Catalogue Search | MBRL
Search Results Heading
Explore the vast range of titles available.
MBRLSearchResults
-
DisciplineDiscipline
-
Is Peer ReviewedIs Peer Reviewed
-
Item TypeItem Type
-
SubjectSubject
-
YearFrom:-To:
-
More FiltersMore FiltersSourceLanguage
Done
Filters
Reset
779
result(s) for
"Prodrugs - pharmacokinetics"
Sort by:
Clinical Pharmacokinetics and Safety of ALZ-801, a Novel Prodrug of Tramiprosate in Development for the Treatment of Alzheimer’s Disease
2018
Background
ALZ-801 is an orally available, valine-conjugated prodrug of tramiprosate. Tramiprosate, the active agent, is a small-molecule β-amyloid (Aβ) anti-oligomer and aggregation inhibitor that was evaluated extensively in preclinical and clinical investigations for the treatment of Alzheimer’s disease (AD). Tramiprosate has been found to inhibit β-amyloid oligomer formation by a multi-ligand enveloping mechanism of action that stabilizes Aβ42 monomers, resulting in the inhibition of formation of oligomers and subsequent aggregation. Although promising as an AD treatment, tramiprosate exhibited two limiting deficiencies: high intersubject pharmacokinetic (PK) variability likely due to extensive gastrointestinal metabolism, and mild-to-moderate incidence of nausea and vomiting. To address these, we developed an optimized prodrug, ALZ-801, which retains the favorable efficacy attributes of tramiprosate while improving oral PK variability and gastrointestinal tolerability. In this study, we summarize the phase I bridging program to evaluate the safety, tolerability and PK for ALZ-801 after single and multiple rising dose administration in healthy volunteers.
Methods
Randomized, placebo-controlled, phase I studies in 127 healthy male and female adult and elderly volunteers included [
1
] a single ascending dose (SAD) study; [
2
] a 14-day multiple ascending dose (MAD) study; and [
3
] a single-dose tablet food-effect study. This program was conducted with both a loose-filled capsule and an immediate-release tablet formulation, under both fasted and fed conditions. Safety and tolerability were assessed, and plasma and urine were collected for liquid chromatography-mass spectrometry (LC-MS) determination and non-compartmental PK analysis. In addition, we defined the target dose of ALZ-801 that delivers a steady-state plasma area under the curve (AUC) exposure of tramiprosate equivalent to that studied in the tramiprosate phase III study.
Results
ALZ-801 was well tolerated and there were no severe or serious adverse events (AEs) or laboratory findings. The most common AEs were transient mild nausea and some instances of vomiting, which were not dose-related and showed development of tolerance after continued use. ALZ-801 produced dose-dependent maximum plasma concentration (
C
max
) and AUC exposures of tramiprosate, which were equivalent to that after oral tramiprosate, but with a substantially reduced intersubject variability and a longer elimination half-life. Administration of ALZ-801 with food markedly reduced the incidence of gastrointestinal symptoms compared with the fasted state, without affecting plasma tramiprosate exposure. An immediate-release tablet formulation of ALZ-801 displayed plasma exposure and low variability similar to the loose-filled capsule. ALZ-801 also showed excellent dose-proportionality without accumulation or decrease in plasma exposure of tramiprosate over 14 days. Based on these data, 265 mg of ALZ-801 twice daily was found to achieve a steady-state AUC exposure of tramiprosate equivalent to 150 mg twice daily of oral tramiprosate in the previous phase III trials.
Conclusions
ALZ-801, when administered in capsule and tablet forms, showed excellent oral safety and tolerability in healthy adults and elderly volunteers, with significantly improved PK characteristics over oral tramiprosate. A clinical dose of ALZ-801 (265 mg twice daily) was established that achieves the AUC exposure of 150 mg of tramiprosate twice daily, which showed positive cognitive and functional improvements in apolipoprotein E4/4 homozygous AD patients. These bridging data support the phase III development of ALZ-801in patients with AD.
Journal Article
Protocol for a seamless phase 2A-phase 2B randomized double-blind placebo-controlled trial to evaluate the safety and efficacy of benfotiamine in patients with early Alzheimer’s disease (BenfoTeam)
by
Venkatesh, Venky
,
Feldman, Howard H.
,
Luchsinger, José A.
in
Activities of daily living
,
Advertising executives
,
Aged
2024
Benfotiamine provides an important novel therapeutic direction in Alzheimer's disease (AD) with possible additive or synergistic effects to amyloid targeting therapeutic approaches.
