymes or transporters. As a common HIV-1 infection comorbidity, hypercholesterolemia is often treated with statins, including the commonly prescribed atorvastatin. Atorvastatin is subject to drug-drug interactions with cytochrome P450 3A4 (CYP3A4) inhibitors. Increased exposure due to CYP3A4 inhibition may lead to serious adverse events (AEs), including rhabdomyolysis. Furthermore, atorvastatin is a substrate for breast cancer resistance protein (BCRP), of which doravirine may be a weak inhibitor; this may increase atorvastatin exposure. The potential of doravirine to affect atorvastatin pharmacokinetics was investigated in a two-period, fixed-sequence study in healthy individuals. In period 1, a single dose of atorvastatin at 20 mg was administered followed by a 72-h washout. In period 2, doravirine at 100 mg was administered once daily for 8 days, with a single dose of atorvastatin at 20 mg concomitantly being administered on day 5. Sixteen subjects were enrolled, and 14 completed the trial; 2 discontinued due to AEs unrelated to the treatment. The atorvastatin area under the curve from time zero to infinity was similar with and without doravirine (geometric mean ratio [GMR] for doravirine-atorvastatin/atorvastatin, 0.98; 90% confidence interval [CI], 0.90 to 1.06), while the maximum concentration decreased by 33% (GMR for doravirine-atorvastatin/atorvastatin, 0.67; 90% CI, 0.52 to 0.85). These changes were deemed not to be clinically meaningful. Both of the study drugs were generally well tolerated. Doravirine had no clinically relevant effect on atorvastatin pharmacokinetics in healthy subjects, providing support for the coadministration of doravirine and atorvastatin.


2019 ◽  
Vol 6 (Supplement_2) ◽  
pp. S509-S510
Author(s):  
Marguerite L Monogue ◽  
Bonnie C Prokesch

Abstract Background Miltefosine is an alkylphosphocholine compound used primarily for the treatment of leishmaniasis that also demonstrates in vitro and in vivo anti-amebic activity against Acanthamoeba species. As such, recommendations for treatment of amebic encephalitis generally include miltefosine therapy. Data support a minimum amebicidal concentration (MAC) of at least 16 μg/mL is required for most Acanthamoeba species. Given the high mortality associated with amebic encephalitis and a paucity of data regarding miltefosine levels in the plasma and cerebrospinal fluid (CSF) in vivo, we sought to determine whether a patient being treated with oral miltefosine at a higher-than-recommended dose obtained therapeutic plasma and CSF concentrations. Methods A patient with brain-biopsy-confirmed Acanthamoeba encephalitis was initiated on miltefosine 50mg by mouth every 6 hours (q6h), a higher frequency of therapy than recommended in the scant available literature (which suggests doses of 50 mg every 8 hours). Plasma and CSF miltefosine concentrations were collected on day 7 of treatment. CSF was collected via an external ventricular drain over a period of 1 hour. The quantification of miltefosine was performed using a Waters Xevo TQ-S triple quadrupole mass spectrometer coupled with a Waters Acquity UPLC I-class system. Results The trough plasma and CSF concentrations (taken 8 hours post-dose) were 16.2 and 0.007 µg/mL, respectively, resulting in a miltefosine plasma to CSF ratio of 2,440:1 µg/mL. The patient had no adverse reactions during the initial course of miltefosine therapy, though ultimately succumbed to the disease. Conclusion This is the first report to describe plasma and CSF concentrations after administration of miltefosine 50mg q6h for the treatment of amebic encephalitis. The administration of miltefosine 50mg q6h resulted in plasma concentrations at the suggested MAC for Acanthamoebaspp. However, the miltefosine CSF concentration was extremely low compared with the plasma level and did not reach amebicidal concentrations. While miltefosine human brain parenchyma concentrations have yet to be described in the literature, this case questions if oral miltefosine is adequate to veritably treat patients with amebic encephalitis. Disclosures All authors: No reported disclosures.


