Trial designs for chemotherapy-induced peripheral neuropathy prevention: ACTTION recommendations

Overview and critical revision of clinical assessment tools in chemotherapy-induced peripheral neurotoxicity

Chemotherapy-induced peripheral neurotoxicity (CIPN) is a major toxicity of cancer treatment, leading to dose reduction and premature treatment cessation, potentially affecting patient function, and quality of life. The development of accurate and sensitive assessment tools for CIPN is essential to enable clinical monitoring during treatment, follow-up of long-term outcomes and measurement of toxicity in clinical trials. This review examines CIPN clinical assessment scales incorporating clinician-based, composite, and patient-reported outcomes (PROs), providing a systematic review of their properties and an updated critical analysis of recommendations on current evidence for their use. This systematic review of CIPN assessment tools identified 50 papers containing 41 assessment tools, across 4 categories (common toxicity criteria; composite neurological scale; PROs; pain scale). The majority of these tools were PROs, underscoring the importance of patient-based assessment of symptoms. While there has been considerable work in the field over the past 10 years, this review highlights significant gaps, including a lack of evaluation of responsiveness and problematic neuropathic pain evaluation. There remains a need for consensus on the best available tool and the need to modify existing instruments to improve utility.

Chemotherapy-induced peripheral neuropathy: where are we now?

Chemotherapy-induced peripheral neuropathy (CIPN) is a major challenge, with increasing impact as oncological treatments, using potentially neurotoxic chemotherapy, improve cancer cure and survival. Acute CIPN occurs during chemotherapy, sometimes requiring dose reduction or cessation, impacting on survival. Around 30% of patients will still have CIPN a year, or more, after finishing chemotherapy. Accurate assessment is essential to improve knowledge around prevalence and incidence of CIPN. Consensus is needed to standardize assessment and diagnosis, with use of well-validated tools, such as the EORTC-CIPN 20. Detailed phenotyping of the clinical syndrome moves toward a precision medicine approach, to individualize treatment. Understanding significant risk factors and pre-existing vulnerability may be used to improve strategies for CIPN prevention, or to use targeted treatment for established CIPN. No preventive therapies have shown significant clinical efficacy, although there are promising novel agents such as histone deacetylase 6 (HDAC6) inhibitors, currently in early phase clinical trials for cancer treatment. Drug repurposing, eg, metformin, may offer an alternative therapeutic avenue. Established treatment for painful CIPN is limited. Following recommendations for general neuropathic pain is logical, but evidence for agents such as gabapentinoids and amitriptyline is weak. The only agent currently recommended by the American Society of Clinical Oncology is duloxetine. Mechanisms are complex with changes in ion channels (sodium, potassium, and calcium), transient receptor potential channels, mitochondrial dysfunction, and immune cell interactions. Improved understanding is essential to advance CIPN management. On a positive note, there are many potential sites for modulation, with novel analgesic approaches.

Genetic variation in EPHA contributes to sensitivity to paclitaxel-induced peripheral neuropathy

AIMS

Chemotherapy-induced peripheral neuropathy (PN) is a treatment limiting toxicity of paclitaxel. We evaluated if EPHA genetic variation (EPHA4, EPHA5, EPHA6, and EPHA8) is associated with PN sensitivity by accounting for variability in systemic paclitaxel exposure (time above threshold).

METHODS

Germline DNA from 60 patients with breast cancer was sequenced. PN was measured using the 8-item sensory subscale (CIPN8) of the patient-reported CIPN20. Associations for 3 genetic models were tested by incorporating genetics into previously published PN prediction models integrating measured paclitaxel exposure and cumulative treatment. Significant associations were then tested for association with PN-related treatment disruption.

RESULTS

EPHA5 rs7349683 (minor allele frequency = 0.32) was associated with increased PN sensitivity (β-coefficient = 0.39, 95% confidence interval 0.11-0.67, p = 0.007). Setting a maximum tolerable threshold of CIPN8 = 30, optimal paclitaxel exposure target is shorter for rs7349683 homozygous (11.6 h) than heterozygous (12.6 h) or wild-type (13.6 h) patients. Total number of missense variants (median = 0, range 0-2) was associated with decreased PN sensitivity (β-coefficient: -0.42, 95% confidence interval -0.72 to -0.12, P = .006). No association with treatment disruption was detected for the total number of missense variants or rs7349683.

CONCLUSION

Isolating toxicity sensitivity by accounting for exposure is a novel approach, and rs7349683 represents a promising marker for PN sensitivity that may be used to individualize paclitaxel treatment.

