Single-dose Pharmacokinetic Study Research Articles

464 Creating Pragmatic Tools for Reliable Kidney Function Measurement in Patients with Kidney Impairment

OBJECTIVES/GOALS: Estimating kidney function for drug dosing poses safety and efficacy concerns with critical medications. This study aims to develop a pragmatic method for measuring kidney function, ensuring that critical clinical decision points based on kidney function are universally applicable to all patients, leading to improved health outcomes. METHODS/STUDY POPULATION: This is a single-dose pharmacokinetic (PK) study to evaluate the concordance between iopamidol- and iohexol-measured glomerular filtration rate (mGFR), as determined by their respective serum clearances, in a cohort of 24 adults with varying kidney function. Participants with estimated glomerular filtration rates (CKD-EPI eGFRcr) ranging from >30 to 120 mL/min will be recruited from the Michigan Medicine health system. Enrolled participants will be stratified into 3 kidney function groups based on conventual kidney dosing considerations. IV micro doses of iohexol and iopamidol will be administered, followed by blood sampling. PK analysis will be used to compare the clearance of these substances. The agreement between iohexol and iopamidol in measuring GFR will be assessed via bioequivalence analysis. RESULTS/ANTICIPATED RESULTS: We expect no statistically significant difference between iopamidol and iohexol CL due to the high similarity of iopamidol and iohexol molecular and PK properties. We also expect that the ordinary least square regression analysis of iopamidol mGFRand iohexol mGFR will show limited variability across GFR measurements. These expected results will support the use of iopamidol as a marker of mGFR and its interchangeability with the gold standard iohexol. DISCUSSION/SIGNIFICANCE: Addressing eGFR errors is crucial for accurately dosing critical medications. This study aims to develop a novel mGFR methodology that accommodates various kidney function levels. This will enable precision dosing and streamline clinical trials. It also eliminates biological variability, enhancing generalizability and health outcomes.

Pharmacokinetic Modeling to Guide Preclinical Development of an Islatravir-Eluting Reservoir-Style Biodegradable Implant for Long-Acting HIV PrEP.

Long-acting injectable cabotegravir is more effective than daily oral PrEP at preventing HIV transmission due to improved adherence, but requires bi-monthly large-volume intramuscular injections. Subcutaneous (SC) contraceptive implants can be formulated with antiretrovirals for extended-duration HIV PrEP. Islatravir (ISL) is a first-in-class, investigational antiretroviral with pharmacologic properties well-suited for implant delivery. We performed preclinical studies for the development of a reservoir-style, poly(ε-caprolactone) ISL-eluting implant by conducting a single-dose SC ISL dose-ranging pharmacokinetic (PK) study of 0.1, 0.3, and 1 mg/kg in adult Wistar rats. Non-compartmental analysis was conducted, and dose proportionality assessed for ISL plasma and intracellular islatravir-triphosphate (ISL-tp). Population PK models estimated ISL's unit impulse response to deconvolve ISL-implant in vivo absorption rate (mg/day) and cumulative mass (mg) from published rat plasma PK (n = 10). Drug release was interpreted using four kinetic models. Dose proportionality was affirmed for ISL and ISL-tp. A first-order, two-compartment model fitted the SC ISL bolus data. Mean (SD) absorption rate from 0 to 154 days was 0.072 ± 0.024 mg/day, and cumulative mass at 154 days was 8.67 ± 3.22 mg. ISL absorption was well-described by zero-order (r2 = 0.95) and Ritger-Peppas (r2 = 0.98). Our zero-order ISL-release poly(ε-caprolactone) implant is projected to achieve clinical PK above ISL-tp's PrEP efficacy threshold. Continued development for HIV PrEP applications is warranted.

