Single-dose Study Research Articles

A Single-Period, Single-Dose Study of the Pharmacokinetics of Epinephrine After Administration of Intranasal ARS-1 to Pediatric Subjects with a History of Systemic Allergic Reaction

An epinephrine nasal spray (ARS-1) is being developed as a needle-free alternative to autoinjectors for the emergency treatment of systemic allergic reactions including anaphylaxis in children and adults. This study aims to assess the pharmacokinetics of epinephrine after intranasal (IN) administration of ARS-1 in pediatric atopic allergy subjects.

Alternative Pharmacokinetic Metrics in Single-Dose Studies to Ensure Bioequivalence of Prolonged-Release Products at Steady State—A Case Study

(1) Background: this article investigates which PK metrics in a single-dose study (concentration at the end of posology interval, Cτ, partial areas under the curve, pAUCs, or half-value duration, HVD) are more sensitive and less variable for predicting the failure of a prolonged-release product at steady-state that was the bioequivalent for Cmax, AUC0-t and AUC0-inf, in the single-dose study; (2) Methods: a cross-over study was performed in 36 subjects receiving desvenlafaxine 100 mg prolonged-release tablets. Conventional (Cmax, AUC0-t and AUC0-inf) and additional (Cτ, pAUCs and HVD) PK metrics were considered after single-dose conditions. Predicted PK metrics at steady state (AUC0-τ, Cmax,ss, and Cτ,ss) were derived using a population PK model approach; (3) Results: the existing differences in the shape of the concentration-time curves precluded to show equivalence for Cτ,ss in the simulated study at steady state. This failure to show equivalence at steady state was predicted by Cτ, pAUCs and HVD in the single-dose study. Cτ was the most sensitive metric for detecting the different shape, with a lower intra-subject variability than HVD; (4) Conclusions: conventional PK metrics for single-dose studies (Cmax, AUC0-t and AUC0-inf) are not enough to guarantee bioequivalence at steady state for prolonged-release products.

Time-Action Profile of Technosphere Insulin in Children with Type1 Diabetes.

Technosphere insulin (TI) is aninhaled dry powder ultra-rapid-acting insulin. This report describes the results of the first study of TI in children with type1 diabetes (T1D). Pharmacokinetics (PK) of TI and the effect of TI on circulating glucose concentrations were evaluated in a single-arm study that enrolled children ages 8-17years with T1D for more than 1year, on a stable multiple daily insulin injection (MDI) regimen, and meeting pre-defined pulmonary function testing criteria (at least 70% predicted). To assess PK, subjects received an individualized single preprandial dose of TI (4-12U, in 4-U increments) via oral inhalation, basedon their usual meal-time subcutaneously injected rapid-acting insulin dose and meal content. Serum insulin and blood glucose were measured at -30 to 250min relative to dosing. Twenty-seven children with T1D participated in this single-dose PK study. Mean subject age was 13.3years (59% female; 81.5% White). Meanserum insulin Cmax (maximum concentration) was 77.3, 119.15, and 207.7µU/mL for doses of 4, 8, and 12U, respectively. Tmax occurred at 10.5, 13.9, and 14.6min post-dose for 4, 8, and 12U.Glucose lowering 30-60min post-dose was consistent with the PK profile. Serum insulin rapidly increased post-dose and returned to baseline by 120min. The data suggests the PK of TI in youth with T1D ages 8-17years was similar to that seen in previous adult studies. ClinicalTrials.gov identifier, NCT02527265.

Pharmacokinetic and pharmacodynamic properties of the novel basal insulin Fc (insulin efsitora alfa), an insulin fusion protein in development for once-weekly dosing for the treatment of patients with diabetes.

To assess the safety, tolerability, pharmacokinetics (PK) and pharmacodynamics (PD) of basal insulin Fc (BIF; LY3209590), a fusion protein combining a novel single-chain insulin variant together with human IgG2 Fc domain, following single and multiple once-weekly BIF administration. The single ascending dose, 15-day study assessed four BIF doses (5-35 mg) in healthy participants and people with type 2 diabetes (T2D). In the 6-week multiple ascending dose study, people with T2D, previously treated with basal insulin, received insulin glargine daily or a one-time loading dose of BIF followed by 5 weeks of once-weekly dosing (1-10mg). Safety, tolerability and PK and glucose PD were examined. Mean ages of people with T2D (N= 57) and healthy participants (N= 16) in the single-dose study were 58.4 and 35.8 years, respectively; mean body mass index values were 29.5 and 26.1kg/m2 . BIF had a PK half-life of approximately 17 days, which led to a sustained, dose-dependent decrease in fasting blood glucose for 5 days or longer. No severe hypoglycaemia was observed. The 6-week ascending dose study included 33 people with T2D aged 40-69 years. BIF showed a low peak-to-trough ratio of 1.14 after the last dose at week 6 (steady state). Over 6 weeks, BIF seven-point glucose profiles remained constant and were similar to insulin glargine. Rates and duration of BIF hypoglycaemic events were similar to insulin glargine. BIF was well tolerated and the PK/PD profile enabled once-weekly dosing with minimal variation in exposure in a treatment interval of 1week. The findings suggest BIF is suitable for further development as a weekly basal insulin in people with diabetes.

