Evaluation of 8% Capsaicin Patches in Chemotherapy-Induced Peripheral Neuropathy: A Retrospective Study in a Comprehensive Cancer Center

The Effect of Topical Capsaicin 8% on Pain in Chemotherapy-induced Peripheral Neuropathy

BACKGROUND

Chemotherapy-induced peripheral neuropathy (CIPN) can cause chemotherapy dose reductions and impact patients' quality of life. Few proven treatments exist, with generally modest analgesic effects and possible side effects. Small studies show the beneficial effects of topical capsaicin 8% on pain.

AIM

To investigate capsaicin's effects on pain, neurotoxicity, and mood in patients with CIPN.

DESIGN

Prospective data collection in patients treated with capsaicin 8% for painful CIPN.

METHODS

In 17 patients, data was collected before (t0) and directly (t1), 2 weeks (t2), and 8 weeks (t3) after capsaicin 8% treatment. Differences between t0-t2 and t0-3 were assessed for pain (Numeric Rating Scale [NRS]; acceptability), neurotoxicity symptoms (20-item questionnaire [CIPN20]; mechanical detection [MDT] and pain [MPT] thresholds), and mood (Hospital Anxiety and Depression Score [HADS]).

RESULTS

For 9 patients (53%), pain became "acceptable" at t2 and t3, with a significant reduction (pain intensity difference [PID]t0-2: -1.72, PIDt0-3: -2.47, both p < .001), whereas average NRS did not change significantly for patients scoring "unacceptable." HADS anxiety scores remained unchanged, whereas depression scores decreased from baseline (t0-2: -1.47, p = .014; t0-3: -1.36, p = .021). CIPN20 decreased from baseline (t0-2: -1.87, p = .004; t0-3: -3.32 p = .002). MPT was significantly lower post-treatment and MDT did not change.

CONCLUSIONS

Capsaicin 8% can have a beneficial analgesic effect in patients with CIPN-related pain but with a marked "on-off" effect. Mood changes were marginal. Quantitative sensory testing findings do not support earlier findings on nerve degeneration after capsaicin treatment, although the study size was small for definitive conclusions.

Narrative review of the efficacy and safety of the high-concentration (179mg) capsaicin patch in peripheral neuropathic pain with recommendations for clinical practice and future research

High-concentration capsaicin patch (HC capsaicin patch) is a locally acting treatment option for adults with peripheral neuropathic pain (pNeP) of various etiologies. Numerous clinical trials, post hoc analyses, and meta-analyses have investigated the efficacy and tolerability of the HC capsaicin patch. Despite this extensive body of research, a comprehensive narrative review covering publications on different pNeP conditions is lacking. This narrative review aims to fill the gap by analyzing 52 studies, including randomized controlled trials and real-world evidence. The results show that the HC capsaicin patch consistently provides pain relief and improves quality of life for several pNeP conditions, with increasing benefits seen with repeated treatments. It was found to be superior to placebo and comparable to standard care, regardless of the origin of the pain. Early initiation of therapy appears to improve efficacy, although patients with more prolonged pain also benefit. While the exact mechanisms of action are still unclear, there is evidence to suggest a potential benefit from nerve regeneration in some conditions. However, limited information exists regarding the alteration of treatment intervals and the variation in the size of the painful area upon re-treatment. The review also identifies variability in response rates for different types of pNeP and a lack of reliable predictors of treatment success, indicating a need for further research. In conclusion, the HC capsaicin patch is effective and well tolerated across a range of pNeP conditions, with increasing efficacy upon retreatment. It is a valuable treatment option, although more research is needed to refine its clinical use and explore its full therapeutic potential.

Is there a role for capsaicin in cancer pain management?

PURPOSE OF REVIEW

Advances in oncological therapies have resulted in an increase in the number of patients living with and beyond cancer. The personal and societal impact of chronic pain in the survivor population represents an area of significant unmet need. Capsaicin (a TRPV1 agonist) may provide analgesia with limited systemic side effects. This review looks to summarise the most recent evidence regarding the use of capsaicin in the management of cancer pain.