Mixing energy as an adjustment tool for aerodynamic behaviour of an inhaled product: In-vitro and in-vivo effects

This paper describes the development of a fixed dose dry powder combination of indacaterol maleate (Inda) and glycopyrronium bromide (Glyco) in Easyhaler® inhaler for a comparative pharmacokinetic (PK) study, as well as the outcome of such a study. The development aim was to produce formulations with three different in vitro dispersibility profiles for both Inda and Glyco. This so-called ‘rake’ approach allows for quantitation of the candidate formulations relative to the reference product Ultibro® Breezhaler® in terms of the key PK parameters.Three formulations (A, B and C) were produced based on the mixing energy concept. For both APIs, formulation A (lowest mixing energy) displayed the highest fine particle fractions and formulation C (highest mixing energy) the lowest. GMP manufacturing confirmed the performance of the three formulations.The candidate formulations were tested against the reference product in a single dose PK study in healthy volunteers. Clear differences in Inda plasma concentration profiles were observed between the treatments when administered concomitantly with charcoal, with Easyhaler A showing the highest Cmax value and Easyhaler C the lowest. Easyhaler B was bioequivalent to Ultibro Breezhaler with regard to the primary PK parameters of Inda, Cmax and AUC72h. For Glyco, Easyhaler formulations A, B and C provided lower peak concentrations than Ultibro Breezhaler. For AUC72h of Glyco, Easyhaler B was bioequivalent to the reference product. Additional measures for adjustment of formulation performance can be foreseen, whose effects can be predicted based on mixing energy theory.

Multi-dose enteral L-citrulline administration in premature infants at risk of developing pulmonary hypertension associated with bronchopulmonary dysplasia

ObjectiveInformation is needed to guide the design of randomized controlled trials (RCTs) evaluating L-citrulline therapy for premature infants with pulmonary hypertension associated with bronchopulmonary dysplasia (BPD-PH). Based on our single-dose pharmacokinetic study, we evaluated the ability of a multi-dose enteral L-citrulline strategy to achieve a target trough steady-state L-citrulline plasma concentration and its tolerability in premature infants.Study DesignPlasma L-citrulline concentrations were measured in six premature infants receiving 60 mg/kg L-citrulline every 6 h for 72 h before the first and last L-citrulline doses. L-citrulline concentrations were compared to concentration-time profiles from our previous study.ResultsTarget trough plasma L-citrulline concentrations were achieved in 2/6 subjects. No serious adverse events occurred.ConclusionsMulti-dose L-citrulline was well tolerated. These results will assist in the design of phase II RCTs evaluating L-citrulline dosage strategies to achieve target plasma L-citrulline concentrations in infants at risk for BPD-PH. Clinical trials.gov ID: NCT03542812

Absorption of an engineered medium-chain fatty acid analogue in two short bowel syndrome minipig models.

Enteral drug therapy is challenging in short bowel syndrome with intestinal failure (SBS-IF) because of unpredictable absorption. SEFA-6179 is an enterally administered medium-chain fatty acid analogue under development for intestinal failure-associated liver disease. We investigate the pharmacokinetics of two SEFA-6179 formulations in two large-animal models of SBS-IF, including a new pseudojejunostomy model. Twenty Yucatan minipigs were obtained. Half underwent pre-resection pharmacokinetic study with single-dose SEFA-6179 administration. All minipigs then underwent 90% jejunoileal resection, with either a jejunoileal anastomosis or bypass of the intraperitoneal colon with anastomosis just proximal to the rectum (pseudojejunostomy). On postoperative day 3, a single-dose pharmacokinetic study was performed. Both SBS-IF models were well tolerated. Compared with the jejunoileal anastomosis minipigs, pseudojejunostomy minipigs had a more severe malabsorptive phenotype with weight loss by postoperative day 4 (+0.1 vs -0.9 kg, P = 0.03) and liquid diarrhea (Bristol 5 vs Bristol 7, P = 0.0007). Compared with pre-resection minipigs, both jejunoileal and pseudojejunostomy minipigs had lower total plasma exposure of SEFA-6179 measured by area under the curve (jejunoileal: 37% less, P = 0.049; pseudojejunostomy: 74% less, P = 0.0001). Peak plasma concentration was also lower in the pseudojejunostomy group compared with pre-resection (65% less, P = 0.04), but not lower in the jejunoileal group (P = 0.47). In two SBS-IF minipig models, SEFA-6179 had substantially decreased absorption compared with pre-resection minipigs. Dose optimization for different intestinal anatomy and function may be required. We describe a new SBS-IF pseudojejunostomy model that may improve the translation of preclinical research to patients with SBS-IF who have enterostomies.

