Allometric Scaling Approaches for Predicting Human Pharmacokinetic of a Locked Nucleic Acid Oligonucleotide Targeting Cancer-Associated miR-221

Predicting the pharmacokinetics and pharmacodynamics of antisense oligonucleotides: an overview of various approaches and opportunities for PBPK/PD modelling

INTRODUCTION

Advances in research and development (R&D) have enabled many approvals of antisense oligonucleotides (ASOs). Its administration expanded from systemic to local for treating various diseases, where predicting target tissue exposures and pharmacokinetics (PK) and pharmacodynamics (PD) in human can be critical.

AREAS COVERED

A literature search for PBPK/PD models of ASOs was conducted using PubMed and Embase (to 1 April 2023). ASO PK and PD in animals and humans and modeling approaches including physiologically based (PB) are summarized; and relevance and impacts of PBPK/PD modeling are assessed.

EXPERT OPINION

Allometric scaling and compartmental PK/PD modeling have been successful to predict human ASO PK/PD, addressing most R&D needs. Understanding tissue distribution of ASOs can be crucial for their efficacy and safety especially for intrathecal (IT), pulmonary, or other local routes. PBPK/PD modeling is expected to improve such understanding, for which, efforts have been sporadic. However, developing a PBPK/PD model requires careful review of known biology/pharmacology and thoughtful experimental designs. Resulting models have the potential to predict target/specified tissue exposures and responses in human adults and pediatrics. Ultimately, a PBPK/PD modeling approach can lead to more efficient and rational clinical development, resulting in well-informed decision making and a shortened timeline.

Safety and activity of the first-in-class locked nucleic acid (LNA) miR-221 selective inhibitor in refractory advanced cancer patients: a first-in-human, phase 1, open-label, dose-escalation study

BACKGROUND

We developed a 13-mer locked nucleic acid (LNA) inhibitor of miR-221 (LNA-i-miR-221) with a full phosphorothioate (PS)-modified backbone. This agent downregulated miR-221, demonstrated anti-tumor activity against human xenografts in mice, and favorable toxicokinetics in rats and monkeys. Allometric interspecies scaling allowed us to define the first-in-class LNA-i-miR-221 safe starting dose for the clinical translation.

METHODS

In this first-in-human, open-label, dose-escalation phase 1 trial, we enrolled progressive cancer patients (aged ≥ 18 years) with ECOG 0-2 into 5 cohorts. The treatment cycle was based on a 30-min IV infusion of LNA-i-miR-221 on 4 consecutive days. Three patients within the first cohort were treated with 2 cycles (8 infusions), while 14 patients were treated with a single course (4 infusions); all patients were evaluated for phase 1 primary endpoint. The study was approved by the Ethics Committee and Regulatory Authorities (EudraCT 2017-002615-33).

RESULTS

Seventeen patients received the investigational treatment, and 16 were evaluable for response. LNA-i-miR-221 was well tolerated, with no grade 3-4 toxicity, and the MTD was not reached. We recorded stable disease (SD) in 8 (50.0%) patients and partial response (PR) in 1 (6.3%) colorectal cancer case (total SD + PR: 56.3%). Pharmacokinetics indicated non-linear drug concentration increase across the dose range. Pharmacodynamics demonstrated concentration-dependent downregulation of miR-221 and upregulation of its CDKN1B/p27 and PTEN canonical targets. Five mg/kg was defined as the recommended phase II dose.

CONCLUSIONS

The excellent safety profile, the promising bio-modulator, and the anti-tumor activity offer the rationale for further clinical investigation of LNA-i-miR-221 (ClinTrials.Gov: NCT04811898).

Biodistribution and delivery of oligonucleotide therapeutics to the central nervous system: Advances, challenges, and future perspectives

Considerable advances have been made in the research and development of oligonucleotide therapeutics (OTs) for treating central nervous system (CNS) diseases, such as psychiatric and neurodegenerative disorders, because of their promising mode of action. However, due to the tight barrier function and complex physiological structure of the CNS, the efficient delivery of OTs to target the brain has been a major challenge, and intensive efforts have been made to overcome this limitation. In this review, we summarize the representative methodologies and current knowledge of biodistribution, along with the pharmacokinetic/pharmacodynamic (PK/PD) relationship of OTs in the CNS, which are critical elements for the successful development of OTs for CNS diseases. First, quantitative bioanalysis methods and imaging-based approaches for the evaluation of OT biodistribution are summarized. Next, information available on the biodistribution profile, distribution pathways, quantitative PK/PD modeling, and simulation of OTs following intrathecal or intracerebroventricular administration are reviewed. Finally, the latest knowledge on the drug delivery systems to the brain via intranasal or systemic administration as noninvasive routes for improved patient quality of life is reviewed. The aim of this review is to enrich research on the successful development of OTs by clarifying OT distribution profiles and pathways to the target brain regions or cells, and by identifying points that need further investigation for a mechanistic approach to generate efficient OTs.

