Single Intravenous Administration Research Articles

A simple and sensitive ultra-high performance liquid chromatography tandem mass spectrometry method for the quantitative analysis of VX-548 in monkey plasma: Method validation and application to pharmacokinetic study.

VX-548 is an orally active and highly selective NaV 1.8 inhibitor that is undergoing development for the treatment of acute pain. The aim of this study was to develop a liquid chromatography-tandem mass spectrometric (LC-MS/MS) method for the measurement of VX-548 in monkey plasma. VX-548 was extracted from the plasma using acetonitrile-mediated protein precipitation. The quantitative analysis was performed on a Thermo Vantage TSQ mass spectrometer with ibrutinib as an internal standard. Chromatography was performed on a Waters ACQUITY UPLC BEH C18 column with 0.1% aqueous formic acid and acetonitrile as mobile phase. The precursor-to-product ion transitions were m/z 474.2 > 165.0 and m/z 441.2 > 138.1 for VX-548 and internal standard, respectively. This developed method was successfully validated in the concentration range of 1-1000 ng/mL. The calibration curve showed excellent linearity with a correlation coefficient of >0.999. The precision expressed as relative standard deviation (RSD) was <8.4%, whereas the accuracy denoted as relative error (RE) ranged from -5.0% to 9.1%. The mean recovery was >84%. VX-548 was stable in monkey plasma after storage under certain conditions. The validated method was successfully applied to the pharmacokinetic study of VX-548 in monkey plasma after single oral (2 mg/kg) and intravenous (1 mg/kg) administrations.

Research Note: Pharmacokinetics of bromhexine hydrochloride in broilers after single oral and intravenous administration

The current study aimed to investigate the pharmacokinetics of bromhexine hydrochloride in broilers after single intravenous (IV) and oral (PO) administration at 2.5 mg/kg body weight (BW). The trial adopted a randomized, parallel-controlled design, where 20 twelve-wk-old broilers were randomly assigned to either the PO or IV group. Blood samples were collected at predetermined time points, and plasma was further separated for analysis. The bromhexine hydrochloride concentrations in plasma samples were determined using an ultra-performance liquid chromatography-tandem quadrupole mass spectrometry (UPLC-MS/MS) method. Noncompartmental analysis (NCA) using Phoenix software was conducted to analyze the concentration versus time data of bromhexine hydrochloride in every chicken. Subsequently, the main pharmacokinetic parameters between the 2 groups were statistically analyzed using SPSS software. Results from NCA revealed that after oral administration at 2.5 mg/kg BW, bromhexine hydrochloride exhibited slow absorption, reaching an average peak concentration of 32.72 ng/mL at 1.78 h. However, incomplete absorption was observed, with an absolute bioavailability of only 20.06% ± 10.84%. Additionally, bromhexine hydrochloride displayed wide distribution, with a steady-state distribution volume (VSS) of 22.55 ± 13.45 L/kg, and slow elimination, with a clearance (Cl) of 1.52 ± 0.38 L/h/kg. Furthermore, gender effects were assessed on the pharmacokinetics of bromhexine hydrochloride in broilers, revealing better absorption in male broilers compared to females. This disparity may be attributed to the faster blood flow and richer blood volume typically found in male broilers.

Pharmacokinetics of famotidine in goats after intravenous administration.

There is currently limited pharmacokinetic data for the use of famotidine in goats for treatment and prevention of abomasal ulceration. The objective of this study was to determine the pharmacokinetic parameters after a single intravenous administration of famotidine (0.6 mg/kg). Famotidine was administered to six healthy goats and plasma samples were collected over a 24-h period. The famotidine concentration was measured using reverse phase high-performance liquid chromatography (HPLC). Non-compartmental analysis was then used to determine the pharmacokinetic parameters. The maximum plasma concentration was estimated at 5476.68 ± 1530.51 ng/mL and elimination half-life was estimated at 18.455 ± 13.26 min. The mean residence time was determined to be 19.85 ± 12.14 min with the apparent volume of distribution being estimated at 321.924 ± 221.667. The area under the curve was determined to be 54230.08 ± 24947.6 min*ng/mL. Total exposure and elimination half-life were less than what has been reported in cattle and horses. Future research evaluating the pharmacokinetics of subcutaneous administration and looking at the pharmacodynamics of famotidine in goats is needed to determine the effectiveness of famotidine on raising pH levels of the abomasum.

