Water-soluble Prodrug Research Articles

Improvement in edema and cognitive recovery after moderate traumatic brain injury with the neurosteroid prodrug NTS-104

Neuroactive steroids reduce mortality, decrease edema, and improve functional outcomes in preclinical and clinical traumatic brain injury (TBI) studies. In this study, we tested the efficacy of two related novel neuroactive steroids, NTS-104 and NTS-105, in a rat model of TBI. NTS-104 is a water-soluble prodrug of NTS-105, a partial progesterone receptor agonist. To investigate the effects of NTS-104 on TBI recovery, adult male Sprague Dawley rats received moderate parasagittal fluid-percussion injury or sham surgery and were treated with vehicle or NTS-104 (10 ​mg/kg, intramuscularly) at 4, 10, 24, and 48 ​h post-TBI. The therapeutic time window was also assessed using the neuroactive steroid NTS-105 (3 ​mg/kg, intramuscularly). Edema in the parietal cortex and hippocampus, measured at 3 days post-injury (DPI), was reduced by NTS-104 and NTS-105. NTS-105 was effective in reducing edema when given at 4, 10, or 24 ​h post-injury. Sensorimotor deficits in the cylinder test at 3 DPI were ameliorated by NTS-104 and NTS-105 treatment. Cognitive recovery, assessed with cue and contextual fear conditioning and retention of the water maze task assessed subacutely 1–3 weeks post-injury, also improved with NTS-104 treatment. Cortical and hippocampal atrophy at 22 DPI did not improve, indicating that NTS-104/NTS-105 may promote post-TBI cognitive recovery by controlling edema and other processes. These results demonstrate that NTS-104/NTS-105 is a promising therapeutic approach to improve motor and cognitive recovery after moderate TBI.

Sol-moiety: Discovery of a water-soluble prodrug technology for enhanced oral bioavailability of insoluble therapeutics

Though conceptually attractive, the use of water-soluble prodrug technology to enhance oral bioavailability of highly insoluble small molecule therapeutics has not been widely adopted. In large part, this is due to the rapid enzymatic or chemical hydrolysis of prodrugs within the gastrointestinal tract, resulting in drug precipitation and no overall improvement in oral bioavailability relative to standard formulation strategies. We reasoned that an optimal water-soluble prodrug could be attained if the rate of prodrug hydrolysis were reduced to favor drug absorption rather than drug precipitation. In doing so, the rate of hydrolysis provides a pharmacokinetic control point for drug delivery. Herein, we report the discovery of a water-soluble promoiety (Sol-moiety) technology to optimize the oral bioavailability of highly insoluble small molecule therapeutics, possessing various functional groups, without the need for sophisticated, often toxic, lipid or organic solvent-based formulations. The power of the technology is demonstrated with marked pharmacokinetic improvement of the commercial drugs enzalutamide, vemurafenib, and paclitaxel. This led to a successful efficacy study of a water-soluble orally administered prodrug of paclitaxel in a mouse pancreatic tumor model.

Preclinical characterization of a water-soluble low-impact ampakine prodrug, CX1942 and its active moiety, CX1763

Preclinical characterization of a water-soluble low-impact ampakine prodrug, CX1942 and its active moiety, CX1763

Dexamethasone nanocrystals-embedded hydroxypropyl methylcellulose hydrogel increases cochlear delivery and attenuates hearing loss following intratympanic injection