Locked nucleic acid (LNA): A modern approach to cancer diagnosis and treatment

Cancer is responsible for about one in six deaths in the world. Conventional cancer treatments like chemotherapy, radiotherapy, and surgery are associated with drug poisoning and poor prognosis. Thanks to advances in RNA delivery and target selection, new cancer medicines are now conceivable to improve the quality of life and extend the lives of cancer patients. Antisense oligonucleotides (ASOs) and siRNAs are the most important tools in RNA therapies. Locked Nucleic Acids (LNAs) are one of the newest RNA analogs, exhibiting more affinity to binding, sequence specificity, thermal stability, and nuclease resistance due to their unique properties. Assays using LNA are also used in molecular diagnostic methods and provide accurate and rapid mutation detection that improves specificity and sensitivity. This study aims to review the special properties of LNA oligonucleotides that make them safe and effective antisense drugs for cancer treatment by controlling gene expression. Following that, we go over all of the molecular detection methods and cancer treatment antisense tactics that are possible with LNA technology.

miR-221/222 as biomarkers and targets for therapeutic intervention on cancer and other diseases: A systematic review

Among deregulated microRNAs (miRs) in human malignancies, miR-221 has been widely investigated for its oncogenic role and as a promising biomarker. Moreover, recent evidence suggests miR-221 as a fine-tuner of chronic liver injury and inflammation-related events. Available information also supports the potential of miR-221 silencing as promising therapeutic intervention. In this systematic review, we selected papers from the principal databases (PubMed, MedLine, Medscape, ASCO, ESMO) between January 2012 and December 2020, using the keywords “miR-221” and the specific keywords related to the most important hematologic and solid malignancies, and some non-malignant diseases, to define and characterize deregulated miR-221 as a valuable therapeutic target in the modern vision of molecular medicine. We found a major role of miR-221 in this view.

Roles of miRNA dysregulation in the pathogenesis of multiple myeloma

Multiple myeloma (MM) is a malignant disease of plasma cells with complex pathology, causing significant morbidity due to its end-organ destruction. The outcomes of patients with myeloma have significantly improved in the past couple of decades with the introduction of novel agents, such as proteasome inhibitors, immunomodulators, and monoclonal antibodies. However, MM remains incurable and presents considerable individual heterogeneity. MicroRNAs (miRNAs) are short, endogenous noncoding RNAs of 19-22 nucleotides that regulate gene expression at the posttranscriptional level. Numerous studies have shown that miRNA deregulation is closely related to MM pathology, including tumor initiation, progression, metastasis, prognosis, and drug response, which make the complicated miRNA network an attractive and marvelous area of investigation for novel anti-MM therapeutic approaches. Herein, we mainly summarized the current knowledge on the roles of miRNAs, which are of great significance in regulating pathological factors involved in MM progressions, such as bone marrow microenvironment, methylation, immune regulation, genomic instability, and drug resistance. Meanwhile, their potential as novel prognostic biomarkers and therapeutic targets was also discussed.

All-trans retinoic acid induces differentiation in primary acute myeloid leukemia blasts carrying an inversion of chromosome 16

All-trans retinoic acid (ATRA)-based therapy for acute promyelocytic leukemia (APL), a subtype of acute myeloid leukemia (AML), is the most successful example of differentiation therapy. Although ATRA can induce differentiation in some non-APL AML cell lines and primary blasts, clinical results of adding ATRA to standard therapy in non-APL AML patients have been inconsistent, probably due to use of different regimens and lack of diagnostic tools for identifying which patients may be sensitive to ATRA. In this study, we exposed primary blasts obtained from non-APL AML patients to ATRA to test for differentiation potential in vitro. We observed increased expression of differentiation markers, indicating a response to ATRA, in four out of fifteen primary AML samples. Three samples in which CD11b increased in response to ATRA had an inversion of chromosome 16 as well as the CBFB-MYH11 fusion gene, and the fourth sample was from a patient with KMT2A-rearranged, therapy-related AML. In conclusion, we identified a subgroup of non-APL AML patients with inv(16) and CBFB-MYH11 as the most sensitive to ATRA-mediated differentiation in vitro, and our results can help identify patients who may benefit from ATRA treatment.

