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When Drs. Jean and Alastair Carruthers made the critical leap from ophthalmologist Dr. Alan Scott’s seminal use of botulinum as an alternative to strabismus surgery to the cosmetic use of the toxin to treat the glabellar frown lines, no one could have predicted the explosive growth of this agent in the commercial market.1 On April 15, 2002, the US Food and Drug Administration (FDA) approved Allergan, Inc.’s Botox Cosmetic* (botulinum toxin type A) for “temporary improvement in the appearance of moderate-to-severe glabellar lines in adult men and women 65 or younger.” This was the first elective cosmetic indication for which any commercially available botulinum toxin in the US market had been approved.
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The toxin had previously been approved and was marketed as Botox® for the treatment of strabismus, blepharospasm, and cervical dystonia but existing off-label cosmetic use of the toxin had already propelled annual sales to $250 million per year by 2002. With FDA recognition of the cosmetic indication, sales of both Botox® and Botox Cosmetic® surpassed $1 billion per year by the end of 2009. The last half of 2015 and first half of 2016 produced $2.6 billion in sales. Analysts anticipate a $3 billion annual market for Botox® and Botox Cosmetic® in 2017-2018.
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Allergan’s product in the US market has equaled the brand name equity of Pfizer’s product Viagra® (sildenafil citrate). “Botox” is now part of the daily vernacular, used to refer to a class of biologic neurotoxins in much the same way as the well-known trademarks Coke® and Kleenex® are used to refer to carbonated beverages and facial tissue. The clinical utility of the neurotoxin is so widely known today that the word Botox has become a generic term in the public mind for all agents used in cosmetic neurotoxin therapy, although the term is properly reserved for Allergan’s trademarked commercial version of the type A neurotoxin complex.
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In April 2009, the FDA approved a third commercial neurotoxin, a serotype A product, Dysport® (Ipsen [UK]/Medicis [US]) to join Allergan’s Botox®/Botox Cosmetic® and a previously approved serotype B product, Myobloc® (Solstice Neurosciences [US]). In July 2011, the FDA approved a fourth commercial neurotoxin for the US market, a serotype A product, Xeomin® (Merz Pharma GmbH [Germany]). To emphasize the noninterchangeability of these biologic toxins, the FDA in August 2009 required the manufacturers to adopt new drug names: onabotulinumtoxinA (Botox®/Botox Cosmetic®), abobotulinumtoxin A (Dysport®), rimabotulinum toxin B (Myobloc®), and incobotulinum toxin A (Xeomin®).
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Another serotype A toxin in development in 2011, at the time the last edition was written, was called PurTox® (Mentor [US]). This toxin is purportedly a “naked” toxin, that is, without complexing proteins, and probably with a molecular weight similar to that of Xeomin®. Johnson ...