RECENT FINDINGS

Various international guidelines have recently endorsed the use of high concentration capsaicin patches in the treatment of chronic painful chemotherapy induced peripheral neuropathy. Numerous studies support the use of capsaicin in the treatment of peripheral neuropathic pain. This promising data is predominantly yielded from pain secondary to herpes zoster and diabetic neuropathy, with an expanding but small evidence base for its utility in other neuropathic pains. Emerging data suggests that treatments are better tolerated and provide analgesia more rapidly when compared with systemic treatments.

SUMMARY

Whilst randomised controlled trial data in the treatment of cancer pain are lacking, recent large cohort studies, and international guidelines, support the use of high concentration capsaicin patches in a wide variety of neuropathic pain secondary to cancer treatments.

A. T. Agbor F, Jenkins A, Lavoie Smith EM. Exploring social determinants of health on chemotherapy-induced peripheral neuropathy severity in ovarian cancer: An integrative review

Ovarian cancer remains a significant public health concern for women despite advancements in cancer management. Despite comprising only 2.5 % of cancers in women, ovarian cancer ranks as the fifth leading cause of cancer-related deaths among women, with patients frequently receiving late diagnoses. Chemotherapy, a primary treatment, frequently causes chemotherapy-induced peripheral neuropathy (CIPN), affecting over 60 % of patients and leading to severe sensory, motor, and autonomic nerve impairments. This often necessitates dosage reduction or discontinuation of treatment, thereby increasing mortality. While CIPN's impact on patients is well-documented, there is a paucity of knowledge of how structural and intermediary social determinants of health factors (SDOH), such as socioeconomic and political context, material circumstances such as living and walking conditions, area deprivation, and food availability, affect CIPN severity. The aim of this article was to explore the association between various SDOH and CIPN severity in ovarian cancer, identifying potential research gaps and future research directions. This article seeks to inform targeted interventions to mitigate CIPN's impact by elucidating these associations.

Topical treatment of chemotherapy-induced peripheral neuropathy (CIPN) with high-concentration (179 mg) capsaicin patch in breast cancer patients - results of the QUCIP study

Background

Chemotherapy-induced peripheral neuropathy (CIPN) following oral or intravenous chemotherapy often results in neuropathic pain, accompanied by symptoms such tingling, burning and hypersensitivity to stimuli, with a notable decline in quality of life (QoL). Effective therapies for CIPN are lacking, with a high demand for analgesics to address this issue. The QUCIP study aimed to assess the effectiveness of high concentration (179 mg) capsaicin patch (HCCP) in alleviating neuropathic pain and associated symptoms in breast cancer patients with confirmed CIPN.

Methods

QUCIP is a prospective, multi-center observational study spanning 36 weeks with up to three HCCP treatments. Initial treatment (visit V0) was followed by two telephone contacts (T1, T2) and subsequent face-to-face visits every 12 weeks or upon retreatment (visits V1-V3). 73 female patients with painful CIPN post neoadjuvant/adjuvant breast cancer therapy were enrolled. Primary endpoint was the reduction of neuropathic pain symptom score (painDETECT®). Secondary endpoints included improvements in CIPN-specific QoL (QLQ-CIPN20), reductions in pain intensity (numeric pain rating scale, NPRS), and achievement of ≥ 30% and ≥ 50% pain reduction.

Results

Median age was 61 years, with 52.0% of patients experiencing peripheral neuropathic pain for > 1 year (> 2 years: 34.2%). The painDETECT® score significantly decreased from baseline (19.71 ± 4.69) to 15.80 ± 6.20 after initial treatment (p < 0.0001) and continued to decrease at follow-up visits. The NPRS indicated significant pain intensity reduction at each time point, particularly pronounced in patients receiving three HCCP treatments. Clinically significant pain relief of ≥ 30% increased from 25.0% at week 4 (T2) to 36.2%, 43.5%, and 40.0% at weeks 12 (V1), 24 (V2), and 36 (V3), respectively. The percentage of patients achieving pain relief of ≥ 50% increased from 14.7% at T2 to 15.5%, 21.7% and 32.5% at V1, V2 and V3, respectively. Patients further reported a significant improvement in their CIPN-related QoL throughout the study. Adverse drug reactions (ADRs) mainly included application site reactions.