Abstract PO2-06-13: Promising clinical performance of 89Zirconium-labelled Girentuximab PET-CT for imaging metastatic triple negative breast cancer patients (OPALESCENCE)

Abstract Aim: Triple Negative Breast Cancer (TNBC) is aggressive, often with a metastatic evolution and drug-resistant with limited therapeutic options. Evaluating new markers is an unmet need. Recently, the combination of anti-angiogenic and targeted hypoxia effectors agents proved to enhance therapy response. Indeed, anhydrase Carbonic-IX (CA-IX), a hypoxia-mediated breast tumor growth regulator, is important for the BC stem cells maintenance within hypoxic region and is highly overexpressed in TNBC. This pilot prospective study “OPALESCENCE” (NCT04758780) aimed at assessing PET/CT with 89Zr-labeled girentuximab (89Zr-TLX250) targeting CA-IX in 12 metastatic TNBC patients. Methods: Patients underwent FDG and 89Zr-TLX250 PET-CT and conventional imaging (CI) if needed (CT, US, mammography, brain MRI). Without any premedication or dietary preparation, patients received a single slow intravenous administration of 37±10% MBq 89Zr-TLX250 (10 mg). Day 3 or 5 post injection, a skull to mid-thigh PET/CT was acquired with 10 minutes acquisition time per bed position. The gold standard was determined by FDG PET/CT, CI and follow-up; lesion detected at least by 2 modalities was considered as true positive. Immunohistochemistry (IHC) was performed with Bond RX fully automated research stainer with CA-IX antibody (Leica, clone TH22). Staining was evaluated with semi-quantitative analysis (percentage and intensity of tumor cells expression). Human anti-chimeric antibody (HACA) were sampled but will be determined at study end. Results: Enrolment has been completed, a total of 273 lesions confirmed by gold standard as shown on table 1 were detected in 12 patients (231 by 89Zr-TLX250 and 264 by FDG PET/CT). Overall sensitivity of 89Zr-TLX250 PET/CT was 87.5%, with 100% sensitivity for breast, skin, adrenal gland and brain and 88.0%, 91.9% for nodes and bone respectively. Overall sensitivity for FDG-PET/CT was 96.7%. According to table 2, 6 patients had 100% of their lesions highlighted by 89Zr-TLX250 PET. In addition, for 2 other patients only one of the lesions was not detected by immunoPET. 89Zr-TLX250 PET therefore detected almost all of the metastatic lesions in 67% of the patients. For 8/12 patients, IHC was analysed and for 6 patients, CA-IX expression lesions was from 100% to 10% with an intensity from 3+ to 2+, whereas two patients presented no Ca-IX expression on tumour lesions. No 89Zr-TLX250 safety issue was reported. Conclusion: 89Zr-TLX250 PET/CT seems very promising because it allows the CA IX status lesions knowledge on whole body scale with a minimally invasive way, unlike the information provided by biopsies corresponding to only 1 or 2 lesions studied. Moreover, these results illustrated interest of 89Zr-TLX250 PET/CT as targeting agent for TNBC patients leading above all to a theranostic approach possibility. Study analysis (specially IHC, HACA and semi-quantitative PET/CT analysis) is ongoing and supplementary data will be presented during the congress. This is an investigator initiated trial. Investigational medicinal product was provided by Telix Pharmaceuticals. Table 1: Sensitivity of 89Zr-TLX250 PET, FDG PET, and conventional imaging (US, brain MRI and Mammography). Table 2: Number of confirmed lesions according to Gold Standard detected by 89Zr-TLX250 PET/CT (iPET), FDG PET/CT and CI for each patients. Citation Format: Caroline Rousseau, Marie Francoise Heymann, Jean Sebastien FRENEL, Elise Picot-Dilly, Maelle Le Thiec, Manon Taupin, Alexis Mouton, Emmanuelle Bourbouloux, Agnès Morel, Nadia Allam, Amélie Mallet, Mario Campone, Ludovic Ferrer, Françoise Kraeber-Bodéré. Promising clinical performance of 89Zirconium-labelled Girentuximab PET-CT for imaging metastatic triple negative breast cancer patients (OPALESCENCE) [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO2-06-13.

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.

Advancing 6-bromo-7-[11C]methylpurine to clinical use: improved regioselective radiosynthesis, non-clinical toxicity data and human dosimetry estimates

