Preclinical Safety Data Research Articles

Abstract 1581: Nammisomes: Preclinical validation of a platform for selective and synchronized delivery of novel immunotherapy prodrug combinations to tumors

Abstract The approval of checkpoint inhibitors, CAR-T cell therapies, and other immunotherapies has led to a significant improvement in cancer patient survival rates over the past 7 years. However, the pace of improvement has slowed lately as the field moves beyond the minority of patients with immune primed or accessible cancers. It is generally expected that rationale combinations of immunotherapies that provide mechanisms to both induce as well as maintain the immune responses in the face of tumor-derived immune checkpoint mediators, will be required to effectively treat these patients. Systemic exposure to such combinations often can give rise to severe toxicity profiles that limit their therapeutic efficacy. Nammisomes are an innovative and unique platform designed to deliver novel immune modulating prodrugs more selectively and synchronously to the tumor site. The immune active agents are conjugated to lipids to create prodrugs that self-assemble into a liposomal bilayer. By mixing multiple prodrugs at the desired ratio, co-formulations are produced with the optimum stoichiometry. These Nammisomes are iv injected and selectively enter tumors through the leaky vasculature within tumors, while remaining in circulation in normal tissues with intact blood vessels, The enriched phagocytic activity in tumor environments causes the release of the active agents within tumors relative to normal tissues limiting systemic exposure and toxicities. Preclinical efficacy and safety data of Nammisomes delivering combinations of a TLR agonist and a checkpoint inhibitor showing anti-tumor efficacy and tolerability in syngeneic mouse models will be presented. In summary, Nammisomes will be highlighted as a combination therapeutic modality to demonstrate the potential of this approach in anti-cancer therapy. Citation Format: David R. Stover, Dhruba Bharali, Tahmineh Safaie, Bruce A. Hay, Rajesh K. Sharma, Scott Ayers. Nammisomes: Preclinical validation of a platform for selective and synchronized delivery of novel immunotherapy prodrug combinations to tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 1581.

Preclinical toxicological evaluation of measles virus vaccine strain in non-human primates: A two-month intravenous study

Introduction: Based on its ability to kill tumor cells, the vaccine strain of the measles virus is used for oncolytic virotherapy. However, the dose required for cancer therapy is much higher than that used for vaccination. Therefore, this study was conducted to evaluate the preclinical toxicology of the vaccine strain of measles virus in monkeys.
 Methods: 16 healthy Macaca mulata monkeys were randomly divided into four groups, of which one was a control. A preclinical safety evaluation of the vaccine strain of the measles virus was performed, and the three experimental groups were intravenously injected with the strain at doses of 105 TCID50, 106 TCID50 and 107 TCID50 respectively.
 Results: There were no significant abnormalities in the physical, clinical, haematological, and biochemical parameters following the intravenous injection with measles vaccine at doses of 105 TCID50, 106 TCID50 and 107 TCID50. The vaccine strain of measles virus remained in the plasma until the 30th day and disappeared on the 60th, and it did not persist in the tissues on days 30 and 60 post injection. Measles IgG antibody was negative on days 0, 1, 3, and 8 and was positive on days 15, 30, and 60 post administration of the measles virus. The histopathology of target organs was not affected in all groups on days 30 and 60 post injection.
 Conclusions: The systematic preclinical safety data of the present study confirms the safety of two months of concentrated measles vaccine administration in the Macaca mulata monkey for clinical trials.

Development of β-globin gene correction in human hematopoietic stem cells as a potential durable treatment for sickle cell disease.

