Single Subcutaneous Administration Research Articles

Preclinical Pharmacokinetics in Tumors and Normal Tissues of the Antigene PNA Oligonucleotide MYCN-Inhibitor BGA002.

Although MYCN has been considered an undruggable target, MYCN alterations confer poor prognosis in many pediatric and adult cancers. The novel MYCN-specific inhibitor BGA002 is an antigene peptide nucleic acid oligonucleotide covalently bound to a nuclear localization signal peptide. In the present study, we characterized the pharmacokinetics (PK) of BGA002 after single and repeated administration to mice using a novel specific enzyme-linked immunosorbent assay. BGA002 concentrations in plasma showed linear PK, with dose proportional increase across the tested dose levels and similar exposure between male and female and between intravenous and subcutaneous route of administration. Repeated dosing resulted in no accumulation in plasma. Biodistribution up to 7 days after single subcutaneous administration of [14C]-radiolabeled BGA002 showed broad tissues and organ distribution (suggesting a potential capability to reach primary tumor and metastasis in several body sites), with high concentrations in kidney, liver, spleen, lymph nodes, adrenals, and bone marrow. Remarkably, we demonstrated that BGA002 concentrates in tumors after repeated systemic administrations in three mouse models with MYCN amplification (neuroblastoma, rhabdomyosarcoma, and small-cell lung cancer), leading to a significant reduction in tumor weight. Taking into account the available safety profile of BGA002, these data support further evaluation of BGA002 in patients with MYCN-positive tumors.

Structure and pharmacokinetics/pharmacodynamics of the anticoagulant tetradecasaccharide oHG-14 as an intrinsic tenase inhibitor

The intrinsic tenase complex (iXase) is an attractive antithrombotic target to treat or prevent pathological thrombosis with negligible bleeding risk. Fucosylated glycosaminoglycan (FG) is a promising anticoagulant by inhibiting iXase. A depolymerized FG (dHG-5) as an anticoagulant has been approved for clinical trials. Given that dHG-5 is a multi-component drug candidate consisting of a homologous series of oligosaccharides, it is difficult to predict a clear pharmacokinetics. Here, as a major oligosaccharide component, the tetradecasaccharide (oHG-14) was purified from dHG-5 and its structure was defined as L-Fuc3S4S-α(1,3)-L-Δ4,5GlcA-α(1,3)-{D-GalNAc4S6S-β(1,4)-[L-Fuc3S4S-α(1,]3)-D-GlcA-β(1,3)-}3-D-GalNAc4S6S-β(1,4)-[L-Fuc3S4S-α(1,]3)-D-GlcA-ol. oHG-14 showed potent iXase inhibitory activity in vitro and antithrombotic effect in vivo comparable to dHG-5. After single subcutaneous administration of oHG-14 at 8, 14.4 and 32.4 mg/kg to rats, the absolute bioavailability was 71.6 %–80.9 % determined by the validated bioanalytical methods. The maximum concentration (Cmax) was 3.73, 8.07, and 11.95 μg/mL, respectively, and the time reaching Cmax (Tmax) was about 1 h. oHG-14 was mainly excreted by kidney as the parent compound with the elimination kinetics of first-order linear model. Anticoagulant activity of oHG-14 was positively correlated with its concentration in rat plasma. The pharmacokinetics/pharmacodynamics (PK/PD) of oHG-14 is similar to that of dHG-5. This study could provide supportive data for the clinical trial of dHG-5 and further development of pure oligosaccharide as an antithrombotic drug candidate.

Comparative pharmacokinetics of intravenous and subcutaneous pantoprazole in sheep and goats

Abomasal ulcers are a significant concern in intensive animal farming due to their impact on animal health and productivity. While proton pump inhibitors (PPIs) such as pantoprazole (PTZ) show promise in treating these ulcers, data on PTZ's pharmacokinetics (PK) in adult goats and sheep are limited. This study aims to fill this gap by investigating and comparing PTZ's PK in these species following single intravenous (IV) and subcutaneous (SC) administrations. Five healthy male goats and sheep were included in the study. PTZ concentrations in plasma samples were determined using a validated analytical method. Non-compartmental analysis was conducted, and statistical comparisons were made between IV and SC administrations and between species. Sheep and goats showed similar systemic exposure levels regardless of the administration route. However, sheep had a shorter t1/2 due to a higher Vd compared to goats. Cl values were comparable in both species, with low extraction ratio values. There were no significant differences in Cmax and Tmax between the two species with regards to SC administration, and complete bioavailability was observed. The MAT exceeded the t1/2 in both species, indicating a potential flip-flop phenomenon. Considering the AUC as a predictor for drug efficacy, and observing no significant differences in systemic exposure between sheep and goats for any route of administration, dosage adjustment between the two species may not be necessary. In field settings, SC administration proves more practical, providing not only complete bioavailability but also a longer half-life compared to IV. Further studies are warranted to explore the PK/PD of PTZ in small ruminants with abomasal ulcers, to fully comprehend its therapeutic efficacy in such scenarios.