To conduct a seamless phase 2A-2B proof of concept trial investigating tolerability, safety, and efficacy of benfotiamine, a prodrug of thiamine, as a first-in-class small molecule oral treatment for early AD.
This is the protocol for a randomized, double-blind, placebo-controlled 72-week clinical trial of benfotiamine in 406 participants with early AD. Phase 2A determines the highest safe and well-tolerated dose of benfotiamine to be carried forward to phase 2B. During phase 2A, real-time monitoring of pre-defined safety stopping criteria in the first approximately 150 enrollees will help determine which dose (600 mg or 1200 mg) will be carried forward into phase 2B. The phase 2A primary analysis will test whether the rate of tolerability events (TEs) is unacceptably high in the high-dose arm compared to placebo. The primary safety endpoint in phase 2A is the rate of TEs compared between active and placebo arms, at each dose. The completion of phase 2A will seamlessly transition to phase 2B without pausing or stopping the trial. Phase 2B will assess efficacy and longer-term safety of benfotiamine in a larger group of participants through 72 weeks of treatment, at the selected dose. The co-primary efficacy endpoints in phase 2B are CDR-Sum of Boxes and ADAS-Cog13. Secondary endpoints include safety and tolerability measures; pharmacokinetic measures of thiamine and its esters, erythrocyte transketolase activity as blood markers of efficacy of drug delivery; ADCS-ADL-MCI; and MoCA.
The BenfoTeam trial utilizes an innovative seamless phase 2A-2B design to achieve proof of concept. It includes an adaptive dose decision rule, thus optimizing exposure to the highest and best-tolerated dose.
ClinicalTrials.gov identifier: NCT06223360, registered on January 25, 2024. https://classic.clinicaltrials.gov/ct2/show/NCT06223360.
Journal Article
Phase I study on the pharmacokinetics and tolerance of ZT-1, a prodrug of huperzine A, for the treatment of Alzheimer's disease
by
Gui, Yu-zhou
,
Hong, Zhen
,
Jia, Jing-ying
in
Alkaloids - administration & dosage
,
Alkaloids - adverse effects
,
Alkaloids - pharmacokinetics
2013
Aim:
Huperzine A isolated from the Chinese herb Huperzia serrata (Thunb) Trev is a novel reversible and selective AChE inhibitor. The aim of this study was to evaluate the pharmacokinetics and tolerance of single and multiple doses of ZT-1, a novel analogue of huperzine A, in healthy Chinese subjects.
Methods:
This was a double-blinded, placebo-controlled, randomized, single- and multiple-dose study. For the single-dose study, 9 subjects were randomly divided into 3 groups receiving ZT-1 (0.5, 0.75 or 1 mg,
po
) according to a Three-way Latin Square Design. For the multiple-dose study, 9 subjects receiving ZT-1 (0.75 mg/d,
po
) for 8 consecutive days. In the tolerance study, 40 subjects were randomly divided into 5 groups receiving a single dose of ZT-1 (0.5, 0.75, 1, 1.25 or 1.5 mg,
po
). Plasma and urine concentrations of ZT-1 and Hup A were determined using LC-MS/MS. Pharmacokinetic parameters, including C
max
, AUC
0–72 h
and AUC
0–∞
were calculated. Tolerance assessments were conducted throughout the study.
Results:
ZT-1 was rapidly absorbed and converted into huperzine A, thus the plasma and urine concentrations of ZT-1 were below the limit of quantification (<0.05 ng/mL). After single-dose administration of ZT-1, the mean
t
max
of huperzine A was 0.76–0.82 h; the AUC
0–72 h
and
C
max
of huperzine A showed approximately dose-proportional increase over the dose range of 0.5–1 mg. After the multiple-dose administration of ZT-1, a steady-state level of huperzine A was achieved within 2 d. No serious adverse events were observed.
Conclusion:
ZT-1 is a pro-drug that is rapidly absorbed and converted into huperzine A, and ZT-1 is well tolerated in healthy Chinese volunteers.
