title: Predictors of Response in Patients With Postherpetic Neuralgia and HIV-Associated Neuropathy Treated With the 8% Capsaicin Patch (Qutenza).
abstract: OBJECTIVE
  Qutenza is a high-dose capsaicin patch used to relieve neuropathic pain from postherpetic neuralgia (PHN) and HIV-associated neuropathy (HIV-AN). In clinical studies, some patients had a dramatic response to the capsaicin patch. Our objective was to determine the baseline characteristics of patients who best benefit from capsaicin patch treatment.
  
  
  METHODS
  We conducted a meta-analysis of 6 completed randomized and controlled Qutenza studies by pooling individual patient data. Sustained response was defined as>50% decrease in the mean pain intensity from baseline to weeks 2 to 12, and Complete Response as an average pain intensity score≤1 during weeks 2 to 12. Logistic regression was used to identify predictors of response and Complete Response, and subgroups of patients who respond best to the capsaicin patch.
  
  
  RESULTS
  Baseline pain intensity score (BPIS)≤4 was a predictor of Sustained and Complete Response in PHN and HIV-AN patients; absence of allodynia and presence of hypoesthesia, and a McGill Pain Questionnaire (MPQ) sensory score <22 were predictors of Sustained Response in PHN patients; female sex was a predictor of Sustained and Complete Response in HIV-AN patients. Thus, characteristics associated with the highest chance of responding to the capsaicin patch were, for PHN, BPIS≤4, MPQ sensory score≤22, absence of allodynia, and presence of hypoesthesia; for HIV-AN, they were female sex and BPIS≤4. Patients with these characteristics had a statistically significantly greater chance of responding to the capsaicin patch than other patients.
  
  
  CONCLUSIONS
  We identified subpopulations of PHN and HIV-AN patients likely to benefit from the capsaicin patch.
authors.affiliation: *Analgesic Solutions, Natick †LLX Solutions, Watertown ‡Biobridges, Wellesley, MA §Astellas Pharma Global Development, Leiderdorp, The Netherlands.
authors.forename: Nathaniel P
authors.initials: NP
authors.lastname: Katz
authors.forename: Joy
authors.initials: J
authors.lastname: Mou
authors.forename: Florence C
authors.initials: FC
authors.lastname: Paillard
authors.forename: Barry
authors.initials: B
authors.lastname: Turnbull
authors.forename: Jeremiah
authors.initials: J
authors.lastname: Trudeau
authors.forename: Malcolm
authors.initials: M
authors.lastname: Stoker
mesh_terms: D016263:AIDS-Associated Nephropathy / Q000188:drug therapy*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D002211:Capsaicin / Q000008:administration & dosage*; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D051474:Neuralgia, Postherpetic / Q000188:drug therapy*; D010147:Pain Measurement; D011237:Predictive Value of Tests; D018689:Sensory System Agents / Q000008:administration & dosage*; D013997:Time Factors; D057968:Transdermal Patch; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D018689:Sensory System Agents; D002211:Capsaicin