Monoclonal antibodies for the treatment of osteoarthritis

Intra-Articular Injection of Interleukin-8 Neutralizing Monoclonal Antibody Effectively Attenuates Osteoarthritis Progression in Rabbits

OBJECTIVE

Cytokines are implicated in the pathogenesis of osteoarthritis (OA), and this study aims to assess the therapeutic potential of an IL-8 neutralizing monoclonal antibody (mAb) for OA intervention.

DESIGN

The study employed a rabbit model of OA induced by anterior cruciate ligament transection (ACLT) surgery to investigate the effects of an interleukin (IL)-8 neutralizing mAb, with hyaluronic acid (HA) used as a positive control. Primary outcomes assessed in the rabbits included cartilage repair, synovitis, joint effusion, changes in footprints, and lower limb loading conditions.

RESULTS

Compared to HA, intra-articular injection of the IL-8 neutralizing mAb demonstrated a more pronounced attenuation of OA progression and enhancement of cartilage repair. We observed a reduction in synovitis and joint effusion, indications of bone marrow edema, as well as improvements in lower limb function. In knees treated with the neutralizing IL-8 mAb, there was a significant decrease in IL-8 levels within the synovial tissues.

CONCLUSIONS

The IL-8 neutralizing mAb exhibits promising therapeutic potential in the management of OA by attenuating inflammation and facilitating cartilage repair. However, further investigations are warranted to comprehensively elucidate the underlying mechanisms, optimize treatment protocols, and ensure the long-term safety and efficacy of this innovative therapeutic approach.

Bioprinting-Enabled Biomaterials: A Cutting-Edge Strategy for Future Osteoarthritis Therapy

Bioprinting is an advanced technology that allows for the precise placement of cells and biomaterials in a controlled manner, making significant contributions in regenerative medicine. Notably, bioprinting-enabled biomaterials have found extensive application as drug delivery systems (DDS) in the treatment of osteoarthritis (OA). Despite the widespread utilization of these biomaterials, there has been limited comprehensive research summarizing the recent advances in this area. Therefore, this review aims to explore the noteworthy developments and challenges associated with utilizing bioprinting-enabled biomaterials as effective DDS for the treatment of OA. To begin, we provide an overview of the complex pathophysiology of OA, highlighting the shortcomings of current treatment modalities. Following this, we conduct a detailed examination of various bioprinting technologies and discuss the wide range of biomaterials employed in DDS applications for OA therapy. Finally, by placing emphasis on their transformative potential, we discuss the incorporation of crucial cellular components such as chondrocytes and mesenchymal stem cells into bioprinted constructs, which play a pivotal role in promoting tissue regeneration and repair.

Mechanisms of bone pain: Progress in research from bench to bedside

The field of research on pain originating from various bone diseases is expanding rapidly, with new mechanisms and targets asserting both peripheral and central sites of action. The scope of research is broadening from bone biology to neuroscience, neuroendocrinology, and immunology. In particular, the roles of primary sensory neurons and non-neuronal cells in the peripheral tissues as important targets for bone pain treatment are under extensive investigation in both pre-clinical and clinical settings. An understanding of the peripheral mechanisms underlying pain conditions associated with various bone diseases will aid in the appropriate application and development of optimal strategies for not only managing bone pain symptoms but also improving bone repairing and remodeling, which potentially cures the underlying etiology for long-term functional recovery. In this review, we focus on advances in important preclinical studies of significant bone pain conditions in the past 5 years that indicated new peripheral neuronal and non-neuronal mechanisms, novel targets for potential clinical interventions, and future directions of research.

Pharmaceutical therapeutics for articular regeneration and restoration: state-of-the-art technology for screening small molecular drugs

Articular cartilage damage caused by sports injury or osteoarthritis (OA) has gained increased attention as a worldwide health burden. Pharmaceutical treatments are considered cost-effective means of promoting cartilage regeneration, but are limited by their inability to generate sufficient functional chondrocytes and modify disease progression. Small molecular chemical compounds are an abundant source of new pharmaceutical therapeutics for cartilage regeneration, as they have advantages in design, fabrication, and application, and, when used in combination, act as powerful tools for manipulating cellular fate. In this review, we present current achievements in the development of small molecular drugs for cartilage regeneration, particularly in the fields of chondrocyte generation and reversion of chondrocyte degenerative phenotypes. Several clinically or preclinically available small molecules, which have been shown to facilitate chondrogenesis, chondrocyte dedifferentiation, and cellular reprogramming, and subsequently ameliorate cartilage degeneration by targeting inflammation, matrix degradation, metabolism, and epigenetics, are summarized. Notably, this review introduces essential parameters for high-throughput screening strategies, including models of different chondrogenic cell sources, phenotype readout methodologies, and transferable advanced systems from other fields. Overall, this review provides new insights into future pharmaceutical therapies for cartilage regeneration.

