FDA-Approved Botulinum Toxins
Botulinum toxin is a highly purified protein from a naturally occurring bacterium that binds specifically to nerves to temporarily inactivate them.
Through the decades, neurotoxins have been used for both medical indications (ranging from headache to overactive bladder) and cosmetic indications (relaxing of glabellar wrinkles and crow’s feet).
There are currently three botulinum toxins approved in the United States as wrinkle relaxants:
1. Botox (onabotulinumtoxinA; Allergan)
2. Dysport (abobotulinumtoxinA; Galderma)
3. Xeomin (incobotulinumtoxinA; Merz Pharmaceuticals)
“All three products are approved for glabellar lines,” Joel Schlessinger, M.D., chief executive officer of Advanced Skin Research Center in Omaha, Neb., tells The Aesthetic Channel. “The only product, though, that has a second indication in the cosmetic arena at present is Botox, which is also approved for crow’s feet (lateral canthal lines).”
Dr. Schlessinger says all three injectables have also been used off-label as a wrinkle relaxer for the chin, forehead, bunny lines (lines around the nose), neck and chest.
Strategic Patient Use
The best uses for each of the three botulinum toxins vary, based on a clinician’s familiarity with a particular product and his or her level of comfort in addressing specific aesthetic defects, according to Dr. Schlessinger. That said, he believes Botox, Xeomin and Dysport can be roughly categorized as best used within specific patient age groups, with Botox as the most versatile, Dysport for younger patients who may want more activity, and Xeomin for the older population who need a narrower field of action.
“However, many clinicians tend to use simply one product, based on cost or based on their relationship with the manufacturer or savings opportunities for the patient,” Dr. Schlessinger says.
Although a neurotoxin is a neurotoxin, there are subtle differences that can benefit various patients.
Botox is an all-around treatment for Dr. Schlessinger.
Dysport is for patients who prefer slightly more activity, as it tends to have a little more field of action, says Dr. Schlessinger. It is an excellent treatment for forehead wrinkles that extend higher and for a larger field of effect. Lasts slightly longer than other options.
Xeomin is for patients who desire a narrower field of action, particularly for brow ptosis and for people who do not want their frown lines extended to the brow area. It may have slightly shorter duration of effect, according to Dr. Schlessinger.
The amount of botulinum toxin injected “is very personal from physician to physician,” says Dr. Schlessinger.
The recommended dosage of Xeomin and Botox into the glabella is the same: 20 units.
But for Dysport, the recommended dosage is roughly 2.5 times as great: about 50 units.
Generally, there is the same injection pattern for all three products, according to Dr. Schlessinger.
Dysport and Xeomin are comparably priced and less expensive than Botox, based on the manufacturers’ suggested retail price.
Botox commands about a 20% premium.
Dr. Schlessinger says there are no disadvantages to any of the three injectables. “I think they are all very good and useful in the right situation,” he says.
Botulinum Toxin - The Future
Forehead lines is the next indication expected for FDA approval.
Evolus, a new neurotoxin in clinical trials is a joint effort between Alphaeon and the South Korean pharmaceutical firm Daewoo, which should become available in the U.S. next year. The 900 kilodalton (an atomic mass unit) product is similar to Botox for treating glabellar wrinkles, “so there are no real differences in the molecular structure between the two products, but the protein envelope for these two neurotoxins is different,” Dr. Schlessinger says.
Another neurotoxin is in development by Germany-based Croma for glabellar wrinkles.
The company Revance has been investigating for several years now a longer-lasting neurotoxin via a unique carrier for the toxin. The firm also has conducted some studies of topical application of the toxin for indications ranging from crow’s feet to hyperhidrosis (excessive sweating).
Meanwhile, Botox has licensed a toxin from Korean-based Medytox.
“As indications expand and are able to be promoted by the individual companies, these indications will become more popular,” Dr. Schlessinger says.
Disclosure: Dr. Schlessinger reports being an investor in Alphaeon, as well as a shareholder in Allergan and Revance.