Journal Article
Pharmacokinetics, Safety, and Tolerability of Tedizolid Phosphate After Single-dose Administration in Healthy Korean Male Subjects
by
Jang, In-Jin
,
Lee, Dae Young
,
Lee, SeungHwan
in
Administration, Intravenous
,
Administration, Oral
,
Adult
2017
Tedizolid phosphate is a next-generation oxazolidinone prodrug that is transformed into the active moiety tedizolid. Its indication is acute bacterial skin and skin structure infections caused by gram-positive species, including methicillin-resistant Staphylococcus aureus. Although tedizolid phosphate has been marketed in Korea, no data on the pharmacokinetic (PK) properties or tolerability of tedizolid phosphate in Korean subjects are available. This study was designed to evaluate the PK properties, oral bioavailability, and tolerability with a single-dose oral and intravenous administration of tedizolid phosphate in healthy Korean male subjects.
A block-randomized, double-blind, placebo-controlled, single-dose study was conducted in 3 groups (200, 400, and 600 mg; 10 subjects in each group). In the second part of the study, subjects from the 200-mg group received administration orally and intravenously (1-hour infusion) via 2-way crossover for the evaluation of absolute bioavailability. There was a 7-day washout period between treatments in the absolute bioavailability part of the study. Serial blood samples for PK analysis were collected for up to 72 hours. Tolerability was assessed by analysis of adverse events.
Thirty healthy Korean subjects completed the study and were included in the PK and tolerability analyses. Tedizolid phosphate was rapidly converted into tedizolid. After a single oral dose, the Tmax of tedizolid was observed to be 1.5 to 2.5 hours, and the plasma concentration–time curve of tedizolid showed a 2-phase elimination pattern, with a half-life of ~11 hours. Dose-dependent increases were observed in the AUClast value (29,441–78,062 μg · h/L) and in the Cmax value (2679–6980 μg/L) with the administration of tedizolid phosphate 200 to 600 mg PO. The absolute bioavailability of tedizolid was 95.2% (90% CI, 92.7%–97.8%) in the 200-mg administration group. There were no serious adverse events or clinically significant changes in the tolerability assessment.
Tedizolid phosphate at doses of up to 600 mg was well-tolerated in these healthy Korean male subjects. Tedizolid shows dose linearity with oral administration, and no dose adjustment of tedizolid phosphate 200 mg would be needed when switching administration routes. ClinicalTrials.gov identifier: NCT02097043.
Journal Article
Pharmacokinetics of lisdexamfetamine dimesylate and its active metabolite, d-amphetamine, with increasing oral doses of lisdexamfetamine dimesylate in children with attention-deficit/hyperactivity disorder: A single-dose, randomized, open-label, crossover study
2010
Background: Lisdexamfetamine dimesylate (LDX) is a long-acting oral prodrug stimulant indicated for the treatment of attention-deficit/hyperactivity disorder (ADHD) in children 6 to 12 years old and in adults. Information on the pharmacokinetic profile of LDX in children with ADHD is lacking.
Objective: The aim of this study was to assess the pharmacokinetic properties of d-amphetamine delivery from LDX, and intact LDX with increasing doses of LDX administered in children with ADHD.
Methods: This single-dose, randomized, open-label, 3-period crossover study was conducted in children aged 6 to 12 years with ADHD symptoms that adversely affected school performance and required a medication switch. Eligible patients had prior stimulant experience, with good tolerability. Patients were administered a single oral dose of LDX 30, 50, or 70 mg in a randomized sequence. Each study period was separated by a 6-day washout. The pharmacokinetic properties of d-amphetamine and intact LDX were calculated over 48 hours. Adverse events (AEs) were assessed using physical examination, including vital sign measurements, and ECG.
Results: The study enrolled 18 children (mean [SD] age, 9.6 [1.9] years [range, 6–12 years]; 56% boys; weight, 36.0 [7.6] kg; 44% white, 44% black). Mean (%CV) C
max values of d-amphetamine postdose were 53.2 (18.1), 93.3 (19.5), and 134.0 (19.4) ng/mL with LDX 30, 50, and 70 mg, respectively (T
max, ~3.5 hours). These findings suggest that the overall AUC for d-amphetamine was dose proportional. The intact LDX AUC was 10% to 20% higher in girls than in boys, and for d-amphetamine was <10% higher. The most commonly reported AEs, of 17 total cases, with 30-, 50-, and 70-mg LDX were anorexia (4 [22%], 7 [41%], and 8 [47%], respectively), elevated blood pressure (2 [11%], 1 [6%], and 3 [18%]), and abdominal pain (2 [11%], 2 [12%], and 2 [12%]). All AEs were mild or moderate. No serious AEs were reported. One child was withdrawn from the analysis because of pharyngitis considered to be unrelated to LDX use.