Background6-Bromo-7-[11C]methylpurine ([11C]BMP) is a radiotracer for positron emission tomography (PET) to measure multidrug resistance-associated protein 1 (MRP1) transport activity in different tissues. Previously reported radiosyntheses of [11C]BMP afforded a mixture of 7- and 9-[11C]methyl regioisomers. To prepare for clinical use, we here report an improved regioselective radiosynthesis of [11C]BMP, the results of a non-clinical toxicity study as well as human dosimetry estimates based on mouse PET data.Results[11C]BMP was synthesised by regioselective N7-methylation of 6-bromo-7H-purine (prepared under good manufacturing practice) with [11C]methyl triflate in presence of 2,2,6,6-tetramethylpiperidine magnesium chloride in a TRACERlab™ FX2 C synthesis module. [11C]BMP was obtained within a total synthesis time of approximately 43 min in a decay-corrected radiochemical yield of 20.5 ± 5.2%, based on starting [11C]methyl iodide, with a radiochemical purity > 99% and a molar activity at end of synthesis of 197 ± 130 GBq/μmol (n = 28). An extended single-dose toxicity study conducted in male and female Wistar rats under good laboratory practice after single intravenous (i.v.) administration of unlabelled BMP (2 mg/kg body weight) revealed no test item related adverse effects. Human dosimetry estimates, based on dynamic whole-body PET data in female C57BL/6J mice, suggested that an i.v. injected activity amount of 400 MBq of [11C]BMP will deliver an effective dose in the typical range of 11C-labelled radiotracers.Conclusions[11C]BMP can be produced in sufficient amounts and acceptable quality for clinical use. Data from the non-clinical safety evaluation showed no adverse effects and suggested that the administration of [11C]BMP will be safe and well tolerated in humans.

Safety and efficacy of multiple-dose versus single-dose MIBG therapy in patients with refractory pheochromocytoma and paraganglioma: a single-center retrospective analysis.

To investigate the incidence of adverse events (AEs) following single and multiple administrations of I-131 metaiodobenzylguanidine (MIBG) therapy for inoperable pheochromocytomas and paragangliomas (PPGLs). A single-center retrospective study was conducted on patients with inoperable PPGLs who underwent I-131 MIBG therapy between January 2000 and December 2020. A total of 28 patients with available electronic medical records were included. The treatment consisted of a single intravenous administration of 150mCi (5.55GBq) of I-131 MIBG. We evaluated the first MIBG treatment and repeated MIBG treatments performed within 200days of the previous treatment. AEs for each treatment were evaluated using CTCAE version 4.0, and the statistical analysis was conducted at a significance level of p < 0.05. Objective response based on RECIST 1.1 criteria and biochemical response based on urinary catecholamines were assessed. The study included a total of 63 administrations, consisting of 28 single administrations (SAs), including the first administration for all 28 cases, and 35 multiple administrations (MAs), which included the second or later administrations. Hematological AEs were evaluable for 23 SAs and 29 MAs. Grade 3 or higher leukopenia occurred in 9.8% of all administrations, and Grade 3 or higher lymphopenia in 23.5%; both were manageable through observation. There were no significant differences in clinical AE Grades 1-2 (p = 0.32), hematological AE Grades 1-2 (p = 0.22), or hematological AE Grades 3-4 (p = 0.12) between MAs and SAs. Statistical analysis for each type of AE revealed significant increases in leukopenia (p < 0.01) and lymphopenia (p = 0.04). No significant difference in anemia, thrombocytopenia, or neutropenia was observed between MAs and SAs. There was no significant increase in the incidence rate of Grade 3 or higher hematological AEs for any of the parameters. The objective response rate was 0% for SAs and 36% for MAs. Biochemical response rates were 18% for SAs and 67% for MAs. In I-131 MIBG therapy for PPGLs, multiple administrations significantly increased only Grade 1 or 2 lymphopenia and leukopenia compared to single administration.

Effects of Chrysin and Chrysin-7-sulfate on Ochratoxin A-Albumin Interactions and on the Plasma and Kidney Levels of the Mycotoxin in Rats.

The nephrotoxic mycotoxin ochratoxin A (OTA) is a common food contaminant. OTA binds to the Sudlow's Site I region of serum albumin with very high affinity, resulting in its slow elimination. The displacement of OTA from albumin may be beneficial due to the faster excretion of the mycotoxin, while it may also lead to the increased tissue uptake of OTA. Furthermore, it is challenging to displace the mycotoxin from albumin even with high-affinity Site I ligands. In this study, we tested the impacts of Site I and Heme site ligands on OTA-albumin interactions by applying fluorescence spectroscopic, ultracentrifugation, and modeling studies. Chrysin-7-sulfate (C7S) strongly displaced OTA from both human and rat albumins; therefore, the impacts of C7S (single intravenous administration) and the parent flavonoid chrysin (repeated peroral treatment) were examined on the plasma and kidney levels of OTA in rats. Chrysin barely influenced the concentrations of mycotoxin in plasma and kidneys. In the first few hours, C7S significantly decreased the plasma levels of OTA compared to the control animals; while after 24 h, only minor differences were noticed. Our study highlights the superior displacing ability of C7S vs OTA regarding human and rat albumins.

Persistent transgene expression in peripheral tissues one year post intravenous and intramuscular administration of AAV vectors containing the alphaherpesvirus latency-associated promoter 2.