miRNAs and lncRNAs as Novel Therapeutic Targets to Improve Cancer Immunotherapy

Simple Summary

Cancer onset and progression are promoted by high deregulation of the immune system. Recently, major advances in molecular and clinical cancer immunology have been achieved, offering new agents for the treatment of common tumors, often with astonishing benefits in terms of prolonged survival and even cure. Unfortunately, most tumors are still resistant to current immune therapy approaches, and basic knowledge of the resistance mechanisms is eagerly awaited. We focused our attention on noncoding RNAs, a class of RNA that regulates many biological processes by targeting selectively crucial molecular pathways and that, recently, had their role in cancer cell immune escape and modulation of the tumor microenvironment identified, suggesting their function as promising immunotherapeutic targets. In this scenario, we point out that noncoding RNAs are progressively emerging as immunoregulators, and we depict the current information on the complex network involving the immune system and noncoding RNAs and the promising therapeutic options under investigation. Novel opportunities are emerging from noncoding-RNAs for the treatment of immune-refractory tumors.

Abstract

Immunotherapy is presently one of the most promising areas of investigation and development for the treatment of cancer. While immune checkpoint-blocking monoclonal antibodies and chimeric antigen receptor (CAR) T-cell-based therapy have recently provided in some cases valuable therapeutic options, the goal of cure has not yet been achieved for most malignancies and more efforts are urgently needed. Noncoding RNAs (ncRNA), including microRNAs (miRNAs) and long noncoding RNAs (lncRNAs), regulate several biological processes via selective targeting of crucial molecular signaling pathways. Recently, the key roles of miRNA and lncRNAs as regulators of the immune-response in cancer have progressively emerged, since they may act (i) by shaping the intrinsic tumor cell and microenvironment (TME) properties; (ii) by regulating angiogenesis, immune-escape, epithelial-to-mesenchymal transition, invasion, and drug resistance; and (iii) by acting as potential biomarkers for prognostic assessment and prediction of response to immunotherapy. In this review, we provide an overview on the role of ncRNAs in modulating the immune response and the TME. We discuss the potential use of ncRNAs as potential biomarkers or as targets for development or clinical translation of new therapeutics. Finally, we discuss the potential combinatory approaches based on ncRNA targeting agents and tumor immune-checkpoint inhibitor antibodies or CAR-T for the experimental treatment of human cancer.

Application of Pharmacokinetic-Pharmacodynamic Modeling in Drug Delivery: Development and Challenges

With the advancement of technology, drug delivery systems and molecules with more complex architecture are developed. As a result, the drug absorption and disposition processes after administration of these drug delivery systems and engineered molecules become exceedingly complex. As the pharmacokinetic and pharmacodynamic (PK-PD) modeling allows for the separation of the drug-, carrier- and pharmacological system-specific parameters, it has been widely used to improve understanding of the in vivo behavior of these complex delivery systems and help their development. In this review, we summarized the basic PK-PD modeling theory in drug delivery and demonstrated how it had been applied to help the development of new delivery systems and modified large molecules. The linkage between PK and PD was highlighted. In particular, we exemplified the application of PK-PD modeling in the development of extended-release formulations, liposomal drugs, modified proteins, and antibody-drug conjugates. Furthermore, the model-based simulation using primary PD models for direct and indirect PD responses was conducted to explain the assertion of hypothetical minimal effective concentration or threshold in the exposure-response relationship of many drugs and its misconception. The limitations and challenges of the mechanism-based PK-PD model were also discussed.

