Sickle Cell Pain: Intervention With Capsaicin Exposure
Condition: Neuropathic Pain; Sickle Cell Disease
MeSH terms: Neuralgia; Anemia, Sickle Cell
Study type: Interventional
Phase: Phase 1

Summary: 
      This study evaluates the safety and feasibility of using high dose topical capsaicin patches
      for the treatment of neuropathic pain in pediatric patients with sickle cell disease, as well
      as the feasibility of using a number of tests for the evaluation and monitoring of
      neuropathic pain. The hypothesis, based on evidence obtained from studies in adults with
      neuropathic pain related to other diseases as well as a single previously published study of
      capsaicin in pediatric patients, is that capsaicin will be well tolerated in this population.
      Additionally, it is hypothesized that it is feasible to monitor changes in neuropathic pain
      via the testing listed below.
    

Detailed description: 
      Patients with sickle cell disease suffer debilitating painful episodes, as well as chronic,
      often daily, pain that are commonly treated with non-steroidal anti-inflammatory drugs,
      opioids, and other non-pharmacologic supportive measures. Neuropathic pain has been shown to
      be present in these patients, with frequency increasing with age. It is believed, based on
      knowledge of neuropathic pain related to other conditions and from the small number of
      studies in sickle cell patients, to result from repeated vaso-occlusive pain episodes that
      prime central and peripheral pain sensing pathways in a maladaptive manner, leading to
      hyper-sensitization. Very few studies to date have evaluated therapies specifically targeting
      this aspect of the pain experienced by patients with sickle cell disease.

      This is a pilot study for a future longitudinal study of neuropathic pain in pediatric
      patients with sickle cell disease. The first aim of this pilot study is to establish the
      safety of treating participants with sickle cell disease aged fourteen to twenty-one with
      eight percent topical capsaicin patches on an every three-month dosing schedule as
      recommended by the manufacturer. This will be a single-arm safety study. Presence of
      neuropathic pain will be determined by day zero evaluation via the testing shown in the
      outcome measures below. Topical medication will be administered over one hour, every three
      months, for six months (total of three applications), to sites of recurrent vaso-occlusive
      pain, according to the package insert administration guidelines. Subjective and objective
      evaluations of pain and inflammation including questionnaires, blood tests, and quantitative
      sensory testing will be carried out every six weeks throughout the study period until twelve
      weeks after the final capsaicin application. Additionally, participants will record daily
      pain and medication use in a mobile app. Safety will be established by there being no grade
      three or four adverse events according to CTCAE definitions. Grade two adverse events will be
      evaluated on a case by case basis throughout the duration of the study. Feasibility of
      monitoring neuropathic pain with the aforementioned studies will be established by
      participant compliance with greater than eighty percent of all study activities.
    

Intervention name(s): Eight Percent Topical Capsaicin
Intervention type(s): Drug
Intervention description(s): See arm description
Other intervention name(s): Qutenza
Intervention MeSH terms: Capsaicin
Intervention model: Single Group Assignment
Intervention model description: Single arm, safety and feasibility trial assessing the suitability of an FDA approved medication for use in children with an off-label condition.
Masking: None (Open Label)
Primary purpose: Treatment
Keywords: Capsaicin; Topical Analgesia; Quantitative Sensory Testing; Pain