Significant progress has been made in enhancing recombinant adeno-associated virus (rAAV) for clinical investigation. Despite its versatility as a gene delivery platform, the inherent packaging constraint of 4.7 kb imposes restrictions on the range of diseases it can address. In this context, we present findings of an exceptionally compact and long-term promoter that facilitates the expression of larger genes compared to conventional promoters. This compact promoter originated from the genome of the alphaherpesvirus pseudorabies virus, latency-associated promoter 2 (LAP2, 404 bp). Promoter driving an mCherry reporter was packaged into single strand (ss) AAV8 and AAV9 vectors and injected into adult C57BL/6 mice at a dose of 5 × 1011 vg/mouse by single intravenous or intramuscular administration. An ssAAV8 and ssAAV9 vector with elongation factor-1α promoter (EF1α, 1264 bp) was injected side-by-side for comparison. After 400 days, we sacrificed the mice and examined mCherry expression in liver, kidney, heart, lung, spleen, pancreas, skeletal muscle, and brain. We found that LAP2 exhibited robust transgene expression across a wide range of cells and tissues comparable to the larger EF1α, which is currently recognized as a rather potent and ubiquitous promoter. The AAV8-LAP2 and AAV9-LAP2 constructs displayed strong transduction and transcription in liver, kidney, and skeletal muscle on both route of administration. However, no expression was detected in the heart, lung, spleen, pancreas, and brain. The outcomes of our investigation propose the viability of LAP2 for gene therapy applications demanding the expression of large or multiple therapeutic genes following a single viralvector administration.

Abstract 679: TXB-001 is an upgraded conjugated anthracycline that targets tumors with reduced risk of cardiotoxicity, hand-foot syndrome and alopecia

Abstract TXB-001 is a well-optimized N-(2-hydroxypropyl)methacrylamide copolymer-based conjugated pirarubicin (THP) and a novel candidate for developing anticancer drugs. It exhibits tumor-specific accumulation due to the enhanced permeability and retention effects and prolonged circulation time compared with free THP. Its hydrazone bond is dissociated under lower pH conditions, providing selective and rapid release of THP in acidic tumor environments. Therefore, TXB-001 is expected to have high efficacy and low toxicity. Anthracycline anticancer drugs have been widely used for the treatment of several cancers, but their use is limited by several adverse effects (AEs), including cardiotoxicity, which is a life-threatening AE. Furthermore, the maximum lifetime cumulative dose is decided for each anthracycline in clinical use, which leads to discontinuation of the medication. Hand-foot syndrome (HFS) is a dose-limiting AE of DOXIL®, a liposomal formulation of doxorubicin (DOX), and although it is not a life-threatening condition, it significantly deteriorates quality of life (QOL). Alopecia is another common AE, which is relatively noninvasive but adversely affects mental health and reduces QOL. In this study, we confirmed the efficacy of TXB-001 in a mice triple-negative breast cancer (TNBC) model and evaluated the cardiotoxicity-, HFS- and alopecia-inducing effects of TXB-001 in mice and rats to compare the severity with existing anthracycline anticancer drugs, including DOXIL®. The pharmacokinetic (PK) analysis in several tissues, including plasma, tumor, heart, skin of the chest, and palmar and plantar areas, was also performed after a single intravenous administration in rodents. As a result, TXB-001 showed an equivalent or greater antitumor effects than other anthracyclines in the TNBC model, and the AEs were scarcely observed. TXB-001 did not decrease left ventricular ejection fraction, with no or little HFS-like changes compared with DOXIL®, which showed significant histopathological changes. TXB-001 also showed weaker alopecia-inducing effects than DOX, DOXIL®, and THP. In the PK analysis, TXB-001 was distributed in the tumor at a higher concentration than in other tissues, except for plasma. Hence, most of the THP, the active ingredient, was released in the tumor. The exposure of the heart in the TXB-001-treated group was one-tenth of that in the DOXIL®-treated group. Moreover, accumulation in the skin, especially in palmar and plantar areas, was observed for DOXIL®, but no accumulation in the skin was observed for TXB-001. This PK profile consistently demonstrated the antitumor activity of TXB-001, without AEs. TXB-001 reduces the chance of dose-limiting and QOL-threatening AEs, and thus, cancer patients can continue treatment, making it a more convenient anticancer drug in clinical use with a wide safety margin. Citation Format: Keiyu Oshida, Mikito Hirakata, Emi Tomikawa, Chizuka Sakai, Masashi Uchida, Rieko Shimozono, Akiko Izawa, Yoko Koga, Tsubasa Okano, Hideki Narumi, Lisa Munakata, Ryo Suzuki, Miki Nonaka, Yasuhito Uezono. TXB-001 is an upgraded conjugated anthracycline that targets tumors with reduced risk of cardiotoxicity, hand-foot syndrome and alopecia [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 679.

