Abobotulinumtoxin A (Dysport) showed greater improvement in crow’s feet than onabotulinumtoxinA (Botox) at days four and six after injection according to the results of a split-face, double-blind study.
Both medications showed statistically significant changes at day two, when compared with baseline, in treatment of lateral orbital rhytids at maximal contraction and at rest, according to evaluations by both the investigator and the subject (P< 0.001), reported Corey S. Maas, MD, from the Maas Clinic in San Francisco, and colleagues.
There was a nonsignificant trend toward more improvement with abobotulinumtoxinA compared with onabotulinumtoxinA for the primary endpoint of maximum contraction graded by the investigator (P= 0.21) at day two. By day four, improvement in those getting abobotulinumtoxinA had reached significance (P= 0.02), which was maintained through day six (P=0.02). the group wrote in the Archives of Facial Plastic Surgery. Action Points
Explain that abobotulinumtoxinA (Dysport) showed greater improvement in crow’s feet than onabotulinumtoxinA (Botox) at days four and six after injection, according to the results of a split-face.
Note that the primary findings were reinforced by similar results in the secondary endpoints of self-grade by the subject of improvement at rest and maximal contraction, as well as by investigator grade of crow’s feet at rest.
In an email, Kellie Lao, a spokesperson for Allergan, the maker of Botox, said that the study was funded by Medicis, maker of Dysport, although the journal did not list any commercial funder for the research.
Additionally, Lao questioned the study methodology noting that that there “is no dose conversion with Dysport” and that the researchers used “an unconventional injection pattern for Botox Cosmetic.”
Botox Cosmetic, she wrote, is approved for treatment of glabellar wrinkles and for that indication the typical dose is 20 units.
Since the release of a second botulinum product for cosmetic use in 2009, there has been controversy over which product has the quickest onset of action and which might have a greater diffusion effect. The researchers undertook the study to compare the respective onset of action of each product.
From Dec. 1, 2009 through Aug. 30, 2010, 90 patients (77 women) were enrolled in the randomized, double-blind study. Inclusion criteria included subjects of either gender over the age of 18 with moderate to severe lateral orbital rhytids at maximum contraction. They were excluded if they had had a botulinum treatment in the last six months, various other plastic surgery interventions, history of adverse reactions to botulinum, or a history of degenerative neuromuscular disorders.
Treatment involved injecting onabotulinumtoxinA (10 U) in one side of the face and abobotulinumtoxinA (30 U) in the other. Patients were seen and evaluated on days two, four, and six after treatment to capture the onset of action, which is known to occur within one week.
Prior to treatment and at each follow-up, standard five-view photographs were taken for each patient at rest and during maximal contraction. Both patient and investigator independently evaluated crow’s feet at rest and maximal contraction before treatment and at each visit.
The primary findings were reinforced by similar results in the secondary endpoints of self-grade by the subject of improvement at rest and maximal contraction and investigator grade of crow’s feet at rest.
When looking at patient assessment at maximal contraction, both medications showed significant improvement at day two (P<0.001). As in the primary endpoint, the greater change seen with abobotulinumtoxinA trended toward significance at day two (P=0.11) and had achieved statistical significance at day four (P= 0.03), as well as clinical significance by day six (P=0.10).
When the patient self-graded at rest, again a trend toward significance was seen with abobotulinumtoxinA. However, this time, by days four and six there were no significant differences seen between the medications.
There were no significant adverse effects or complications with either product during the study, which confirmed the safety of these neuromodulators, the authors wrote.
The authors noted that it was not clear if the results will transfer to other sites of use such as the glabella and forehead.
“The observed difference between abobotulinumtoxinA and onabotulinumtoxinA may be related to the morphologic characteristics of the muscle being treated,” they explained.
Although they had validated the five-photograph scale to measure crow’s feet, it was found during actual use that this was a crude instrument for the purpose, and this was a study limitation.
“Both abobotulinumtoxinA and onabotulinumtoxinA achieved statistically significant onset of action on day two,” the authors concluded. “AbobotulinumtoxinA had a trend toward greater improvement than onabotulinumtoxinA at day two and statistically significant greater improvement at days four and six when looking at maximal contraction.”