Conclusion: The findings from this study in a small, select population of children with ADHD suggest that the concentrations of d-amphetamine, the active metabolite of LDX, after single-dose administration of LDX at increasing doses appeared to be dose proportional and had low interpatient variability.
Journal Article
Safety, tolerability, pharmacokinetics, and pharmacodynamics of a TLR7 agonist prodrug RO6870868 in healthy volunteers
by
Folitar, Ilia
,
Calleja, Elizabeth
,
Rodriguez, Ignacio
in
Administration, Oral
,
Adolescent
,
Adult
2021
RO6870868 is an oral prodrug of the toll‐like receptor 7 (TLR7) specific agonist, RO6871765. TLR7 agonists augment host immune activity and are in development to treat hepatitis B infection. We evaluated the safety, tolerability, pharmacokinetics (PKs), and pharmacodynamics (PDs) of RO6870868 in a first‐in‐human, phase I, randomized, single ascending oral dose study in 60 healthy volunteers at 6 dose levels (200–2000 mg). Single oral doses were generally well‐tolerated with a predictable safety profile associated with dose‐dependent increases in systemic interferon. No serious adverse events (AEs) were reported and no subject withdrew from the study due to an AE. No clinically significant changes were observed in vital signs, electrocardiograms, or laboratory parameters. Following oral RO6870868 doses, plasma RO6871765 concentrations increased rapidly, exhibiting mean terminal half‐life ranging 2–6 h across all cohorts, with area under the plasma concentration versus time curve extrapolated to infinity (AUC0‐∞) increasing proportionally with dose. A pattern of dose and time‐dependent PD activity was demonstrated consistent with engagement of the TLR7 system. Single RO6870868 doses activated components of the TLR innate immune system in a dose‐dependent manner with adequate safety and tolerability. Single‐dose data in healthy volunteers are useful to evaluate safety, PK, and PD activity of TLR7 agonists and help to guide dose and regimen selection for further trials in patients with chronic hepatitis B.
Journal Article
Pharmacokinetics and Abuse Potential of Asalhydromorphone, a Novel Prodrug of Hydromorphone, After Intranasal Administration in Recreational Drug Users
by
Mickle, Travis C
,
Kelsh, Debra
,
Smith, Adam
in
Administration, Intranasal
,
Adult
,
Analgesics, Opioid - administration & dosage
2020
Abstract
Objectives
Hydromorphone (HM) is a potent μ-opioid receptor agonist with high susceptibility for abuse. A prodrug of hydromorphone, asalhydromorphone (ASAL-HM), has been designed to deter nonoral forms of abuse associated with hydromorphone. This study evaluated the intranasal (IN) pharmacokinetics and exploratory abuse potential of ASAL-HM compared with HM.
Design
Single-center, randomized, double-blind, crossover study.
Setting
Clinical research site.
Subjects
Healthy adult, nondependent recreational opioid users.
Methods
Subjects (N = 26) were randomized to receive IN administration of 16.1 mg of ASAL-HM and 8.0 mg of HM (molar-equivalent with respect to hydromorphone). Blood samples were taken through 24 hours postdose, and pharmacodynamic end points (Drug Liking, Feeling High, Take Drug Again, Overall Drug Liking) were assessed through eight hours postdose. Nasal irritation and safety were also assessed.
Results
Relative to IN HM, the rate (Cmax) and extent (area under the curve [AUC0-last, AUC0-inf]) of exposure to hydromorphone following IN ASAL-HM were reduced by ≥50%. Consistent with these findings, scores on “at-the-moment” (i.e., Drug Liking Emax, High Emax) and retrospective (i.e., Take Drug Again, Overall Drug Liking) end points were statistically significantly lower for IN ASAL-HM, with mean/median differences ranging from 11.4 to 25.0 points. ASAL-HM produced greater nasal-related effects, such as nasal burning and facial pain, and a lower incidence of typical opioid-related adverse events such as euphoria, pruritus, and somnolence.
Conclusions
The novel hydromorphone prodrug ASAL-HM produced marked reductions in hydromorphone exposure and abuse-related effects following IN administration compared with HM. ASAL-HM has desirable molecular features for incorporation into putative abuse-deterrent immediate-release and extended-release hydromorphone products.
