The Efficacy of Nerve Growth Factor Antibody for the Treatment of Osteoarthritis Pain and Chronic Low-Back Pain: A Meta-Analysis

Targeting nerve growth factor for pain relief: pros and cons

Nerve growth factor (NGF) is a neurotrophic protein that has crucial roles in survival, growth and differentiation. It is expressed in neuronal and non-neuronal tissues. NGF exerts its effects via two types of receptors including the high affinity receptor, tropomyosin receptor kinase A and the low affinity receptor p75 neurotrophin receptor highlighting the complex signaling pathways that underlie the roles of NGF. In pain perception and transmission, multiple studies shed light on the effects of NGF on different types of pain including inflammatory, neuropathic, cancer and visceral pain. Also, the binding of NGF to its receptors increases the availability of many nociceptive receptors such as transient receptor potential vanilloid 1, transient receptor potential ankyrin 1, N-methyl-D-aspartic acid, and P2X purinoceptor 3 as well as nociceptive transmitters such as substance P and calcitonin gene-related peptide. The role of NGF in pain has been documented in pre-clinical and clinical studies. This review aims to shed light on the role of NGF and its signaling in different types of pain.

Characterization of adverse joint outcomes in patients with osteoarthritis treated with subcutaneous tanezumab

OBJECTIVE

Due to the risk of rapidly progressive osteoarthritis (RPOA), the phase III studies of subcutaneous (SC) tanezumab in patients with moderate to severe hip or knee osteoarthritis (OA) included comprehensive joint safety surveillance. This pooled analysis summarizes these findings.

METHOD

Joint safety events in the phase III studies of SC tanezumab (2 placebo- and 1- nonsteroidal anti-inflammatory drug [NSAID]-controlled) were adjudicated by a blinded external committee. Outcomes of RPOA1 and RPOA2, primary osteonecrosis, subchondral insufficiency fracture, and pathological fracture comprised the composite joint safety endpoint (CJSE). Potential patient- and joint-level risk factors for CJSE, RPOA, and total joint replacement (TJR) were explored.

RESULTS

Overall, 145/4541 patients (3.2%) had an adjudicated CJSE (0% placebo; 3.2% tanezumab 2.5 mg; 6.2% tanezumab 5 mg; 1.5% NSAID). There was a dose-dependent risk of adjudicated CJSE, RPOA1, and TJR with tanezumab vs NSAID. Patient-level cross-tabulation found associations between adjudicated RPOA with more severe radiographic/symptomatic (joint pain, swelling, and physical limitation) OA. Risk of adjudicated RPOA1 was highest in patients with Kellgren-Lawrence (KL) grade 2 or 3 OA at baseline. Risk of adjudicated RPOA2 or TJR was highest in patients with KL grade 4 joints at baseline. A higher proportion of joints with adjudicated RPOA2 had a TJR (14/26) than those with adjudicated RPOA1 (16/106).

CONCLUSION

In placebo- and NSAID controlled studies of SC tanezumab for OA, adjudicated CJSE, RPOA, and TJR most commonly occurred in patients treated with tanezumab and with more severe radiographic or symptomatic OA. NCT02697773; NCT02709486; NCT02528188.

Role of imaging for eligibility and safety of a-NGF clinical trials

Nerve growth factor (a-NGF) inhibitors have been developed for pain treatment including symptomatic osteoarthritis (OA) and have proven analgesic efficacy and improvement in functional outcomes in patients with OA. However, despite initial promising data, a-NGF clinical trials focusing on OA treatment had been suspended in 2010. Reasons were based on concerns regarding accelerated OA progression but were resumed in 2015 including detailed safety mitigation based on imaging. In 2021, an FDA advisory committee voted against approving tanezumab (one of the a-NGF compounds being evaluated) and declared that the risk evaluation and mitigation strategy was not sufficient to mitigate potential safety risks. Future clinical trials evaluating the efficacy of a-NGF or comparable molecules will need to define strict eligibility criteria and will have to include strategies to monitor safety closely. While disease-modifying effects are not the focus of a-NGF treatments, imaging plays an important role to evaluate eligibility of potential participants and to monitor safety during the course of these studies. Aim is to identify subjects with on-going safety findings at the time of inclusion, define those potential participants that are at increased risk for accelerated OA progression and to withdraw subjects from on-going studies in a timely fashion that exhibit imaging-confirmed structural safety events such as rapid progressive OA. OA efficacy- and a-NGF studies apply imaging for different purposes. In OA efficacy trials image acquisition and evaluation aims at maximizing sensitivity in order to capture structural effects between treated and non-treated participants in longitudinal fashion. In contrast, the aim of imaging in a-NGF trials is to enable detection of structural tissue alterations that either increase the risk of a negative outcome (eligibility) or may result in termination of treatment (safety).

