study of ngx-4010 for the treatment of painful hiv-associated neuropathy

Conditions: HIV Infections; Peripheral Nervous System Diseases; Pain

Summary: the purpose of the study is to determine if an investigational drug, ngx-4010 (high-concentration capsaicin patch), is effective in treating painful hiv-associated neuropathy.

the c107 study is a randomized, double-blind, controlled dose finding study of ngx-4010 for the treatment of painful symptoms of hiv-associated neuropathy. participants will be randomly assigned to receive initial treatment according to one of three doses (application durations), and to receive double-blind ngx-4010 patch (high-concentration capsaicin) or matching control (low-concentration capsaicin). participants who complete study evaluations through week 12 will have the option of receiving up to 3 additional open-label treatments.

Eligibility criteria:
inclusion criteria: * at least 18 years of age * documented evidence of hiv-1 infection * documented diagnosis of painful hiv-associated distal symmetrical polyneuropathy established by a neurologist resulting from hiv disease and/or antiretroviral drug exposure, with primary symptoms of pain, burning or dysesthetic discomfort in both feet for at least 2 months prior to screening visit, and absent or diminished ankle reflexes, and at least one of the following: distal diminution of vibration sensation or pain or temperature sensation in the legs * either no neurotoxic antiretroviral (didanosine, zalcitabine or stavudine) exposure for at least 8 weeks prior to screening visit, or currently on stable dose(s) of any neurotoxic antiretroviral(s) for at least 8 weeks prior to screening visit * screening pain sum score of 12 to 36 * karnofsky performance score of greater than or equal to 60 * intact, unbroken skin over the painful area(s) to be treated * if taking chronic pain medications, be on a stable (not prn) regimen for at least 21 days prior to treatment visit and willing to maintain these medications at the same stable dose(s) and schedule throughout the study * female subjects with child-bearing potential: negative serum pregnancy test performed at screening visit * willing to use effective methods of birth control and/or refrain from participating in a conception process during study and for 30 days following experimental drug exposure * willing and able to comply with protocol requirements for duration of study exclusion criteria: * concomitant opioid medication, unless orally or transdermally administered and not exceeding a total daily dose of morphine 60 mg/day, or equivalent. parenteral opioid use is excluded, regardless of dose * unavailability of an effective rescue medication strategy for the subject, such as unwillingness to use opioid analgesics during treatment, or high tolerance to opioids precluding the ability to relieve treatment-associated discomfort with roxicodone® or vicodin®, as judged by the investigator * active substance abuse or history of chronic substance abuse within the past year, or prior chronic substance abuse judged likely to recur during the study period by the investigator * recent use (within 21 days preceding the treatment visit of any topically applied pain medication, such as non-steroidal anti-inflammatory drugs, menthol, methyl salicylate, local anesthetics (including lidoderm®), steroids or capsaicin products on the painful areas * current use of any investigational agent or class 1 anti-arrhythmic drugs * significant pain of an etiology other than painful hiv-associated neuropathy; significant ongoing pain from other cause(s) that may interfere with judging hiv-associated neuropathy pain * evidence of another contributing cause for peripheral neuropathy, e.g., diabetes mellitus requiring medication control (i.e., oral hypoglycemics, insulin); hereditary neuropathy; vitamin b12 deficiency (b12 level ≤ 200 pg/ml) or less than 3 months of b12 supplementation prior to screening visit; or treatment within 90 days prior to screening visit with any drug that may have contributed to the sensory neuropathy * any implanted medical device (spinal cord stimulator, intrathecal pump or peripheral nerve stimulator) for the treatment of neuropathic pain * treatment for acute opportunistic infections within 14 days before treatment visit * presence of acute, active opportunistic infection, except oral thrush; oral, genital, or rectal herpes; and mycobacterium avium bacteremia within 2 weeks prior to screening visit * currently have active malignant disease * significant ongoing or untreated abnormalities in cardiac, renal, hepatic, or pulmonary function that may interfere either with the ability to complete the study or the evaluation of adverse events * hypersensitivity to capsaicin (i.e., chili peppers or otc capsaicin products), local anesthetics, roxicodone®, vicodin®, or adhesives

Keywords: dermal assessment pain measurement diary analgesics/*therapeutic use capsaicin/*administration & dosage/adverse effects hiv infections/*complications/*drug therapy peripheral nervous system diseases/*complications/diagnosis/*therapy peripheral nervous system diseases/drug therapy/*etiology/physiopathology