Abstract LB118: HM16390, a novel long-acting IL-2 analog with fine-tuned binding affinities to IL-2 receptor subunits for favorable safety profile, exhibits potent tumor killing effect in the various tumor syngeneic models

Abstract Although recombinant human IL-2 (rhIL-2, aldesleukin) produced approximately a 15% objective response rate in patients with renal cell carcinoma (RCC) and metastatic melanoma, its IL-2Rα (CD25)-biased binding and short half-life (t1/2 in human: 13-85 min) require a high dose and frequent dosing interval, leading to systemic toxicity such as vascular leak syndrome (VLS) and cytokine release syndrome (CRS). To overcome this limitation, various research groups are developing engineered IL-2 muteins with abolished CD25 binding affinity. While such IL-2 muteins may reduce CD25-mediated toxicity, there is a risk of a lopsided immune response. Furthermore, concomitantly reduced affinity to IL-2Rβ (CD122) may cause insufficient anti-tumor activity. We are developing HM16390, a long-acting IL-2 analog with a significantly increased binding affinity to CD122 for potent tumor killing effect. Simultaneously, optimal binding property to CD25 was introduced for a suppression of uncontrolled systemic immune response via peripheral Treg expansion. From these novel sequence modifications, HM16390 exhibited approximately 14-fold potent activity in human NK and CD8+ T cells compared to rhIL-2 and comparable activity with rhIL-2 in human Tregs (EC50 of STAT5 phosphorylation) without undesired release of cytokines associated with CRS. In B16F10 mouse model, HM16390 has a longer-lasting PK property (t1/2: 14.2~26.0 hr) after single subcutaneous (SC) administration. CD8+ T cells were significantly increased in peripheral blood along with a transient increase of peripheral Tregs, suggesting that HM16390 not only has a significant effect on expansion of CD8+ T cells but can simultaneously modulate exaggerated peripheral immune response. It is also noteworthy that, unlike in the peripheral, Tregs were drastically reduced in the tumor immune microenvironment, and CD8+ T cells were significantly increased. Next, in orthotopic model of mouse RCC (RENCA-luc cell implantation), across treatment groups, 40%(n=4/10) to 80%(n=8/10) of animals achieved complete tumor regression in dose-dependent manner after once weekly SC injection of HM16390 for 4 weeks. Furthermore, tumor nodules were not observed in lung and kidney after intravenous (IV) rechallenge of RENCA cells in the mice cured by HM16390 for at least 4 months after drug discontinuation. This indicates a long-term immunological memory response of generated memory cells by treatment of HM16390. In conclusion, HM16390 demonstrates potent and durable anti-tumor activity in various murine tumor models via its enhanced CD122 binding affinity, and incorporated optimal CD25 binding affinity may alleviate systemic toxicity by immunomodulatory role of peripheral Tregs. Citation Format: Sol-Bi Shin, Jinyoung Kim, Jaehyuk Choi, Seongju Jeong, Yunjae Kim, Jooyun Byun, Sungmin Bae, Daejin Kim, In Young Choi. HM16390, a novel long-acting IL-2 analog with fine-tuned binding affinities to IL-2 receptor subunits for favorable safety profile, exhibits potent tumor killing effect in the various tumor syngeneic models [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr LB118.

A Potent Neutralizing Monoclonal Antibody to Human Growth Hormone Suppresses Insulin-Like Growth Factor-1 in Female Rats.

Acromegaly and gigantism are disorders caused by hypersecretion of growth hormone (GH), usually from pituitary adenomas. Although somatostatin analogues (SSA), dopamine agonists, and GH receptor antagonists are important therapeutic agents, all of these have issues with their effectiveness, safety, and/or convenience of use. To overcome these, we developed a GH-specific potent neutralizing a mouse monoclonal antibody (mAb) named 13H02. 13H02 selectively bound both to human and monkey GH with high affinity, and strongly inhibited the biological activity of GH in the Nb2 rat lymphoma cell proliferation assay. In hypophysectomized/GH-supplemented rats, a single subcutaneous administration of 13H02 significantly and dose-dependently lowered the serum insulin-like growth factor-1 levels. To pursue the therapeutic potential of this antibody for acromegaly and gigantism, we humanized 13H02 to reduce its immunogenicity and applied a single amino acid mutation in the Fc region to extend its serum half-life. The resulting antibody, Hu-13H02m, also showed GH-specific neutralizing activity, similar to the parental 13H02, and showed improved binding affinity to human FcRn.

