Trial Summary
What is the purpose of this trial?Morton s neuroma is an irritation of the nerves that affect the feet. People with this condition may have burning or shooting pain in the balls of their feet. They may also have numbness in adjacent areas. These symptoms may become more frequent and severe over time. The pain may become permanent. Current treatments tend to be short-lived, and they do not work in all people. Better treatments are needed.
Objective:
To test a study drug, resiniferatoxin (RTX), in people with Morton s neuroma.
Eligibility:
Healthy people aged 18 and older who have Morton s neuroma and have tried other standard treatments that did not ease their pain.
Design:
Participants will be involved in the study up to 4 months.
They will be screened. They will have a physical exam with blood tests. They will have a test of their heart function. They will have X-rays of their affected feet. They will have tests to assess their pain and how their feet react to touch and changes in temperature. They will complete questionnaires about their pain.
RTX is injected into the foot at the site of the nerve pain. Participants will receive a shot to numb the area before the RTX is administered. They will be monitored in the clinic for 4 hours after they receive the RTX.
Participants will receive up to 5 follow-up phone calls per week. Each call will take 5 to 10 minutes. They will be asked about their foot pain and whether they have had any side effects from the RTX.
Participants will return to the clinic 4 weeks after the treatment. Previous tests will be repeated.
Is the drug Resiniferatoxin (RTX) a promising treatment for Morton's Neuroma pain?Yes, Resiniferatoxin (RTX) is a promising drug for treating Morton's Neuroma pain. Studies show that it can completely alleviate and prevent different types of nerve pain by targeting specific pain-causing cells. This suggests it could be effective in reducing the pain associated with Morton's Neuroma.5781012
What safety data exists for Resiniferatoxin (RTX) treatment?The safety data for Resiniferatoxin (RTX) treatment is limited and somewhat controversial. While studies have shown RTX to be effective in alleviating neuropathic pain in animal models, concerns about its neurotoxicity and safety margin have not been fully addressed. RTX has been used in various administration routes, such as intraplantar, intrathecal, and perineural injections, showing potential in reducing pain and inflammation. However, the potential neurotoxic effects and the lack of comprehensive safety evaluations suggest that caution is needed when considering RTX for clinical use.1261012
What data supports the idea that Resiniferatoxin for Morton's Neuroma Pain is an effective treatment?The available research does not provide specific data on the effectiveness of Resiniferatoxin for Morton's Neuroma Pain. However, it does mention other treatments like botulinum toxin A, radiofrequency, and steroid injections, which have shown some effectiveness in reducing pain and symptoms. For example, a study on steroid injections reported a significant reduction in the size of the neuroma. Without direct data on Resiniferatoxin, it's unclear how it compares to these treatments.347911
Do I need to stop taking my current medications for the trial?The trial protocol does not specify if you need to stop taking your current medications. However, you cannot participate if you've had injection or ablation treatments in the affected foot within one month before the study or if you're currently on another investigational drug.
Eligibility Criteria
This trial is for adults over 18 in good health with Morton's neuroma, who've tried other pain treatments without relief. They must be willing to follow the study procedures and use effective contraception if of reproductive potential. Excluded are those with allergies to local anesthetics or chili peppers, certain medical conditions, or concurrent investigational drug use.Inclusion Criteria
I have severe foot pain from Morton's neuroma, rating 5 or higher on a pain scale.
I have been diagnosed with a painful condition in my foot known as Morton's neuroma.
Exclusion Criteria
I have another painful foot condition besides Morton's neuroma.
I have or had rheumatoid arthritis or nerve damage in my hands or feet.
I have skin issues or infections where I might get the study drug injection.
I have diabetes or peripheral vascular disease, regardless of how well it is managed.
I had surgery to remove a nerve in my foot due to Morton's neuroma.
I have more than one Morton's neuroma in my foot that will be treated.