Effect of hesperetin on the pharmacokinetics of metoprolol succinate in rats

BackgroundMetoprolol is a substrate of CYP3A4, 2B6, CYP2D6, CYP2C9, and p-glycoprotein (p-gp). Hesperetin was reported as an inhibitor of cytochrome P-450 (CYP) enzymes and p-gp. The objective of this study was to investigate the effect of hesperetin on the pharmacokinetics of metoprolol in rats and in vitro models. In in vivo studies, male Wistar rats were treated with metoprolol (30 mg/kg) once a day for 15 consecutive days alone and in combination with hesperetin (25, 50, and 100 mg/kg). Blood samples were withdrawn from the tail vein on the 1st day in the single-dose pharmacokinetic study and on the 15th day in the repeated-dose pharmacokinetic study. In in vitro studies, metoprolol was incubated in the presence or absence of hesperetin and traditional p-gp inhibitors using rat-everted gut sacs. Reverse phase-high-performance liquid chromatography (RP-HPLC) was used to determine the amounts of metoprolol in the plasma and incubated samples (RP-HPLC).ResultsThe Cmax, AUC, and half-life (t1/2) of metoprolol significantly increased by twofold compared to the metoprolol group in rats pre-treated with hesperetin. The clearance and volume of distribution both decreased significantly. Metoprolol transport was dramatically increased in the presence of hesperetin and quinidine (standard p-gp inhibitor) in in vitro study.ConclusionThe present study results revealed that hesperetin significantly increased the absorption of metoprolol in rats and everted gut sacs in vitro might be due to the inhibition of CYP and p-gp.

Bioequivalence Study Comparing a Generic and Innovator Drug of Rosuvastatin 20 mg

The bioequivalence study was conducted to compare the bioavailability of two rosuvastatin 20 mg film-coated tablet formulations (test and reference formulation). This study was an open-label, randomized, single-dose, two-periods, twotreatments, and crossover study which included 32 healthy adult male and female subjects under fasting conditions. Each of the two study periods was separated by a 7 days washout period. A single oral dose of test or reference drug was administered to the subject in each period based on the randomization scheme. Plasma concentrations of the drug were determined by LC-MS/MS method. The pharmacokinetic parameters assessed in this study were the area under the plasma concentration-time curve from time zero to 72 h (AUC0-72h), area under the plasma concentration-time curve from time zero to infinity (AUC0-∞), the peak plasma concentration of the drug (Cmax), time needed to achieve the peak plasma concentration (Tmax), and the elimination half-life (T1/2). The geometric mean ratio (GMR) and 90% Confidence Interval (90% CI) for AUC0-72h and Cmax of test/reference drug for rosuvastatin were 97.05 % (89.07%– 105.74%) and 101.15% (89.53%– 114.26%). Since the 90% CI with α 0.05% for AUC0-72h and Cmax of rosuvastatin were within the standard bioequivalence range (80.00– 125.00%), it was concluded that the two rosuvastatin film-coated tablets (test and reference drug) were bioequivalence in terms of the rate and extent of absorption.

Genotoxic and mutagenic potential of 7-methylxanthine: an investigational drug molecule for the treatment of myopia

7-Methylxanthine (7-MX, CAS No. 552-62-5, purity 99.46%) is the first orally administered drug candidate, which showed anti-myopic activity in different pre-clinical studies. In the present study, we investigated the in-vivo genotoxic and mutagenic toxicity of 7-MX in Wistar rats using comet/single-cell gel electrophoresis, chromosomal aberration and micronucleus assays after oral administration. For the single-dose study (72 h), two doses of 7-MX 300 and 2000 mg/kg body weight were selected. For a repeated dose 28 d study, three doses (250, 500, and 1000 mg/kg) of 7-MX were selected. The doses were administered via oral gavage in the suspension form. Blood and major vital organs such as bone marrow, lung and liver were used to perform comet/single cell gel electrophoresis, chromosomal aberration, and micronucleus assays. The in-vitro Ames test was performed on TA98 and TA100 strains. In the chromosomal aberration study, a non-significant increase in deformities such as stickiness, ring chromosome, and endoreduplication was observed in bone marrow cells of 7-MX treated groups. These chromosomal alterations were observed upon treatment with doses of 2000 mg/kg single dose for 72 h and 1000 mg/kg repeated dose for 28 d. At a dose of 500 mg/kg, DNA damage in terms of tail length, tail moment, % tail DNA and the olive tail moment was also found to be non-significant in 7-MX treated groups. The Ames test showed the non-mutagenic nature of 7-MX in both strains of TA98 and TA100 of Salmonella typhimurium with or without metabolic activation. Thus, the present work is interesting in view of the non- genotoxicity and non-mutagenicity of repeated doses of 7-MX.

A Pharmacokinetic Study of Different Quercetin Formulations in Healthy Participants: A Diet-Controlled, Crossover, Single- and Multiple-Dose Pilot Study.