Prophylactic effect of ensitrelvir in mice infected with SARS-CoV-2

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the etiological cause of coronavirus disease 2019 (COVID-19) and continues to be a major health concern worldwide. Strategies to protect individuals at high risk of COVID-19 are critical but are currently a largely unmet need. We evaluated the oral antiviral drug ensitrelvir, which specifically targets the SARS-CoV-2 3CL protease, for its efficacy as a pre-exposure prophylactic treatment. Aged BALB/c mice were subcutaneously treated with various doses of ensitrelvir 24 h prior to a lethal SARS-CoV-2 challenge infection. Mouse body weight changes, survival rates, and viral titers in the lungs were evaluated, and plasma concentrations of ensitrelvir were determined. A single subcutaneous administration of ensitrelvir at 64 mg/kg or greater 24 h prior to SARS-CoV-2 challenge infection significantly protected aged mice against lethality and inhibited body weight loss. Pharmacokinetic analysis of ensitrelvir in the aged mice suggested that plasma concentrations ≥2.99 μg/mL resulted in a significant prophylactic effect against SARS-CoV-2 infection. In the aged mouse prophylaxis model, SARS-CoV-2 titers were suppressed in the lungs of mice treated with ensitrelvir 24 h prior to challenge infection, suggesting that the prophylactic administration of ensitrelvir exerted its prophylactic effect by suppressing viral proliferation. These findings suggest that ensitrelvir is a candidate drug for pre-exposure prophylactic treatment of individuals at high risk of COVID-19.

Intracellular activity and in vivo efficacy in a mouse model of septic arthritis of the novel pseudopeptide Pep16 against Staphylococcus aureus clinical isolates.

Assessing the therapeutic potential of a novel antimicrobial pseudopeptide, Pep16, both in vitro and in vivo for the treatment of septic arthritis caused by Staphylococcus aureus. Seven clinical isolates of S. aureus (two MRSA and five MSSA) were studied. MICs of Pep16 and comparators (vancomycin, teicoplanin, daptomycin and levofloxacin) were determined through the broth microdilution method. The intracellular activity of Pep16 and levofloxacin was assessed in two models of infection using non-professional (osteoblasts MG-63) or professional (macrophages THP-1) phagocytic cells. A mouse model of septic arthritis was used to evaluate the in vivo efficacy of Pep16 and vancomycin. A preliminary pharmacokinetic (PK) analysis was performed by measuring plasma concentrations using LC-MS/MS following a single subcutaneous injection of Pep16 (10 mg/kg). MICs of Pep16 were consistently at 8 mg/L for all clinical isolates of S. aureus (2- to 32-fold higher to those of comparators) while MBC/MIC ratios confirmed its bactericidal activity. Both Pep16 and levofloxacin (when used at 2 × MIC) significantly reduced the bacterial load of all tested isolates (two MSSA and two MRSA) within both osteoblasts and macrophages. In MSSA-infected mice, Pep16 demonstrated a significant (∼10-fold) reduction on bacterial loads in knee joints. PK analysis following a single subcutaneous administration of Pep16 revealed a gradual increase in plasma concentrations, reaching a peak of 5.6 mg/L at 12 h. Pep16 is a promising option for the treatment of septic arthritis due to S. aureus, particularly owing to its robust intracellular activity.

Combination of Styrylbenzoazole Compound and Hydroxypropyl Methylcellulose Enhances Therapeutic Effect in Prion-Infected Mice

Prion diseases are fatal transmissible neurodegenerative disorders. Tremendous efforts have been made for prion diseases; however, no effective treatment is available. Several anti-prion compounds have a preference for which prion strains or prion-infected animal models to target. Styrylbenzoazole compound called cpd-B is effective in RML prion-infected mice but less so in 263K prion-infected mice, whereas hydroxypropyl methylcellulose is effective in 263K prion-infected mice but less so in RML prion-infected mice. In the present study, we developed a combination therapy of cpd-B and hydroxypropyl methylcellulose expecting synergistic effects in both RML prion-infected mice and 263K prion-infected mice. A single subcutaneous administration of this combination had substantially a synergistic effect in RML prion-infected mice but had no additive effect in 263K prion-infected mice. These results showed that the effect of cpd-B was enhanced by hydroxypropyl methylcellulose. The complementary nature of the two compounds in efficacy against prion strains, chemical properties, pharmacokinetics, and physical properties appears to have contributed to the effective combination therapy. Our results pave the way for the strategy of new anti-prion agents.

The TLR2/TLR6 ligand FSL-1 mitigates radiation-induced hematopoietic injury in mice and nonhuman primates.