Herein, dexamethasone (DEX) nanocrystalline suspension (NS)-embedded hydrogel (NS-G) was constructed using a hydroxypropyl methylcellulose (HPMC) polymer to enhance cochlear delivery and attenuate hearing loss following intratympanic (IT) injection. Hydrophobic steroidal nanocrystals were prepared using a bead milling technique and incorporated into a polysaccharide hydrogel. The NS-G system with HPMC (average molecular weight, 86,000 g/mol; 15 mg/mL) was characterized as follows: rod-shaped drug crystalline; particle size <300 nm; and constant complex viscosity ≤1.17 Pa·s. Pulverization of the drug particles into submicron diameters enhanced drug dissolution, while the HPMC matrix increased the residence time in the middle ear cavity, exhibiting a controlled release profile. The IT NS-G system elicited markedly enhanced and prolonged drug delivery (> 9 h) to the cochlear tissue compared with that of DEX sodium phosphate (DEX-SP), a water-soluble prodrug. In mice with kanamycin- and furosemide-induced ototoxicity, NS-G markedly enhanced hearing preservation across all frequencies (8–32 kHz), as revealed by an auditory brainstem response test, compared with both saline and DEX-SP. Moreover, treatment with NS-G showed enhanced anti-inflammatory effects, as evidenced by decreased levels of inflammation-related cytokines. Therefore, the IT administration of DEX NS-loaded HPMC hydrogels is a promising strategy for treating hearing loss.

Minnelide exhibits antileukemic activity by targeting the Ars2/miR-190a-3p axis

BackgroundThe identification of a novel and effective strategy for the clinical treatment of acute leukemia (AL) is a long-term goal. Minnelide, a water-soluble prodrug of triptolide, has recently been evaluated in phase I and II clinical trials in patients with multiple cancers and has shown promise as an antileukemic agent. However, the molecular mechanism underlying minnelide's antileukemic activity remains unclear. PurposeTo explore the molecular mechanisms by which minnelide exhibits antileukemic activity. MethodsAL cells, primary human leukemia cells, and a xenograft mouse model were treated with triptolide and minnelide. The molecular mechanism was elucidated using western blotting, immunoprecipitation, flow cytometry, GSEA and liquid chromatography-mass spectrometry analysis. ResultsMinnelide was highly effective in inhibiting leukemogenesis and improving survival in two complementary AL mouse models. Triptolide, an active form of minnelide, causes cell cycle arrest in G1 phase and induces apoptosis in both human AL cell lines and primary AL cells. Mechanistically, we identified Ars2 as a new chemotherapeutic target of minnelide for AL treatment. We found that triptolide directly targeted Ars2, resulting in the downregulation of miR-190a-3p, which led to the disturbance of PTEN/Akt signaling and culminated in G1 cell cycle arrest and apoptosis. ConclusionsOur findings demonstrate that targeting Ars2/miR-190a-3p signaling using minnelide could represent a novel chemotherapeutic strategy for AL treatment and support the evaluation of minnelide for the treatment of AL in clinical trials.

Abstract CT218: Phase II open label trial of Minnelide™ in patients with chemotherapy refractory metastatic pancreatic cancer