A phase I, randomized, double-blind, single-dose pharmacokinetic study to evaluate the biosimilarity of SB16 (proposed denosumab biosimilar) with reference denosumab in healthy male subjects

ABSTRACT Background SB16 is a biosimilar to reference denosumab (DEN). This study assessed pharmacokinetic (PK) equivalence and evaluated pharmacodynamic (PD), safety, tolerability, and immunogenicity between SB16, European Union-sourced DEN (EU-DEN), and United States-sourced DEN (US-DEN). Research design and methods In this double-blind, parallel group, and single-dose study, healthy male subjects were randomized 1:1:1 to receive a single 60 mg dose of either SB16, EU-DEN, or US-DEN subcutaneously. PK, PD, safety, and immunogenicity were evaluated for 197 days. Primary PK endpoints were area under the concentration-time curve (AUC) from time zero to infinity, AUC from time zero to the last quantifiable concentration, and maximum serum concentration (Cmax). Equivalence was determined if 90% confidence intervals (CIs) for the ratio of geometric least squares means (LS Means) were within the equivalence margin of 0.80 to 1.25. Results A total of 168 subjects (56 per treatment group) were randomized. All of the corresponding 90% CI of geometric LS Means ratio of primary PK parameters were within the pre-defined equivalence margin. PD, safety, and immunogenicity profiles were also comparable between the treatment groups. Conclusion This study demonstrated PK bioequivalence between SB16, EU-DEN, and US-DEN in healthy male subjects. TrialRegistration CT.gov identifier: NCT04621318

Evaluation of Tetrazine Tracers for Pretargeted Imaging within the Central Nervous System.

The pretargeting approach separates the biological half-life of an antibody from the physical half-life of the radioisotope label, providing a strategy for reducing the radiation burden. A widely explored pretargeting approach makes use of the bioorthogonal click reaction between tetrazines (Tzs) and trans-cyclooctenes (TCOs), combining the targeting specificity of monoclonal antibodies (mAbs) with the rapid clearance and precise reaction of Tzs and TCOs. Such a strategy can allow for the targeting and imaging (e.g., by positron emission tomography (PET)) of molecular markers, which cannot be addressed by solely relying on small molecules. Tz derivatives that undergo inverse electron-demand Diels-Alder (IEDDA) reactions with an antibody bearing TCO moieties have been investigated. This study describes the synthesis and characterization of 11 cold Tz imaging agent candidates. These molecules have the potential to be radiolabeled with 18F or 3H, and with the former label, they could be of use as imaging tracers for positron emission tomography studies. Selection was made using a multiparameter optimization score for the central nervous system (CNS) PET tracers. Novel tetrazines were tested for their pH-dependent chemical stability. Those which turned out to be stable in a pH range of 6.5-8 were further characterized in in vitro assays with regard to their passive permeability, microsomal stability, and P-glycoprotein transport. Furthermore, selected Tzs were examined for their systemic clearance and CNS penetration in a single-dose pharmacokinetic study in rats. Two tetrazines were successfully labeled with 18F, one of which showed brain penetration in a biodistribution study in mice. Another Tz was successfully tritium-labeled and used to demonstrate a bioorthogonal click reaction on a TCO-modified antibody. As a result, we identified one Tz as a potential fluorine-18-labeled CNS-PET agent and a second as a 3H-radioligand for an IEDDA-based reaction with a modified brain-penetrating antibody.

Pharmacokinetics of Sirolimus Eye Drops Following Topical Ocular Administration in Rabbits.

Purpose: To evaluate the pharmacokinetics of sirolimus eye drops following topical instillation in rabbits. Methods: The study included 2 experiments. In single-dose pharmacokinetic study, rabbits received a single bilateral instillation of 0.05% sirolimus eye drops (0.5 mg/mL, 50 μL/eye). In repeat-dose pharmacokinetic study, 0.05% sirolimus eye drops (0.5 mg/mL, 50 μL/eye/time) were instilled into both eyes of rabbits four times a day for 6 consecutive days and one time on day 7. Whole blood, tears, aqueous humor, cornea, and conjunctiva samples were collected. Sirolimus concentration was determined by a validated liquid chromatography-tandem mass spectrometry. Results: Sirolimus was hardly detected in plasma or aqueous humor after either single or repeated dosing. The Cmax of sirolimus in tears, cornea, and conjunctiva after a single instillation was 163.34 ± 69.30 μg/g, 150.56 ± 84.98 ng/g, and 113.22 ± 49.82 ng/g, respectively. As the number of instillation elevated, the Cmax of sirolimus was increased to 486.18 ± 297.93 μg/g, 418.63 ± 41.07 ng/g, and 314.25 ± 63.74 ng/g, respectively. In repeat-dose administration, the steady state of sirolimus concentration was achieved on the third day. Ocular exposure to sirolimus after single and repeated dosing, based on AUC0-t, was highest in tears, followed by cornea and conjunctiva. Compared with single administration, a significant increase in sirolimus exposure as measured by AUC0-t was observed in tears, cornea, and conjunctiva following repeated administration. Conclusions: Topical administration of sirolimus eye drops results in extensive distribution of sirolimus in tears, cornea, and conjunctiva, while aqueous humor and systemic exposure were negligible. Repeat-dose administration increases sirolimus exposure in tears, cornea, and conjunctiva.