Sickle cell disease (SCD) is the most common serious monogenic disease with 300,000 births annually worldwide. SCD is an autosomal recessive disease resulting from a single point mutation in codon six of the β-globin gene (HBB). Ex vivo β-globin gene correction in autologous patient-derived hematopoietic stem and progenitor cells (HSPCs) may potentially provide a curative treatment for SCD. We previously developed a CRISPR-Cas9 gene targeting strategy that uses high-fidelity Cas9 precomplexed with chemically modified guide RNAs to induce recombinant adeno-associated virus serotype 6 (rAAV6)-mediated HBB gene correction of the SCD-causing mutation in HSPCs. Here, we demonstrate the preclinical feasibility, efficacy, and toxicology of HBB gene correction in plerixafor-mobilized CD34+ cells from healthy and SCD patient donors (gcHBB-SCD). We achieved up to 60% HBB allelic correction in clinical-scale gcHBB-SCD manufacturing. After transplant into immunodeficient NSG mice, 20% gene correction was achieved with multilineage engraftment. The long-term safety, tumorigenicity, and toxicology study demonstrated no evidence of abnormal hematopoiesis, genotoxicity, or tumorigenicity from the engrafted gcHBB-SCD drug product. Together, these preclinical data support the safety, efficacy, and reproducibility of this gene correction strategy for initiation of a phase 1/2 clinical trial in patients with SCD.

Guidelines for FAIR sharing of preclinical safety and off-target pharmacology data

Pre-competitive data sharing can offer the pharmaceutical industry significant benefits in terms of reducing the time and costs involved in getting a new drug to market through more informed testing strategies and knowledge gained by pooling data. If sufficient data is shared and can be co-analyzed, then it can also offer the potential for reduced animal usage and improvements in the in silico prediction of toxicological effects. Data sharing benefits can be further enhanced by applying the FAIR Guiding Principles, reducing time spent curating, transforming and aggregating datasets and allowing more time for data mining and analysis. We hope to facilitate data sharing by other organizations and initiatives by describing lessons learned as part of the Enhancing TRANslational SAFEty Assessment through Integrative Knowledge Management (eTRANSAFE) project, an Innovative Medicines Initiative (IMI) partnership which aims to integrate publicly available data sources with proprietary preclinical and clinical data donated by pharmaceutical organizations. Methods to foster trust and overcome non-technical barriers to data sharing such as legal and IPR (intellectual property rights) are described, including the security requirements that pharmaceutical organizations generally expect to be met. We share the consensus achieved among pharmaceutical partners on decision criteria to be included in internal clearance procedures used to decide if data can be shared. We also report on the consensus achieved on specific data fields to be excluded from sharing for sensitive preclinical safety and pharmacology data that could otherwise not be shared.

Toxicokinetics of U-47700, tramadol, and their main metabolites in pigs following intravenous administration: is a multiple species allometric scaling approach useful for the extrapolation of toxicokinetic parameters to humans?

New synthetic opioids (NSOs) pose a public health concern since their emergence on the illicit drug market and are gaining increasing importance in forensic toxicology. Like many other new psychoactive substances, NSOs are consumed without any preclinical safety data or any knowledge on toxicokinetic (TK) data. Due to ethical reasons, controlled human TK studies cannot be performed for the assessment of these relevant data. As an alternative animal experimental approach, six pigs per drug received a single intravenous dose of 100 µg/kg body weight (BW) of U-47700 or 1000 µg/kg BW of tramadol to evaluate whether this species is suitable to assess the TK of NSOs. The drugs were determined in serum and whole blood using a fully validated method based on solid-phase extraction and LC–MS/MS. The concentration–time profiles and a population (pop) TK analysis revealed that a three-compartment model best described the TK data of both opioids. Central volumes of distribution were 0.94 L/kg for U-47700 and 1.25 L/kg for tramadol and central (metabolic) clearances were estimated at 1.57 L/h/kg and 1.85 L/h/kg for U-47700 and tramadol, respectively. The final popTK model parameters for pigs were upscaled via allometric scaling techniques. In comparison to published human data, concentration–time profiles for tramadol could successfully be predicted with single species allometric scaling. Furthermore, possible profiles for U-47700 in humans were simulated. The findings of this study indicate that unlike a multiple species scaling approach, pigs in conjunction with TK modeling are a suitable tool for the assessment of TK data of NSOs and the prediction of human TK data.