Sex-Related Pain Behavioral Differences following Unilateral NGF Injections in a Rat Model of Low Back Pain

Low back pain (LBP) is a globally prevalent and costly societal problem with multifactorial etiologies and incompletely understood pathophysiological mechanisms. To address such shortcomings regarding the role of neurotrophins in the underlying mechanisms of pain, an LBP model was developed in rats involving two unilateral intramuscular injections of nerve growth factor (NGF) into deep trunk muscles. To date, behavioral investigations of this NGF-LBP model have been limited, especially as it pertains to female pain behaviors. This study compared mechanical sensitivity to noxious (hyperalgesia) and non-noxious (hypersensitivity) stimuli in control and NGF-injected male and female rats through pain resolution. Although the baseline testing revealed no differences between males and females, NGF-injected females demonstrated prolonged ipsilateral deep trunk mechanical hyperalgesia that resolved seven days later than males. Moreover, females showed bilateral trunk mechanical sensitivity to noxious and non-noxious stimuli compared to only ipsilateral behaviors in males. Sex differences were also observed in the severity of behavioral responses, with females displaying greater mean differences from baseline at several timepoints. Overall, these NGF-LBP behavioral findings mirror some of the sex differences reported in the clinical presentation of LBP and accentuate the translatability of this NGF-LBP model. Future studies using this LBP-NGF model could help to elucidate the neurobiological mechanisms responsible for the development, severity, and/or resolution of muscular LBP as well as to provide insights into the processes governing the transition from acute to chronic LBP.

Pharmacological use of gamma-aminobutyric acid derivatives in osteoarthritis pain management: a systematic review

Background

Pain is the major complication of osteoarthritis (OA) patients and is a decisive symptom for medical intervention. Gamma-aminobutyric acid (GABA) derivatives are optional painkillers but not widely used in pain management of OA patients. We synthesized the efficacy and safety of GABA derivatives for OA pain management.

Methods

We searched Medline, Cochrane CENTRAL, Embase, and ClinicalTrals.gov from inception to 13 October 2021 and included randomized controlled trials (RCTs) comparing the efficacy and safety of GABA derivatives with placebo or standard control in OA pain management. Two independent reviewers extracted data and assessed these studies for risk of bias using Cochrane Collaboration’s tool for RCT.

Results

In total, three eligible RCTs (n = 3) meeting the eligibility criteria were included. Among these RCTs, one focused on hand OA pain management, while two RCTs focused on knee OA. In hand OA, pregabalin reduced numerical rating scale (NRS) score and the Australian/Canadian Osteoarthritis Hand Index (AUSCAN) pain score significantly compared with placebo, and caused 55 AEs. In knee OA, pregabalin reduced visual analogue scale (VAS) score and the Western Ontario and McMaster Universities Arthritis Index (WOMAC) pain score significantly with no recorded adverse event (AE). Meanwhile, in knee OA, gabapentin reduced both VAS score and WOMAC pain score compared with acetaminophen and caused 9 AEs.

Conclusions

GABA derivatives seem to be effective and safe in OA pain management. However, future researches with large sample size are needed to further prove the efficacy of GABA derivatives in OA pain control.

Trial registration: CRD42021240225.

Supplementary Information

The online version contains supplementary material available at 10.1186/s41927-022-00257-z.

Efficacy and Safety of Anti–Nerve Growth Factor Antibody Therapy for Hip and Knee Osteoarthritis: A Meta-analysis

Background:

The efficacy and safety of anti–nerve growth factor (NGF) antibody therapy used for osteoarthritis (OA) pain are controversial.