Drug Research ◽  
2019 ◽  
Vol 70 (02/03) ◽  
pp. 91-96
Author(s):  
Soha Mahmoud El-Masry ◽  
Noha Mahmoud El-Khodary

AbstractNifedipine is one of calcium channel blockers that commonly used clinically to treat hypertension and angina in Egyptian patients. A sustained-release (SR) formulation of nifedipine is available in the Egyptian community and administered twice daily. This study aimed to to compare the pharmacokinetics and safety profiles of a 20 mg SR and IR (immediate release) formulation of nifedipine after single-dose administration in healthy Egyptian subjects. Randomized, crossed open-label two- way clinical trial, in 16 healthy adult volunteers, of 24.75±5.20 years, with BMI 23.26±1.756 were assessed. Blood samples were collected at predefined times for 48 h and analyzed for Nifedipine plasma concentrations using validated reversed phase liquid chromatography method with ultraviolet detection. Pharmacokinetics was determined using non- compartmental model pharmacokinetics and analyzed using one-way ANOVA (P≤0.05). Following a single oral administration, SR formulation had a lower Cmax, compared to IR formulation (54.46±17.75 , 107.45±29.85 ng/mL, respectively), and Tmax was significantly longer (2.97 vs. 1.13 h) for the SR and IR formulation, respectively. There was no significant difference between the SR and the IR formulations for AUC0–last and AUC0-∞ (326.7±98.28 vs. 309.27±105.53 ng·h·mL−1 and 380.9 ± 105.24 vs. 334.36±108.1 ng·h·mL−1, respectively). SR formulation of nifedipine showed similar pharmacokinetics to the IR Formulation (F%=1.049), but it additionally allows a less frequent administration. Therefore, The nifedipine SR and IR formulations were well tolerated and displayed comparable safety profiles.


2011 ◽  
Vol 2011 ◽  
pp. 1-4 ◽  
Author(s):  
Pauline Byakika-Kibwika ◽  
Mohammed Lamorde ◽  
Peter Lwabi ◽  
Wilson B. Nyakoojo ◽  
Violet Okaba-Kayom ◽  
...  

Background. We aimed to assess cardiac conduction safety of coadministration of the CYP3A4 inhibitor lopinavir/ritonavir (LPV/r) and the CYP3A4 substrate artemether-lumefantrine (AL) in HIV-positive Ugandans. Methods. Open-label safety study of HIV-positive adults administered single-dose AL (80/400 mg) alone or with LPV/r (400/100 mg). Cardiac function was monitored using continuous electrocardiograph (ECG). Results. Thirty-two patients were enrolled; 16 taking LPV/r -based ART and 16 ART naïve. All took single dose AL. No serious adverse events were observed. ECG parameters in milliseconds remained within normal limits. QTc measurements did not change significantly over 72 hours although were higher in LPV/r arm at 24 (424 versus 406; P=.02) and 72 hours (424 versus 408; P=.004) after AL intake. Conclusion. Coadministration of single dose of AL with LPV/r was safe; however, safety of six-dose AL regimen with LPV/r should be investigated.


Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 1149-1149
Author(s):  
Bruce A. Wallin ◽  
Denise Ramjit ◽  
Michael Seiberling ◽  
David Zopf

Abstract NE-180 is a glycoPEGylated recombinant human erythropoietin that binds to and activates the erythropoietin (EPO) receptor. It has demonstrated in vitro activities comparable to EPO and an extended serum half-life in animal studies. This may allow less frequent dosing in patients being treated with chronic anemia. METHODS: A single center, open-label study of NE-180, administered as single escalating doses given by the SC or IV route, was conducted to assess the safety, tolerability, PK and PD. Subjects (male or female NHV) were planned to be assigned to one of 4 dose groups, 10 subjects per dose with 5 SC and 5 IV subjects per group: 0.5, 1.5, 3, or 4.5 mg/kg. Each dose group was planned to be initiated in an ascending, sequential fashion unless or until stopping rules were met. RESULTS: 25 NHV (16 females) were enrolled in the first two dose cohorts and have completed 56 day follow-up. The 1.5 mg/kg IV cohort met the protocol-specified Hb rate of rise stopping rule (change in Hb greater than 1 g/dL during any 14 day period). Injections were generally well tolerated with no discontinuations for adverse events or serious adverse events. Reticulocyte increases were dose proportional. Average reticulocyte count at baseline was 1.0±0.3%. The maximal increase occurred at day 7. The mean change from baseline for the 0.5 and 1.5 mg/kg SC group was: 0.9±0.4% and 2.2±0.9%, respectively. The mean change from baseline for the 0.5 and 1.5 mg/kg IV group was: 1.7±0.8% and 2.3±0.8%, respectively. PK data will be presented. CONCLUSIONS: Single doses up to 1.5 mg/kg of NE-180 administered to NHV were generally well tolerated and demonstrated potent dose-dependent erythropoietic activity.


Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 3900-3900
Author(s):  
Eric Eldering ◽  
Christian R Geest ◽  
Martin FM de Rooij ◽  
Nora Liu ◽  
Bogdan I Florea ◽  
...  

Abstract Abstract 3900 In the lymph node (LN) microenvironment, chronic lymphocytic leukemia (CLL) cells are protected from apoptosis by upregulation of anti-apoptotic proteins. In vitro, this can be mimicked via CD40-stimulation of CLL cells, which also provides resistance to various chemotherapeutics. Novel drugs that target kinases involved in B cell signalling, including the broad spectrum kinase inhibitor dasatinib, are currently in clinical development for CLL. We have shown previously that dasatinib prevents CD40-mediated anti-apoptotic changes in CLL (Hallaert et Blood 2008). However, the kinase(s) involved remain unidentified. Here, we coupled dasatinib to an affinity matrix and pulled down its targets from CD40-stimulated CLL cells. By mass-spectrometry and Western blotting, Abl and Btk were identified as dominant targets of dasatinib. Functional analysis revealed that CD40-mediated anti-apoptotic signals and drug-resistance could be overcome both by dasatinib and the Abl inhibitor imatinib, but not by the novel Btk inhibitor PCI-32765 (ibrutinib), whereas BCR- and chemokine-controlled adhesion could be abolished by dasatinib and ibrutinib, but not by imatinib. Thus, dasatinib combines two key aspects that are clinically relevant: inhibition of Abl overrides chemoprotective survival signals, whereas inhibition of Btk impairs integrin-mediated adhesion of CLL cells in the microenvironmental niche. This combined inhibition of Abl and Btk was put to an initial test in an open-label phase 2 trial of dasatinib combined with fludarabine in twenty refractory CLL patients. As might be expected based on the in vitro data, reductions in lymph node size were observed in most patients. A LN reduction of ≥20% provided a significant improved PFS (256 days) and OS (510 days) as compared to non-responders (80 days and 158 days respectively). Details of the clinical study will be presented separately. In conclusion, in agreement with in vitro molecular studies, dasatinib seems to have clinical efficacy in heavily pretreated refractory CLL patients. Combined, these data encourage further studies on a broad-spectrum kinase inhibitor like dasatinib in combination with other classes of drugs in relapsed and refractory CLL. Disclosures: No relevant conflicts of interest to declare.


2007 ◽  
Vol 25 (18_suppl) ◽  
pp. 14026-14026 ◽  
Author(s):  
R. B. Klisovic ◽  
G. Tricot ◽  
S. Coutre ◽  
T. Kovacsovics ◽  
F. Giles ◽  
...  

14026 Background: AVN-944 is an inhibitor of inosine monophosphate dehydrogenase (IMPDH), an enzyme that catalyzes the rate- limiting step in guanine nucleotide synthesis, and induces apoptosis in malignant hematopoietic cell lines in vitro. Methods: This phase I study employed open-label dose escalations in patients (pts) with relapsed, refractory hematologic cancers with safety, pharmacokinetic (PK), pharmacodynamic, & efficacy endpoints. Between 12/05 and 1/07 a total of 70 cycles of AVN944 at 25 (7pts), 50 (6pts), 75 (7pts), 100 (7pts) or 125 mg (3pts) b.i.d. orally X 21d every 28d were administered to 30 pts with AML (12), ALL (2), CLL (3), and multiple myeloma (13). Peripheral blood mononuclear cell (PBMC) or leukemic blast samples were obtained from all pts pre and post-receiving AVN944 to determine effects on GTP pools, IMPDH activity, and to correlate these changes to response in a 32-gene set that relates directly to cellular pathways dependent upon guanine nucleotide biosynthesis. Results: Pharmacokinetics were dose proportional with mean Tmax=1 hour, T1/2=1.5 hours, Cmax=2800 ng/ml and AUC=7228 hr.ng/ml at the 100 mg b.i.d. dose. Toxicities were generally mild-moderate and/or not attributed to AVN944. Twelve serious adverse events (SAEs) occurred in 8 pts; 7 of 8 had AML. No SAEs was attributed to AVN944. DLT was not seen. No protocol defined responses were seen. Twelve of 24 assessable pts had stable disease of 2 to 10 months duration. Changes in the gene expression set correlated with disease stability. Conclusions: AVN944 is well tolerated with oral b.i.d. dosing. Stabilization of disease was observed in half of the pts. Gene expression correlated with stable versus progressive disease. [Table: see text]


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