Abstract 6028: Preferential tumor-to-normal tissue biodistribution and single-dose efficacy with ABD147, a DLL3-targeted engineered antibody-based radiotherapeutic, in preclinical small cell lung cancer models

Abstract Targeted radiotherapies represent an emerging treatment modality for aggressive cancers with limited treatment options, such as small cell lung cancer (SCLC). ABD147 is a Delta Ligand 3 (DLL3)-targeted antibody conjugate designed to carry and deliver cytotoxic radioactive isotopes to DLL3-expressing tumor cells. DLL3 is commonly expressed on the cell surface of neuroendocrine cancer cells, including SCLC, but has limited and predominantly intracellular expression in non-malignant tissues. The ABD147 antibody specifically binds human DLL3 with high affinity and is internalized by DLL3-expressing cancer cells. To minimize radiation exposure to normal tissue, ABD147 has been engineered to clear quickly from the blood compartment. Using indium-111 to determine ABD147 pharmacokinetics and biodistribution in mice, we demonstrate rapid blood and normal tissue clearance of 111In-ABD147, as designed, following a single intravenous dose administration. However, 111In-ABD147 retains high tumor accumulation (activity concentration of up to 30% ID/g) in xenograft mouse models of SCLC despite low DLL3 surface antigen expression on tumor cells (≤ 3000 copies). 111In-ABD147 shows a favorable tumor-to-normal tissue distribution with predominant liver clearance. Following ABD147 therapeutic radioisotope delivery of actinium-225 or lutetium-177 (225Ac-ABD147, 177Lu-ABD147), we demonstrate single-dose tumor regression and dose-dependent sustained anti-tumor efficacy, corresponding to an extension of survival out to 84 days in multiple SCLC xenograft models. In summary, ABD147 can preferentially deliver radionuclides to DLL3-expressing tumor tissue while substantially reducing the systemic radioactive exposure typical of conventional IgG radioconjugates. Following promising results in preclinical models, including potent anti-tumor activity, 225Ac-ABD147 is now progressing into clinical development. Citation Format: Iva Kulic, Etienne S. Melese, Emma Cummins, Alex Mandel, Raja Viswas, Michael Abrams, Adam Judge. Preferential tumor-to-normal tissue biodistribution and single-dose efficacy with ABD147, a DLL3-targeted engineered antibody-based radiotherapeutic, in preclinical small cell lung cancer models [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6028.

TXB-001, a newly-developed polymer-conjugated anthracycline: Significantly lower adverse effects in animal models of alopecia and hand-foot syndrome

Anthracycline anti-cancer drugs have been widely used in the treatment of several cancers; however, their use is limited by adverse effects (AEs). Alopecia is a common AE that is minimally invasive, but adversely affects mental health and reduces quality of life (QoL). Hand-foot syndrome (HFS) is a dose-limiting AE of DOXIL, a liposomal formulation of doxorubicin (DOX). Although it is not a life-threatening condition, HFS affects function and reduces QoL. TXB-001 is a new candidate polymer-conjugated anthracycline anti-cancer drug, and modified and optimized polymerized pirarubicin (THP), known as P-THP, is expected to have low toxicity and high efficacy. The anti-cancer effects of TXB-001 were examined using the 4T1 mouse model. An alopecia mouse model and HFS rat model were used to evaluate the alopecia- and HFS-inducing effects of TXB-001 and compare their severity with existing anthracycline anti-cancer drugs. A pharmacokinetic analysis of plasma as well as chest, palmar, and plantar skin samples after the single intravenous administration of DOXIL and TXB-001 to rats was also performed. The results obtained revealed that TXB-001 exerted similar anti-cancer effects to those of DOXIL in mice, weaker alopecia-inducing effects than DOX, DOXIL, and THP in mice, and no or markedly weaker HFS-like changes than DOXIL, which induced significant histopathological changes. The results of the pharmacokinetic analysis showed the accumulation of DOXIL, but not TXB-001, in skin, particularly palmar and plantar skin samples, and these differences were considered to contribute to their HFS-inducing effects.

Abstract 6057: Evaluation of a highly potent and selective STAT3 degrader as a new class of immunotherapy