Purpose:

To evaluate the efficacy and safety of anti-NGF antibody therapy via a meta-analysis of randomized controlled trials (RCTs).

Study Design:

Systematic review; Level of evidence, 1.

Methods:

PubMed, the Cochrane Central Register of Controlled Trials, Embase, and the Web of Science databases were searched for RCTs assessing anti-NGF antibody treatments for hip and knee OA. A total of 623 records were retrieved from the databases. A random-effects model was used to assess primary and secondary outcomes. Bias was assessed using the Cochrane Collaboration tool, funnel plots, and the Egger test. Subgroup analyses were used to assess the efficacy and safety of the independent variables. Sensitivity analysis was conducted to evaluate the effectiveness of tanezumab and the effectiveness of anti-NGF antibodies compared to active comparator drugs. We present the effects of dose, administration mode, and treatment duration on the efficacy and safety of anti-NGF antibody therapy.

Results:

There were 19 RCTs included in our meta-analysis. Anti-NGF antibody treatment showed significant improvements on the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) for pain, physical function, and stiffness as well as on a patient global assessment (PGA). The overall standardized mean differences were as follows: WOMAC pain (–0.31 [95% CI, –0.36 to –0.26]; Z = 11.75; P < .001; I² = 38%), WOMAC physical function (−0.36 [95% CI, –0.41 to –0.30]; Z = 12.67; P < .001; I² = 44%), WOMAC stiffness (–3.59 [95% CI, –4.87 to –2.30]; Z = 5.47; P < .001; I² = 98%), and PGA (−0.28 [95% CI, –0.34 to –0.22]; Z = 9.39; P < .001; I² = 50%). Anti-NGF antibody treatment resulted in a greater incidence of adverse events (risk ratio, 1.09 [95% CI, 1.06 to 1.12]; Z = 5.60; P < .001; I² = 0%). The incidence of serious adverse events was similar between the treatment and control groups (risk ratio, 1.15 [95% CI, 0.98 to 1.34]; Z = 1.71; P = .09; I² = 0%).

Conclusion:

Anti-NGF antibody treatment significantly relieved pain and improved function in patients with hip and knee OA. However, no conclusion could be drawn regarding the optimal treatment plan for anti-NGF antibodies when all 3 variables (dose, administration mode, and treatment duration) were combined in the analyses.

Efficacy and safety of biologic agents for the treatment of osteoarthritis: a meta-analysis of randomized placebo-controlled trials

Background:

We aimed to evaluate the efficacy and safety of biologic agents targeting three main cytokines, that is, nerve growth factor (NGF), interleukin-1 (IL-1), and tumor necrosis factor-α (TNF-α), for osteoarthritis (OA) treatment.

Methods:

Databases (PubMed, Embase, and Cochrane Library) and ClinicalTrials.gov were systematically searched for randomized placebo-controlled trials (RCTs) of biologic agents from inception to November 15, 2020. The outcomes were the mean change in pain, function scores, and the risk of adverse effects (AEs).

Results:

Out of the 28 studies with 29 RCTs (8555 individuals) included, biologic agents were superior to placebo in pain relief (standardized mean difference [SMD] = 0.28, 95% confidence interval [CI] = 0.17–0.38, p < 0.001) and function improvement (SMD = 0.30, 95% CI = 0.18–0.43, p < 0.001). The incidence of any AEs (risk ratio [RR] = 1.09, 95% CI = 1.05–1.14, p < 0.001) and discontinuations due to AEs (RR = 1.39, 95% CI = 1.05–1.83, p = 0.021) were higher following treatment with biologic agents while no significant difference was found in serious AEs. Subgroup analyses showed that NGF inhibitors provided superior pain relief (SMD = 0.36, 95% CI = 0.26–0.47, p < 0.001) and function improvement (SMD = 0.41, 95% CI = 0.30–0.51, p < 0.001), whereas IL-1 inhibitors and TNF-α inhibitors did not. Meanwhile, NGF inhibitors increased the incidence of any AEs (RR = 1.12, 95% CI = 1.07–1.17, p < 0.001) and discontinuations due to AEs (RR = 1.48, 95% CI = 1.07–2.06, p = 0.018). IL-1 inhibitors and TNF-α inhibitors showed no difference in safety compared with placebo.