The Gordian Knot of Glutaraldehyde-Treated Autologous Pericardium in Open Cardiac Surgery

Glutaraldehyde is classified as a biocide-pesticide under the hazard class for toxic substance and control laws for the human health and environmental worldwide. The regulatory bodies restrict the intended use to disinfectant or laboratory application in hospital. The parenteral pathway in human is not considered and then not allowed, for the high-risk profile, so the constraints are an integral part of the Classification Labeling and Packaging for exposure of occupational health. Contextually, there are no preclinical-safety data as Risk Related Reference (DMEL probability of occurrence and severity of adverse effect (s)/event (s) in a given population under defined exposure conditions), or Chemical Safety Reports that justify any authorization for patient consumer uses. In the context of cardiac surgery, the biomechanical stability in treating the autologous pericardium with glutaraldehyde in solution, results as a hand-built biotech for a patient valve device. Theoretically, the surgeon is a manufacturer that uses a toxic chemical compound for the own product that does not comply to the law and regulations. Contrary to pharmaceutical definition for marketing authorized drugs, the off-label not allowed use of toxic chemical derived manufacture, expose the physicians to legal vulnerability of which it is inclusive the malpractice for the-patient’s informed consent.

The Potential Use of Mesenchymal Stem Cells and Their Derived Exosomes as Immunomodulatory Agents for COVID-19 Patients.

A novel severe acute respiratory syndrome coronavirus (SARS-CoV-2) causing lethal acute respiratory disease emerged in December 2019. The World Health Organization named this disease “COVID-19” and declared it a pandemic on March 11, 2020. Many studies have shown that mesenchymal stem cells (MSCs) and their exosomes (MSCs-Exo), which are isolated from allogenic bone marrow stem cells, significantly lower the risk of alveolar inflammation and other pathological conditions associated with distinct lung injuries. For example, in acute respiratory distress syndrome (ARDS) and pneumonia patients, MSCs-Exo and MSCs provide similar healing properties and some clinical trials have used cell-based inhalation therapy which show great promise. MSCs and MSCs-Exo have shown potential in clinical trials as a therapeutic tool for severely affected COVID-19 patients when compared to other cell-based therapies, which may face challenges like the cells' sticking to the respiratory tract epithelia during administration. However, the use of MSCs or MSCs-Exo for treating COVID-19 should strictly adhere to the appropriate manufacturing practices, quality control measurements, preclinical safety and efficacy data, and the proper ethical regulations. This review highlights the available clinical trials that support the therapeutic potential of MSCs or MSCs-Exo in severely affected COVID-19 patients.

Ibudilast for alcohol use disorder: study protocol for a phase II randomized clinical trial

BackgroundAlcohol use disorder (AUD) is a chronic and relapsing condition for which current pharmacological treatments are only modestly effective. The development of efficacious medications for AUD remains a high research priority with recent emphasis on identifying novel molecular targets for AUD treatment and to efficiently screen new compounds aimed at those targets. Ibudilast, a phosphodiesterase inhibitor, has been advanced as a novel addiction pharmacotherapy that targets neurotrophin signaling and neuroimmune function.MethodsThis study will conduct a 12-week, double-blind, placebo controlled randomized clinical trial of ibudilast (50 mg BID) for AUD treatment. We will randomize 132 treatment-seeking men and women with current AUD. We will collect a number of alcohol consumption outcomes. Primary among these is percent heavy drinking days (PHDD); secondary drinking outcomes include drinks per day, drinks per drinking day, percent days abstinent, percent subjects with no heavy drinking days, and percent subjects abstinent, as well as measures of alcohol craving and negative mood. Additionally, participants will have the option to opt-in to a neuroimaging session in which we examine the effects of ibudilast on neural activation to psychosocial stress and alcohol cues. Finally, we will also collect plasma levels of proinflammatory markers, as well as subjective and biological (salivary cortisol) markers of stress response.DiscussionThis study will further develop ibudilast, a safe and promising novel compound with strong preclinical and clinical safety data for AUD, and will probe biological mechanisms underlying the effects of Ibudilast on stress, neuroinflammation, and alcohol cue-reactivity and craving. If ibudilast proves superior to placebo in this study, it will set the stage for a confirmatory multi-site trial leading to FDA approval of a novel AUD treatment.Trial registrationClinicalTrials.gov NCT03594435 “Ibudilast for the Treatment of Alcohol Use Disorder”. Registered on 20 July 2018.