Abstract Background: Triptolide and its water-soluble prodrug, Minnelide™, have shown promising activity against pancreatic ductal adenocarcinoma (PDAC) in both in vitro and in vivo experiments. Triptolide induces apoptosis in pancreatic cancer cells by different pathways, including caspase-dependent apoptotic death and caspase -independent autophagic death. It inhibits the activity of the TFIIH general transcription factor complex and modulates the transcriptional landscape of both the stroma and cancer cell compartments. In the epithelial tumour compartment, triptolide down-regulates key transcription factors such as c-MYC. Preclinical investigations indicate significant activity against super enhancer targets. In the phase I clinical trial of Minnelide™ activity in highly refractory metastatic pancreatic carcinoma was observed. Hence, we undertook this study in patients with chemotherapy refractory metastatic PDAC. Our aims were to determine clinical anticancer effects, and to define effects of the drug on super enhancer expression and downstream effects. Methods: Eligibility criteria included stage IV PDAC progressing on standard chemotherapy, Karnofsky performance status ≥ 70%, and measurable disease by RECIST 1.1. Planned sample size was up to 35 patients with interim analysis after the first 18 evaluable patients, aiming for at least a 20% difference in DCR (10% v 30%). Minnelide™ 0.67 mg/m2 was administered intravenously over 30 minutes on days 1-21, followed by a 7-day rest period in a 28-day cycle. Exploratory objectives included: analyses of paired tumour biopsies for changes in immune cell infiltration, stromal activation, chromatin accessibility, proteomics and metabolism. Results: 17 patients were treated. There were no RECIST responses or stable disease. However, evidence of activity was observed in 4 of 15 evaluable patients. This activity included progression after 117 days treatment in 1 patient and reductions in CT tumour size or FDG-PET uptake and/or significant decreases in circulating CA19.9 levels in 3 others. Minnelide was generally well tolerated. Treatment related toxicities &amp;gt; 3 were: neutropenia 4 patients and cerebellar ataxia 1 patient.Exploratory analyses included ATAC-Seq on paired biopsies where gene ontology analyses showed downregulation of genes negatively regulating cell cycle and upregulation of genes controlling cell cycle checkpoints. Other exploratory analyses will be presented. Conclusions: The study identified a tolerable drug dose and evidence of activity in a highly chemotherapy-refractory population which provides encouraging proof for the principle of targeting TFIIH in human PDAC. Supported by SU2C, Cancer Research UK, Lustgarten Foundation Citation Format: David Propper, Erkut Borazanci, Peter J. O'Dwyer, Daniel Von Hoff, Joseph Hartlebury, Corina E. Antal, Gerard I. Evan, HaiYong Han, Michael Downes, Ronald Evans, Joshua Rabinowitz, Emmanuel Petricoin, Ashok Saluja, Mohana Velagapudi, Hitendra Patel. Phase II open label trial of Minnelide™ in patients with chemotherapy refractory metastatic pancreatic cancer [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 CT218.

Abstract 1818: Novel efficient isolation and water-soluble prodrug preparation of anti-cancer natural product narciclasine

Abstract Narciclasine is a promising anti-cancer agent produced by plants of the family Amaryllidaceae. Narciclasine has been shown to be a potent anti-cancer agent against a variety of cancers carrying dismal outcomes, including glioblastoma, non-small cell lung cancer, and non-Hodgkin’s lymphoma. It is particularly effective in animal studies of brain cancer both primary, such as glioblastoma, metastatic tumors to the brain, such as melanoma and non-small cell lung cancer. Its isolation from plants has generally been accompanied with variable success as it depends on the plant species, their location and the time of plant collection. In this study, an optimized procedure for the extraction of narciclasine yielding 300 mg/kg of dried plant material. This represents a crucial step towards the development of optimized narciclasine derivatives, as the price of narciclasine from commercial sources ranges from $100-$500 per milligram. Additionally, clinical advancement of narciclasine and its derivatives has been severely thwarted, potentially owing to its sparing water-solubility. Insolubility in water makes administration at therapeutic dosages difficult and can lead to unfavorable pharmacokinetic and pharmacodynamic characteristics. To this effort, the synthesis of five prodrug esters of narciclasine is presented, with the target of a water-soluble narciclasine prodrug. Citation Format: Alexander Kornienko, Ryan Rutledge. Novel efficient isolation and water-soluble prodrug preparation of anti-cancer natural product narciclasine [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 1818.

Design, Synthesis, and Biological Evaluation of Water-Soluble Prodrugs of C5-Curcuminoid GO-Y030 Based on Reversible Thia-Michael Reaction.