Abstract STAT3 (signal transducer and activator of transcription 3) is a transcription factor and a promising therapeutic target for cancer and other human diseases. In addition to its role in regulation of tumor cells, STAT3 also plays a key role in regulation of immunity and is a promising therapeutic target for the development of new immuno-oncology drugs. Our laboratory has previously reported the development of potent and highly selective STAT3 degraders, including SD-36 and SD-91. Extensive optimization of SD-36 and SD-91 yielded new, highly potent, selective and efficacious STAT3 degraders. In direct comparison, our most potent, new STAT3 degrader (compound 1) is &amp;gt;50-times more potent than SD-36 in inducing STAT3 degradation in cells and demonstrates &amp;gt;500-fold degradation selectivity over other STAT members. A single intravenous administration of compound 1 in mice is highly effective in inducing complete depletion of STAT3 protein in tissues for 48-96 h without reducing the levels of other STAT proteins. Compound 1 is very effective in inhibition of tumor growth not only in tumor models responsive to immune checkpoint blockade (ICB) but also in tumor models resistant to ICB. Furthermore, combination of compound 1 with PD-1/PD-L1 antibodies greatly enhances the antitumor activity as compared to SD-1218 or ICB. Of significance, compound 1 is well tolerated in mice without any signs of toxicity in mice at highly efficacious doses. Our mechanistic studies show that STAT3 depletion has a major effect in modulation of the immune cells in mice. Collectively, our data suggest that selective STAT3 degradation hold great promise for new cancer immunotherapy. Citation Format: Longchuan Bai, Haibin Zhou, Jiajia Zhou, Dimin Wu, Ranjan Kumar Acharyya, Hoda Metwally, Donna McEachern, Bo Wen, Duxin Sun, Weiping Zou, Shaomeng Wang. Evaluation of a highly potent and selective STAT3 degrader as a new class of immunotherapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6057.

Abstract 6050: Targeting KRAS G12D mutant tumors with the PROTAC degrader RP03707

Abstract RAS oncogene mutations are prevalent in approximately 19% of cancer patients, with the most frequent alteration occurring in codon 12 of the KRAS gene, resulting in a variety of G12X oncoproteins. Recent advances in drug discovery have yielded several KRAS G12C inhibitors currently in clinical use, benefiting a subset of patients. However, addressing the high-prevalence G12D mutation remains a substantial unmet medical need. Targeted protein degradation using PROTAC molecules offers a promising approach for treating KRAS G12D-associated tumors, potentially providing superior efficacy and mitigating the development of resistance, a challenge frequently observed with KRAS G12C inhibitors in clinical settings. In the present study, we report a PROTAC compound RP03707 that efficiently induces the degradation of the KRAS G12D mutant protein and inhibits tumor growth. Treatment of AsPc-1 cells with RP03707 results in significant degradation of the KRAS G12D protein, with a DC50 value in the sub-nanomolar range. Within 24 hours, the compound eliminates over 90% of G12D proteins and effectively suppresses downstream cellular MAPK signaling. Additional in vitro experiments demonstrate that RP03707 inhibits cell proliferation in multiple KRAS G12D mutant cell lines, surpassing the anti-tumor efficacy of enzyme inhibitors. In a mouse GP2d xenograft tumor model, a single intravenous administration of RP03707 at 10 mpk results in excellent compound penetration and retention in tumor tissues, followed by 90% reduction of G12D protein levels for 7 days. Profound inhibition of tumor growth is observed not only in mouse GP2d xenograft but also in other mouse KRAS G12D tumor models, even when the compound is administered in low and infrequent doses. Moreover, RP03707 exhibits high selectivity for degrading the KRAS G12D protein and possesses favorable drug-like properties. RP03707, therefore, meets the criteria for advancing into drug development and represents a valuable therapeutic option for treating KRAS G12D-associated tumors. Citation Format: Xiang Ji, Huanping Li, Gang Wu, Qiguo Zhang, Xiaolin He, Yanpeng Wu, Bing Zong, Xiaojin Xu, Chao Liang, Beibei Wang, Yuwei Zhang, Qingyao Hu, Jiaxin Zhou, Weihui Guo, Bing Bai, Lin Wang, Jinchao Ai, Leduo Zhang, Honggui Zhou, Shihao Sun, Yijie Wang, Youhong Wang, Qiming Fan, Dawei Chen, Tianlun Zhou, Jiasheng Lu. Targeting KRAS G12D mutant tumors with the PROTAC degrader RP03707 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6050.

Abstract 4509: Discovery of potent and highly efficacious STAT3 PROTAC degraders capable of achieving long-lasting tumor regression

Abstract STAT3 (signal transducer and activator of transcription 3) is a transcription factor and a promising therapeutic targets for cancer and other human diseases. We have previously reported the discovery of SD-36 and SD-91 as potent, selective and highly efficacious STAT3 degraders. In the present study, we report the discovery of highly potent, selective and efficacious new STAT3 degraders. These STAT3 degraders were designed using our high-affinity STAT3 ligands and high-affinity VHL-1 ligands, with UM-STAT3-3100 being the best. In direct comparison, UM-STAT3-3100 is &amp;gt;10-times more potent than SD-36 and SD-91 in inducing STAT3 degradation in cells and are highly selective over other STAT members in vitro and in vivo. A single intravenous administration of UM-STAT3-3100 resulted in complete and long-lasting depletion of STAT3 protein for &amp;gt;48 hrs in tumor and native tissues. Weekly administration of UM-STAT3-3100 at 10 mg/kg achieved complete and long-lasting tumor regression in animal models of human cancer without any signs of toxicity. UM-STAT3-3100 is a promising compound for extensive evaluation for the treatment of human cancers and other human diseases in which STAT3 plays a key role. Citation Format: Ranjan K. Acharyya, Longchuan Bai, Haibin Zhao, Dimin Wu, Metwally Hoda, McEachern Donna, Wen Bo, Duxin Sun, Shaomeng Wang. Discovery of potent and highly efficacious STAT3 PROTAC degraders capable of achieving long-lasting tumor regression [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4509.