International Society for Extracellular Vesicles and International Society for Cell and Gene Therapy statement on extracellular vesicles from mesenchymal stromal cells and other cells: considerations for potential therapeutic agents to suppress coronavirus disease-19

STATEMENT: The International Society for Cellular and Gene Therapies (ISCT) and the International Society for Extracellular Vesicles (ISEV) recognize the potential of extracellular vesicles (EVs, including exosomes) from mesenchymal stromal cells (MSCs) and possibly other cell sources as treatments for COVID-19. Research and trials in this area are encouraged. However, ISEV and ISCT do not currently endorse the use of EVs or exosomes for any purpose in COVID-19, including but not limited to reducing cytokine storm, exerting regenerative effects or delivering drugs, pending the generation of appropriate manufacturing and quality control provisions, pre-clinical safety and efficacy data, rational clinical trial design and proper regulatory oversight.

Preclinical safety evaluation of body protective compound-157, a potential drug for treating various wounds

BPC157 displays protective activity in various organs and tissues. This report presents preclinical toxicity studies with BPC157 in mice, rats, rabbits and dogs. The single-dose toxicity study did not show any test-related effects that could be attributed to the test article. In repeated-dose toxicity evaluations, BPC157 was well tolerated in dogs, with no abnormal changes between the BPC157-treated groups and the solvent control group, with the exception of a decrease in creatinine level at a dose of 2 mg/kg but not at lower doses. The animals recovered spontaneously after 2 weeks of withdrawal. This may be due to the pharmacological activity of BPC157. A local tolerance test showed that the irritation caused by BPC157 was mild. BPC157 also showed no genetic or embryo-fetal toxicity. In summary, BPC157 was well tolerated and did not cause any serious toxicity in mice, rats, rabbits and dogs. These preclinical safety data contribute to the initiation of an ongoing clinical study. Based on the stability and protective effect of BPC157, which has been widely reported, BPC157 may have a better application prospect than the widely used cytokine drugs in wound therapy.

A Short Review on the Safety of Bromphenol Blue for Dye-Assisted Vitreoretinal Interventions.

Bromphenol blue was approved for the intraoperative staining of the vitreous, epiretinal membranes, and internal limiting membrane of the retina several years ago. It has been marketed as a combined dye formulation of bromphenol blue (1.3 mg/mL) and brilliant blue G (0.25 mg/mL). So far, comprehensive information on preclinical and clinical safety data of bromphenol blue is lacking. A PubMed analysis of available literature was performed. Ten relevant publications on preclinical and clinical evaluations of bromphenol blue were found. It is striking that almost no safety data is available on the presently used clinical product. Current clinical use seems not completely be justified by scientific safety data.

Workshop Report

Given that cardiovascular safety concerns remain the leading cause of drug attrition at the preclinical drug development stage, the National Center for Toxicological Research of the US Food and Drug Administration hosted a workshop to discuss current gaps and challenges in translating preclinical cardiovascular safety data to humans. This white paper summarizes the topics presented by speakers from academia, industry, and government intended to address the theme of improving cardiotoxicity assessment in drug development. The main conclusion is that to reduce cardiovascular safety liabilities of new therapeutic agents, there is an urgent need to integrate human-relevant platforms/approaches into drug development. Potential regulatory applications of human-derived cardiomyocytes and future directions in employing human-relevant platforms to fill the gaps and overcome barriers and challenges in preclinical cardiovascular safety assessment were discussed. This paper is intended to serve as an initial step in a public-private collaborative development program for human-relevant cardiotoxicity tools, particularly for cardiotoxicities characterized by contractile dysfunction or structural injury.