This study aimed to evaluate the blood concentrations of quercetin in healthy participants after the administration of different formulations in single- and multiple-dose phases. Ten healthy adults (males, 5; females, 5; age 37 ± 11 years) participated in a diet-controlled, crossover pilot study. Participants received three different doses (250 mg, 500 mg, or 1000 mg) of quercetin aglycone orally. In the single-dose study, blood concentrations (AUC0-24 and Cmax) of standard quercetin were compared with those of LipoMicel®-a food-grade delivery form of quercetin. In the multiple-dose study, blood concentrations of formulated quercetin were observed over 72 h, after repeated doses of LipoMicel (LM) treatments. The AUC0-24 ranged from 77.3 to 1128.9 ng·h/ml: LM significantly increased blood concentrations of quercetin by 7-fold (LM 500) compared to standard quercetin, when tested at the same dose, over 24 h (p < 0.001); LM administered at a higher dose (LM 1000) achieved 15-fold higher absorption (p < 0.001); LM tested at half a dose of standard quercetin increased concentration by approx. 3-fold (LM 250). Quercetin blood concentrations were attained over 72 h. The major metabolites measured in the blood were methylated, sulfate, and glutathione (GSH) conjugates of quercetin. Significant differences in concentrations between quercetin conjugates (sulfate vs. methyl vs. GSH) were observed (p < 0.001). Data obtained from this study suggest that supplementation with LipoMicel® is a promising strategy to increase the absorption of quercetin and its health-promoting effects in humans. However, due to the low sample size in this pilot study, further research is still warranted to confirm the observations in larger populations. This trial is registered with NCT05611827.

Pharmacokinetics of a Modified-Release Dexamphetamine Sulfate Formulation Following Single and Multiple Dosing in Healthy Adults: Comparative Bioavailability with Immediate-Release Dexamphetamine Sulfate, between Strengths, Assessment of Food and Meal Composition Effects.

A modified-release dexamphetamine sulfate formulation (DEX-MR) is under development for the treatment of attention-deficit/hyperactivity disorder. We investigated the bioequivalence of once-daily DEX-MR to twice-daily immediate-release dexamphetamine sulfate (DEX-IR) after single and multiple dosing and between strengths, and effects of food and meal types. Three randomized, open-label, crossover studies in healthy males were conducted. In the single-dose study, participants received DEX-MR 20 mg, DEX-MR 10 mg (20 mg dose), and twice-daily DEX-IR 10 mg under fasted conditions and after a high-fat, high-calorie breakfast. In the breakfast study, participants received DEX-MR 20 mg and twice-daily DEX-IR 10 mg after a normocaloric and a high-fat, high-calorie breakfast. In the multiple-dose study, participants received DEX-MR 20 mg and twice-daily DEX-IR 10 mg for seven days each. In the run-in period (five days), participants consumed a normocaloric breakfast; on profile days, participants consumed a normocaloric breakfast (day 6) or a high-fat, high-calorie breakfast (day 7). Once-daily DEX-MR at a dose of 20 mg was bioequivalent to twice-daily DEX-IR 10 mg after single dosing under fasted and fed conditions and after multiple dosing under fed conditions. DEX-MR 10 mg and DEX-MR 20 mg were bioequivalent when administered as a single 20 mg dose. Food slightly reduced the rate and extent of absorption of DEX-MR and delayed the time to peak plasma concentration (tmax) by approximately two hours compared to the fasted state. Bioavailability of DEX-MR was comparable under different meal conditions (normocaloric vs. high-fat, high-calorie breakfast) both after single and multiple dosing. Bioequivalence of once-daily DEX-MR and twice-daily DEX-IR was established. 1×2 DEX-MR 10 mg was bioequivalent to 1×1 DEX-MR 20 mg. DEX-MR should be administered with/after a meal to achieve the targeted pharmacokinetic profile (delayed tmax). Bioavailability of DEX-MR is not affected by meal composition (i.e., fat and caloric content).

Phytochemical Screening, Toxic Effects, and Antimicrobial Activity Studies of Digitaria abyssinica (Hochst. ex A.Rich.) Stapf (Poaceae) Rhizome Extracts against Selected Uropathogenic Microorganisms.

In Kenya, the D. abyssinica rhizome's decoction is traditionally used to treat urinary tract infections (UTIs), mainly gonorrhea and candidiasis. UTIs are the most severe public health problems that affect over one hundred and fifty million people worldwide annually. They are caused by a wide range of microorganisms where Escherichia coli is known to be the main causative pathogen. Medicinal plants are used in traditional Kenya set up for treatment and most recently as an alternative source of treatment for UTIs due to the increased cost of treatment and many challenges experienced with antibiotic therapy. The current study is designed to investigate the phytochemical composition, acute oral toxicity, and antimicrobial activity of Digitaria abyssinica rhizome extracts against Staphylococcus aureus, Escherichia coli, Neisseria gonorrhea, and Candida albicans. The rhizomes of D. abyssinica were obtained, dried, ground, and extracted using water and organic solvents. The phytochemical assay was carried out using standard phytochemical screening methods. Single-dose toxicity studies were done to determine LD50 while disk diffusion and microbroth dilution techniques were used to determine antimicrobial activity. Results revealed that saponins, phenolics, alkaloids, cardiac glycosides, tannins, flavonoids, steroids, and terpenes were present in the powder, aqueous, methanol, and dichloromethane : methanol extracts. All the extracts had an LD50 of above 2,000 mg/kg of body weight and there was no observation of behavioral changes. Also, the aqueous and methanol extracts revealed antifungal activity against Candida albicans with the lowest average minimum zone of inhibition at MIC of 31.25 mg/ml. The study did not reveal antibacterial activity for any extract against the studied uropathogenic bacteria, Staphylococcus aureus, Escherichia coli, and Neisseria gonorrhoeae. The results from the current study suggested that D. abyssinica rhizome aqueous and methanol extracts have potential antifungal activity against C. albicans, thus validating the folklore of its use to treat candidiasis.