The National Cancer Institute Clinical Trials Planning Meeting for Prevention and Treatment of Chemotherapy-Induced Peripheral Neuropathy

Although recent scientific advances have improved our understanding of basic biological mechanisms underlying chemotherapy-induced peripheral neuropathy (CIPN), few interventions are available to prevent or treat CIPN. Although some biological targets from preclinical studies show promise in nonhuman animal models, few targets have been translated to successful clinical trials. To address this problem, the National Cancer Institute's Symptom Management and Health-Related Quality of Life Steering Committee convened a meeting of experts in the CIPN and oncology symptom management fields to participate in a Clinical Trials Planning Meeting (CTPM). Investigators presented data from preclinical and translational studies for possible CIPN interventions; these were evaluated for readiness of randomized clinical trial testing by experts, and recommendations were provided. Breakout sessions were convened to discuss and develop future studies. The CTPM experts concluded that there is compelling evidence to move forward with selected pharmacological and nonpharmacological clinical trials for the prevention and treatment of CIPN. Several key feasibility issues need to be addressed, however. These include identification of optimal outcome measures to define the CIPN phenotype, establishment of parameters that guide the evaluation of clinically meaningful effects, and adoption of approaches for inclusion of translational and biomarker and/or genetic measures. The results of the CTPM provide support for conducting clinical trials that include both pharmacological and nonpharmacological approaches, alone or in combination, with biomarkers, genetics, or other measures designed to inform underlying CIPN mechanisms. Several working groups were formed to design rigorous CIPN clinical trials, the results of which are ongoing.

Pathogenesis of paclitaxel-induced peripheral neuropathy: A current review of in vitro and in vivo findings using rodent and human model systems

Paclitaxel (Brand name Taxol) is widely used in the treatment of common cancers like breast, ovarian and lung cancer. Although highly effective in blocking tumor progression, paclitaxel also causes peripheral neuropathy as a side effect in 60-70% of chemotherapy patients. Recent efforts by numerous labs have aimed at defining the underlying mechanisms of paclitaxel-induced peripheral neuropathy (PIPN). In vitro models using rodent dorsal root ganglion neurons, human induced pluripotent stem cells, and rodent in vivo models have revealed a number of molecular pathways affected by paclitaxel within axons of sensory neurons and within other cell types, such as the immune system and peripheral glia, as well skin. These studies revealed that paclitaxel induces altered calcium signaling, neuropeptide and growth factor release, mitochondrial damage and reactive oxygen species formation, and can activate ion channels that mediate responses to extracellular cues. Recent studies also suggest a role for the matrix-metalloproteinase 13 (MMP-13) in mediating neuropathy. These diverse changes may be secondary to paclitaxel-induced microtubule transport impairment. Human genetic studies, although still limited, also highlight the involvement of cytoskeletal changes in PIPN. Newly identified molecular targets resulting from these studies could provide the basis for the development of therapies with which to either prevent or reverse paclitaxel-induced peripheral neuropathy in chemotherapy patients.

The Relationship Between Evaluation Methods for Chemotherapy-Induced Peripheral Neuropathy

Numbness and pain are currently evaluated using subjective methods such as the visual analogue scale (VAS). PainVision (PV) is an analytical instrument that was designed to quantitatively assess sense perception and nociception in patients. Chemotherapy-induced peripheral neuropathy (CIPN) is one of the most important adverse events that renders prolonged chemotherapy difficult. To assess the features of CIPN, we aimed to compare PV methods with existing methods. A total of 73 patients received oxaliplatin for metastatic colorectal cancer. Registered patients included 37 men and 36 women in the range of 37 to 89 years (median 70). CIPN was evaluated a total of 483 times (median per patient six times). Our study examined the correlation between evaluation methods of CIPN using VAS and PV, respectively. The average VAS (hand), VAS (foot) and PV scores of CIPN were 18.4 (range: 0–100), 23.8 (range: 0–100), and 24.7 (range: 0–496), respectively. VAS (hand), VAS (foot), and FACT/GOG-NTX (NTX2, NTX4 and NTX8) were significantly correlated with PV. PV showed no correlation with a Disk-Criminator or the monofilament test used as a quantitative evaluation. The evaluation of CIPN is complex, and further improvement is required for evaluation with PV.

Optimizing Clinical Screening for Chemotherapy-Induced Peripheral Neuropathy

CONTEXT

Efficient and accurate clinical screening for treatment-related toxicities is a critical component of optimal patient management. A number of alternate screening tools for chemotherapy-induced peripheral neuropathy (CIPN) have been proposed in response to demonstrated limitations with standard clinical screening, although their relative diagnostic value is unclear.

OBJECTIVES

The aim of this study is to evaluate the relative construct validity and discriminant properties of available CIPN screening tools.