Interleukin-35 Regulates Angiogenesis Through P38 Mitogen-Activated Protein Kinase Signaling Pathway in Interleukin-1β-Stimulated SW1353 Cells and Cartilage Bioinformatics Analysis

We aimed to investigate the effects of interleukin (IL)-35 on proangiogenic factors in IL-1β-pretreated chondrocyte-like SW1353 cells and screen-related genes that participated in osteoarthritis (OA) cartilage with IL-35, proangiogenic factors, and P38 mitogen-activated protein kinase (MAPK) signaling pathway. Different concentrations of IL-35 incubated with IL-1β stimulated SW1353 cells with or without SB203580 (inhibitor of P38 MAPK). Proangiogenic molecule expression was assessed by real-time polymerase chain reaction and enzyme-linked immunosorbent assay. Microarray datasets were downloaded from the Gene Expression Omnibus database of OA cartilage. Protein-protein interaction of genes was visualized by Search Tool for the Retrieval Interacting Genes and Cytoscape. Database for Annotation, Visualization, and Integrated Discovery was used to screen biological processes and pathways. IL-35 inhibited mRNA expression of proangiogenic factors in IL-1β-stimulated SW1353 cells through the P38 MAPK signaling pathway. IL-35 inhibited angiopoietin-2 secretion. We found that 8 related genes, 18 biological processes, and 6 pathways may associate with IL-35, P38 MAPK signaling pathway, and cartilage angiogenesis. IL-35 regulated the expression of proangiogenic factors through P38 MAPK signaling pathway in IL-1β-stimulated SW1353 cells. IL-35 and P38 MAPK pathway may participate in neovascularization of cartilage. Our findings may provide molecular mechanisms and possible genes target treatment for OA.

Overview of MMP-13 as a Promising Target for the Treatment of Osteoarthritis

Osteoarthritis (OA) is a common degenerative disease characterized by the destruction of articular cartilage and chronic inflammation of surrounding tissues. Matrix metalloproteinase-13 (MMP-13) is the primary MMP involved in cartilage degradation through its particular ability to cleave type II collagen. Hence, it is an attractive target for the treatment of OA. However, the detailed molecular mechanisms of OA initiation and progression remain elusive, and, currently, there are no interventions available to restore degraded cartilage. This review fully illustrates the involvement of MMP-13 in the initiation and progression of OA through the regulation of MMP-13 activity at the molecular and epigenetic levels, as well as the strategies that have been employed against MMP-13. The aim of this review is to identify MMP-13 as an attractive target for inhibitor development in the treatment of OA.

Neuroscience and Neuroimmunology Solutions for Osteoarthritis Pain: Biological Drugs, Growth Factors, Peptides and Monoclonal Antibodies Targeting Peripheral Nerves

Neuroscience is a vast discipline that deals with the anatomy, biochemistry, molecular biology, physiology and pathophysiology of central and peripheral nerves. Advances made through basic, translational, and clinical research in the field of neuroscience have great potential for long-lasting and beneficial impacts on human and animal health. The emerging field of biological therapy is intersecting with the disciplines of neuroscience, orthopaedics and rheumatology, creating new horizons for interdisciplinary and applied research. Biological drugs, growth factors, therapeutic peptides and monoclonal antibodies are being developed and tested for the treatment of painful arthritic and rheumatic diseases. This concise communication focuses on the solutions provided by the fields of neuroscience and neuroimmunology for real-world clinical problems in the field of orthopaedics and rheumatology, focusing on synovial joint pain and the emerging biological treatments that specifically target pathways implicated in osteoarthritis pain in peripheral nerves.