Pharmacokinetics, safety and tolerability of valbenazine in Korean CYP2D6 normal and intermediate metabolizers.

Valbenazine is a selective vesicular monoamine transporter 2 (VMAT2) inhibitor approved for tardive dyskinesia treatment by the US Food and Drug Administration; its major active metabolite (NBI-98782) is a 45-fold more potent inhibitor of VMAT2 than the parent drug. This study aimed to evaluate the pharmacokinetics (PKs), safety, and tolerability and the effect of cytochrome P450 2D6 (CYP2D6) genotypes to the PKs after the administration of valbenazine in Korean participants. A randomized, double-blind, placebo-controlled, single- and multiple-dose study was conducted in healthy Korean male participants. The single-dose study was conducted for both 40 and 80 mg valbenazine and the multiple dose study was conducted for 40 mg. After a 1-week washout, the 40 mg dose group participants received valbenazine 40 mg or placebo once daily for 8 days. Serial blood samples were collected up to 96 h postdose for PK analysis. The CYP2D6 genotypes of the participants were retrospectively analyzed. A total of 50 participants were randomized, and 43 and 20 participants completed the single- and multiple-dose phases of the study, respectively. After single doses, the PK characteristics of valbenazine and its metabolites were similar between the 40 and 80 mg dose groups. After multiple doses, the mean accumulation ratios of valbenazine and NBI-98782 were ~1.6 and 2.4, respectively. Plasma concentrations of valbenazine and NBI-98782 were similar between CYP2D6 normal and intermediate metabolizers. Valbenazine was well-tolerated in healthy Koreans, and its PK characteristics were similar to results previously reported in Americans.

A novel drug-like water-soluble small molecule Focal Adhesion Kinase (FAK) activator promotes intestinal mucosal healing

Non-steroidal anti-inflammatory drugs (NSAIDs) injure the proximal and distal gut by different mechanisms. While many drugs reduce gastrointestinal injury, no drug directly stimulates mucosal wound healing. Focal adhesion kinase (FAK), a non-receptor tyrosine kinase, induces epithelial sheet migration.We synthesized and evaluated a water-soluble FAK-activating small molecule, M64HCl, with drug-like properties. Monolayer wound closure and Western blots measured migration and FAK phosphorylation in Caco-2 ​cells, in vitro kinase assays established FAK activation, and pharmacologic tests assessed drug-like properties. 30 ​mg/kg/day M64HCl was administered in two murine small intestine injury models for 4 days.M64HCl (0.1–1000 ​nM) dose-dependently increased Caco-2 FAK-Tyr 397 phosphorylation, without activating Pyk2 and accelerated Caco-2 monolayer wound closure. M64HCl dose-responsively activates the FAK kinase domain vs. the non-salt M64, increasing the Vmax of ATP-binding. Pharmacologic tests suggested M64HCl has drug-like properties and is enterally absorbed. M64HCl 25 ​mg/kg/day continuous infusion promoted healing of ischemic jejunal ulcers and indomethacin-induced small intestinal injury in C57Bl/6 mice. M64HCl-treated mice exhibited smaller ulcers 4 days after ischemic ulcer induction or indomethacin injury. Renal histology and plasma creatinine were normal. Mild hepatic inflammatory changes and ALT elevation were similar among M64HCl-treated mice and controls. M64HCl was concentrated in kidney and gastrointestinal mucosa and functional nephrectomy studies suggested predominantly urinary excretion. Little toxicity was observed in vitro or in single-dose mouse toxicity studies until >1000x higher than effective concentrations. M64HCl, a water-soluble FAK activator, promotes epithelial restitution and intestinal mucosal healing and may be useful to treat gut mucosal injury.

Comparative Bioavailability and Benefits on Mental Functions of Novel Extended-Release Caffeine Capsules against Immediate-Release Caffeine Capsules: An Open-Label, Randomized, Cross-over, Single-Dose Two-Way Crossover Study