Although curcumin and its analogs exhibit anticancer activity, they are still not used as anticancer drugs because of their water insolubility and extremely poor bioavailability. This study describes the development of water-soluble prodrugs of GO-Y030, a potent antitumor C5-curcuminoid, in an attempt to enhance its bioavailability. These prodrugs release the parent compound via a retro-thia-Michael reaction. To endow sufficient hydrophilicity onto GO-Y030 via a single thia-Michael reaction of an aqueous entity, we used a modified glycoconjugate with a thiol group. The water-solubilizing motif was installed on GO-Y030 by the thia-Michael reaction of propargyl-polyethylene glycol (PEG)-thiol and subsequent click chemistry (CuAAC) reaction with 1-glycosyl azide. Turbidity measurements revealed a significantly improved water solubility of the prodrugs, demonstrating that disaccharide conjugates were completely dissolved in water at 100 µM. Their cytotoxicity was comparable to that of the parent compound GO-Y030, indicating the gradual in situ release of GO-Y030. The release of GO-Y030 from GO-Y199 via the retro-thia-Michael reaction was demonstrated through a degradation study in water. Our retro-thia-Michael reaction-based prodrug system can be used for targeting cancer cells.

First-in-Human Phase I Study of Minnelide in Patients With Advanced Gastrointestinal Cancers: Safety, Pharmacokinetics, Pharmacodynamics, and Antitumor Activity.

Minnelide is a water-soluble prodrug of triptolide. Triptolide is an anticancer agent that targets cancer resistance through several mechanisms. Minnelide was evaluated in a phase I study in patients with advanced GI carcinomas to establish the safety, pharmacodynamic, antitumor activity, and recommended phase II dose (RP2D). Patients with refractory GI carcinoma and with measurable disease on CT scan were eligible. The study used a 3 + 3 dose-escalation scheme. Due to neutropenia toxicity, 2 dosing schedules were evaluated to determine the RP2D for future studies. Response was assessed using RECIST 1.1 and Choi criteria. Minnelide and triptolide PK were evaluated. Patients who completed the first 28-day treatment cycle without DLTs continued treatment until disease progression or unacceptable toxicity. Forty-five patients were enrolled (23 pancreatic cancer, 10 colorectal, and the remaining 9 had other GI tumors); 42 patients received at least one dose of Minnelide. Grade ≥ 3 toxicities occurred in 69% of patients, most common neutropenia (38%). 2 patients with severe cerebellar toxicity who had a 2-fold higher triptolide concentration than other participants. ORR was 4%; the disease control rate (DCR) was 54% (15/28). Choi criteria demonstrated a decrease in average tumor density in 57% (16/28) patients. This first-in-human, phase I clinical study identified a dose and schedule of Minnelide in patients with refractory GI cancers. The primary toxicity experienced was hematologic. Evidence of efficacy of Minnelide treatment in this group of patients was observed. The DCR ranged from ~2 to 6 months in 14/28 (50%) of evaluable patients. Studies in monotherapy and combination treatments are underway.

Pyridinyl 4-(2-oxoalkylimidazolidin-1-yl)benzenesulfonates and their hydrochloride salts as novel water soluble antimitotic prodrugs bioactivated by cytochrome P450 1A1 in breast cancer cells.

We developed first-in-class antimitotic prodrugs phenyl 4-(2-oxo-alkylimidazolidin-1-yl)benzenesulfonates (PAIB-SOs) bioactivated by cytochrome P450 (CYP) 1A1 that are highly selective toward several breast cancer cells. However, they show sparingly water solubility. Therefore, we replaced their phenyl ring B with a substituted pyridinyl group preparing novel pyridinyl 4-(2-oxo-3-alkylimidazolidin-1-yl)benzenesulfonates (PYRAIB-SOs) and their hydrochloride salts. Our results evidence that PYRAIB-SO hydrochloride salts show higher water solubility compared to their neutral and PAIB-SO counterparts by up to 625-fold. PYRAIB-SOs with a nitrogen atom at position 3 of the pyridinyl ring exhibited strong antiproliferative activity (IC50: 0.03-3.3 μM) and high selectivity (8->1250) toward sensitive CYP1A1-positive breast cancer cells and cells stably transfected with CYP1A1. They induce cell cycle arrest in the G2/M phase and disrupt microtubule dynamic assembly. Enzymatic assays confirmed that CYP1A1 metabolizes PYRAIB-SOs into their active form with in vitro hepatic half-lives (55-120 min) in rodent and human liver microsomes. Overall, this will allow to increase drug concentration for in vivo studies.