Spezielle Schmerztherapie bei rheumatischen Erkrankungen

Schmerz als Hauptsymptom vieler chronisch-entzündlicher Erkrankungen stellt für den Patienten, aber auch für den behandelnden Arzt besonders in seiner chronifizierten Form eine große Herausforderung dar. Es gibt leider keine „Wunderpille“ mit der man Schmerzen für jeden gleich zuverlässig beseitigen kann. Es gibt aber viele Ansätze pharmakologischer als auch nicht-pharmakologischer Art und deren Kombination, um für den einzelnen Patienten wirksame Behandlungsstrategien zu finden. Um diese Strategien für jeden Patienten individuell optimal festzulegen, bedarf es zum einen eines fundamentierten Wissens über das Spektrum zur Verfügung stehender Mittel, zum anderen aber auch Erkenntnis darüber, wie diese sinnvoll nach Art der vorliegenden Schmerzformen einzusetzen sind. In dieser Übersicht wird beides behandelt, mit einem Fokus auf die medikamentöse Therapie von Schmerzen bei entzündlich-rheumatischen Erkrankungen. Dabei wird herausgearbeitet, dass es für die in diesem Zusammenhang relevantesten Formen des Schmerzes, akut-entzündlich nozizeptiv, neuropathisch und durch periphere und zentrale Sensibilisierung chronifizierte Schmerzen, jeweils andere wirksame Konzepte gibt.

Where Two Common Conditions of Aging Meet: Osteoarthritis and Sarcopenia

Osteoarthritis and sarcopenia are the most frequently described musculoskeletal disorders in older persons but the intertwining of these conditions and of their functional and cellular causes is complex. This narrative review aims to identify the links between osteoarthritis and sarcopenia described 1-in clinical studies, 2-in in vitro studies, and 3-the available treatment strategies for both conditions. Electronic databases were used for the literature search of all studies investigating the relationship between sarcopenia and the presence of concomitant osteoarthritis. This review identified a limited number of clinical and morphometric studies on the complex relationship between osteoarthritis and sarcopenia. Studies present a number of methodological limitations due to definition and assessment of both entities. Low lean mass is one of the main actors of this cross-talk between muscle and bone, and adipose tissue plays a major role that had been underestimated. Bone Morphogenetic Proteins and myostatin pathways are key mediators and play an important role in both muscle and bone homeostasis. Common therapeutic recommendations are still missing. There is a need for good quality prospective studies on concomitant sarcopenia and osteoarthritis, more translational research, and pharmacological and non-pharmacological therapies in order to identify common denominators for the management of sarcopenia, osteoarthritis, and their comorbidities.

Towards an Effective and Safe Treatment of Inflammatory Pain: A Delphi-Guided Expert Consensus

OBJECTIVE

The clinical management of inflammatory pain requires an optimal balance between effective analgesia and associated safety risks. To date, mechanisms associated with inflammatory pain are not completely understood because of their complex nature and the involvement of both peripheral and central mechanisms. This Expert Consensus document is intended to update clinicians about evolving areas of clinical practice and/or available treatment options for the management of patients with inflammatory pain.

METHOD

An international group of experts in pain management covering the pharmacology, neurology and rheumatology fields carried out an independent qualitative systematic literature search using MEDLINE, EMBASE and the Cochrane Central Register of Controlled Trials.

RESULTS

Existing guidelines for pain management provide recommendations that do not satisfactorily address the complex nature of pain. To achieve optimal outcomes, drug choices should be individualized to guarantee the best match between the characteristics of the patient and the properties of the medication. NSAIDs represent an important prescribing choice in the management of inflammatory pain, and the recent results on paracetamol question its appropriate use in clinical practice, raising the need for re-evaluation of the recommendations in the clinical practice guidelines.

CONCLUSIONS

Increasing clinicians' knowledge of the available pharmacologic options to treat different pain mechanisms offers the potential for safe, individualized treatment decisions. We hope that it will help implement the needed changes in the management of inflammatory pain by providing the best strategies and new insights to achieve the ultimate goal of managing the disease and obtaining optimal benefits for patients.

FUNDING

Dompé Farmaceutici SPA and Paolo Procacci Foundation.

Regulatory Effects and Interactions of the Wnt and OPG-RANKL-RANK Signaling at the Bone-Cartilage Interface in Osteoarthritis