Treatment Details
The trial tests resiniferatoxin (RTX), a new drug injected into the foot to manage severe pain from Morton's neuroma. Participants will undergo screening, receive RTX treatment, and have follow-up calls and clinic visits to monitor their condition and any changes in their foot pain.
1Treatment groups
Experimental Treatment
Group I: ResiniferatoxinExperimental Treatment1 Intervention
Resiniferatoxin
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Research locations nearbySelect from list below to view details:
National Institutes of Health Clinical CenterBethesda, MD
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Who is running the clinical trial?
National Institutes of Health Clinical Center (CC)Lead Sponsor
References
Perineural resiniferatoxin prevents hyperalgesia in a rat model of postoperative pain. [2021]Resiniferatoxin (RTX) is a vanilloid agonist with a unique spectrum of activities. Vanilloids bind to the transient receptor potential ion channel subtype 1, a nonselective cation ionophore important in the integration of different noxious signals. Vanilloid agonists selectively decrease sensitivity to noxious stimuli. In this study, we sought to determine whether perineural RTX prevents hyperalgesia in a model of incisional pain. In a rat model, RTX was administered percutaneously to the sciatic and saphenous nerves before the plantar incision. The withdrawal response to von Frey filaments, the struggle response to pressure on the paw, and pain scoring based on weight bearing were measured before RTX and at various intervals for 8 days after RTX. A percutaneous injection of RTX (0.0003%) to the sciatic (0.1 mL) and saphenous (0.05 mL) nerves completely prevented incisional hyperalgesia. Two hours after incision, the withdrawal threshold was 51 mN without and 456 mN with RTX (P
Selective ablation of nociceptive neurons for elimination of hyperalgesia and neurogenic inflammation. [2022]Neuropathic pain is mediated by nociceptive neurons that selectively express the vanilloid receptor 1 (VR1). Resiniferatoxin (RTX) is an excitotoxic VR1 agonist that causes destruction of VR1-positive neurons. To determine whether RTX can be used to ablate VR1-positive neurons selectively and to eliminate hyperalgesia and neurogenic inflammation without affecting tactile sensation and motor function, the authors infused it unilaterally into the trigeminal ganglia in Rhesus monkeys.
[Regression of Morton neuroma after local injection of steroids]. [2019]Morton neuroma is a non neoplastic lesion corresponding to perineural fibrosis encircling the common interdigital plantar nerve. Several therapeutic approaches are possible: conservative treatment or surgery. We report a case treated by local steroid injection where follow-up MR showed near complete regression of the lesion. Although local injection of steroid is a classical treatment, it is the first time to our knowledge that resolution or such a striking diminution of size is reported after infiltration.
Ultrasound-guided interdigital neuroma injections: short-term clinical outcomes after a single percutaneous injection--preliminary results. [2021]To describe the procedure of ultrasound-guided Morton's neuroma and recurrent stump neuroma injections and early clinical outcomes after a single injection.
Resiniferatoxin mediated ablation of TRPV1+ neurons removes TRPA1 as well. [2019]Resiniferatoxin, the most potent agonist of inflammatory pain/vanilloid receptor/cation channel (TRPV1) can be used for neuron subtype specific ablation of pain generating cells at the level of the peripheral nervous system by Ca(2+)-excytotoxicity. Molecular neurosurgery is an emerging technology either to alleviate severe pain in cancer or treat/prevent different local neuropathies. Our aim was determining sensory modalities that may be lost after resiniferatoxin treatment.
P2X3-mediated peripheral sensitization of neuropathic pain in resiniferatoxin-induced neuropathy. [2022]Patients suffering from sensory neuropathy due to skin denervation frequently have paradoxical manifestations of reduced nociception and neuropathic pain. However, there is a lack of satisfactory animal models to investigate these phenomena and underlying mechanisms. We developed a mouse system of neuropathy induced by resiniferatoxin (RTX), a capsaicin analog, and examined the functional significance of P2X3 receptor in neuropathic pain. From day 7 of RTX neuropathy, mice displayed mechanical allodynia (p
Treatment of Morton neuroma with botulinum toxin A: a pilot study. [2022]Morton neuroma is a common cause of metatarsalgia of neuropathic origin. Systematic reviews suggest that insufficient studies have been performed on the efficacy of the different treatments available. OnabotulinumtoxinA has shown a degree of usefulness in other conditions associated with neuropathic pain. The aim of this study was to investigate the therapeutic potential of onabotulinumtoxinA in Morton neuroma.