Molecular Docking of Combretastatin Derivatives to Combat Human Cancer Cells

Abstract Cancer is defined as the group of diseases which involve abnormal cell growth or controlled growth of abnormal cells that are present in any part of the body. The causative agents of cancer are chemical, environmental, viral, and mutagenic, which lead to the mutation of genes into oncogenes, which provoke or demean regulatory biochemicals, resulting in accelerated cellular growth. Combretastatin was selected as the candidate because it is a water-soluble prodrug which is quickly converted into combretastatin A4, a cancer-fighting substance. It has longer circulation, better drug targeting, increased efficiency, and fewer side effects. The research was carried out to find a potential drug that could inhibit the action of cancer in humans. In the experiment, 21 derivatives of combretastatin were subjected to molecular docking for analyzing the binding interactions of the derivative with the active site using the Protein Data Bank: 3DK9 through Molegro Virtual Docker 6.0. The docking showed that the (E)-1-(2,6-dimethoxypyridin-4-yl)-3-(1H-indol-3-yl)-2-methylprop-2-en-1-one was the most potent, had a Mol Dock score of-194.925 and gave interactions with Asp331, Gly31, and Thr57. Thus, this research can be further extended further to have more potent drugs.

Synthesis and biological evaluation of structurally diverse 6-aryl-3-aroyl-indole analogues as inhibitors of tubulin polymerization

The synthesis and evaluation of small-molecule inhibitors of tubulin polymerization remains a promising approach for the development of new therapeutic agents for cancer treatment. The natural products colchicine and combretastatin A-4 (CA4) inspired significant drug discovery campaigns targeting the colchicine site located on the beta-subunit of the tubulin heterodimer, but so far these efforts have not yielded an approved drug for cancer treatment in human patients. Interest in the colchicine site was enhanced by the discovery that a subset of colchicine site agents demonstrated dual functionality as both potent antiproliferative agents and effective vascular disrupting agents (VDAs). Our previous studies led to the discovery and development of a 2-aryl-3-aroyl-indole analogue (OXi8006) that inhibited tubulin polymerization and demonstrated low nM IC50 values against a variety of human cancer cell lines. A water-soluble phosphate prodrug salt (OXi8007), synthesized from OXi8006, displayed promising vascular disrupting activity in mouse models of cancer. To further extend structure-activity relationship correlations, a series of 6-aryl-3-aroyl-indole analogues was synthesized and evaluated for their inhibition of tubulin polymerization and cytotoxicity against human cancer cell lines. Several structurally diverse molecules in this small library were strong inhibitors of tubulin polymerization and of MCF-7 and MDA-MB-231 human breast cancer cells. One of the most promising analogues (KGP591) caused significant G2/M arrest of MDA-MB-231 cells, disrupted microtubule structure and cell morphology in MDA-MB-231 cells, and demonstrated significant inhibition of MDA-MB-231 cell migration in a wound healing (scratch) assay. A phosphate prodrug salt, KGP618, synthesized from its parent phenolic precursor, KGP591, demonstrated significant reduction in bioluminescence signal when evaluated in vivo against an orthotopic model of kidney cancer (RENCA-luc) in BALB/c mice, indicative of VDA efficacy. The most active compounds from this series offer promise as anticancer therapeutic agents.