US and EU radiopharmaceutical diagnostic and therapeutic nonclinical study requirements for clinical trials authorizations and marketing authorizations

New regulatory guidance documents from the United States Food and Drug Administration (FDA) and the European Medicines Agency (EMA) have recently been finalized or are in draft format outlining new pathways for preclinical safety testing. The US and the European Union appear to be moving in a similar direction focussing and refining preclinical safety data requirements for both radiodiagnostics and radiotherapeutics. We here summarize these recent documents from both the US and European perspective.

A Noninvasive Imaging Toolbox Indicates Limited Therapeutic Potential of Conditionally Activated Macrophages in a Mouse Model of Multiple Organ Dysfunction.

Cell-based regenerative medicine therapies require robust preclinical safety, efficacy, biodistribution, and engraftment data prior to clinical testing. To address these challenges, we have developed an imaging toolbox comprising multispectral optoacoustic tomography and ultrasonography, which allows the degree of kidney, liver, and cardiac injury and the extent of functional recovery to be assessed noninvasively in a mouse model of multiorgan dysfunction. This toolbox allowed us to determine the therapeutic effects of adoptively transferred macrophages. Using bioluminescence imaging, we could then investigate the association between amelioration and biodistribution. Macrophage therapy provided limited improvement of kidney and liver function, although not significantly so, without amelioration of histological damage. No improvement in cardiac function was observed. Biodistribution analysis showed that macrophages homed and persisted in the injured kidneys and liver but did not populate the heart. Our data suggest that the limited improvement observed in kidney and liver function could be mediated by M2 macrophages. More importantly, we demonstrate here the utility of the imaging toolbox for assessing the efficacy of potential regenerative medicine therapies in multiple organs.

P139 OLORINAB, A PERIPHERALLY RESTRICTED, HIGHLY SELECTIVE AGONIST OF THE CANNABINOID RECEPTOR TYPE 2 FOR THE MANAGEMENT OF VISCERAL PAIN IN INFLAMMATORY BOWEL DISEASE (IBD) – PRECLINICAL AND EARLY CLINICAL DEVELOPMENT

Abdominal pain is common and persistent in patients with IBD. Available anti-inflammatory treatments often fail to relieve pain despite disease remission. Cannabinoid receptor agonists have shown efficacy in visceral pain, but development has been limited by psychotropic effects mediated by the cannabinoid receptor type 1. Olorinab is a peripherally restricted, highly selective agonist of the cannabinoid receptor type 2 (CB2 receptor). Herein is an overview of preclinical efficacy, clinical safety, and pharmacokinetics (PK) data from early studies. Male Sprague Dawley rats (6-7 weeks old) were randomly assigned to study groups. Colitis was induced using 12 mg 2,4,6-trinitrobenzene sulfonic acid in 35% ethanol applied rectally. Control or colitis rats were given oral olorinab (3 or 30 mg/kg) or vehicle twice daily for 5 days, starting 1 day before colitis induction. Visceral hypersensitivity was measured in vivo as visceromotor responses (VMR) to colorectal distension (CRD; 0-80 mm Hg). In 2 double-blind, placebo-controlled, Phase 1 studies, healthy young adult male and female volunteers were randomized to receive either a single ascending dose (SAD; 10-400 mg) or multiple ascending doses (MAD; 50-200 mg 3 times daily [TID] for 10 days) of oral olorinab or placebo. Safety, tolerability, and PK were evaluated. Olorinab-treated colitis rats had reduced VMR to CRD versus vehicle-treated colitis rats (VMR normalized to control levels, p < 0.001, n = 9/group). Olorinab was generally well tolerated as 1 dose up to 400 mg and in multiple doses up to 200 mg TID. In the SAD study, 45% (19/42) of olorinab and 21% (3/14) of placebo subjects reported adverse events (AEs; most mild). Most common AEs in olorinab subjects were dry mouth, somnolence, diarrhea, dizziness, and headache, mostly at the highest doses. In the MAD study, 26% (7/27) of olorinab and 33% (3/9) of placebo subjects reported AEs (all mild). Most common AEs in olorinab subjects were headache and nausea. Olorinab exposure increased during single and multiple doses less than dose proportionally. The mean Tmax was ∼1.5 hours, and mean t1/2 was 3.11-4.23 hours with single doses up to 400 mg. In the MAD study plasma steady state occurred within 4 days. The peripherally restricted CB2 receptor agonist, olorinab, showed preclinical efficacy in a rat model of colitis-induced visceral hypersensitivity. In healthy volunteers, olorinab was safe and well tolerated without psychotropic AEs. These preclinical and early clinical safety data support the continued clinical development of olorinab for the treatment of visceral pain associated with IBD.