Cartilage and the bordering subchondral bone form a functionally active regulatory interface with a prominent role in osteoarthritis pathways. The Wnt and the OPG-RANKL-RANK signaling systems, as key mediators, interact in subchondral bone remodeling. Osteoarthritic osteoblasts polarize into two distinct phenotypes: a low secretory and an activated, pro-inflammatory and anti-resorptive subclass producing high quantities of IL-6, PGE2, and osteoprotegerin, but low levels of RANKL, thus acting as putative effectors of subchondral bone sclerosis. Wnt agonists, Wnt5a, Wisp-1 initiate excessive bone remodeling, while Wnt3a and 5a simultaneously cause loss of proteoglycans and phenotype shift in chondrocytes, with decreased expression of COL2A, aggrecan, and Sox-9. Sclerostin, a Wnt antagonist possesses a protective effect for the cartilage, while DKK-1 inhibits VEGF, suspending neoangiogenesis in the subchondral bone. Experimental conditions mimicking abnormal mechanical load, the pro-inflammatory milieu, but also a decreased OPG/RANKL ratio in the cartilage, trigger chondrocyte apoptosis and loss of the matrix via degradative matrix metalloproteinases, like MMP-13 or MMP-9. Hypoxia, an important cofactor exerts a dual role, promoting matrix synthesis via HIF-1α, a Wnt silencer, but turning on HIF-2α that enhances VEGF and MMP-13, along with aberrant collagen expression and extracellular matrix deterioration in the presence of pro-inflammatory cytokines.

Recent advances in understanding the regulation of metalloproteinases

Metalloproteinases remain important players in arthritic disease, in part because members of this large enzymatic family, namely matrix metalloproteinase-1 (MMP-1) and MMP-13, are responsible for the irreversible degradation of articular cartilage collagen. Although direct inhibition of MMPs fell out of vogue with the initial clinical disappointment of the first generation of compounds, interest in other mechanisms that control these important enzymes has always been maintained. Since these enzymes are critically important for tissue homeostasis, their expression and activity are tightly regulated at many levels, not just by direct inhibition by their endogenous inhibitors the tissue inhibitors of metalloproteinases (TIMPs). Focussing on MMP-13, we discuss recent work that highlights new discoveries in the transcriptional regulation of this enzyme, from defined promoter functional analysis to how more global technologies can provide insight into the enzyme’s regulation, especially by epigenetic mechanisms, including non-coding RNAs. In terms of protein regulation, we highlight recent findings into enzymatic cascades involved in MMP-13 regulation and activation. Importantly, we highlight a series of recent studies that describe how MMP-13 activity, and in fact that of other metalloproteinases, is in part controlled by receptor-mediated endocytosis. Together, these new discoveries provide a plethora of novel regulatory mechanisms, besides direct inhibition, which with renewed vigour could provide further therapeutic opportunities for regulating the activity of this class of important enzymes.

Emerging Trend in the Pharmacotherapy of Osteoarthritis

Osteoarthritis (OA) is a degenerative joint disorder and one of the most prevalent diseases among the elderly population. Due to the limited spontaneous healing capacity of articular cartilage, it still remains challenging to find satisfactory treatment for OA. This review covers the emerging trends of pharmacologic therapies for OA such as traditional OA drugs (acetaminophen, non-steroidal anti-inflammatory drugs (NSAIDs), opioids, serotonin-norepinephrine reuptake inhibitors (SNRIs), intra-articular injections of corticosteroids, and dietary supplements), which are effective in pain relief but not in reversing damage, and are frequently associated with adverse events. Alternatively, disease-modifying drugs provide promising alternatives for the management of OA. The development of these emerging OA therapeutic agents requires a comprehensive understanding of the pathophysiology of OA progression. The process of cartilage anabolism/catabolism, subchondral bone remodeling and synovial inflammation are identified as potential targets. These emerging OA drugs such as bone morphogenetic protein-7 (BMP-7), fibroblast growth factor-18 (FGF-18), human serum albumin (HSA), interleukin-1 (IL-1) inhibitor, β-Nerve growth factor (β-NGF) antibody, matrix extracellular phosphoglycoprotein (MEPE) and inverse agonist of retinoic acid-related orphan receptor alpha (RORα) etc. have shown potential to modify progression of OA with minimal adverse effects. However, large-scale randomized controlled trials (RCTs) are needed to investigate the safety and efficacy before translation from bench to bedside.

Disease-modifying drugs in osteoarthritis: current understanding and future therapeutics

INTRODUCTION

Osteoarthritis (OA) is a leading cause of pain and disability among adults with a current prevalence of around 15% and a predicted prevalence of 35% in 2030 for symptomatic OA. It is increasingly recognized as a heterogeneous multi-faceted joint disease with multi-tissue involvement of varying severity. Current therapeutic regimens for OA are only partially effective and often have significant associated toxicities. There are no disease-modifying drugs approved by the regulatory bodies. Areas covered: We reviewed the opportunities within key OA pathogenetic mechanism: cartilage catabolism/anabolism, pathological remodeling of subchondral bone and synovial inflammation to identify targeted disease-modifying osteoarthritis drugs, based on compounds currently in Phase II and III stages of clinical development in which x-ray and/or MRI was used as the structural outcome with/without symptomatic outcomes according to regulatory requirements. Expert opinion: Given the heterogeneity of the OA disease process and complex overlapping among these phenotypes, a 'one size fits all' approach used in most clinical trials would unlikely be practical and equally effective in all patients, as well as in all anatomical OA sites. On the other hand, it is a challenge to develop a targeted drug with high activity, specificity, potency, and bioavailability in the absence of toxicity for long-term use in this chronic disease of predominantly older adults. Further research and insight into evaluation methods for drug-targeted identification of early OA and specific characterization of phenotypes, improvement of methodological designs, and development/refinement of sensitive imaging and biomarkers will help pave the way to the successful discovery of disease-modifying drugs and the optimal administration strategies in clinical practice.

Anti-nerve growth factor monoclonal antibodies for the control of pain in dogs and cats

Nerve growth factor (NGF) is essential for the survival of sensory and sympathetic neurons during development. However, in the adult, NGF and its interaction with tropomyosin receptor kinase A receptor (TrkA) has been found to play a critical role in nociception and nervous system plasticity in pain conditions. Thus, various monoclonal antibody (mAb) therapies targeting this pathway have been investigated in the development of new pharmacotherapies for chronic pain. Although none of the mAbs against NGF are yet approved for use in humans, they look very promising for the effective control of pain. Recently, species-specific anti-NGF mAbs for the management of osteoarthritis (OA)-associated pain in dogs and cats has been developed, and early clinical trials have been conducted. Anti-NGF therapy looks to be both very effective and very promising as a novel therapy against chronic pain in dogs and cats. This review outlines the mechanism of action of NGF, the role of NGF in osteoarthritis, research in rodent OA models and the current status of the development of anti-NGF mAbs in humans. Furthermore, we describe and discuss the recent development of species-specific anti-NGF mAbs for the treatment of OA-associated pain in veterinary medicine.

Investigational drugs for the treatment of osteoarthritis, an update on recent developments

INTRODUCTION

Osteoarthritis (OA) is the leading cause of pain, loss of function, and disability among elderly, with the knee the most affected joint. It is a heterogeneous condition characterized by complex and multifactorial etiologies which contribute to the broad variation in symptoms presentation and treatment responses that OA patients present. This poses a challenge for the development of effective treatment on OA.

AREAS COVERED

This review will discuss recent development of agents for the treatment of OA, updating our previous narrative review published in 2015. They include drugs for controlling local and systemic inflammation, regulating articular cartilage, targeting subchondral bone, and relieving pain.

EXPERT OPINION

Although new OA drugs such as monoclonal antibodies have shown marked effects and favorable tolerance, current treatment options for OA remain limited. The authors believe there is no miracle drug that can be used for all OA patients'; treatment and disease stage is crucial for the effectiveness of drugs. Therefore, early diagnosis, phenotyping OA patients and precise therapy would expedite the development of investigational drugs targeting at symptoms and disease progression of OA.

Cartilage diseases

Hyaline cartilages, fibrocartilages and elastic cartilages play multiple roles in the human body including bearing loads in articular joints and intervertebral discs, providing joint lubrication, forming the external ears and nose, supporting the trachea, and forming the long bones during development and growth. The structure and organization of cartilage's extracellular matrix (ECM) are the primary determinants of normal function. Most diseases involving cartilage lead to dramatic changes in the ECM which can govern disease progression (e.g., in osteoarthritis), cause the main symptoms of the disease (e.g., dwarfism caused by genetically inherited mutations) or occur as collateral damage in pathological processes occurring in other nearby tissues (e.g., osteochondritis dissecans and inflammatory arthropathies). Challenges associated with cartilage diseases include poor understanding of the etiology and pathogenesis, delayed diagnoses due to the aneural nature of the tissue and drug delivery challenges due to the avascular nature of adult cartilages. This narrative review provides an overview of the clinical and pathological features as well as current treatment options available for various cartilage diseases. Late breaking advances are also described in the quest for development and delivery of effective disease modifying drugs for cartilage diseases including osteoarthritis, the most common form of arthritis that affects hundreds of millions of people worldwide.

Hierarchical, imbalanced pro-inflammatory cytokine networks govern the pathogenesis of chronic arthropathies

BACKGROUND

Chronic inflammatory arthropathies, such as rheumatoid arthritis (RA), spondyloarthritis, including psoriatic arthritis (PsA), ankylosing spondyloarthritis (AS), osteoarthritis (OA), and intervertebral disc degenerative disease (DDD) constitute major public health problems that are anticipated to grow significantly as the human population ages. However, many aspects concerning the molecular mechanisms underlying their onset and progression remain unclear.

DESIGN

This narrative review critically analyzes the molecular mechanisms underlying the inflammation-associated pathogenesis of the aforementioned joint diseases. This includes, in particular, the major role played by several key soluble factors (such as cytokines and the associated signaling pathways, designated as "fragile nodes") produced by local cells and recruited to the joints' immune cells, whose elimination by specific drugs has dramatically improved the diseases' symptomatology and outcome in human clinical trials or in rodent arthritis models.

HYPOTHESIS AND THE AIM OF THIS REVIEW

We hypothesize that the pathogenesis of chronic inflammatory arthropathies is governed by hierarchical, imbalanced pro-inflammatory cytokine networks (HIPICNs) (comprising a combination of fragile nodes) that are created during the development of both autoimmune (RA, PsA, and AS) and non-autoimmune (OA and DDD) disorders. The main aim of this review is to provide evidence that despite substantial pathobiological differences between these arthropathies, the HIPICNs created are quite common, thus justifying the merging of these disorders mechanistically and suggesting that these common mechanisms exist in the onset and progression of different joint diseases.

Carboxymethyl-chitosan attenuates inducible nitric oxide synthase and promotes interleukin-10 production in rat chondrocytes

Osteoarthritis (OA) is a common age-related degenerative joint disease, which is caused by the breakdown of joint cartilage and the underlying bone. Carboxymethyl (CM)-chitosan is a soluble derivative of chitosan that has similar physicochemical properties to the extracellular proteoglycans identified in hyaline cartilage. Previous studies have demonstrated that CM-chitosan serves a protective role in a rabbit OA model. The aim of the present study was to investigate the effect of CM-chitosan on NO production and inflammation through its upregulation of interleukin (IL)-10, and the activation of the janus kinase (JAK)/signal transducer and activator of transcription (STAT)/suppressor of cytokine signaling (SOCS) signaling pathway. In the present study primary rat chondrocytes were induced to inflammation with 2 µg/ml lipopolysaccharide. The cells were subsequently subjected to increasing concentrations of CM-chitosan (50, 100 and 200 µg/ml) and the relative mRNA and protein expression of inducible nitric oxide synthase (iNOS), IL-10, JAK1, STAT3 and SOCS3 were measured by RT-qPCR and western blot analysis respectively. The results revealed that CM-chitosan attenuated inflammation by significantly reducing iNOS expression and upregulating the anti-inflammatory cytokine IL-10 in a dose-dependent manner (P<0.05). The expression of JAK1, STAT3 and SOCS3 were also significantly upregulated by CM-chitosan (all P<0.05). The protective role of CM-chitosan against NO production was due to its upregulation of IL-10 and its activation of the JAK/STAT/SOCS signaling pathway.

Monoclonal antibodies for chronic pain: a practical review of mechanisms and clinical applications

Context

Monoclonal antibodies are being investigated for chronic pain to overcome the shortcomings of current treatment options.

Objective

To provide a practical overview of monoclonal antibodies in clinical development for use in chronic pain conditions, with a focus on mechanisms of action and relevance to specific classes.

Methods

Qualitative review using a systematic strategy to search for randomized controlled trials, systematic and nonsystematic (narrative) reviews, observational studies, nonclinical studies, and case reports for inclusion. Studies were identified via relevant search terms using an electronic search of MEDLINE via PubMed (1990 to June 2017) in addition to hand-searching reference lists of retrieved systematic and nonsystematic reviews.

Results

Monoclonal antibodies targeting nerve growth factor, calcitonin gene-related peptide pathways, various ion channels, tumor necrosis factor-α, and epidermal growth factor receptor are in different stages of development. Mechanisms of action are dependent on specific signaling pathways, which commonly involve those related to peripheral neurogenic inflammation. In clinical studies, there has been a mixed response to different monoclonal antibodies in several chronic pain conditions, including migraine, neuropathic pain conditions (e.g., diabetic peripheral neuropathy), osteoarthritis, chronic back pain, ankylosing spondylitis, and cancer. Adverse events observed to date have generally been mild, although further studies are needed to ensure safety of monoclonal antibodies in early stages of development, especially where there is an overlap with non-pain-related pathways. High acquisition cost remains another treatment limitation.

Conclusion

Monoclonal antibodies for chronic pain have the potential to overcome the limitations of current treatment options, but strategies to ensure their appropriate use need to be determined.