JSKN003, A NOVEL BIPARATOPIC ANTI-HER2 ANTIBODY-DRUG CONJUGATE, EXHIBITS POTENT ANTITUMOR EFFICACY

Abstract In human advanced solid tumors, expression of HER2 protein has been reported in various tumor tissues and a variety of cultured tumor cell lines including breast cancer, gastric cancer, pancreatic cancer, lung cancer, colorectal cancer, and ovarian cancer. Due to the critical roles of HER2 in carcinogenesis, two main targeted therapies have been developed in the past two decades to block the HER2-driven pathways, which include small molecule compounds that inhibit the tyrosine kinase activity of the intracellular domain, and mono-antibodies (mAbs) that target the extracellular domain (ECD) of the receptors. JSKN003 is an antibody-drug conjugate (ADC) comprised of a recombinant, humanized anti-human epidermal growth factor receptor 2 (HER2) bispecific antibody conjugated to a topoisomerase I inhibitor via a dibenzocyclooctyne tetrapeptide linker. The anti-HER2 component, KN026, is a recombinant, humanized bispecific antibody that targets both extra-cellular domains II (pertuzumab binding site) and IV (trastuzumab binding site) of HER2. JSKN003 showed high affinity binding to human HER2 with KDs of 2.209 E-10M, which is comparable to its parental antibody KN026 and bound to NCI-N87 and BxPC-3 cells in a concentration-dependent manner. At the same time JSKN003 showed more extensive and faster internalization than DS8201 on NCI-N87 cells. As expected, JSKN003 showed directly inhibits growth by targeting HER2 positive tumor model (NCI-N87 and BT474 cell models). The single dose and multiple dose pharmacokinetics study in cynomolgus monkey indicated that JSKN003, total antibody and DXd had general linear dynamic characteristics, and pharmacokinetics parameters showed no significant differences between males and females in the range 0.3-30 mg/kg. The HNSTD (highest non-severely toxic dose) of JSKN003 was determined as 30mg/kg in cynomolgus monkeys. These preclinical data suggest that JSKN003 could potentially benefit patients with tumors co-expressing HER2 through improved drug selectivity and efficacy. JSKN003’s safety, tolerability and preliminary anti-tumor activity are currently being evaluated in a first-in-human phase I study in advanced stage solid tumors in Australia (NCT05494918) using a BOIN design. This ADC is targeted on the subjects who has HER2 expression and/or HER2-gene mutation and may address an unmet medical need for these patients.

Appetite stimulation with cannabis-based medicine and methods for assessment of glomerular filtration in older patients with medical illness: a study protocol.

Malnutrition in older patients is linked to poor appetite. Cannabis-based medicine may have orexigenic properties in older patients, but this has to our knowledge never been investigated. In older patients, uncertainty applies to the accuracy of estimated glomerular filtration rate (eGFR) based on creatinine, which is crucial for medication prescribing. In older patients with poor appetite, the study aims 1) to assess the efficacy of Sativex® (8.1 mg delta-9-tetrahydrocannabinol (THC) and 7.5 mg cannabidiol (CBD)) to stimulate appetite and 2) to compare the performance of various GFR-estimates and measured-GFR (mGFR) for determining gentamicin clearance utilising population pharmacokinetic (popPK) modelling methods. This study is composed of two sub-studies. Sub-study 1 is an investigator-initiated single-center, double-blinded, randomised, placebo-controlled, superiority, cross-over study. Sub-study 1 will recruit 17 older patients with poor appetite, who will also be invited to sub-study 2. Sub-study 2 is a single-dose pharmacokinetics study and will recruit 55 patients. Participants will receive Sativex® and placebo in sub-study 1 and gentamicin with simultaneous measurements of GFR in sub-study 2. The primary endpoints are: sub-study 1) difference in energy intake between Sativex® and placebo conditions, and sub-study 2) accuracy of different eGFR equations compared to mGFR. The secondary endpoints include safety parameters, changes in the appetite hormones, total ghrelin and GLP-1 and subjective appetite sensations and the creation of popPK models of THC, CBD, and gentamicin.