Conclusions:

The efficacy and safety of biologic agents vary by mechanism of action. NGF inhibitors can relieve OA-related pain and improve function but involve safety concerns. IL-1 inhibitors and TNF-α inhibitors are relatively safe options but with limited efficacy.

Nerve Growth Factor (NGF) Inhibitors and Related Agents for Chronic Musculoskeletal Pain: A Comprehensive Review

Musculoskeletal pain such as osteoarthritis (OA) and low back pain (LBP) are very common and contribute to enormous burden and societal costs, despite dramatic therapeutic advances over recent decades. Novel approaches and targeted therapies are required to satisfy the urgent unmet medical need of musculoskeletal pain relief in both conditions. Nerve growth factor (NGF) inhibitors have utilized novel mechanisms different from conventional drugs, which have a variety of gastrointestinal, cardiac, or renal adverse effects. Several phase 2/3 studies have been accomplished for these drugs, such as tanezumab, fasinumab, and tyrosine receptor kinase A (TrkA) inhibitors. We searched the literature using the PubMed database and clinical trials using ClinicalTrials.gov to identify original papers, meta-analyses as well as ongoing clinical trials assessing the efficacy and safety profile of these drugs. In this narrative review, we briefly overview the disease burden of musculoskeletal pain, the role of NGF signaling and its receptors in the genesis of pain, and the mechanisms of action of inhibitors of NGF signaling and downstream pathways, and then discuss the efficacy and safety of each investigational drug in OA and LBP. Finally, we briefly review two serious adverse effects of NGF inhibitors, namely rapidly progressive OA and sympathetic system effects, and conclude with possible barriers and potential research directions to overcome these.

Targeting Neurotrophic Factors for Low Back Pain and Sciatica: A Systematic Review and Meta-analysis

OBJECTIVES

This meta-analysis aims to investigate the efficacy and safety of medicines that target neurotrophic factors for low back pain (LBP) or sciatica.

METHODS

We searched published and trial registry reports of randomised controlled trials evaluating the effect of medicines that target neurotrophic factors to LBP or sciatica in seven databases from inception to December 2020. Two reviewers independently identified studies, extracted data, and assessed the risk of bias and certainty in the evidence.

RESULTS

Nine studies (3349 participants) were included in the meta-analyses. Low certainty evidence showed that anti-NGF may reduce pain at four weeks (MD -6.63, 95% CI -8.51 to -4.76), and 12 weeks (MD -6.10, -8.34 to -3.87), and may increase adverse effects for chronic LBP (OR 1.16, 0.99-1.36). Higher doses of anti-NGF may offer a clinically important reduction in pain at the cost of increased adverse effects for chronic LBP. Very low certainty evidence showed that anti-NGF and glial cell line-derived neurotrophic factor (pro-GDNF) may not reduce pain for sciatica at four weeks (MD -1.40, -8.26-5.46), at 12 weeks (MD -2.91, -13.69-7.67), and may increase adverse effects for sciatica (OR 3.27, 1.78-6.00).

CONCLUSION

Anti-NGF may offer small reductions in pain intensity for chronic LBP. The effect may depend on the dose and types of medicines. For sciatica, anti-NGF or pro-GDNF may not reduce pain. Medicines that target neurotrophic factors for LBP or sciatica are associated with different adverse effects from commonly prescribed medicines for these conditions.

Is Targeting Nerve Growth Factor Antagonist a New Option for Pharmacologic Treatment of Low Back Pain? A Supplemental Network Meta-Analysis of the American College of Physicians Guidelines

Objective: It has been found that targeting nerve growth factor antagonists (ANGF) have excellent effects in the treatment of chronic pain, and the current pharmacologic treatments have very limited effects on low back pain (LBP). Thus we conducted this network meta-analysis (NMA) to study the efficacy and safety of ANGF for the treatment of LBP, and to guide for clinical practice and further research.

Method: PubMed, Scopus, Embase, CNKI, and the Cochrane Library were searched from January 1980 to March 2021. A frequentist framework network meta-analysis with a random-effect model was performed. Ranking effects were calculated by surface under the cumulative ranking analysis (SUCRA) and clusterank analysis.

