Evaluating the Efficacy of Anti-wrinkle Products in USA

  • Kang Sewon (Department of Dermatology. University of Michigan Medical School)
  • Published : 2003.11.01


Introducing to the market place, safe and effective product is an important responsibility of clinical investigators as well as regulatory agencies in all developed countries. Products claiming to improve skin wrinkles are no exceptions. To date, Renova(R) (all-trans retinoic acid), Avage(R) (tazarotene), and Botox(R) (botulinum toxin) are the only agents FDA approved to ameliorate wrinkles associated with photoaged skin in the USA. For all three, clinical evaluation of wrinkle severity was the primary endpoint required for the approval process. No sophisticated instrument measurements of wrinkles were required, nor used in the pivotal studies. The Division of Dermatologic & Dental Products of the US FDA (Director, Jonathan Wilkin, MD) is not against the use of mechanical instruments in assessing wrinkle severity. Its position on this issue however, remains that any such device must be grounded in patients' or product users' perspective, which means that the evaluation instrument must be clinically relevant and clinically perceptible. Sophisticated devices that can detect minimal improvement, but imperceptible to the users are considered useless in the eyes of the US FDA. Two instruments that have been tried in some antiwrinkle studies in the USA are silicone replicas and Primos. Despite their sophistications, they have clear limitations; thus have never replaced clinical evaluations in these studies. At most, they have served as secondary measures to provide corroborative data on the clinical efficacy of antiwrinkle products. For the foreseeable future, at least in the USA, careful clinical assessment of wrinkles will continue to serve as the critical benchmark to determine whether an antiwrinkle product has enough efficacy to benefit its users. We must not lose sight of the fact that sophisticated devices are only to serve in generating supportive evidence, and not the primary evidence, in any clinical studies.