Activated Glia Increased the Level of Proinflammatory Cytokines in a Resiniferatoxin-Induced Neuropathic Pain Rat Model. [2022]Administration of resiniferatoxin (RTX) can mimic the clinical symptoms of postherpetic neuralgia. However, it is unclear whether activated glia contribute to the pathogenesis of RTX-induced neuropathic pain; furthermore, the relationship between p38, N-methyl-D-aspartate receptor type 2B (NR2B) as well as proinflammatory cytokines and activated glia remains unknown.
Ultrasound-Guided Percutaneous Radiofrequency for the Treatment of Morton's Neuroma. [2022]Morton's neuroma (MN) is a leading cause of disability. The purpose of this study was to investigate the effectiveness of radiofrequency (RF) in patients with chronic pain refractory to conservative therapies.
Antiallodynic effect of intrathecal resiniferatoxin on neuropathic pain model of chronic constriction injury. [2018]Injuries and/or dysfunctions in the somatosensory system can lead to neuropathic pain. Transient receptor potential vanilloid sub‑type 1 (TRPV1) play an important role in the development of allodynia and hyperalgesia following injury and the ensuing inflammatory conditions. Resiniferatoxin (RTX) is an ultrapotent synthetic TRPV1 agonist and many different administration routes are available for different mechanisms and different effects. RTX is used intraperitonially as a model of neuropathic pain or epidurally and topically to produce prolonged analgesic effects. However, the use of RTX is controversial because its neurotoxicity and margin of safety have not been addressed adequately. The present study evaluates the effect of intrathecal RTX on the induction and allodynia behavior of animals submitted to neuropathic pain by chronic constriction injury (CCI).
Patient-Related Outcome Measures (PROMs) With Nonoperative and Operative Management of Morton's Neuroma. [2022]Morton's neuroma is associated with chronic pain and disability. There is a paucity of literature regarding patient-related outcome measures (PROMs) in patients managed nonoperatively. We sought to investigate nonoperative and operative management of Morton's neuroma using PROMs in patients with follow-up to 1 year.
Cutaneous Injection of Resiniferatoxin Completely Alleviates and Prevents Nerve-Injury-Induced Neuropathic Pain. [2023]Fifth lumbar (L5) nerve injury in rodent produces neuropathic manifestations in the corresponding hind paw. The aim of this study was to investigate the effect of cutaneous injection of resiniferatoxin (RTX), a TRPV1 receptor agonist, in the rat's hind paw on the neuropathic pain induced by L5 nerve injury. The results showed that intraplantar injection of RTX (0.002%, 100 µL) (1) completely reversed the development of chronic thermal and mechanical hypersensitivity; (2) completely prevented the development of nerve-injury-induced thermal and mechanical hypersensitivity when applied one week earlier; (3) caused downregulation of nociceptive pain markers, including TRPV1, IB4 and CGRP, and upregulation of VIP in the ipsilateral dorsal horn of spinal cord and dorsal root ganglion (DRG) immunohistochemically and a significant reduction in the expression of TRPV1 mRNA and protein in the ipsilateral DRG using Western blot and qRT-PCR techniques; (4) caused downregulation of PGP 9.5- and CGRP-immunoreactivity in the injected skin; (5) produced significant suppression of c-fos expression, as a neuronal activity marker, in the spinal neurons in response to a second intraplantar RTX injection two weeks later. This work identifies the ability of cutaneous injection of RTX to completely alleviate and prevent the development of different types of neuropathic pain in animals and humans.