METHODS

Patients treated with known potentially neurotoxic therapies underwent CIPN evaluation at one or multiple timepoints (N = 316 patients; age = 56 ± 13 years). At each testing session (N = 644 testing sessions), patients were evaluated using screening tools and comprehensive CIPN assessments. Comprehensive assessments were clinician-rated (Total Neuropathy Score, reduced) or patient-reported outcome (PRO; Functional Assessment of Cancer Therapy-Gynecologic Oncology Group/Neurotoxicity questionnaire). Similarly, screening tools were clinician-rated (National Cancer Institute Common Terminology Criteria for Adverse Events [NCI-CTCAE]) or PRO (Patient Neurotoxicity Questionnaire, PRO-CTCAE).

RESULTS

Analyses revealed moderate-to-high correlations between screening tools and comprehensive assessments (0.55 ≤ rho ≤ 0.75; P < 0.001) and similar discriminant properties across screening tools (P > 0.01). Screening tool grading corresponding to clinically significant (grade 2/3) vs. low-grade (grade 0/1) CIPN would correspond to greater ratings of CIPN severity by more comprehensive assessments in a predicted 77%-91% of cases (c-statistic = 0.77-0.91; P < 0.01).

CONCLUSIONS

PRO screening tools provide adequate CIPN screening while avoiding potential biases demonstrated to limit currently used clinician-rated screening tools. Addition of a brief objective test did not add value to PRO screening. Up to 23% of patients would be misidentified through screening, providing quantitative evidence of the limitations of available screening tools. More extensive CIPN evaluations are critical in patients at risk of serious neurotoxicity.

Chemotherapy-induced peripheral neuropathy (CIPN) and its treatment: an NIH Collaboratory study of claims data

PURPOSE

Chemotherapy-induced peripheral neuropathy (CIPN) is a disabling complication of many chemotherapies. We investigated the feasibility of using health plan claims and administrative data to identify CIPN occurrence by comparing patients who received neurotoxic and non-neurotoxic chemotherapies.

METHODS

The sample included over 53,000,000 patients from two regional and one national insurer in the USA (> 400,000 exposed to chemotherapy). Peripheral neuropathy was identified using a broad definition (definition 1) and a specific definition (i.e., drug-induced polyneuropathy code) (definition 2).

RESULTS

CIPN incidence as measured by definition 1 within 6 months of chemotherapy initiation was 18.1% and 6.2% for patients who received neurotoxic and non-neurotoxic chemotherapy, respectively (relative risk neurotoxic vs. non-neurotoxic (RR), 2.93 (95% CI, 2.87-2.98)). For definition 2, these incidences were 3.6% and 0.1% (RR, 25.2 (95% CI, 22.8-27.8)). The incidences of new analgesic prescriptions for neurotoxic and non-neurotoxic groups were as follows: gabapentin, 7.1%/1.7%; pregabalin, 0.69%/0.31%; and duloxetine, 0.78%/0.76%. The incidence of CIPN as defined by definitions 1 and 2 was low compared with that of published research studies, but the relative risk of CIPN among patients who received neurotoxic chemotherapies compared with those who received non-neurotoxic chemotherapies was high using definition 2.

CONCLUSIONS

These data suggest that as used currently by clinicians, administrative codes likely underestimate CIPN incidence. Thus, studies using administrative data to estimate CIPN incidence are not currently feasible. However, the drug-induced polyneuropathy code is a specific indicator of CIPN in administrative data and may be useful for investigating predictors or potentially preventive therapies of CIPN.

Effectiveness assessment of riluzole in the prevention of oxaliplatin-induced peripheral neuropathy: RILUZOX-01: protocol of a randomised, parallel, controlled, double-blind and multicentre study by the UNICANCER-AFSOS Supportive Care intergroup

INTRODUCTION

Most patients (>70%) experience acute neuropathic symptoms shortly after oxaliplatin infusions. These symptoms are not always resolved between infusions. Overall, 30%-50% of patients suffer from chronic oxaliplatin-induced peripheral neuropathy (OIPN). This cumulative and dose-dependent sensory neuropathy limits compliance or results in oxaliplatin-based chemotherapies to be substituted with less neurotoxic agents. These treatment changes impair clinical outcomes, and may be associated with comorbidities, such as distress, depression and anxiety. Currently, no drug used to prevent or treat OIPN is sufficiently effective to be used routinely in clinical practice. There is, thus, an unmet therapeutic need to reduce the intensity of and/or prevent OIPN. We hypothesised that riluzole would be an excellent candidate to address this public health issue. Riluzole is approved for treating amyotrophic lateral sclerosis. In animals, there is a beneficial effect on sensorimotor and pain disorders, as well as related comorbidities, after repeated administration of oxaliplatin. In humans, riluzole has shown neuroprotective, anxiolytic and antidepressive effects.