Conclusion

In this study, HCCP shows benefit in managing CIPN in real-world settings. The data demonstrate a sustained and progressive reduction in neuropathic pain and symptomatology, confirming the clinical benefit of repeated treatment observed in former clinical trials. HCCP treatment has also the potential to significantly improve the QoL associated with CIPN. The safety profile of HCCP was confirmed, supporting its use in clinical practice.

Characteristics and outcomes of peripheral neuropathic pain patients with repeated applications of high-concentration capsaicin cutaneous patch: Results of a retrospective chart review in Germany

OBJECTIVE

The aim of this study was to evaluate patient characteristics, concomitant analgesic medication, and pain intensity in a real-world setting in Germany, focusing on the repeated application of high-concentration capsaicin patch (HCCP) for neuropathic pain.

DESIGN

Data were collected from electronic medical records of patients who received at least two HCCP treatments between January 2011 and July 2022. Subgroup analyses were performed based on the number of HCCP treatments, age groups, and specific neuropathic pain conditions.

SETTING

The study was conducted at an outpatient pain center in Wiesbaden, Germany.

SUBJECTS

The study included 97 patients, primarily diagnosed with neuropathic back pain, postoperative or post-traumatic neuropathic pain, and postherpetic neuralgia.

METHODS

The daily dose of concomitant medications (eg, opioids and anticonvulsants) at the start of capsaicin therapy was compared with the average within 2 years of capsaicin therapy. The last observation carried forward method was used if HCCP treatment was discontinued before the end of the 2-year period.

RESULTS

The majority of patients received concomitant medications, with opioids, anticonvulsants, and antidepressants being the most common. The average daily morphine equivalent dose decreased significantly during HCCP treatment. Pain intensity at baseline was generally high, but substantial improvements were observed in patients who received at least three HCCP applications.

CONCLUSIONS

This study provides evidence for the effectiveness of HCCP treatment in reducing pain intensity and concomitant opioid use in patients with neuropathic pain. Further research is needed to explore the long-term outcomes and optimal treatment regimens for different patient populations.

Targeting TRP channels for pain relief: A review of current evidence from bench to bedside

Several decades of research support the involvement of transient receptor potential (TRP) channels in nociception. Despite the disappointments of early TRPV1 antagonist programs, the TRP family remains a promising therapeutic target in pain disorders. High-dose capsaicin patches are already in clinical use to relieve neuropathic pain. At present, localized injections of the side-directed TRPV1 agonist capsaicin and resiniferatoxin are undergoing clinical trials in patients with osteoarthritis and bone cancer pain. TRPA1, TRPM3, and TRPC5 channels are also of significant interest. This review discusses the role of TRP channels in human pain conditions.

Targeting TRPV1 for Cancer Pain Relief: Can It Work?

Chronic intractable pain affects a large proportion of cancer patients, especially those with metastatic bone disease. Blocking sensory afferents for cancer pain relief represents an attractive alternative to opioids and other drugs acting in the CNS in that sensory nerve blockers are not addictive and do not affect the mental state of the patient. A distinct subpopulation of sensory afferents expresses the capsaicin receptor TRPV1. Intrathecal resiniferatoxin, an ultrapotent capsaicin analog, ablates TRPV1-expressing nerve endings exposed to the cerebrospinal fluid, resulting in permanent analgesia in women with cervical cancer metastasis to the pelvic bone. High-dose capsaicin patches are effective pain killers in patients with chemotherapy-induced peripheral neuropathic pain. However, large gaps remain in our knowledge since the mechanisms by which cancer activates TRPV1 are essentially unknown. Most important, it is not clear whether or not sensory denervation mediated by TRPV1 agonists affects cancer progression. In a murine model of breast cancer, capsaicin desensitization was reported to accelerate progression. By contrast, desensitization mediated by resiniferatoxin was found to block melanoma growth. These observations imply that TRPV1 blockade for pain relief may be indicated for some cancers and contraindicated for others. In this review, we explore the current state of this field and compare the analgesic potential of TRPV1 antagonism and sensory afferent desensitization in cancer patients.

Correction: Bienfait et al. Evaluation of 8% Capsaicin Patches in Chemotherapy-Induced Peripheral Neuropathy: A Retrospective Study in a Comprehensive Cancer Center. Cancers 2023, 15, 349

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