Development and validation of bioanalytical methods for LNA-i-miR-221 quantification in human plasma and urine by LC-MS/MS

LNA-i-miR-221, a 13-mer oligonucleotide, has proved favorable efficacy and safety profiles in the preclinical studies, leading to being approved for use in clinical trials by regulatory authorities. The objective of this study was to develop and validate LC-MS/MS methods to quantify LNA-i-miR-221 in human plasma and urine. Chromatographic separation was performed with a gradient system on HALO C18 column using hexafluoro-2-propanol/triethylamine buffer and methanol as mobile phase. LNA-i-miR-221 was detected on tandem mass spectrometer with electrospray ionization source in negative ion mode. The methods showed good linearity within the calibration range of 50-25000 ng/mL and 50-50000 ng/mL for human plasma and urine, respectively. The methods proved to be accurate, precise and selective in both human matrices. These validated methods are reliable and are currently in use to support a first-in-human clinical trial of LNA-i-miR-221 in patients affected by refractory multiple myeloma and advanced solid tumors.

Circulating mRNA and microRNA profiling analysis in patients with ischemic stroke

To provide insight into molecular diagnosis and individualized treatment of ischemic stroke (IS), several available datasets in IS were analyzed to identify the differentially expressed genes and microRNAs (miRNAs). Series matrix files from GSE22255 and GSE16561 (mRNA profiles), a well as GSE110993 (miRNA profile) were downloaded from the Gene Expression Omnibus database. System-level clustering was performed with GeneCluster 3.0 software, and gene annotation and pathway enrichment were performed with gene ontology analysis and Database for Annotation, Visualization and Integrated Discovery software. For a protein-protein interaction (PPI) network, Biological General Repository for Interaction Datasets and IntAct interaction information were integrated to determine the interaction of differentially expressed genes. The selected miRNA candidates were imported into the TargetScan, miRDB and miRecords databases for the prediction of target genes. The present study identified 128 upregulated and 231 downregulated genes in female stroke patients, and 604 upregulated and 337 downregulated genes in male stroke patients compared with sex- and age-matched controls. The construction of a PPI network demonstrated that male stroke patients exhibited YWHAE, CUL3 and JUN as network center nodes, and in female patients CYLD, FOS and PIK3R1 interactions were the strongest. Notably, these interactions are mainly involved in immune inflammatory response, apoptosis and other biological pathways, such as blood coagulation. Female and male upregulated genes were cross-validated with another set of Illumina HumanRef-8 v3.0 expression beadchip (GSE16561). Functional item association networks, gene function networks and transcriptional regulatory networks were successfully constructed, and the relationships between miRNAs and target genes were successfully predicted. The present study identified a number of transcription factors, including DEFA1, PDK4, SDPR, TCN1 and MMP9, and miRNAs, including miRNA (miR)-21, miR-143/145, miR-125-5p and miR-122, which may serve important roles in the development of cerebral stroke and may be important molecular indicators for the treatment of IS.

Dose-Finding Study and Pharmacokinetics Profile of the Novel 13-Mer Antisense miR-221 Inhibitor in Sprague-Dawley Rats

miR-221 is overexpressed in several malignancies where it promotes tumor growth and survival by interfering with gene transcripts, including p27Kip1, PUMA, PTEN, and p57Kip2. We previously demonstrated that a novel 13-mer miR-221 inhibitor (locked nucleic acid [LNA]-i-miR-221) exerts antitumor activity against human cancer with a pilot-favorable pharmacokinetics and safety profile in mice and non-naive monkeys. In this study, we report a non-good laboratory practice (GLP)/GLP dose-finding investigation of LNA-i-miR-221 in Sprague-Dawley rats. The safety of the intravenous dose (125 mg/kg/day) for 4 consecutive days, two treatment cycles, was investigated by a first non-GLP study. The toxicokinetics profile of LNA-i-miR-221 was next explored in a GLP study at three different doses (5, 12.5, and 125 mg/kg/day). Slight changes in blood parameters and histological findings in kidney were observed at the highest dose. These effects were reversible and consistent with an in vivo antisense oligonucleotide (ASO) class effect. The no-observed-adverse-effect level (NOAEL) was established at 5 mg/kg/day. The plasma exposure of LNA-i-miR-221, based on C₀ (estimated concentration at time 0 after bolus intravenous administration) and area under the curve (AUC), suggested no differential sex effect. Slight accumulation occurred between cycles 1 and 2 but was not observed after four consecutive administrations. Taken together, our findings demonstrate a safety profile of LNA-i-miR-221 in Sprague-Dawley rats and provide a reference translational framework and path for the development of other LNA miR inhibitors in phase I clinical study.