Cationic Nano-Lipidic Carrier Mediated Ocular Delivery of Triamcinolone Acetonide: A Preclinical Investigation in the Management of Uveitis.

The current study was undertaken to evaluate the efficacy of a novel nano-lipoidal eye drop formulation of triamcinolone acetonide (TA) for the topical treatment of uveitis. The triamcinolone acetonide-loaded nanostructured lipid carriers (cTA-NLC) were developed by employing 'hot microemulsion method' using biocompatible lipids, which exhibited a sustained release nature and enhanced efficacy when evaluated in vitro. The in vivo efficacy of this developed formulation was tested on Wistar rats, and a single-dose pharmacokinetic study was conducted in rabbits. The eyes of animals were examined for any signs of inflammation using the 'Slit-lamp microscopic' method. The aqueous humor collected from the sacrificed rats was tested for total protein count and cell count. The total protein count was determined using BSA assay method, while the total cell count was determined by Neubaur's hemocytometer method. The results showed that the cTA-NLC formulation had negligible signs of inflammation, with a clinical score of uveitis 0.82 ± 0.166, which is much less than control/untreated (3.80 ± 0.3) and free drug suspension (2.66 ± 0.405). The total cell count was also found to be significantly low for cTA-NLC (8.73 ± 1.79 × 105) as compared to control (52.4 ± 7.71 × 105) and free drug suspension (30.13 ± 3.021 × 105). Conclusively, the animal studies conducted showed that our developed formulation holds the potential for effective management of uveitis.

Pharmacological and toxicological studies of a novel goserelin acetate extended-release microspheres in rats.

LY01005 is an investigational new drug product of goserelin acetate which is formulated as extended-release microspheres for intramuscular injection. To support the proposed clinical trials and marketing application of LY01005, pharmacodynamics, pharmacokinetics and toxicity studies were performed in rats. In the pharmacological study in rats, LY01005 induced an initial supra-physiological level increase of testosterone at 24h post-dosing which then rapidly fell to castration level. The potency of LY01005 was comparable to the comparator Zoladex® but its effect lasted longer and more stable. A single-dose pharmacokinetics study in rats demonstrated that the Cmax and AUClast of LY01005 increased in a dose-proportional manner in the range of 0.45-1.80mg/kg and the relative bioavailability was 101.0% between LY01005 and Zoladex®. In the toxicity study, almost all of the positive findings of LY01005 in rats including the changes in hormones (follicle-stimulating hormone, luteinizing hormone, testosterone, progestin) and in reproductive system (uterus, ovary, vagina, cervix uteri, mammary gland, testis, epididymis and prostate) were related to the direct pharmacological effects of goserelin. Mild histopathological changes in foreign body removal reaction induced by excipient were also observed. In conclusion, LY01005 displayed a sustained-release profile of goserelin, and exerted a continuous efficacy in vivo in animal models, which had a comparable potency but with a more sustained effect than that of Zoladex®. The safety profile of LY01005 was largely the same with Zoladex®. These results strongly support the planned LY01005 clinical trials.

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.

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.

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.

Pharmacological Validation of Long-Term Treatment with Antiretroviral Drugs in a Model of SIV-Infected Non-Human Primates.