Present study aimed compared pharmacokinetic profile of sustained-release CaffXtend® capsules (SR-Caffeine) with immediate-release caffeine capsules (IR-Caffeine), and the effect of SR-caffeine on memory, motivation, concentration, and attention. This open-label, randomized, single-dose, two-treatment, two-sequence, two-period, two-way crossover oral bioavailability study block randomized (1:1) healthy subjects (N = 15) to receive SR-Caffeine (200 mg) and IR-Caffeine (200 mg). Blood samples were collected at 0.25, 0.50, 0.75, 1, 1.5, 2, 3, 4, 5, 6, 8, 10, 12, 24, 36 and 48 h in each period. Primary study outcome included comparing relative bioavailability of SR-Caffeine 200 mg and IR-Caffeine 200 mg under fasting conditions, and changes in caffeine research visual analogue scale (Caff-VAS) scores (‘relaxed’, ‘alert’, ‘jittery’, ‘tired’, ‘tense’, ‘headache’, ‘overall mood’ and ‘mentally fatigued’) were also evaluated. Fifteen subjects completed the study. Mean tmax was 4.08 ± 2.13h for SR-Caffeine compared to 0.83 ± 0.39h for IR-Caffeine, (p < 0.0001). Similarly, mean t½ was 7.07 ± 3.48h for SR-Caffeine compared to 5.78 ± 2.11h for IR-Caffeine (p = 0.04189). However, total exposure was similar for SR-Caffeine and IR-Caffeine (90% CI: 89.89–120.50% to 94.49–123.82% for geometric least square mean of ln-transformed AUC0-t and AUC0-∞). In the Caff-VAS evaluation, the SR-Caffeine group showed significantly better scores for ‘jitteriness’, ‘tiredness’, ‘alertness’ and ‘overall mood’ for 8–12 h than the IR-Caffeine group. No adverse events were reported. Results demonstrated sustained release of caffeine over 24 h from SR-Caffeine as compared to IR-Caffeine, which showed significant improvements in the scores for ‘relaxed’, ‘alertness’ and ‘overall mood’ and significantly lower scores for the parameters-‘jittery’ and ‘tired’ for extended period. Clinical trial registration: CTRI/2021/06/034185

652: OXYGENATOR IMPACT ON REMDESIVIR IN EXTRACORPOREAL MEMBRANE OXYGENATION CIRCUITS

Introduction: Extra-corporeal membrane oxygenation (ECMO) is a treatment modality known to alter drug pharmacokinetics (PK). The PK changes can result from drug binding to the oxygenator, alterations in clearance, and drug adsorption or sequestration. Levels of drug absorption by polymers, silicone rubber and other materials have been linked to the drugs’ lipophilicity and the published literature is mostly outdated. Additionally, there is limited data regarding the impact of the oxygenator on drug changes in ECMO circuits in comparison to the other components of the ECMO circuit. The purpose of this study was to determine the impact of the Quadrox-i pediatric and adult oxygenators on the PK of remdesivir (RDV) in contemporary ECMO circuits. Methods: One 1/4-in. and one 3/8-in. closed loop ECMO circuits were prepared using custom tubing with polyvinylchloride and superTygon® (Medtronic Inc., Minneapolis, MN) and a Quadrox-i adult or pediatric oxygenator (Maquet). Additionally, one 1/4-in. and one 3/8-in. closed loop ECMO circuits were assembled without an oxygenator in series. RDV was added to the circuit and levels were obtained pre-and post-oxygenator at the following time intervals; 5 mins, 1, 2, 3, 4, 5, 6, 8, 12, and 24 hrs. RDV was also maintained in a glass vial and samples obtained at the same time periods for control purposes. RDV samples were analyzed by liquid chromatography tandem mass spectrometry. Results: For the 3/8-in. circuit with and without an oxygenator, there was a 60-70% RDV loss during the study period. For the 1/4-in. circuits with an oxygenator, there was a 35-60% RDV loss during the study period. For the 1/4-in. circuits without an oxygenator, there was a 5-20% RDV loss during the study period. Conclusions: There was RDV loss within the circuit during the study period and the RDV loss was more pronounced with the larger 3/8-in circuit when compared with the 1/4-in. circuit. This preliminary data suggests RDV dosing may need to be adjusted for concern of drug loss via the ECMO circuit. Additional single and multiple dose studies are needed to validate these findings.

Bioencapsulation is a feasible method of terbinafine administration in Emydomyces testavorans-infected western pond turtles (Actinemys marmorata).

To evaluate the pharmacokinetics of terbinafine administered to western pond turtles (Actinemys marmorata) via oral gavage and bioencapsulated in earthworms. 7 western pond turtles. A randomized complete crossover single-dose pharmacokinetic study was performed. Compounded terbinafine (25 mg/mL; 30 mg/kg) was administered through oral gavage (OG) directly into the stomach or bioencapsulated (BEC) into an earthworm vehicle. Blood (0.2 mL) was drawn from the jugular vein at 0, 0.5, 1, 2, 4, 8, 12, 24, 48, 72, and 120 hours after administration. Plasma terbinafine levels were measured using high-performance liquid chromatography. Peak plasma terbinafine concentrations of 786.9 ± 911 ng/mL and 1,022.2 ± 911 were measured at 1.8 ± 2.8 and 14.1 ± 12.3 hours after OG and BEC administration, respectively. There was a significant (P = .031) increase in area under the curve with BEC compared to OG. Using steady-state predictions, with once-daily terbinafine administration, 3/7 and 7/7 turtles had plasma concentrations persistently greater than the minimum inhibitory concentration (MIC) for Emydomyces testavorans for the OG and BEC administration routes of administration, respectively. With administration every 48 hours, 3/7 turtles for the OG phase and 6/7 turtles for the BEC phase had concentrations greater than the E. testavorans MIC throughout the entire dosing interval. Administration of terbinafine (30 mg/kg) every 24 or 48 hours via earthworm bioencapsulation in western pond turtles may be appropriate for the treatment of shell lesions caused by E. testavorans. Clinical studies are needed to assess the efficacy of treatment.