Thrombocytopenia, hemorrhage, anemia, and infection are life-threatening issues following accidental or intentional radiation exposure. Since few therapeutics are available, safe and efficacious small molecules to mitigate radiation-induced injury need to be developed. Our previous study showed the synthetic TLR2/TLR6 ligand fibroblast stimulating lipopeptide (FSL-1) prolonged survival and provided MyD88-dependent mitigation of hematopoietic acute radiation syndrome (H-ARS) in mice. Although mice and humans differ in TLR number, expression, and function, nonhuman primate (NHP) TLRs are like those of humans; therefore, studying both animal models is critical for drug development. The objectives of this study were to determine the efficacy of FSL-1 on hematopoietic recovery in small and large animal models subjected to sublethal total body irradiation and investigate its mechanism of action. In mice, we demonstrate a lack of adverse effects, an easy route of delivery (subcutaneous) and efficacy in promoting hematopoietic progenitor cell proliferation by FSL-1. NHP given radiation, followed a day later with a single subcutaneous administration of FSL-1, displayed no adversity but showed elevated hematopoietic cells. Our analyses revealed that FSL-1 promoted red blood cell development and induced soluble effectors following radiation exposure. Cytologic analysis of bone marrow aspirates revealed a striking enhancement of mononuclear progenitor cells in FSL-1-treated NHP. Combining the efficacy of FSL-1 in promoting hematopoietic cell recovery with the lack of adverse effects induced by a single administration supports the application of FSL-1 as a viable countermeasure against H-ARS.

Pharmacokinetics and Biodistribution of 16,16 dimethyl Prostaglandin E2 in Non-Irradiated and Irradiated Mice and Non-Irradiated Non-Human Primates.

Exposure to high-dose ionizing radiation can lead to life-threatening injuries and mortality. Bone marrow is the most sensitive organ to radiation damage, resulting in the hematopoietic acute radiation syndrome (H-ARS) with the potential sequelae of infection, hemorrhage, anemia, and death if untreated. The development of medical countermeasures (MCMs) to protect or mitigate radiation injury is a medical necessity. In our well-established murine model of H-ARS we have demonstrated that the prostaglandin E2 (PGE2) analog 16,16 dimethyl-PGE2 (dmPGE2) has survival efficacy as both a radioprotectant and radiomitigator. The purpose of this study was to investigate the pharmacokinetics (PK) and biodistribution of dmPGE2 when used as a radioprotector in irradiated and non-irradiated inbred C57BL/6J mice, PK in irradiated and non-irradiated Jackson Diversity Outbred (JDO) mice, and the PK profile of dmPGE2 in non-irradiated non-human primates (NHPs). The C57BL/6J and JDO mice each received a single subcutaneous (SC) dose of 35 ug of dmPGE2 and were randomized to either receive radiation 30 min later or remain non-irradiated. Plasma and tissue PK profiles were established. The NHP were dosed with 0.1 mg/kg by SC administration and the PK profile in plasma was established. The concentration time profiles were analyzed by standard non-compartmental analysis and the metrics of AUC0-Inf, AUC60-480 (AUC from 60-480 min), Cmax, and t1/2 were evaluated. AUC60-480 represents the postirradiation time frame and was used to assess radiation effect. Overall, AUC0-Inf, Cmax, and t1/2 were numerically similar between strains (C57BL/6J and JDO) when combined, regardless of exposure status (AUC0-Inf: 112.50 ng·h/ml and 114.48 ng·h/ml, Cmax: 44.53 ng/ml and 63.96 ng/ml; t1/2: 1.8 h and 1.1 h, respectively). PK metrics were numerically lower in irradiated C57BL/6J mice than in non-irradiated mice [irradiation ratio: irradiated values/non-irradiated values = 0.71 for AUC60-480 (i.e., 29% lower), and 0.6 for t1/2]. In JDO mice, the radiation ratio was 0.53 for AUC60-480 (i.e., 47% lower), and 1.7 h for t1/2. The AUC0-Inf, Cmax, and t1/2 of the NHPs were 29.20 ng·h/ml, 7.68 ng/ml, and 3.26 h, respectively. Despite the numerical differences seen between irradiated and non-irradiated groups in PK parameters, the effect of radiation on PK can be considered minimal based on current data. The biodistribution in C57BL/6J mice showed that dmPGE2 per gram of tissue was highest in the lungs, regardless of exposure status. The radiation ratio for the different tissue AUC60-480 in C57BL/6J mice ranged between 0.5-1.1 (50% lower to 10% higher). Spleen, liver and bone marrow showed close to twice lower exposures after irradiation, whereas heart had a 10% higher exposure. Based on the clearance values from mice and NHP, the estimated allometric scaling coefficient was 0.81 (95% CI: 0.75, 0.86). While slightly higher than the current literature estimates of 0.75, this scaling coefficient can be considered a reasonable estimate and can be used to scale dmPGE2 dosing from animals to humans for future trials.