Phototoxicity in vitro and safety in vivo of the emulsion photosensitizer based on furanocoumarins of Heracleum sosnowskyi

The use of plants such as giant hogweed as raw materials for the manufacture of dosage forms has been little explored. In this study, we utilized furanocoumarins from the Heracleum sosnowskyi plant to create an experimental emulsion dosage form (EmFHS). The EmFHS was finely dispersed (481.8 nm ± 71.1 nm), shelf-stable, and contained predominantly 8-methoxypsoralen at a concentration of 1 mg/ml.Phototoxicity analysis of EmFHS for THP-1 cells under UV (365 nm) irradiation showed an IC50 of 19.1 µg/ml (24 h) and 6.3 µg/ml (48 h). In relation to spheroids (L929), EmFHS exhibited a phototoxic effect in the concentration range of 31.25–125 µg/ml8-MOP. A full phototoxic effect was observed 48 h after UV irradiation. The phototoxic effect of EmFHS in vitro was dose-dependent and comparable to the effect of emulsion synthetic 8-methoxypsoralen and chlorin e6 solution. EmFHS cytotoxicity was caused solely by UV radiation, and toxicity in the dark was minimal.EmFHS, administered at a dose of 3 mg/kg8-MOP, was found to be safe after a single intravenous administration to rats. It had a photosensitizing effect in the form of local photodermatitis when exposed to UV irradiation at a dose of 44 J/cm2.The biokinetics of emulsion furanocoumarins showed that the phototoxic effect of EmFHS is due to the high penetration ability of the emulsion into cells of spheroids. At the same time, it has a low degree of cumulation when administered intravenously.The obtained data suggest that EmFHS may be a promising treatment for PUVA therapy of various dermatological diseases. Additionally, the plant Heracleum sosnowskyi shows potential as a basis for creating new dosage forms with phototherapeutic effects.

Pharmacokinetic Study of Ultrasmall Superparamagnetic Iron Oxide Nanoparticles HY-088 in Rats.

HY-088 injection is an ultrasmall superparamagnetic iron oxide nanoparticle (USPIOs) composed of iron oxide crystals coated with polyacrylic acid (PAA) on the surface. The purpose of this study was to investigate the pharmacokinetics, tissue distribution, and mass balance of HY-088 injection. The pharmacokinetics of [55Fe]-HY-088 and [14C]-HY-088 were investigated in 48 SD rats by intravenous injection of 8.5 (low-dose group), 25.5 (medium-dose group), and 85 (high-dose group) mg/100 μCi/kg. Tissue distribution was studied by intravenous injection of 35 mg/100 μCi/kg in 48 SD rats, and its tissue distribution in vivo was obtained by ex vivo tissue assay. At the same time, [14C]-HY-088 was injected intravenously at a dose of 25.5 mg/100 μCi/kg into 16 SD rats, and its tissue distribution in vivo was studied by quantitative whole-body autoradiography. [14C]-HY-088 and [55Fe]-HY-088 were injected intravenously into 24 SD rats at a dose of 35 mg/100 μCi/kg, and their metabolism was observed. In the pharmacokinetic study, [55Fe]-HY-088 reached the maximum observed concentration (Cmax) at 0.08 h in the low- and medium-dose groups of SD rats. [14C]-HY-088 reached Cmax at 0.08 h in the three groups of SD rats. The area under the concentration-time curve (AUC) of [55Fe]-HY-088 and [14C]-HY-088 increased with increasing dose. In the tissue distribution study, [55Fe]-HY-088 and [14C]-HY-088 were primarily distributed in the liver, spleen, and lymph nodes of both female and male rats. In the mass balance study conducted over 57 days, the radioactive content of 55Fe from [55Fe]-HY-088 was primarily found in the carcass, accounting for 86.42±4.18% in females and 95.46±6.42% in males. The radioactive recovery rates of [14C]-HY-088 in the urine of female and male rats were 52.99±5.48% and 60.66±2.23%, respectively. Following single intravenous administration of [55Fe]-HY-088 and [14C]-HY-088 in SD rats, rapid absorption was observed. Both [55Fe]-HY-088 and [14C]-HY-088 were primarily distributed in the liver, spleen, and lymph nodes. During metabolism, the radioactivity of [55Fe]-HY-088 is mainly present in the carcass, whereas the 14C-labeled [14C]-HY-088 shell PAA is eliminated from the body mainly through the urine.