Comparison of Pyrrolobenzodiazepine Dimer Bis-imine versus Mono-imine: DNA Interstrand Cross-linking, Cytotoxicity, Antibody-Drug Conjugate Efficacy and Toxicity.

Antibody-drug conjugates (ADC) delivering pyrrolobenzodiazepine (PBD) DNA cross-linkers are currently being evaluated in clinical trials, with encouraging results in Hodgkin and non-Hodgkin lymphomas. The first example of an ADC delivering a PBD DNA cross-linker (loncastuximab tesirine) has been recently approved by the FDA for the treatment of relapsed and refractory diffuse large B-cell lymphoma. There has also been considerable interest in mono-alkylating PBD analogs. We conducted a head-to-head comparison of a conventional PBD bis-imine and a novel PBD mono-imine. Key Mitsunobu chemistry allowed clean and convenient access to the mono-imine class. Extensive DNA-binding studies revealed that the mono-imine mediated a type of DNA interaction that is described as "pseudo cross-linking," as well as alkylation. The PBD mono-imine ADC demonstrated robust antitumor activity in mice bearing human tumor xenografts at doses 3-fold higher than those that were efficacious for the PBD bis-imine ADC. A single-dose toxicology study in rats demonstrated that the MTD of the PBD mono-alkylator ADC was approximately 3-fold higher than that of the ADC bearing a bis-imine payload, suggesting a comparable therapeutic index for this molecule. However, although both ADCs caused myelosuppression, renal toxicity was observed only for the bis-imine, indicating possible differences in toxicologic profiles that could influence tolerability and therapeutic index. These data show that mono-amine PBDs have physicochemical and pharmacotoxicologic properties distinct from their cross-linking analogs and support their potential utility as a novel class of ADC payload.

Evaluation of toxic effects of Coleus forskohlii extract on various body organs of experimental animals-rats

Background: The study aimed observation of pharmacological actions and any adverse effects on various body organs of rats with Coleus forskohlii (CF) extract. Aims and Objectives: The present study was undertaken to evaluate toxic effects of CF extract in experiments animals. Materials and Methods: In the single-dose oral toxicity study, groups of five healthy male and female rats were dosed orally with CF extract at 2000mg/kg BW as per organization of economic cooperation and development guidelines and were observed once daily for 14 consecutive days for toxicity, general behavior, and pharmacological effects. In sub-acute oral toxicity, the test substance was administered for 28 days with daily doses of 200, 400, and 800 mg/kg body weight. In subacute oral toxicity study, groups of five male and five female rats were subjected to 10% forskolin for 28 days. Initially autonomic symptoms (gross behavioral study), followed by hematological, biochemical, and histological parameters, were evaluated. Results: No deaths were reported in all the toxicity studies performed. No significant changes were observed in the hematology and serum biochemistry values from the control group animals. The body weight changes and necropsy results were normal. There was no apparent progression of organ damage in any of these toxicity tests. Furthermore, CF extract did not produce any significant toxic effects in Wistar rats at 2000 mg/kg body weight and had no potential to induce organ damage. Conclusion: The “no observed adverse effect level” of CF extract was determined up to 2000 mg/kg.

A Phase 1/1b Multicenter Ascending Dose Study to Evaluate the Safety of HA-1 Minor Histocompatibility Antigen-Reactive TCR-Modified T Cells (BSB-1001) in Patients Undergoing HLA-Matched Allogenic Hematopoietic Stem Cell Transplant (alloSCT) for MRD+ AML or ALL or Poor/Very Poor Risk MDS