Plasma disposition and faecal excretion of eprinomectin following subcutaneous administration in Saanen and Alpine goats

Eprinomectin is extensively used in veterinary medicine, particularly in the treatment of internal and external parasites in livestock, including goats. The pharmacokinetic behavior of eprinomectin in plasma and faeces was studied after a single subcutaneous administration in two different goat breeds at a dose of 0.2 mg/kg body weight. The study was conducted on one-year-old female Saanen (n = 8) and Alpine (n = 8) goats in a parallel design. There were no significant differences between Saanen and Alpine goats on the peak plasma concentration (Cmax, 28.59 ± 7.46 ng/mL vs. 37.69 ± 14.89 ng/mL), area under the curve (AUC0-∞, 93.08 ± 11.66 ng.d/mL vs. 116.98 ± 48.36 ng.d/mL), area under the first moment curve (AUMC0-∞, 311.05 ± 67.23 ng.d2/mL vs. 348.25 ± 202.64 ng.d2/mL) and mean residence time (MRT, 3.24 ± 0.77 d vs. 2.74 ± 0.64 d) values. The plasma terminal half-life and the time to reach peak plasma concentration were significantly higher in Saanen goats (T1/2λz, 2.18 ± 0.43 d; Tmax, 1.21 ± 0.25 d) than in Alpine goats (T1/2λz, 1.66 ± 0.41 d; Tmax, 0.79 ± 0.25 d). The results revealed that the plasma concentration of eprinomectin did not differ depending on the breed in Saanen and Alpine goats. However, it was determined that the eprinomectin clearance from the body may vary depending on the breed in goats. The faecal eprinomectin concentration of Saanen and Alpine goats was 90 and 80 times higher than the plasma eprinomectin concentration, respectively. Although high faecal excretion of eprinomectin confers a high efficacy advantage against parasites in the gastrointestinal tract, it may pose an ecotoxicological risk to manure fauna and aquatic organisms with high susceptibility to this compound.

Prolonged CXCR4 Receptor Occupancy By Motixafortide Following a Single Subcutaneous Injection Is Associated with Extended Mobilization of CD34+ Cells in Peripheral Blood for > 24 Hours

Background: Interaction between CXCL12 (SDF-1) and its receptor, CXCR4, plays a critical role in the retention of CD34+ hematopoietic stem and progenitor cells (HSPCs) in the bone marrow. Motixafortide (motix) is a novel selective CXCR4 antagonist with high affinity for CXCR4 (IC 50 0.42 - 4.5nM), slow dissociation (Kd = 3.38e-5 s-1), and high plasma protein binding (>99%). In the Phase 3 GENESIS trial (NCT03246529), motix added to G-CSF (G) resulted in significantly higher mobilization of HSPCs in patients with multiple myeloma (MM) prior to autologous stem cell transplantation, with 88.8% of patients collecting ≥6x10 6 CD34+ cells/kg (local lab) in 1 leukapheresis procedure (LP) 10-14 hours following a single dose of motix (1.25mg/kg). Of note, GENESIS trial patients requiring additional LPs to meet HSPC mobilization goals underwent a second LP at 34-38 hours post-motix, with a total of 92.5% of patients meeting their collection goal. Here, we report in-vitro receptor occupancy, as well as clinical pharmacokinetics (PK) and pharmacodynamics (PD) of peripheral blood (PB) mobilization of CD34+ cells/ μL in healthy volunteers (HV) and patients with MM following motix administration. Methods: CXCR4 receptor occupancy and dissociation rate were assessed by incubating increasing doses of motix (3-500nM) with Jurkat cells in vitro followed by washing and incubation 0-72 hours later with either an anti-CXCR4 12G5 fluorophore-conjugated monoclonal antibody (mAb) (competes with motix for binding to CXCR4) or an anti-CXCR4 1D9 fluorophore-conjugated mAb (binds to CXCR4 but does not compete with motix) followed by flow cytometry. In HV (NCT05293171), PB samples were collected following a single subcutaneous (SC) administration of motix (1.25mg/kg). PK timepoints were pre-dose and at 0.25, 0.5, 0.75, 1, 1.5, 2, 3, 4, 6, 8, 12, 16, and 24 hours post-motix; and PD timepoints were pre-dose and at 0.75, 2, 4, 8, 12, 16, and 24 hours post-motix. In patients with MM, PB samples were collected following SC motix (1.25mg/kg) added to G. PK timepoints were pre-motix (post-G) and 0.25, 0.5, 1, 2, 4, 8, and 12 hours post- motix; and PD timepoints were pre-motix (post-G) and 12 hours post-motix. Results: In vitro studies demonstrated complete CXCR4 receptor occupancy at 3 nM (6.48 ng/mL) of motix, with increasing concentrations resulting in longer receptor occupancy of >72 hours. Due to high protein binding, a minimum total plasma concentration of 800 ng/mL is required to achieve a free fraction of 3nM. This level was achieved following administration with doses ≥ 1.0 mg/kg (Fig 1A). PK analysis in HVs and in patients with MM dosed with 1.25 mg/kg demonstrated that motix was rapidly absorbed (maximum concentration within 0.25-1 hours). Mean maximal plasma concentrations were 2245 ± 791 ng/mL (1040nM) in HVs and 1800 ± 695 ng/mL (834nM) in patients with MM. Notably, the half-life of motix was 1-3 hours. However, despite the short half-life, the high CXCR4 receptor affinity and slow dissociation rate of motix led to an extended PD effect. In HVs who received motix as monotherapy, median PB CD34+ counts increased from baseline of 1.6 CD34+ cells/µl to 17 CD34+ cells/ μL within 4 hours post-motix, reached maximal levels of 43 CD34+ cells/μL at 16 hours post-motix and remained elevated at 36 CD34+ cells/μL at the last observation time point 24 hours post-motix (Fig 1B). In MM patients who received motixafortide after 4 doses of G-CSF, there was a 6.6 fold increase in median PB CD34+ cell counts, from 15.8 cells/μL (post-G-CSF, pre-motix) to 116.0 CD34+ cells/μL at 12 hours post-motix (Fig 1B). Conclusions: In vitro studies demonstrated complete receptor occupancy by motix starting at a concentration of 3nM. Increasing concentrations resulted in longer duration of receptor occupancy. Mobilization of CD34+ cells to PB was observed within 2 hours after motix injection (1.25mg/kg), peaked at 12-16 hours, and remained elevated (>20 CD34+ cells/μL) for >24 hours post-motix. These PK/PD characteristics of motix result in rapid and robust PB CD34+ HSPC mobilization (median 116.0 CD34+ cells/μL); enabling 88.8% of patients to collect ≥6x10 6 CD34+ cells/kg in 1 LP with 1 dose of motix added to G. Furthermore, the extended PD effect of motix supports a flexible administration window that allows for LP to be performed > 24 hours post-motix administration.