The Bisdioxopiperazine ICRF-193 Attenuates LPS-induced IL-1β Secretion by Macrophages

Inhibiting pathological secretion of Interleukin-1β has shown beneficial effects in disease models and in the clinic and thus there is interest in finding inhibitors that can reduce its release from macrophages in response to their activation by foreign pathogens. We used an in vitro human macrophage model to investigate whether ICRF-193, a Topoisomerase II inhibitor could modulate IL1B mRNA expression and IL-1β secretion. These macrophage-like cells readily secrete IL-1β in response to Lipopolysaccharide (LPS). Upon exposure to a non-toxic dose of ICRF-193, IL-1β secretion was diminished by ~ 40%; however, level of transcription of IL1B was unaffected. We show that there was no Topoisomerase 2B (TOP2B) binding to several IL1B gene sites, which may explain why ICRF-193 does not alter IL1B mRNA levels. Hence, we show for the first time that ICRF-193 can reduce IL-1β secretion. Its low cost and the development of water-soluble prodrugs of ICRF-193 warrants its further investigation in the modulation of pathological secretion of this cytokine for the treatment of inflammatory disorders. (165 words).

Tumor permeable self-delivery nanodrug targeting mitochondria for enhanced chemotherapy

Drug self-delivery systems (DSDSs) have been extensively exploited to enhance drug loading capacity and avoid excipient-related toxicity issues. However, deficient tumor targeting, inferior tumor permeability, prominent burst release, and nonspecific subcellular distribution remain major obstacles. Herein, we reported a ROS-responsive amphiphilic prodrug (CPT-S-NO) synthesized by the conjugation of zwitterionic tertiary amine-oxide (TAO) moiety and hydrophobic camptothecin (CPT) through a thioether linkage, which formed a nanoparticulate DSDS in an aqueous solution. CPT-S-NO, compared with CPT-11 and the water-soluble TAO-modified CPT prodrug (CPT-NO), exhibited prolonged blood circulation, enhanced tumor accumulation, deep tumor penetration, efficient mitochondrial targeting, and ROS-activated drug release to induce mitochondrial dysfunction, corporately conducing to the superior antitumor efficacy in vivo. This TAO decoration strategy promises potential applications in designing multipotent DSDSs for various drugs.

Self-Assembly Properties of an Amphiphilic Phosphate Ester Prodrug Designed for the Treatment of COVID-19

PF-07304814 is a water-soluble phosphate ester prodrug of a small molecule inhibitor for the SARS CoV-2 3CL protease designed for the treatment of COVID-19. The amphiphilicity and self-assembly behavior of the prodrug was investigated computationally and experimentally via multiple orthogonal techniques to better design formulations for intravenous infusion. The self-assembly of PF-07304814 into micellar structures enabled an increase in the solubility of lipophilic impurities by up to 1900x in clinically relevant formulations. The observed solubilization could help extend the drug product shelf-life and in use stability through inhibition of precipitation, without the need for solubilizing excipients. The work presented in this manuscript provides a roadmap for the characterization of prodrug self-assembly and highlights the potential for prodrug modifications to enhance solubility of both active ingredients and impurities and to extend drug product shelf-life.

Protective Effect of Water-Soluble Acacetin Prodrug on APAP-Induced Acute Liver Injury Is Associated with Upregulation of PPARγ and Alleviation of ER Stress.

A water-soluble acacetin prodrug has been synthesized and reported by our group previously. Acetaminophen (APAP) overdose is a leading cause of acute liver injury. We found that subcutaneous injection of acacetin prodrug (5, 10, 20 mg/kg) decreased serum ALT, AST, and ALP, corrected the abnormal MDA and GSH in liver, and improved intrahepatic hemorrhage and destruction of liver structures in APAP (300 mg/kg)-treated mice. Molecular mechanism analysis revealed that the expressions of endoplasmic reticulum (ER) stress markers ATF6, CHOP, and p-PERK, apoptosis-related protein BAX, and cleaved caspase 3 were decreased by acacetin in a dose-dependent manner in vivo and in vitro. Moreover, via the acacetin-upregulated peroxisome-proliferator-activated receptor gamma (PPARγ) of HepG2 cells and liver, the suppressive effect of acacetin on ER stress and apoptosis was abolished by PPARγ inhibitor (GW9662) or PPARγ-siRNA. Molecular docking revealed that acacetin can bind to three active pockets of PPARγ, mainly by hydrogen bond. Our results provide novel evidence that acacetin prodrug exhibits significant protective effect against APAP-induced liver injury by targeting PPARγ, thereby suppressing ER stress and hepatocyte apoptosis. Acacetin prodrug is likely a promising new drug candidate for treating patients with acute liver injury induced by APAP.