The development of animal models undergoing long-term antiretroviral treatment (ART) makes it possible to understand a number of immunological, virological, and pharmacological issues, key factors in the management of HIV infection. We aimed to pharmacologically validate a non-human primate (NHP) model treated in the long term with antiretroviral drugs after infection with the pathogenic SIVmac251 strain. A single-dose pharmacokinetic study of tenofovir disoproxil fumarate, emtricitabine, and dolutegravir was first conducted on 13 non-infected macaques to compare three different routes of administration. Then, 12 simian immunodeficiency virus (SIV)-infected (SIV+) macaques were treated with the same regimen for two years. Drug monitoring, virological efficacy, and safety were evaluated throughout the study. For the single-dose pharmacokinetic study, 24-h post-dose plasma concentrations for all macaques were above or close to 90% inhibitory concentrations and consistent with human data. During the two-year follow-up, the pharmacological data were consistent with those observed in humans, with low inter- and intra-individual variability. Rapid and sustained virological efficacy was observed for all macaques, with a good safety profile. Overall, our SIV+ NHP model treated with the ART combination over a two-year period is suitable for investigating the question of pharmacological sanctuaries in HIV infection and exploring strategies for an HIV cure.

PHARMACOKINETICS OF MELOXICAM AFTER A SINGLE 1.5 MG/KG INTRAMUSCULAR ADMINISTRATION TO NURSEHOUND SHARKS (SCYLIORHINUS STELLARIS) AND ITS EFFECTS ON HEMATOLOGY AND PLASMA BIOCHEMISTRY.

A single-dose meloxicam pharmacokinetic (PK) study was performed with eight clinically healthy nursehound sharks (Scyliorhinus stellaris) maintained under human care. Meloxicam was administered IM at a dosage of 1.5 mg/kg to six animals; two animals were administered elasmobranch physiological saline solution (EPSS) IM as a negative control group. Blood samples were obtained prior to and at 12 predetermined times during the first 36 h after administration. Effects on hematology and plasma biochemistry were compared prior to and 24 h after administration. No animal died or showed clinical signs during the study. A significant increase in creatinine kinase and aspartate aminotransferase was found in both EPSS and meloxicam groups and could be considered a direct consequence of sampling and handling required for the PK study. Observed mean time to maximum plasma concentration ± SEM was 2.58 ± 0.47 h and observed mean maximum plasma concentration ± SEM was 806 ± 66 ng/ml; mean terminal half-life ± SEM was 15.97 ± 1.20 h; mean residency time ± SEM was 23.40 ± 2.25 h. Area under the plasma concentration-versus-time curve extrapolated to infinity ± SEM was 15.52 ± 1.70 h·µg/ml. This study suggests that meloxicam 1.5 mg/kg IM in nursehound sharks is likely to result in clinically relevant plasma levels for periods of 24 h without producing significant alterations in blood analytics, although further PK studies with meloxicam IV in sharks are needed. Future PK and pharmacodynamic studies with different drugs and doses are needed in elasmobranchs to establish safe and effective treatment protocols.

Abstract 3346: BBT-207, a novel, 4th generation, epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) with broad-spectrum activity to both treatment-emergent and drug-naïve mutants for the treatment of NSCLC

Abstract Background: Activating mutations in EGFR, e.g., L858R (L) and Del19 (D), are observed in 14.1-32.3% of NSCLC worldwide and defines a druggable entity. Single agent EGFR TKI treatment was established in clinical trials. However, a treatment-emergent mutation of T790M (T) was identified as a major source of drug resistance. Irreversible 2nd and 3rd generation EGFR TKIs were shown effective. Mutant-specific inhibition by 3rd generation EGFR TKIs reduced adverse events such as skin toxicities. The emergence of a missense mutation at C797 (C), to which irreversible TKIs covalently bind, limited their efficacy. Patients harboring treatment-emergent C mutations are left with few therapeutic options. Despite anecdotal reports of efficacy from 1st generation TKIs, these complex molecular variants involving C797 are an increasing clinical concern. To prevent the emergence of drug-resistant subclones, a broad-spectrum EGFR TKI against both treatment-emergent and drug-naïve mutants is required. Such a 4th generation EGFR TKI must also enable monotherapy, allowing precise dose adjustment in case of toxicity. Method: Derived from BBT-176 which is under clinical evaluation (NCT04820023), we synthesized BBT-207 and other related molecules. Using Promega ADP-Glo™ kinase assay, we tested compounds against wild-type (WT) and mutated EGFR proteins. Ba/F3 cells harboring WT and mutated EGFR genes were created and cell viability was measured by CellTiter-Glo® and SpectraMax iD3®. In vivo anti-tumor activity was evaluated in Ba/F3 cell-derived xenograft models and an Osimertinib-resistant patient-derived xenograft model. Single dose pharmacokinetic (PK) study was performed in animals. Results: BBT-207 showed IC50 values < 10 nM against EGFR triple mutants (DTC and LTC) and comparable IC50 values against double mutants (DC and LC), while Osimertinib was ineffective in both groups. BBT-207 was also as active as Gefitinib to single mutants (D and L). Double mutants containing T790M (DT and LT) were inhibited effectively by BBT-207 and Osimertinib at similar concentrations, while not by Gefitinib. In in vivo models to which Osimertinib was inactive (LC and DTC), significant tumor growth inhibition was observed from BBT-207 alone, which was enhanced by the addition of Osimertinib. PK studies in mouse, rat, dog and monkey were consistent with high exposure and sustained drug concentrations above the IC50 values, with evidence of penetration into the central nervous system. Conclusion: BBT-207 is a reversible, mutant-specific, broad-spectrum TKI, active to clinically observed mutations of EGFR and is expected to be compatible with monotherapy of QD schedule in humans. BBT-207 is well-positioned to augment the treatment of EGFR mutated NSCLC, either for acquired drug resistance or in earlier line. Citation Format: Taiguang Jimmy Jin, Sang-Uk Kang, Chulwon Kim, Jehrod Brenneman, Mihee Song, Pavel Printsev, Bo-Bae Seo, Yong-Hee Lee, Sang-Yoon Lee. BBT-207, a novel, 4th generation, epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) with broad-spectrum activity to both treatment-emergent and drug-naïve mutants for the treatment of NSCLC [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3346.