Journal Article
A Controlled Trial of Valganciclovir as Induction Therapy for Cytomegalovirus Retinitis
by
Walmsley, Sharon
,
Wolitz, Richard A
,
Georgiou, Panos
in
Acquired Immunodeficiency Syndrome - complications
,
Administration, Oral
,
Adult
2002
This randomized trial involved 160 patients with the acquired immunodeficiency syndrome (AIDS) and newly diagnosed cytomegalovirus retinitis. After four weeks, the response to induction therapy was satisfactory in 72 percent of patients who received oral valganciclovir, as compared with 77 percent of those who received intravenous ganciclovir. The median time to progression of retinitis was 160 days for the valganciclovir group and 125 days for the ganciclovir group.
Cytomegalovirus retinitis remains the leading cause of visual loss in patients with the acquired immunodeficiency syndrome (AIDS).
1
–
3
Induction therapy with intravenous ganciclovir,
4
,
5
foscarnet,
5
,
6
or cidofovir,
7
,
8
followed by maintenance therapy, can effectively make cytomegalovirus retinitis inactive. If recovery of immune function is not possible, indefinite treatment is needed, and an indwelling catheter and daily intravenous medication may be required. The cost, the risk of sepsis, and the adverse effect on the quality of life associated with an indwelling catheter spurred the development of an oral formulation of ganciclovir.
9
When administered orally, ganciclovir requires three doses (up to . . .
Journal Article
Effects of ranitidine (antacid), food, and formulation on the pharmacokinetics of fostamatinib: results from five phase I clinical studies
2017
Purpose
Fostamatinib is an orally dosed phosphate prodrug that is cleaved by intestinal alkaline phosphatase to the active metabolite R406. Clinical studies were performed to assess the effect of food and ranitidine on exposure, to support in vitro-in vivo relationships (IVIVR) understanding and formulation transitions and to investigate absolute oral bioavailability.
Methods
A series of in vitro dissolution and clinical pharmacokinetic studies were performed to support the design and introduction of a new formulation, understand the impact of changes in in vitro dissolution on in vivo performance for two fostamatinib formulations, to characterize the effects of food and ranitidine on exposure, and determine the absolute oral bioavailability.
Results
The in vivo performance of fostamatinib was generally insensitive to changes in in vitro dissolution performance, although marked slowing of the dissolution rate did impact exposures. Food and ranitidine had minor effects on R406 exposure that were not considered clinically relevant. The absolute oral bioavailability of fostamatinib was 54.6 %.
Conclusions
The absolute oral bioavailability of fostamatinib was ~55 %. Food and ranitidine had minor effects on R406 exposure. An in vitro dissolution versus clinical performance relationship was determined that supported formulation transitions.
Journal Article
Pharmacokinetics and pharmacogenetics of capecitabine and its metabolites following replicate administration of two 500 mg tablet formulations
by
Wargenau, M.
,
Van Os, S. H. G.
,
Kubeš, V.
in
Activation, Metabolic - genetics
,
Administration, Oral
,
Adult
2015
Purpose
To describe concentration versus time profiles of capecitabine and its metabolites 5′-DFUR, 5′-DFCR and 5-FU, depending on tablet formulation and on frequent and/or relevant genetic polymorphisms of cytidine deaminase, dihydropyrimidine dehydrogenase, thymidylate synthase and methylenetetrahydrofolate reductase (MTHFR).
Methods
In 46 cancer patients on chronic capecitabine treatment, who voluntarily participated in the study, individual therapeutic doses were replaced on four consecutive mornings by the study medication. The appropriate number of 500 mg test (T) or reference (R) capecitabine tablets was given in randomly allocated sequences TRTR or RTRT (replicate design). Average bioavailability was assessed by ANOVA.
Results
Thirty female and 16 male patients suffering from gastrointestinal or breast cancer (mean age 53.4 years; mean dose 1739 mg) were included. The T/R ratios for AUC
0–
t
(last)
and
C
max
were 96.7 % (98 % CI 90.7–103.2 %) and 87.2 % (98 % CI 74.9–101.5 %), respectively. Within-subject variability for AUC
0–
t
(last)
and
C
max
(coefficient of variation for R) was 16.5 and 30.2 %, respectively. Similar results were seen for all metabolites. No serious adverse events occurred. For the MTHFR C677T (rs1801133) genotype, an increasing number of 677C alleles showed borderline correlation with an increasing elimination half-life of capecitabine (
p
= 0.043).
Conclusions
The extent of absorption was similar for T and R, but the rate of absorption was slightly lower for T. While such differences are not considered as clinically relevant, formal bioequivalence criteria were missed. A possible, probably indirect role of the MTHFR genotype in pharmacokinetics of capecitabine and/or 5-FU should be investigated in further studies.
Journal Article