Tools for studying the metabolism of new psychoactive substances for toxicological screening purposes – A comparative study using pooled human liver S9, HepaRG cells, and zebrafish larvae

New psychoactive substances (NPS) are an emerging topic amongst abused compounds. New varieties appear constantly on the market, without any knowledge about their toxicodynamic and/or -kinetic properties and knowledge of their metabolism is crucial for the development of analytical methods employed for their detection. Controlled human studies would of course be best suited but due to ethical reasons and lack of preclinical safety data, they are usually not available. Often, in vitro models are used to evaluate similarities to human in vivo hepatic phase I and II metabolism and systems explored include primary human hepatocytes, pooled human S9 fraction, and HepaRG, a human hepatic cell line. All these in vitro models have considerable limitations and drug distribution, reabsorption, enterohepatic circulation, and renal elimination cannot be studied. In the recent years, zebrafish (Danio rerio) larvae (embryos) were discussed as a potential in vivo model to overcome these limitations. To date, no studies demonstrating its suitability for studying NPS metabolism in the context of analytical toxicology are available. The aim of this study was to elucidate whether zebrafish larvae can serve as a surrogate for human hepatic metabolism of NPS to develop toxicological screening procedures. Here, we used methyl 2‐(1‐(5‐fluoropentyl)‐1H‐pyrrolo[2,3‐b]pyridine‐3‐carboxamido)‐3,3‐dimethylbutanoate (7′N‐5F‐ADB), a new synthetic cannabinoid, whose human metabolism was recently described in the literature, as a model compound to evaluate zebrafish larvae as a new tool for metabolism studies. Different conditions for zebrafish larvae and HepaRG protocols were tested. As zebrafish larvae and HepaRG cell incubations provided the highest number of metabolites and the most authentic spectrum of human metabolites. The most suitable larvae protocol was the incubation via medium and the analysis of the extracted zebrafish larvae. The zebrafish larvae model might be a promising preclinical surrogate for human hepatic metabolism of NPS.

Novel therapeutic avenues in triple-negative breast cancer: PI3K/AKT inhibition, androgen receptor blockade, and beyond.

Multiomic analyses have shed light upon the molecular heterogeneity and complexity of triple-negative breast cancers (TNBCs). With increasing recognition that TNBC is not a single disease entity but encompasses different disease subtypes, a one-size-fits-all treatment paradigm has become obsolete. In this context, the inhibition of phosphatidylinositol 3-kinase/protein kinase B (PI3K/AKT) and androgen receptor (AR) signaling pathways have emerged as potential therapeutic strategies against selected tumors. In this paper, we reviewed the preclinical rationale, predictive biomarkers, efficacy, and safety data from early phase trials, and the future directions for these two biomarker-directed treatment approaches in TNBC.