Reproductive and margin of safety of a fixed-dose combination injectable endectocide (0.2 mg/kg doramectin; 6.0 mg/kg levamisole hydrochloride) in cattle

We present a fixed-dose combination injectable (FDCI) solution for cattle formulated for a single subcutaneous administration at a dose rate of 1 ml/25 kg of body weight to deliver a dose of 0.2 mg/kg of doramectin and 6.0 mg/kg of levamisole hydrochloride (5.1 mg/kg base equivalent). This drug product is marketed in the United States under the tradename Valcor® and in Australia and New Zealand under the tradename Dectomax V®. Both levamisole and doramectin have histories of safe and effective use in ruminants, with safety margins of 3X and 25X, respectively. Three studies were conducted to demonstrate the safety of the new FDCI: margin of safety (Study 1), and reproductive safety in sexually nulliparous beef heifers (Studies 2 and 3). In Study 1, 3-month-old sexually intact male and female calves were given either saline (control) or 1X, 2X, or 3X FDCI on Days 0, 14, and 28. General health, clinical, and neurological observations were made throughout the study, and clinical and pathology evaluations were made at study end. Studies 2 and 3 demonstrated the reproductive safety of the FDCI on sexually nulliparous beef heifers using estrus synchronization and timed artificial insemination. Treatments of either saline (control) or 3X FDCI were administered to coincide with either folliculogenesis, implantation, organogenesis, early gestation, or late gestation. Reproductive safety was demonstrated by evaluating rates of conception, calving, abortion, and stillbirth, dystocia scores, and calf health. In all studies, the FDCI at 1X, 2X, or 3X dosages was well tolerated. In the margin of safety study, 3X calves showed increased incidence of salivation for up to 8 h post-dosing compared to other groups. Injection sites were palpable post-dosing in all three FDCI groups but resolved by Day 28 in all but one animal each in 2X and 3X. In the reproductive safety studies, the FDCI had no effect on conception, pregnancy, fetal development, or postnatal viability. Injection site swelling was increased in frequency and duration compared to controls. The studies demonstrate the safety of the new FDCI in cattle from 3 months of age and in reproducing heifers during all reproductive stages from folliculogenesis through gestation and up to a month post-partum.

Polycaprolactone microparticles for the subcutaneous administration of cannabidiol: in vitro and in vivo release.

Cannabidiol (CBD) has become a highly attractive entity in therapeutics. However, its low aqueous solubility, instability and handling problems limit the development of effective CBD formulations. Subcutaneously administered CBD-loaded polycaprolactone microparticles (MP) represent an interesting strategy to overcome these challenges. This work focuses on evaluating the pharmacokinetics of CBD formulated in polymer microparticles for subcutaneous administration and characterising its release. The mean release time (MRLT) parameter is used to compare the release of CBD from two microparticle formulations in vitro and in a mouse model. After the administration of CBD in solution, a bicompartmental distribution is observed due to the extensive diffusion to the brain, being the brain/blood AUC ratio 1.29. The blood and brain mean residence time (MRT) are 0.507 ± 0.04 and 0.257 ± 0.0004days, respectively. MP prepared with two drug/polymer ratios (15/150-MP and 30/150-MP) are designed, showing similar in vitro dissolution profiles (similarity factor (f2) is 63.21), without statistically significant differences between MRLTin vitro values (4.68 ± 0.63 and 4.32 ± 0.05days). However, considerable differences in blood and brain profiles between both formulations are detected. The blood and brain MRT values of 15/150-MP are 6.44 ± 0.3days and 6.15 ± 0.25days, respectively, whereas significantly lower values 3.91 ± 0.29days and 2.24 ± 0.64days are obtained with 30/150-MP. The extended release of CBD during 10days after a single subcutaneous administration is achieved.