METHODS AND ANALYSIS

RILUZOX-01 trial was designed as a randomised, controlled, double-blind study to evaluate the efficacy of riluzole to prevent OIPN. Patients with colorectal cancer and initiating adjuvant oxaliplatin-based chemotherapy are eligible. Patients (n=210) will be randomly assigned to either riluzole or placebo, concomitantly with chemotherapy. The primary endpoint is the change in OIPN intensity, assessed by the sensory scale of the QLQ-CIPN20, after six 2-week cycles of chemotherapy. Secondary endpoints include incidence and severity of neuropathy, grade of sensory neuropathy, intensity and features of neuropathic pain, health-related quality of life, disease-free survival, overall survival and safety.

ETHICS AND DESSIMINATION

The study was approved by a French ethics committee (ref:39/18_1, 'Comité de Protection des Personnes' Ouest-IV, France) and plans to start enroling patients in September 2019. The trial is registered in EudraCT and clinicaltrials.gov.

TRIAL REGISTRATION NUMBER

N°2017-002320-25; NCT03722680.

Mobility in survivors with chemotherapy-induced peripheral neuropathy and utility of the 6-min walk test

BACKGROUND

Chemotherapy-induced peripheral neuropathy (CIPN) is a significant and often lasting side effect of cancer treatment, with increasing CIPN severity associated with increasing deficits in balance, gait, and mobility. The 6-min walk test (6MWT) is a widely validated and utilized measure of general physical functioning and mobility, although its utility in a CIPN context is unclear. This study aimed to determine the utility of the 6MWT as an assessment of mobility deficits in a CIPN cohort and utilize the 6MWT to compare mobility data from CIPN patients to those of healthy and clinical populations.

METHODS

Cancer survivors exposed to neurotoxic chemotherapies (N = 100; mean 17 ± 13 months post-treatment; mean age 59 ± 13 years) completed a single cross-sectional assessment of patient-reported and objective CIPN, mobility (6MWT), and disability.

RESULTS

CIPN symptoms were reported in the majority of the cohort (87%). Increasing age, patient-reported and objective CIPN symptoms, and disability were associated with decreasing 6MWT distance (.48 ≤ R ≤ .63; p < .001) in bivariate models. Multiple regression models of 6MWT distance included age, sex, and patient-reported or objective CIPN severity as significant independent correlates (.62 ≤ R ≤ .64; p < .03). 6MWT distances in patients with CIPN symptom severity above the cohort mean were consistent with mean values reported in diabetic neuropathy and clinical populations.

CONCLUSIONS

Increased CIPN symptoms are associated with increased mobility deficits. The 6MWT demonstrates promising utility as a mobility assessment in a CIPN cohort.

IMPLICATIONS FOR CANCER SURVIVORS

The impact of the progression of CIPN on mobility deficits in survivors emphasizes the need for effective interventions to treat and prevent CIPN.

Can External Use of Chinese Herbal Medicine Prevent Cumulative Peripheral Neuropathy Induced by Oxaliplatin? A Systematic Literature Review With Meta-analysis

Background. Peripheral neurotoxicity caused by oxaliplatin (OXA) chemotherapy is the main limitation preventing continuation of chemotherapy in patients with gastrointestinal cancer. The purpose of this study was to determine the efficacy of external use of Chinese herbal medicine (CHM) on the incidence of cumulative OXA-induced peripheral neurotoxicity (OIPN). Method. Scientific literature databases were searched to identify controlled clinical trials analyzing CHM in OIPN. Clinical studies that included at least 1 relevant primary outcome were analyzed by 2 independent reviewers. Meta-analysis was performed on the software RevMan 5.3. Results. 700 cancer patients of 9 studies were reported, of whom 352 received external CHM and 348 received warm water baths, conventional medicine, or no intervention as controls. Neurotoxicity incidence (Levi grade ≥ 1) was significantly decreased in CHM group, compared with no intervention (P < .01). The incidence of cumulative neurotoxicity (Levi grade ≥2) was also significantly lower in the CHM group than in all the control groups (P < .05), and the cumulative neurotoxicity in the CHM group was significantly reduced (Levi grade ≥ 3) in comparision with no intervention (P < .01). These results were consistent with those of the subgroup analyses for preventing OIPN at each of the chemotherapy treatment cycles. There was no difference in the incidence of adverse events between groups (P > .05). Conclusion. External use of CHM may be beneficial in preventing the OXA-induced cumulative neurotoxicity. However, given the low quality of the evidence, the results should be interpreted with caution.