By Zachary Rome
When we set out to design our Phase 2b CONTROL study evaluating an investigational topical treatment for a rare dermatologic condition called congenital ichthyosis (CI), we knew we would need a plan to tackle the unique challenges associated with conducting clinical trials for small patient populations. There has never been a drug approved by the FDA for the treatment of CI, so we had no precedent for which study endpoints to evaluate. We also needed a plan for dosing – CI patients can have up to 90% of their body surface area affected by the condition, so there is a high degree of variability in how much drug each patient needs based on how much of their skin needs to be treated. And, as in any topical dermatology study, we needed to account for the potential of relatively high vehicle response rates. In dermatology, there is no such thing as a true placebo, as anything you put on the skin may have some effect, and simply moisturizing the skin can improve some conditions to a certain degree.