Synthesis and antitumor activity of a 2-hydroxy substituted chalcone (C6)

Cancers account for approximately 13% of all deaths each year with breast cancer being one of the most common. Chemotherapeutic agents used in cancer usually have nonspecific toxicity which kills both tumor and normal cells and cause serious side effects that often limit their efficacy. This study aimed to synthesize chalcone and evaluate its antitumor activity. Chalcone was synthesized using Claisen-Schmidt condensation and characterized using spectroscopic techniques. The LD50 of the synthesized compound was estimated using OECD-425 guidelines in rats. A mammary tumor was induced with a single subcutaneous administration of 65 mg/kg of 1-methyl nitrosourea (MNU). The rats were palpated weekly to determine the size of the tumor. Eight weeks post MNU administration, the rats were divided into five groups of six rats each and treated with graded doses (12.5, 25, and 50 mg/kg) of the compound and paclitaxel (10 mg/kg) for six weeks. Before treatment, three rats were randomly selected and sacrificed, and mammary gland samples were subjected to histological assessment to confirm the induction of the tumor. At the end of the treatment, the rats were euthanized, and mammary glands were collected and subjected to histological evaluation. The possible mechanism of action of the synthesized compound was elucidated in silico using molecular docking. The compound was synthesized and named C6. C6 was found to be relatively safe with LD50 above 2000 mg/kg and exhibited remarkable antitumor activity. MNU-induced mammary tumor rats treated with C6 produced a significant decrease in tumor diameter when compared with the untreated group, histology slides displayed fewer signs of hyperplasia and small numbers of connective tissue with larger lobules when compared with the untreated group. In silico tubulin-binding interactions revealed that C6 binding to tubulin was like that of colchicine, and also has higher affinity to tubulin than colchicine. The synthesized chalcone demonstrated significant antitumor activities in MNU-induced mammary tumors in rats postulated via inhibition of tubulin polymerization.

Long-acting lenacapavir acts as an effective preexposure prophylaxis in a rectal SHIV challenge macaque model.

Long-acting antiretroviral agents for preexposure prophylaxis (PrEP) represent a promising new alternative to daily oral regimens for HIV prevention. Lenacapavir (LEN) is a first-in-class long-acting capsid inhibitor approved for the treatment of HIV-1 infection. Here, we assessed the efficacy of LEN for PrEP using a single high-dose simian-human immunodeficiency virus (SHIV) rectal challenge macaque model. In vitro, LEN showed potent antiviral activity against SHIV, as it did for HIV-1. In macaques, a single subcutaneous administration of LEN demonstrated dose proportional increases in and durability of drug plasma levels. A high-dose SHIV inoculum for the PrEP efficacy evaluation was identified via virus titration in untreated macaques. LEN-treated macaques were challenged with high-dose SHIV 7 weeks after drug administration, and the majority remained protected from infection, as confirmed by plasma PCR, cell-associated proviral DNA, and serology testing. Complete protection and superiority to the untreated group was observed among animals whose LEN plasma exposure exceeded its model-adjusted clinical efficacy target at the time of challenge. All infected animals had subprotective LEN concentrations and showed no emergent resistance. These data demonstrate effective SHIV prophylaxis in a stringent macaque model at clinically relevant LEN exposures and support the clinical evaluation of LEN for HIV PrEP in humans.

Pharmacokinetics and Safety of iGlarLixi in Healthy Chinese Participants: Results of a Phase 1 Randomized Study.

The Chinese Diabetes Society recommends basal insulin and glucagon-like peptide-1 receptor agonists as an add-on therapy to first-line oral antihyperglycemic drugs for people with type 2 diabetes (T2D). Fixed-ratio combination of insulin glargine 100 U/ml (iGlar) and lixisenatide (iGlarLixi) is known to improve glycemic control in adults with T2D. However, the pharmacokinetics of iGlarLixi has not been evaluated in Chinese participants. The present study evaluated pharmacokinetics and safety of two iGlarLixi (10 U/10μg and 30 U/15μg) doses following single subcutaneous administration in healthy Chinese participants. This was a Phase 1, single-center, open-label, parallel-group, randomized study in healthy Chinese adults who were randomized to receive a single dose of iGlarLixi with either 1:1 (10 U/10μg) or 2:1 (30 U/15μg) ratio of iGlar and lixisenatide. Primary objectives include assessment of pharmacokinetics of iGlar in iGlarLixi 30 U/15μg group and the pharmacokinetics of lixisenatide in both the groups (iGlarLixi 10 U/10μg and iGlarLixi 30 U/15μg). Safety and tolerability were also assessed. In iGlarLixi 30 U/15μg group, iGlar concentrations were low and quantifiable in three of ten participants, while its main metabolite (M1) was quantifiable in all participants, reflecting rapid conversion of iGlar to M1. Median INS-tmax was 14.00h for iGlar and 13.00h post-dose for M1. Absorption of lixisenatide was similar in both dose groups with median tmax of 3.25 and 2.00h post-dose in both groups. The exposure increase was dose proportionate with a 1.5-fold increase in the lixisenatide dose. Adverse events observed were consistent with those previously reported with iGlar or lixisenatide. iGlarLixi administration resulted in early absorption of both iGlar and lixisenatide with a good tolerability profile in healthy Chinese participants. These results are consistent with the previously published data from other geographic regions. U1111-1194-9411.