Pharmacokinetics of a Novel Sustained-Release Vitamin C Oral Tablet: A Single Dose, Randomized, Double-Blind, Placebo-Controlled Trial

Objectives To evaluate the pharmacokinetics of a novel sustained-release oral tablet (C-Fence, Inventia Healthcare Limited, Mumbai, India). Methods We conducted a randomized, placebo-controlled, parallel-design, 500 mg single-dose pharmacokinetic study of this new preparation in 18 healthy adult human subjects (nine in each group) under fasting conditions. The concentration-time profile and pharmacokinetic parameters of L-ascorbic acid, including Cmax (maximum plasma concentration), Tmax (time to reach Cmax), and AUC0-24h (area under the plasma concentration versus time curve from time 0 h to 24 h) were calculated using baseline-corrected values. Results The sustained-release tablets resulted in mean Cmax and AUC0-24h, respectively, of 1.39 ± 1.21 µg/mL and 11.72 ± 10.73 µg.h/mL against 0.18 ± 0.10 µg/mL and 0.89 ± 0.27 µg.h/mL, respectively, in the placebo group. The mean Tmax with the sustained-release tablets was 4.3 ± 2.5 h. At 12, 16, and 24 h from dosing, the concentrations were 0.6, 0.4, and 0.3 µg/mL, respectively, above baseline values. Conclusion Novel sustained-release formulations of vitamin C are expected to help achieve plasma vitamin C values above the homeostatic saturation level and result in higher steady-state plasma concentration, which might result in better cellular uptake.

Investigating the Role of the Reduced Solubility of the Pirfenidone-Fumaric Acid Cocrystal in Sustaining the Release Rate from Its Tablet Dosage Form by Conducting Comparative Bioavailability Study in Healthy Human Volunteers.

Pirfenidone (PFD) is the first pharmacological agent approved by the US Food and Drug Administration (FDA) in 2014 for the treatment of idiopathic pulmonary fibrosis (IPF). The recommended daily dosage of PFD in patients with IPF is very high (2403 mg/day) and must be mitigated through additives. In the present work, sustained-release (SR) formulations of the PFD-FA cocrystal of two different strengths such as 200 and 600 mg were prepared and its comparative bioavailability in healthy human volunteers was studied against the reference formulation PIRFENEX (200 mg). A single-dose pharmacokinetic study (200 mg IR vs 200 mg SR) demonstrated that the test formulation exhibited lower Cmax and Tmax in comparison to the reference formulation, which showed that the cocrystal behaved like an SR formulation. Further in the multiple-dose comparative bioavailability study (200 mg IR thrice daily vs 600 mg SR once daily), the test formulation was found bioequivalent to the reference formulation. In conclusion, the present study suggests that cocrystallization offers a promising strategy to reduce the solubility of PFD and opens the door for potential new dosage forms of this important pharmaceutical.