![Key icon]( "Key icon")
Key Points
- Xeomin (incobotulinumtoxinA, Merz) exhibits efficacy similar to Botox (onabotulinumtoxinA, Allergan), studies show
- Results of Xeomin comparable to Botox for treatment of glabellar frown lines, blepharospasm, cervical dystonia
- Xeomin does not include complexing, accessory proteins
As the popularity of botulinum toxins for both cosmetic and therapeutic applications continues to grow, so too does development of new techniques and formulations. IncobotulinumtoxinA (Xeomin, Merz), the newest of the toxin formulations, is a promising product that according to clinical studies exhibits similar efficacy to onabotulinumtoxinA (Botox, Allergan), despite having a distinctly different biological makeup.
Timothy C. Flynn, M.D., of Cary Skin Center, Cary, N.C., participated in clinical studies of Xeomin as well as first-generation botulinum toxin products. He says Xeomin is unique biologically because it is free of complexing proteins. "Xeomin is 100 percent active toxin, so we were curious to see how it related to first-generation botulinum toxins," Dr. Flynn says.
XEOMIN BACKGROUND The Food and Drug Administration approved Xeomin for the temporary improvement in the appearance of moderate-to -severe glabellar lines in July 2011. Approval was based on results of two U.S. clinical trials involving 16 investigational sites and 547 patients. In both studies, Xeomin significantly improved the appearance of glabellar lines 30 days following the first injection, when compared to placebo.
"IncobotulinumtoxinA has been approved under the brand name Bocouture in all major European markets for the treatment of glabellar frown lines and under the brand names Xeomin and Xeomeen in Argentina, Mexico and Russia for the treatment for hyperkinetic facial lines," Dr. Flynn says. "It is free from the complexing proteins that are included in other currently available BoNT-A formulations (Botox and Dysport/abobotulinumtoxinA, Medicis), and although standard clinical practice uses a 1-to-1 unit equivalency for incobotulinumtoxinA and onabotulinumtoxinA formulations, in vitro biochemical assays have shown differences in the total protein load."1,2,3Clinical trials have shown that when administered at the same dose, incobotulinumtoxinA is non-inferior to onabotulinumtoxinA for the treatment for blepharospasm,4 glabellar frown lines5 and cervical dystonia,6 and that both preparations display comparable treatment duration and waning of effect,7 according to Dr. Flynn.
"We participated in some of the dose-finding trials and the repeat dosing trials, and then we also had the opportunity to participate in a direct head-to-head trial that compared the use of 24 units of Botox to 24 units of Xeomin in the glabella," he says. "We found a non-inferiority of the Xeomin when compared to Botox, and there was no increase in adverse effects, either."
Because Xeomin doesn't include complexing, accessory proteins, all it comprises is the active toxin itself. "There are, of course, stabilizing proteins that keep the product from sticking to the side of the glass vile and some sucrose, but in terms of the toxin itself, all that's in there is 100 units of type A toxin," Dr. Flynn says.
"In essence, our injection techniques and everything else are completely the same as with onabotulinumtoxinA," he says. "While these formulations are not biologically similar, they are used clinically in much the same way. If you would inject 20 units of Botox in the glabella, we believe you could put 20 units of Xeomin and get the same result."
Dysport has been shown in several studies to require more for the same effect as Botox or Xeomin, Dr. Flynn says. "The generally accepted ratio is about 2.5 units of Dysport for every one unit of Botox or Xeomin. There are also a number of studies showing that when you dose at a 2.5-to-1 ratio you get a little bit of increased diffusion with Dysport in the area in which you inject."