Neurotherapeutic Potential of Water-Soluble pH-Responsive Prodrugs of EIDD-036 in Traumatic Brain Injury.

The C-20 oxime of progesterone, EIDD-036 (2), demonstrates neuroprotection and improved outcomes in animal models of traumatic brain injury (TBI). However, 2 suffers from poor solubility, which renders it unsuitable for rapid administration. Previous prodrugs of 2 aimed at improving solubility by incorporating enzymatically labile amino acid and phosphate ester promoieties. These approaches were effective but led to limitations with in vivo administration. Herein, we disclose a pH-responsive water-soluble prodrug strategy to improve exposure to 2 through enzyme-independent activation. Compound 13l was identified as a lead that exhibits water-solubility, stability in acidic solutions, and rapid conversion to 2 at physiological pH. Administration of 13l to rats resulted in a twofold increase in exposure to 2 compared to the previous generation phosphate prodrug, EIDD-1723 (6). In a rat model of TBI, treatment with 13l resulted in a significant decrease in cerebral edema when administered postinjury.

Abstract 1838: Immunomodulatory effects of curcumin monoglucuronide on PD1 immune checkpoint blockade in mouse Pten-null prostate cancer

Abstract Prostate cancer is notoriously resistant to immune checkpoint blockade (ICB) immunotherapy due to its immunosuppressive tumor microenvironment (TME). Thus, reprograming the TME could improve antitumor immune responses to ICB. Curcumin is a naturally derived compound with chemopreventive and immunomodulatory properties, however, its potential is limited due to its poor bioavailability. Curcumin monoglucuronide (CMG) is a water-soluble prodrug with improved bioavailability over free-form of curcumin. We previously demonstrated the immunomodulatory potential of CMG in a transgenic mouse model of Pten-null prostate cancer, here we examine its ability to improve the antitumor immune response to ICB of the programmed death cell protein 1 (PD1). Thirty-two-week-old PSA-Cre/Ptenf/f knockout (KO) mice were treated with anti-PD1 (aPD1) blocking antibody, CMG alone and in combination for 17 days weeks. Antitumor responses were determined by prostate weight, histology, and cancer proliferation and apoptosis by quantitative immunohistochemistry (qIHC). Immune responses were assessed by focused panel qRT-PCR, qIHC, and flow cytometric (FC) analysis. Systemic immune responses were assessed by FC analysis if peripheral blood and secondary lymphoid organs. Short-term dosing of aPD1 alone or in combination did not affect tumor burden as assessed by a reduction of prostate weight, however, histological analysis revealed that mice treated with CMG/aPD1 exhibited an increase in the proportion of edematous dilated glands and a non-significant reduction of solid tumor. Mice treated with CMG/aPD1 showed a significant reduction of s cancer cell proliferation (Ki67) and mice treated with CMG/aPD1 showed a 1.5-fold increase in cancer cell apoptosis. Gene expression analysis indicated upregulation of genes associated with NKT, NK and dendritic cells with combination therapy. FC and qIHC analysis indicated that T cell activation and T cell cytotoxicity was improved when CMG was administered together with aPD-1. Systemically, treatments with PD-L1 alone or in combination with CMG were associated with increased circulating myeloid-derived suppressor cells (MDSCs). Our findings provide preclinical evidence for the antitumor and immune modulatory activity of CMG in mouse Pten-deficient prostate cancer and supports further study to evaluate long-term therapy and explore additional treatment combinations. Citation Format: Yurie Kura, Marco A. De Velasco, Kazuko Sakai, Naomi Ando, Noriko Sako, Kazutoshi Fujita, Eri Banno, Yasunori Mori, Mamoru Hashimoto, Masahiro Nozawa, Kazuhiro Yoshimura, Hideaki Kakeya, Kazuto Nishio, Hirotsugu Uemura. Immunomodulatory effects of curcumin monoglucuronide on PD1 immune checkpoint blockade in mouse Pten-null prostate cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 1838.

Minnelide Markedly Reduces Proteinuria in Mice with Adriamycin Nephropathy by Protecting Against Podocyte Injury

Minimal change disease (MCD) is the most common cause of idiopathic nephrotic syndrome in children. The current major therapy is hormones for most steroid-sensitive patients. However, many patients have recurrent relapses of the disease and require long-term immunosuppression, leading to significant morbidity due to the side effects of the drugs. Therefore, better drugs need to be urgently explored to treat nephrotic syndrome while avoiding the side effects of drugs. Minnelide, a water-soluble prodrug of triptolide, has been proved to be effective in treating cancers in many clinical trials. This study aimed to investigate the therapeutic effect of minnelide in mice with adriamycin (ADR) nephropathy, its underlying protection mechanisms, and its reproductive toxicity. Minnelide was administered intraperitoneally to 6–8-week female mice with adriamycin nephropathy for 2 weeks, and the urine, blood, and kidney tissues were taken to analyze the therapeutic effect. In addition, we evaluated reproductive toxicity by measuring the levels of gonadal hormones and observing the histological changes in ovaries and testes. Primary mouse podocytes were exposed to puromycin (PAN) to damage the cytoskeleton and induce apoptosis, and then, triptolide was used to evaluate the therapeutic effect and underlying protection mechanisms in vitro. It was observed that minnelide dramatically alleviated proteinuria and apoptosis in mice with adriamycin nephropathy. In vitro, triptolide ameliorated puromycin-induced cytoskeletal rearrangement and apoptosis via reactive oxygen species-mediated mitochondrial pathway. In addition, minnelide caused no reproductive toxicity to male and female mice. The results suggested that minnelide might be a promising drug for nephrotic syndrome.

Population Pharmacokinetics, Exposure-Safety, and Probability of Target Attainment Analyses for Isavuconazole in Japanese Patients With Deep-Seated Mycoses.

Isavuconazonium sulfate is the water-soluble prodrug of the novel, broad-spectrum, triazole antifungal agent isavuconazole. Its pharmacokinetics (PK) and exposure-response relationship have been well investigated, but not in a Japanese patient population. The objectives of this analysis were to (1) develop a population PK model for Japanese patients with deep-seated mycoses and healthy subjects, and to identify significant covariates; (2) determine the probability of PK-pharmacodynamic (PK-PD)target attainment in Japanese patients by a clinical dosing regimen; and (3) evaluate the exposure-safety relationship of isavuconazole in Japanese patients. Data from 2 phase 1 studies and 1 phase 3 study in Japanese patients were pooled to develop the population PK model using NONMEM. The PK of isavuconazole in Japanese patients was best described as a 2-compartment model with a Weibull absorption function and first-order elimination. The identified covariates on clearance were creatinine clearance and lean body mass. The probability of target attainment showed that >90% of simulated Japanese patients would achieve the PK-PD target, an exposure index corresponding to 50% survival of nonneutropenic infected mice, with minimal inhibitory concentration values of ≤1mg/L according to Clinical and Laboratory Standards Institute methodology and of ≤2mg/L according to European Committee on Antimicrobial Susceptibility Testing methodology by the clinical dosing regimen. No apparent relationships were found for any of the exposure parameters of isavuconazole with any assessed safety end points in Japanese patients. Taken together, the clinical dosing regimen is appropriate for the treatment of Japanese patients with deep-seated mycoses.