Pharmacokinetics and Tissue Distribution of Bee Venom-Derived Phospholipase A2 Using a Sandwich ELISA after Subcutaneous Injection of New Composition Bee Venom in Rats.

Bee venom is a traditional drug used to treat the nervous system, musculoskeletal system, and autoimmune diseases. A previous study found that bee venom and one of its components, phospholipase A2, can protect the brain by suppressing neuroinflammation and can also be used to treat Alzheimer's disease. Thus, new composition bee venom (NCBV), which has an increased phospholipase A2 content of up to 76.2%, was developed as a treatment agent for Alzheimer's disease by INISTst (Republic of Korea). The aim of this study was to characterize the pharmacokinetic profiles of phospholipase A2 contained in NCBV in rats. Single subcutaneous administration of NCBV at doses ranging from 0.2 mg/kg to 5 mg/kg was conducted, and pharmacokinetic parameters of bee venom-derived phospholipase A2 (bvPLA2) increased in a dose-dependent manner. Additionally, no accumulation was observed following multiple dosings (0.5 mg/kg/week), and other constituents of NCBV did not affect the pharmacokinetic profile of bvPLA2. After subcutaneous injection of NCBV, the tissue-to-plasma ratios of bvPLA2 for the tested nine tissues were all <1.0, indicating a limited distribution of the bvPLA2 within the tissues. The findings of this study may help understand the pharmacokinetic characteristics of bvPLA2 and provide useful information for the clinical application of NCBV.

O47 | Robenacoxib pharmacokinetics in goats (Capra hircus) following single oral, subcutaneous and intravenous administration

Journal of Veterinary Pharmacology and TherapeuticsVolume 46, Issue S1 p. 50-51 ORAL PRESENTATIONS O47 | Robenacoxib pharmacokinetics in goats (Capra hircus) following single oral, subcutaneous and intravenous administration First published: 11 June 2023 https://doi.org/10.1111/jvp.13213Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL No abstract is available for this article. Volume46, IssueS1Special Issue: 15th International Congress of the European Association for Veterinary Pharmacology and Toxicology held Bruges, Belgium, July 2–5, 2023June 2023Pages 50-51 RelatedInformation

Pharmacokinetics of robenacoxib following single intravenous, subcutaneous and oral administrations in Baladi goats (Capra hircus).

The purpose of this study was to assess the pharmacokinetics of robenacoxib (RX), a COX-2 selective non-steroidal anti-inflammatory drug, in goats after single intravenous (IV), subcutaneous (SC) and oral (PO) administrations. 5-month-old healthy female goats (n = 8) were used. The animals were subjected to a three-phase, two-dose (2 mg/kg IV, 4 mg/kg SC, PO) unblinded, parallel study design, with a four-month washout period between the IV and SC treatment, and a one-week period between the SC and PO treatment. Blood was drawn from the jugular vein in heparinized vacutainer tubes at 0, 0.085 (for IV only), 0.25, 0.5, 0.75, 1, 1.5, 2, 4, 6, 8, 10 and 24 h. Plasma RX concentrations were measured using HPLC coupled to a UV multiple wavelength detector, and the data were pharmacokinetically analysed using ThothPro™ 4.3 software in a non-compartmental approach. Following IV administration, terminal elimination half-life, volume of distribution and total clearance were 0.32 h, 0.24 L/kg and 0.52 L/h/kg, respectively. For SC and PO, the mean peak plasma concentrations were 2.34 and 3.34 μg/mL at 1.50 and 0.50 h, respectively. The t1/2λz was significantly different between the IV and the extravascular (EV) administrations (0.32 h IV vs 1.37 h SC and 1.63 h PO), suggesting the occurrence of a flip-flop phenomenon. The significant difference in Vd values between IV (0.24 L/kg) and EV (0.95 L/kg SC and 1.71 L/kg; corrected for F %) routes might have also triggered the t1/2λz difference. The absolute average SC and PO bioavailability were high (98% and 91%, respectively). In conclusion, the IV administration of RX might not be suitable for goats, due to its short t1/2λz. The EV routes, however, appear to be convenient for the drug's occasional use.