Respiratory Safety Pharmacological Testing with Single Intravenous Administration of Caffeine in Sprague-Dawley Rats.

As caffeine consumption continues to increase, both positive and negative effects are becoming evident. Caffeine directly affects the cardiovascular system, including heart function and rate. Thus, understanding the current respiratory safety pharmacological responses is of utmost importance. To elucidate the respiratory safety pharmacological characteristics of caffeine, male Sprague-Dawley rats, aged 6 weeks, were intravenously administered doses of 0, 2, 6, and 20 mg/kg of caffeine. Respiratory rate, tidal volume, and minute volume were subsequently measured. In this study, we observed a significant increase in respiratory rate and minute volume, but a remarkable reduction in tidal volume following the intravenous administration of caffeine at doses exceeding 6 mg/kg. These changes were evident within the timeframe of 0.25 to 1.5 h. The data we have collected can serve as valuable foundational scientific information for future research on caffeine, encompassing absorption, distribution, metabolism, excretion, and pharmacological core-battery experiments.

Tolerability, safety, and pharmacokinetics of a single intravenous administration of a novel recombinant humanized anti-interleukin-6 receptor monoclonal antibody in healthy Chinese volunteers.

Aim: VDJ001 is a novel recombinant humanized monoclonal antibody against the anti-interleukin-6 receptor. As an analog of tocilizumab, it exhibited improved affinity and in vitro activity. Based on preclinical studies, a first-in-human clinical study was conducted to evaluate the safety, tolerability, and pharmacokinetics of VDJ001. Methods: This is a single-center, randomized, double-blinded, placebo-controlled phase I dose-escalation study conducted in healthy Chinese volunteers. Four cohorts were designed with dosages ranging from 1 to 8mg/kg. There were equal numbers of female and male volunteers in each cohort. Enrolled subjects randomly received a single intravenous administration of VDJ001 or placebo (VDJ001: placebo = 4:1 in both female and male volunteers). Three sentinel volunteers in the 1mg/kg cohort were first administered, and the treatment of the other seven volunteers was carried out after a safety assessment on D15. The following cohort was conducted only when the safety profile was evaluated as acceptable on D29 of the previous cohort. Samples for pharmacokinetics (PK), pharmacodynamics (PD), and immunogenicity were collected at specified time points and analyzed through validated methods. Adverse events and the results of the examination and laboratory were analyzed to assess the safety profile. Results: All cohorts were carried out according to the protocol. With the escalation of dosage, Cmax increased linearly, and AUC0-t and AUC0-∞ increased in a non-linear manner, while clearance decreased and t1/2 prolonged. Six volunteers who received VDJ001 tested ADA-positive, among whom one participant tested Nab-positive on D57. One volunteer in the placebo group tested ADA-positive but Nab-negative. CRP concentrations were not found to be correlated with the dosage. Both IL-6 and sIL-6R concentrations increased after the administration of VDJ001. All adverse events were mild to moderate in severity. No serious adverse events were reported in this study. No unexpected or clinically significant safety issues were found. Conclusion: The safety and tolerability of VDJ001 are acceptable with a single intravenous dosage of 1∼8mg/kg. Further clinical trials are warranted.

A low-anticoagulant heparin suppresses metastatic dissemination through the inhibition of tumor cell-platelets association

Metastasis is the leading cause of cancer-related deaths. Despite this relevance, there is no specific therapy targeting metastasis. The interaction of the tumor cell with platelets, forming microemboli is crucial for successful hematogenous dissemination. Heparin disrupts it by a P-selectin-mediated event. However, its clinical use for this purpose is hindered by the requirement of high doses, leading to anticoagulant-related side effects. In this study, we obtained a low-anticoagulant heparin through the fractionation of a pharmaceutical bovine heparin. This derivative was referred to as LA-hep and we investigated its efficacy in inhibiting metastases and explored its capacity of suppressing the interaction between tumor cells and platelets. Our data revealed that LA-hep is as efficient as porcine unfractionated heparin in attenuating lung metastases from melanoma and colon adenocarcinoma cells in an assay with a single intravenous administration. It also prevents platelet arrest shortly after cell injection in wild-type mice and suppresses melanoma-platelets interaction in vitro. Moreover, LA-hep blocks P-selectin's direct binding to tumor cells and platelet aggregation, providing further evidence for the role of P-selectin as a molecular target. Even in P-selectin-depleted mice which developed a reduced number of metastatic foci, both porcine heparin and LA-hep further inhibited metastasis burden. This suggests evidence of an additional mechanism of antimetastatic action. Therefore, our results indicate a dissociation between the heparin anticoagulant and antimetastatic effects. Considering the simple and highly reproducible methodology used to purify LA-hep along with the data presented here, LA-hep emerges as a promising drug for future use in preventing metastasis in cancer patients.