Results: This NMA identified 30 studies, involving 9,508 patients with LBP. ANGF reported both superior effect on pain relief {SUCRA 82.1%, SMD 0.89, 95% CI [(0.26,1.51)]} and function improvement {SUCRA 77.3%, SMD 0.93, 95% CI [(0.27,1.58)]} than placebo, and did not showed any higher risk of treatment-emergent adverse effects {RR 1.11, 95% CI [(0.97,1.27)]} or serious adverse effects {RR 1.03, 95% CI [(0.54,1.97)]}, but it was associate with a special risk of rapidly progressive osteoarthritis. ANGF displayed the greatest potential to be the most effective and safest treatment (cluster-rank value for function improvement and safety: 4266.96, for pain relief and safety: 4531.92).

Conclusion: ANGF could relieve pain and improve function effectively and are superior to other traditional drugs recommended by guidelines. Although no significant difference in tolerability and safety between ANGFs and placebo was found, the rapid progression of original osteoarthritis which may be related to the use of ANGFs still needs special attention and furtherly verification by clinical trials.

Systematic Review Registration: PROSPERO, identifier [CRD42021258033].

Treating osteoarthritis pain: mechanisms of action of acetaminophen, nonsteroidal anti-inflammatory drugs, opioids, and nerve growth factor antibodies

Osteoarthritis (OA) is a common difficult-to-treat condition where the goal, in the absence of disease-modifying treatments, is to alleviate symptoms such as pain and loss of function. Acetaminophen, nonsteroidal anti-inflammatory drugs (NSAIDs), and opioids are common pharmacologic treatments for OA. Antibodies directed against nerve growth factor (NGF-Abs) are a new class of agents under clinical investigation for the treatment of OA. This narrative review describes (and uses schematics to visualize) nociceptive signaling, chronification of pain, and the mechanisms of action (MOAs) of these different analgesics in the context of OA-related pain pathophysiology. Further, the varying levels of efficacy and safety of these agents observed in patients with OA is examined, based on an overview of published clinical data and/or treatment guidelines (when available), in the context of differences in their MOAs.

Systematic review on the incidence of low back pain as well as on the rehabilitation treatment methods used

Introduction. Low back pain is a growing condition both in terms of sampling and incidence, reaching to affect any of us at some point. Material and method. In order to write the article, four international libraries were used, where search criteria were used such as: "low back pain", "low back pain incidence" and "low back pain treatment". The articles used in this paper were carefully selected according to their relevance for this study, but only considered articles published in 2020. Results and discussions. The obtained results indicated that both physical therapy and physiotherapy have beneficial effects in ameliorating the symptoms generated by low back pain, but due to the lack of an optimal protocol patients turn to alternative therapies that have shown greater efficacy than physical therapy in amelioration. symptoms generated by low back pain. Conclusions. The lack of an optimal physiotherapeutic treatment protocol causes patients to turn to alternative therapies that are more effective, as well as a lower cost per treatment.

Of mice and men: converging on a common molecular understanding of osteoarthritis

Despite an increasing burden of osteoarthritis in developed societies, target discovery has been slow and there are currently no approved disease-modifying osteoarthritis drugs. This lack of progress is due in part to a series of misconceptions over the years: that osteoarthritis is an inevitable consequence of ageing, that damaged articular cartilage cannot heal itself, and that osteoarthritis is driven by synovial inflammation similar to that seen in rheumatoid arthritis. Molecular interrogation of disease through ex-vivo tissue analysis, in-vitro studies, and preclinical models have radically reshaped the knowledge landscape. Inflammation in osteoarthritis appears to be distinct from that seen in rheumatoid arthritis. Recent randomised controlled trials, using treatments repurposed from rheumatoid arthritis, have largely been unsuccessful. Genome-wide studies point to defects in repair pathways, which accords well with recent promise using growth factor therapies or Wnt pathway antagonism. Nerve growth factor has emerged as a robust target in osteoarthritis pain in phase 2-3 trials. These studies, both positive and negative, align well with those in preclinical surgical models of osteoarthritis, indicating that pathogenic mechanisms identified in mice can lead researchers to valid human targets. Several novel candidate pathways are emerging from preclinical studies that offer hope of future translational impact. Enhancing trust between industry, basic, and clinical scientists will optimise our collective chance of success.