Table 6.
Primary effective outcome.
| Adverse events | NGX-4010: 161/225 control: 45/82 Dropouts due to adverse events: NGX-4010, n = 2; control, n = 1. | % of patients with >1 AE: 93% NGX-4010, 83% control group. | Drop out: Capsaicin cream n = 5 (burning) |
| Data | NRPS scores from baseline to week 12, Mean (SD): NGX 4080 −22.8% (30.6), control −10.7% (30.8), p = 0.0026 >30% change in pain: NGX 4080 76/225, control 15/82 |
Change from baseline to weeks 2–12, mean (SE): NGX 4010 −1.8 (0.1) Control, −1.4 (0.2), p > 0.05. >30% pain reduction: NGX-4010 43/332, control 36/162 p > 0.05 | BPI at study endpoint Mean (SD); capsaicin 5.50 (2.68) Control 3.10 (2.12), p = 0.042 |
|
Outcome
measures |
Primary: % change in the pain NPRS score, from baseline to weeks 2 to 12. Secondary: Change from baseline pain for weeks 2–4 and 2–8; proportion of patients with a >30% mean decrease “average pain; percent change from baseline in the “worst pain for the past 24 h” and “pain now”. Change from baseline to week 12 assessed with GPS sf McGill, BPI, PGIC and CGIC | Primary: percent change in NPRS scores from baseline during weeks 2–12, patients with a >30% average pain reduction, the percentage of patients improved on PGIC and CGIC, changes from screening in sfMcGill Pain Questionnaire and SF-36v2 | Change in BPI, Quality of Life Index (QLI), Profile of Mood States (POMS), Sickness Impact Profile (SIP) |
| Intervention | NGX-4010 (capsaicin 640 mcg/cm2, 8% w/w) Patch or control patch (patch (3.2 mcg/cm2, 0.04% w/w) applied for 30, 60, or 90 min, up to 4 patches each | NGX-4010 (capsaicin 640 mg/cm2, 8% w/w; or control capsaicin (3.2 mg/cm2, 0.04% w/w) patch, for 30 or 60 min to both feet (up to 1120 cm2) | Topical capsaicin (0.075%) plus usual therapy, or placebo plus usual therapy, 4 times daily for 4 weeks |
| ARV therapy | No ART or on stable doses for >8 weeks | Exposure NGX-4010: 25/332, control: 8/162 |
No use of didenine or didectosine |
|
Sex
F/M |
NGX 4010: 18/207 Control 3/79 |
NGX 4010: 42/332 Control 20/162 | 1/25 |
| Age | Mean (SD): NGX-4010 47.7 (8.4) Control 48.4 (7.6) | Mean (SD) NGX-4010 49.7 (8.5) Control 49.7 (8.7) |
Mean (SD): 40.3 (6.0) |
| Diagnostic criteria | Pain, burning, dysesthetic discomfort in both feet, diminished ankle reflexes, and diminution of vibration, pain, or temperature sensation in the distal legs | Diagnosed with HIV-DSP for >2 months and an average baseline numeric pain rating scale (NPRS) score of 3–9 | Diagnosed HIV-related DSPN |
| Duration | 12 weeks | 12 weeks | 4 weeks |
| Design | Randomized-controlled parallel group | Randomized-controlled parallel group | Randomized-controlled parallel group |
| Participants randomized (completed) | 307 (274 completed, 302 analysed) | 494(234) | 26 (14) |
| Reference | Simpson et al., 2008 [39] | Clifford et al., 2012 [38] | Paice 2000b |
Abbreviations: DSP = distal sensory polyneuropathy, ART = antiretroviral therapy, NPRS = Numerical Pain rating scale.