Background: AlloSCT can cure patients with acute leukemia and high-risk myelodysplastic syndromes (MDS). However, post-transplant relapse remains the greatest single cause of post-transplant death, occurring in up to 80% of high-risk patients. In HLA-matched alloSCT, alloreactive donor T cells target minor histocompatibility antigens (miHAs), which are peptide products of coding polymorphisms that distinguish recipients from donors. These alloreactive T cells can target leukemic cells, mediating the graft-vs-leukemia (GVL) effect; unfortunately, they also can cause graft-vs-host disease (GVHD). Pre-clinical mouse models (Blood, 2011) demonstrate that CD8+ T cells that target miHAs with expression limited to hematopoietic cells can mediate GVL without causing GVHD. To translate this concept for how to safely augment GVL to the clinic, BlueSphere Bio (BSB) used its high throughput T cell receptor (TCR) discovery and characterization platforms to clone a panel of TCRs reactive against the HLA-A*02-restricted miHA, HA-1, which is expressed mostly in hematopoietic cells. These receptors were cloned from a multiparous A*02:01 HA-1- woman who was immunized to HA-1 through pregnancy. A high affinity TCR specific for HA-1 and not reactive against allogeneic HLA molecules was chosen to create a cellular therapeutic designed to mediate GVL and enhance donor engraftment with a lower risk for GVHD, relative to polyclonal donor T cells. The anti-HA-1 T cell product (BSB-1001) is composed of donor CD8+ T cells transduced with a lentivirus vector encoding the anti-HA-1 TCR and the RQR8 tag, which expresses an epitope from CD20, thereby enabling the in vivo killing of BSB-1001 cells with rituximab. CRISPR-cas9 editing of the CD8+ T cells deletes the endogenous TCRα and β chains with >95% efficiency. This increases expression of the TCR and reduces risk of GVHD caused by native TCRs, as well as possible off-target reactivities generated by pairing of endogenous and introduced TCR chains. BSB-1001 cells specifically kill HLA-A*02:01, HA-1+ targets, with no activity against cells that are HLA-A*02:01+ but HA-1-, or cells that are HA-1+ but are HLA-A*02:01-. BSB-1001 is also not reactive against a panel of B lymphoblastic cell lines (LCL) expressing allogeneic HLA molecules. Importantly, efficient target killing is seen at effector:target ratios as low as 0.1, and maintained after several rounds of ex-vivo expansion following target cell challenge, a likely predictor of potency and persistence in vivo. Study Design: The first in human Phase 1/1b study is a multicenter, open-label, single dose study with a 3+3 ascending design with the option to expand accrual at a promising dose. Subjects must have ALL, AML or high-risk MDS with evidence of disease after the last therapy, be HLA-A*02:01 HA-1+ and have a 10/10 HLA-matched HA-1- related or unrelated donor. GCSF-mobilized donors will undergo leukapheresis. From this product, a small fraction of cells will be removed for BSB-1001 manufacturing; the remainder will undergo CD34-selection and cryopreservation until SCT. After BSB-1001 manufacturing is complete, patients will undergo ablative conditioning (choice of three regimens), followed by infusion of the CD34-selected cells and then BSB-1001. Patients will not receive anti-T cell antibodies and will receive no prophylactic pharmacologic immunosuppression. Subjects must otherwise be suitable for ablative conditioning using standard criteria. The primary objective is to establish a recommended dose of BSB-1001 based on its dose-limiting toxicities and the magnitude of post-infusion BSB-1001 expansion. The primary endpoint is determining the incidence of treatment-emergent adverse events, including dose-limiting toxicities. Additional endpoints include rates of engraftment, incidences of cytokine release syndrome (CRS) and acute and chronic GVHD, quantitation of malignant hematopoiesis and lineage-specific donor chimerism. CRS and GVHD, should they occur, will be treated per institutional standards. Rituximab can be administered to kill BSB-1001 cells in case of refractory CRS or GVHD. Enrollment is anticipated to begin in 1Q2023. BSB is also developing panels of TCRs targeting additional relatively hematopoietically-restricted miHAs with prioritization based on the frequencies of the restricting HLAs and the immunogenic/nonimmunogenic miHA alleles.

Pharmacokinetics and Pharmacodynamics of Nipocalimab Administered at Different Rates of Intravenous Infusion in Healthy Participants: Results of a Phase 1 Placebo-Controlled Single-Dose Study

Background: Warm autoimmune hemolytic anemia (wAIHA) is a rare autoimmune condition driven by autoantibodies that can significantly impact a patient's quality of life. wAIHA is characterized by the premature destruction of red blood cells (RBCs) in the presence of autoantibodies which preferentially bind to RBCs at 37°C. There is currently no approved treatment for wAIHA. Patients with severely symptomatic anemia are typically managed with corticosteroids and rituximab, both of which are associated with potential relapse and adverse events. Nipocalimab, which is in clinical development for the treatment of wAIHA (NCT04119050), is a fully human, aglycosylated, effectorless IgG1 monoclonal antibody that targets the IgG binding site on the neonatal Fc receptor (FcRn) with high affinity to lower circulating IgG levels. This study assessed the pharmacokinetics (PK) and pharmacodynamics (PD) of single doses of nipocalimab administered at different IV infusion rates in healthy adults to support the potential use of shortened infusions in future studies. Nipocalimab was generally safe and well-tolerated at all doses and infusion rates; detailed safety results have been presented separately [Leu JH, et al. EHA 2022. Presentation P1534]. Methods: The trial was a single dose, sequential, randomized, double-blind, placebo-controlled, escalating dose and infusion rate study. Eligible participants were males or females aged 18-55 years with no clinically significant medical or physical conditions. Participants were randomized to 1 of 5 cohorts (n=8 per cohort [6 nipocalimab, 2 placebo]) to receive nipocalimab 30 mg/kg IV infused over 60, 30, 15 or 7.5 min (0.5, 1, 2, or 4 mg/kg/min), nipocalimab 60 mg/kg IV infused over 15 min (4 mg/kg/min) or matching placebo. Escalation to the next dose level was permitted following review by a safety monitoring committee. Pharmacokinetic sampling of nipocalimab was conducted predose, midpoint of infusion (MOI), end of infusion (EOI), EOI + 0.083h, EOI + 0.25h, EOI + 1h, start of infusion + 24h, Day 8, and Day 15 postdose; MOI and EOI varied for each dose. In terms of PD, total serum IgG was assessed. Results: A total of 40 participants (70% female, 93% white) received study drug, of which 30 were included in the PK analysis; 39 completed the study. Mean serum nipocalimab concentration-time profiles were similar following all 30 mg/kg doses regardless of infusion rate; mean serum concentrations were ~2 times higher following a 60 mg/kg infusion. Nipocalimab remained detectable up to ~169 hours postdose for 30 mg/kg groups and ~337 hours postdose for the 60 mg/kg group. Geometric mean peak (Cmax) and overall exposure (AUC) to nipocalimab were unaffected by infusion rate when administered at 30 mg/kg. Following a 60 mg/kg infusion, AUCs were 2.4-2.8 times higher and Cmax was 2.0-2.2 times higher than with 30 mg/kg infusions. Median Tmax was approximately at EOI following the 60 mg/kg infusion. Mean half-life (t½) values were similar in all treatment groups. In terms of total serum IgG, changes from baseline were decreased among all nipocalimab cohorts at all postdose time points. The maximum decrease in mean serum IgG levels was 79% at day 15 with nipocalimab 60 mg/kg. Conclusion: Nipocalimab Cmax and AUC were not affected by infusion rates when given at a dose of 30 mg/kg, but Tmax was delayed at the fastest infusion rates. Following the 60 mg/kg infusion, peak and overall nipocalimab exposures were 2-2.8 times higher than following 30 mg/kg infusions.

