Challenges encountered in dermatologic drug development.

Few truly new drugs are developed primarily for the treatment of dermatologic diseases. We discuss challenges and special considerations of dermatology drug development which contribute to this relative absence of novel drugs in dermatology. The issues considered are: a) the economic potential of dermatologic drugs including the potential return on investment (ROI); b) the benefit-to-risk ratio for treatments of skin disease; c) the relative absence of surrogate end points for topically applied drugs; d) drug penetration and vehicles; e) shelf life, stability, emulsifiers, preservatives; f ) contact irritancy, contact allergy, contact photoallergy and photocarcinogenicity; g) drugs with more than one active; h) semi-quantitative or soft primary end points; i) inadequate basic knowledge of pathophysiology of skin diseases. Of the many challenges, we conclude it is the low economic potential or ROI available with skin disease treatments which inhibits the creation of novel therapies for dermatologic disease.