Safety Studies of Pneumococcal Endolysins Cpl-1 and Pal.

Bacteriophage-derived endolysins have gained increasing attention as potent antimicrobial agents and numerous publications document the in vivo efficacy of these enzymes in various rodent models. However, little has been documented about their safety and toxicity profiles. Here, we present preclinical safety and toxicity data for two pneumococcal endolysins, Pal and Cpl-1. Microarray, and gene profiling was performed on human macrophages and pharyngeal cells exposed to 0.5 µM of each endolysin for six hours and no change in gene expression was noted. Likewise, in mice injected with 15 mg/kg of each endolysin, no physical or behavioral changes were noted, pro-inflammatory cytokine levels remained constant, and there were no significant changes in the fecal microbiome. Neither endolysin caused complement activation via the classic pathway, the alternative pathway, or the mannose-binding lectin pathway. In cellular response assays, IgG levels in mice exposed to Pal or Cpl-1 gradually increased for the first 30 days post exposure, but IgE levels never rose above baseline, suggesting that hypersensitivity or allergic reaction is unlikely. Collectively, the safety and toxicity profiles of Pal and Cpl-1 support further preclinical studies.

Exploring the Leaves of Annona muricata L. as a Source of Potential Anti-inflammatory and Anticancer Agents.

The use of anti-inflammatory natural products to treat inflammatory disorders for cancer prevention and therapy is an appealing area of interest in the last decades. Annona muricata L. is one of the many plant extracts that have been explored owing to their anti-inflammatory and anticancer effects. Different parts of A. muricata especially the leaves have been used for various ethnomedicinal purposes by traditional healers to treat several diseases including cancer, inflammation, diabetes, liver diseases, and abscesses. Some of these experience-based claims on the use of the plant have been transformed into evidence-based information by scientific investigations. The leaves of the plant have been extensively investigated for its diverse pharmacological aspects and found eminent for anti-inflammatory and anticancer properties. However, most studies were not on the bioactive isolates which were responsible for the activities but were based on crude extracts of the plant. In this comprehensive review, all significant findings from previous investigations till date on the leaves of A. muricata, specifically on their anti-inflammatory and anticancer activities have been compiled. The toxicology of the plant which has been shown to be due to the presence of neurotoxic annaceous acetogenins and benzyltetrahydro-isoquinoline alkaloids has also been updated to provide recent information on its safety aspects. The present knowledge of the plant has been critically assessed, aimed at providing direction toward improving its prospect as a source of potential anti-inflammatory and anticancer agents. The analysis will provide a new path for ensuring research on this plant to discover new agents to treat inflammatory diseases and cancer. Further in vitro and in vivo studies should be carried out to explore the molecular mechanisms underlying their anti-inflammatory responses in relation to anticancer activity and more detail toxicity study to ensure they are safe for human consumption. Sufficient preclinical data and safety data generated will allow clinical trials to be pursued on this plant and its bioactive compounds.

A pre-clinical safety study of PEGylated recombinant human endostatin (M2ES) in Sprague Dawley rats

PEGylated recombinant human endostatin (M2ES) exhibited prolonged serum half-life and enhanced antitumor activity when compared with endostatin. A pre-clinical study was performed to evaluate the safety of M2ES in rats. After intravenous (IV) infusions of M2ES at a dose level of 3, 15 and 75 mg/kg in Sprague Dawley (SD) rats, M2ES was well tolerated in animals, with no observable changes in clinical observation, body weight, food consumption, urine analysis, hematology and serum biochemical analysis. The increase of kidney weights, and slight to severe vacuolation and necrosis of proximal tubule epithelial cells in kidney were observed in 15 and 75 mg/kg M2ES groups, but this adverse-effect was reversible. In summary, the major toxicity target organ of M2ES might be kidney, and the no observed adverse effect level (NOAEL) of M2ES in rats was 3 mg/kg in this study. These pre-clinical safety data contribute to the initiation of the ongoing clinical study.