Evaluation of Dosage and Food Effect on L-Glutamine Exposure for Sickle Cell Anemia: A Population Pharmacokinetic Analysis

Introduction: L-glutamine (Endari®) is an amino acid approved for the treatment of sickle cell disease (SCD). The mechanism of action of L-glutamine in SCD is not fully understood but believed to involve, at least partly, augmentation of the de novo synthesis of intracellular glutathione, which can protect sickle erythrocytes from oxidant injury. As an endogenous compound, the pharmacokinetics (PK) of L-glutamine have not been extensively studied, and currently recommended dosing is based on single-dose studies. It is also unclear how physiology, food intake, and dose impact L-glutamine drug exposure in patients with SCD. Our objective was to understand the PK of multiple dose L-glutamine therapy using a population PK analysis to identify factors that may inform optimal dosing of L-glutamine in children and adults with SCD. Methods: A total of 400 L-glutamine plasma concentration-time data points collected from 12 participants (NCT04684381) were available for population PK analysis. Each participant received 3 ascending oral doses (0.1 and 0.3 g/kg given BID and 0.6 g/kg given once daily) during a four-week study. Plasma L-glutamine and other amino acid levels were obtained before and after oral L-glutamine doses at each visit and quantified by ion exchange chromatography. Population PK analysis was performed using nonlinear mixed effect modeling by NONMEM 7.4 (ICON, Ellicott City, MD, USA). Multiple base model structures including one-compartment and two-compartment models were explored to describe the L-glutamine PK. In addition to the primary PK parameters clearance (CL/F) and volume of distribution (V/F), a relative bioavailability (F) was included in the modeling to account for the potential impact of dose and food on L-glutamine PK. Patient demographics and laboratory data, including body weight, body surface area, age, serum creatinine levels, urine creatinine levels, baseline glutamine level, meal intake, and dosages were evaluated as potential covariates using the stepwise selection method. The change in the objective function value (OFV) between two nested models was assumed to follow the χ2 distribution and was tested at a significance level of <0.01 (-6.64 points in OFV). The final model was evaluated by goodness-of-fit (GOF) plots and visual predictive check (VPC) analysis. For the VPC analysis, one thousand replicates of simulated datasets were generated using the final model, and the distribution of simulated observations was compared with the actual observations. Results: A one-compartment with first-order absorption model best described the oral dose L-glutamine concentration-time profiles. The data did not support the inclusion of a lag time in drug absorption, which is consistent with the observed rapid absorption. In accordance with allometric theory, body size was found to be significantly correlated with glutamine oral clearance (CL/F; where F represents bioavailability, which is not measured and therefore unknown) and volume of distribution (V/F). We therefore used allometrically scaled body weight to account for differences in body size. Dose-normalized peak concentration (Cmax) decreased with dose escalation (Figure 1), indicating capacity-limited, non-linear PK of oral L-glutamine. Covariate analysis identified that baseline glutamine levels and dosages negatively correlated with glutamine clearance, whereas food intake did not significantly impact glutamine clearance. Higher doses decreased the relative bioavailability of oral glutamine, again indicating a non-linear saturable absorption. Model evaluation indicated no systemic bias (Figure 2). The estimates of L-glutamine oral clearance and volume of distribution were 66 L/h/70 kg and 140 L/70 kg, respectively. Conclusions: This is the first report of a population PK analysis of L-glutamine in patients with SCD. We identified that higher baseline glutamine levels and higher doses were associated with lower L-glutamine clearance. In addition, increased doses reduced relative bioavailability, indicating that higher doses (>0.3 g/kg) may not provide higher drug concentrations. Food intake did not have a significant influence on glutamine clearance, implying that L-glutamine can be taken with or without food. Our findings will help to inform optimized dosing of L-glutamine for patients with SCD and potentially permit individualized PK-guided dosing to maximize treatment benefits. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal