Tanezumab for Painful Osteoarthritis

Transcriptome Analysis of Rheumatoid Arthritis Uncovers Genes Linked to Inflammation-Induced Pain

Autoimmune diseases such as rheumatoid arthritis (RA) can promote states of chronic Inflammation with accompanying tissue destruction and pain. RA can cause inflammatory synovitis in peripheral joints, particularly within the hands and feet, but can also sometimes trigger temporomandibular joint (TMJ) arthralgia. To better understand the effects of ongoing Inflammation-induced pain signaling, dorsal root ganglia (DRGs) were acquired from individuals with RA for transcriptomic study. We conducted RNA sequencing from the L5 DRGs because it contains the soma of the sensory neurons that innervate the affected joints in the foot. DRGs from 5 RA patients were compared with 9 non-arthritic controls. RNA-seq of L5 DRGs identified 128 differentially expressed genes (DEGs) that were dysregulated in the RA subjects as compared to the non-arthritic controls. The DRG resides outside the blood brain barrier and, as such, our initial transcriptome analysis detected signs of an autoimmune disorder including the upregulated expression of immunoglobulins and other immunologically related genes within the DRGs of the RA donors. Additionally, we saw the upregulation in genes implicated in neurogenesis that could promote pain hypersensitivity. overall, our DRG analysis suggests that there are upregulated inflammatory and pain signaling pathways that can contribute to chronic pain in RA.

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.

Peripheral mechanisms of peripheral neuropathic pain

Peripheral neuropathic pain (PNP), neuropathic pain that arises from a damage or disease affecting the peripheral nervous system, is associated with an extremely large disease burden, and there is an increasing and urgent need for new therapies for treating this disorder. In this review we have highlighted therapeutic targets that may be translated into disease modifying therapies for PNP associated with peripheral neuropathy. We have also discussed how genetic studies and novel technologies, such as optogenetics, chemogenetics and single-cell RNA-sequencing, have been increasingly successful in revealing novel mechanisms underlying PNP. Additionally, consideration of the role of non-neuronal cells and communication between the skin and sensory afferents is presented to highlight the potential use of drug treatment that could be applied topically, bypassing drug side effects. We conclude by discussing the current difficulties to the development of effective new therapies and, most importantly, how we might improve the translation of targets for peripheral neuropathic pain identified from studies in animal models to the clinic.

Contemporary perspectives on heterotopic ossification

Heterotopic ossification (HO) is the formation of ectopic bone that is primarily genetically driven (fibrodysplasia ossificans progressiva [FOP]) or acquired in the setting of trauma (tHO). HO has undergone intense investigation, especially over the last 50 years, as awareness has increased around improving clinical technologies and incidence, such as with ongoing wartime conflicts. Current treatments for tHO and FOP remain prophylactic and include NSAIDs and glucocorticoids, respectively, whereas other proposed therapeutic modalities exhibit prohibitive risk profiles. Contemporary studies have elucidated mechanisms behind tHO and FOP and have described new distinct niches independent of inflammation that regulate ectopic bone formation. These investigations have propagated a paradigm shift in the approach to treatment and management of a historically difficult surgical problem, with ongoing clinical trials and promising new targets.

Dhanabalan K, Agarwal S, Agarwal R. Resolvin D1-loaded nanoliposomes promote M2 macrophage polarization and are effective in the treatment of osteoarthritis

Current treatments for osteoarthritis (OA) offer symptomatic relief but do not prevent or halt the disease progression. Chronic low-grade inflammation is considered a significant driver of OA. Specialized proresolution mediators are powerful agents of resolution but have a short in vivo half-life. In this study, we have engineered a Resolvin D1 (RvD1)-loaded nanoliposomal formulation (Lipo-RvD1) that targets and resolves the OA-associated inflammation. This formulation creates a depot of the RvD1 molecules that allows the controlled release of the molecule for up to 11 days in vitro. In surgically induced mice model of OA, only controlled-release formulation of Lipo-RvD1 was able to treat the progressing cartilage damage when administered a month after the surgery, while the free drug was unable to prevent cartilage damage. We found that Lipo-RvD1 functions by damping the proinflammatory activity of synovial macrophages and recruiting a higher number of M2 macrophages at the site of inflammation. Our Lipo-RvD1 formulation was able to target and suppress the formation of the osteophytes and showed analgesic effect, thus emphasizing its ability to treat clinical symptoms of OA. Such controlled-release formulation of RvD1 could represent a patient-compliant treatment for OA.

Analgesic effects of nerve growth factor-directed monoclonal antibody on diabetic neuralgia in an animal model

Current treatment options for diabetic neuralgia are limited and unsatisfactory. Tanezumab, a monoclonal antibody that blocks nerve growth factor (NGF) signaling, has been shown to be effective in relieving the clinical symptoms of osteoarthritis pain, chronic low back pain, cancer pain induced by bone metastasis, and diabetic neuralgia. However, the clinical development of tanezumab has been terminated due to the risk of induction of rapidly progressive osteoarthritis (RPOA), and no other NGF antibodies have been examined for their ability to treat diabetic neuralgia in either animal models or clinical trials. In this study, a humanized high‐affinity NGF monoclonal antibody (mAb), huAb45 that could neutralize the interaction between NGF and its high‐affinity receptor TrkA. In a mouse diabetic neuralgia model, it effectively relieved neuropathic pain. This study may serve as the necessary foundation for future studies of huAb45 to potentially treat diabetic neuralgia.

Safety of Low-Dose Tanezumab in the Treatment of Hip or Knee Osteoarthritis: A Systemic Review and Meta-analysis of Randomized Phase III Clinical Trials

OBJECTIVES

To evaluate the safety of low-dose tanezumab in the treatment of knee or hip osteoarthritis (OA).

METHODS

Databases were searched up to September 2019 for phase III randomized controlled trials (RCTs). Eleven phase III RCTs comprising 11,455 patients were eligible. The pooled estimates of safety outcomes were assessed and expressed using relative risks (RRs) and 95% confidence intervals with a random-effects model.

RESULTS

Tanezumab significantly increased the incidence of rapidly progressive OA (RPOA; RR = 9.07, 95% CI = 1.21-67.90, P = 0.03) and abnormal peripheral sensation (APS; RR = 2.68, 95% CI = 1.64-4.37, P < 0.00001) compared with placebo. No significant difference was found in terms of incidence of total joint replacement (TJR; RR = 1.13, 95% CI = 0.76-1.68, P = 0.55) or withdrawal due to adverse effects (AEs; RR = 1.26, 95% CI = 0.79-2.00, P = 0.33). The tanezumab group showed a statistically higher incidence of RPOA (RR = 3.96, 95% CI = 2.23-7.04, P < 0.00001) and APS (RR = 1.2, 95% CI = 1.44-2.56, P < 0.00001) compared with the nonsteroidal anti-inflammatory drugs and opioids group. No significant difference was found in terms of TJR (RR = 1.51, 95% CI = 0.65-3.47, P = 0.33) and withdrawal (RR = 0.54, 95% CI = 0.20-1.40, P = 0.20). Subgroup analysis revealed that 2.5 mg of tanezumab did not show an advantage over 5 mg of tanezumab in reducing AEs.

CONCLUSIONS

These results demonstrate that RPOA and APS should be the most concerning AEs when using tanezumab in OA patients. Additional data are needed to define the optimal dose to minimize risk and to determine the optimal subjects to receive this treatment.

Review Article: Is Wnt Signaling an Attractive Target for the Treatment of Osteoarthritis?

Osteoarthritis is the most common chronic joint disease affecting millions of people worldwide and a leading cause of pain and disability. Increasing incidence of obesity and aging of the population are two factors that suggest that the impact of osteoarthritis will further increase at the society level. Currently, there are no drugs available that can manage both structural damage to the joint or the associated pain. Increasing evidence supports the view that the Wnt signaling pathway plays an important role in this disease. The current concept, based on genetic and functional studies, indicates that tight regulation of Wnt signaling in cartilage is essential to keep the joint healthy. In this review, we discuss how this concept has evolved, provide insights into the regulation of Wnt signaling, in particular by Wnt modulators such as frizzled-related protein and DOT1-like histone lysine methyltransferase, and summarize preclinical evidence and molecular mechanisms of lorecivivint, the first Wnt antagonist in clinical development for osteoarthritis.

Extracorporeal Shock Wave Therapy for the Treatment of Osteoarthritis: A Systematic Review and Meta-Analysis

Background

Osteoarthritis is the most common musculoskeletal disease. Extracorporeal shockwave therapy had shown an effect on osteoarthritis in both some animal experiments and clinical studies, but there was no systematic review to confirm the value of shockwave therapy in the treatment of all types of osteoarthritis and compare it with other traditional therapies (especially traditional Chinese medicine).

Method

PubMed, Medline, the Cochrane Central Register of Controlled Trials, Web of Science, Chinese National Knowledge Infrastructure, WANFANG database, and VIP database were searched up to December 10, 2019, to identify randomized controlled trials comparing shockwave therapy and other treatments for osteoarthritis. Visual analogue scale and the Western Ontario and McMaster Universities Osteoarthritis Index were extracted and analyzed by RevMan and STATA software as outcomes of pain reduction and functional improvement. Adverse reactions were recorded to evaluate the safety of shockwave therapy.

Results

Shockwave therapy had significant improvement in both pain reduction and functional improvement compared with placebo, corticosteroid, hyaluronic acid, medication, and ultrasound (P < 0.05). In functional improvement, shockwave therapy showed statistical improvement compared with kinesiotherapy and moxibustion (P < 0.05) but not with acupotomy surgery (P = 0.24). A significant difference between shockwave therapy and platelet-rich plasma was observed in pain reduction (P < 0.05) but not in functional improvement (P = 0.89). Meanwhile, a statistical difference was found between shockwave therapy and fumigation in functional improvement (P < 0.05) but not in pain reduction (P = 0.26). Additionally, there was no statistically significant difference between shockwave therapy and manipulation in both pain reduction (P = 0.21) and functional improvement (P = 0.45). No serious adverse reaction occurred in all of studies.

Conclusions

Extracorporeal shockwave therapy could be recommended in the treatment of osteoarthritis as a noninvasive therapy with safety and effectiveness, but the grade of recommendations needs to be discussed in a further study.