PrabotulinumtoxinA vs OnabotulinumtoxinA for the Treatment of Adult Males With Moderate to Severe Glabellar Lines: Post-hoc Analyses of the Phase III Clinical Study Data.

BACKGROUND: Despite a growing interest among men in cosmetic procedures such as botulinum toxin, comparator clinical trial data in this population are limited. OBJECTIVES: The authors sought to compare the efficacy and safety of prabotulinumtoxinA and onabotulinumtoxinA for the treatment of males with moderate to severe glabellar lines. METHODS: Post-hoc analyses were performed on the subpopulation of male patients treated with either a single dose of 20 U prabotulinumtoxinA (n = 25) or 20 U onabotulinumtoxinA (n = 31) in the EVB-003 Phase III glabellar line clinical study. One key efficacy endpoint was the proportion of responders with a ≥1-point improvement from baseline at maximum frown on the 4-point Glabellar Line Scale. RESULTS: Compared with onabotulinumtoxinA-treated males, the percentages of responders who had a ≥1-point improvement on the Glabellar Line Scale at maximum frown were higher at all postbaseline time points for prabotulinumtoxinA-treated males (P > 0.05 at all visits) by an absolute overall mean difference of 10.1% across all visits. Similar trends were observed for efficacy endpoints based on global aesthetic improvement and subject satisfaction. PrabotulinumtoxinA-treated males had a higher incidence of treatment-related headache and eyelid ptosis. CONCLUSIONS: The percentages of patients who met the definition of a responder were higher at almost all time points examined for prabotulinumtoxinA-treated males. Despite the high level of consistency across all measures, differences between the 2 treatment groups did not reach statistical significance. Further study is warranted to establish if these post-hoc analyses observations are reproducible in a larger male patient population.

A Multicenter, Randomized, Double-Blind, Placebo-Controlled, Single-Dose, Phase III, Non-Inferiority Study Comparing PrabotulinumtoxinA and OnabotulinumtoxinA for the Treatment of Moderate to Severe Glabellar Lines in Adult Patients.

BACKGROUND: PrabotulinumtoxinA is a 900-kDa botulinum toxin type A produced by Clostridium botulinum. OBJECTIVES: The authors sought to investigate the efficacy and safety of prabotulinumtoxinA compared to onabotulinumtoxinA and placebo for the treatment of glabellar lines. METHODS: This was a 150-day, multicenter, double-blind, controlled, single-dose Phase III study. Adult patients (n = 540) with moderate to severe glabellar lines at maximum frown as assessed by the investigator on the validated 4-point Glabellar Line Scale (0 = no lines, 1 = mild, 2 = moderate, 3 = severe), who also felt that their glabellar lines had an important psychological impact, were enrolled. Patients were randomized 5:5:1 to receive a single treatment (0.1 mL injected into each of 5 glabellar sites) of 20 U prabotulinumtoxinA (n = 245), 20 U onabotulinumtoxinA (n = 246), or placebo (n = 49). The primary efficacy endpoint was the proportion of responders (patients with a Glabellar Line Scale score of 0 or 1 at maximum frown by investigator assessment) on day 30. RESULTS: Responder rates for the primary efficacy endpoint were 87.2%, 82.8%, and 4.2% in the prabotulinumtoxinA, onabotulinumtoxinA, and placebo groups, respectively. The absolute difference between prabotulinumtoxinA and onabotulinumtoxinA groups was 4.4% (95% confidence interval [-1.9, 10.8]). Given that the lower bound of the 95% confidence interval for the difference was less than -10.0%, noninferiority of prabotulinumtoxinA vs onabotulinumtoxinA was concluded. Five patients (3 prabotulinumtoxinA, 1.2%; 1 onabotulinumtoxinA, 0.4%; 1 placebo, 2.0%) experienced serious adverse events, none of which were study drug related. CONCLUSIONS: A single treatment of 20 U prabotulinumtoxinA was safe and effective and noninferior to 20 U onabotulinumtoxinA for the treatment of moderate to severe glabellar lines.

UVB-irradiated dendritic cells fail to tolerize murine CD8 naïve or effector T cells.

UVB radiation has been shown to induce T cell tolerance most likely via modulation of the function of antigen-presenting cells like dendritic cells (DC), which are therefore of interest for vaccination therapy. Since little is known about the effects of UVB-irradiated dendritic cells (UVB-DC) on CD8(+) T cells, which are the dominant effectors in various allergic and autoimmune diseases, we have investigated the potential of low dose UVB (100-200 J per m(2)) irradiated bone marrow-derived dendritic cells to induce tolerance in murine CD8(+) T cells specific for the contact allergen trinitrophenyl (TNP) or for a viral peptide. In contrast to the previously reported successful tolerization of primed CD4(+) Th1 cells, neither naïve CD8(+) T cells nor CD8(+) Tc1 effector cells or established CD8(+) T cell clones could be tolerized by TNP-modified or peptide-pulsed UVB-DC in vitro or in vivo. We observed, however, a reduced capacity of UVB-DC to prime naïve CD8(+) T cells. Our data demonstrate an important difference in the susceptibility of CD4(+) and CD8(+) T cells for tolerance induction using low-dose UVB-irradiated DC and have implications for DC therapy of CD8(+) T cell-mediated diseases.

Induction of CD4+ T cell apoptosis as a consequence of impaired cytoskeletal rearrangement in UVB-irradiated dendritic cells.

Low dose UVB irradiation of dendritic cells (DC) dose-dependently decreases their allostimulatory capacity and inhibits alloreactive T cell proliferation. The reduction of the stimulatory capacity is not associated with a perturbation of CD28 costimulation. To examine the underlying mechanism, cell cycle analysis of T cells from cocultures with UVB-irradiated DC (UVB-DC) was performed, revealing no cell cycle arrest, but an increased number of apoptotic T cells in sub-G(0) phase. We confirmed T cells to undergo apoptosis after coincubation with UVB-DC by TUNEL staining and DNA laddering. To analyze whether T cell apoptosis requires the Fas/Fas ligand (FasL) pathway, MLRs were performed with Fas-, FasL-deficient, and wild-type DC and T cells. No differences were found on comparison of wild-type DC with Fas-/FasL-deficient DC or T cells. Likewise, addition of a neutralizing anti-TNF-alpha mAb to cocultures could not overcome inhibition of T cell proliferation by UVB-DC, excluding involvement of the TNF-alpha/TNF-alphaR pathway. FACS analysis of CD69 and CD25 revealed no up-regulation on T cells cocultured with UVB-DC, suggesting a perturbation of early T cell activation. Analysis of UVB-DC by confocal microscopy demonstrated impaired filamentous actin bundling, a process critical for T cell stimulation. To investigate the functional relevance of these observations, time lapse video microscopy was performed. Indeed, calcium signaling in CD4(+) T cells was significantly diminished after interaction with UVB-DC. In conclusion, UVBR of DC impairs their cytoskeletal rearrangement and induces apoptosis in CD4(+) T cells by disruption of early DC-T cell interaction, resulting in a reduced Ca(2+) influx in T cells.