FDA Drafts New Approach to Skin Safety Testing for Topical Drugs
The US Food and Drug Administration (FDA) on Friday issued draft guidance providing recommendations to drugmakers on how to assess the risk of contact dermatitis when developing new topical drugs.FDA explains that in the past, drugmakers were asked to conduct dedicated dermal safety studies for new topical drugs in healthy volunteers that involved repeated application of the drug under occlusion on the upper arm or back.
“The Division of Dermatology and Dental Products (DDDP) became concerned that these provocative studies, conducted under augmented conditions, were not informative for drug development, did not provide information that was useful for labeling, and induced adverse reactions in study subjects that might result in permanent harm,” FDA writes.
Those concerns led DDDP to hold a public workshop in September 2018 where the consensus among participants was that dedicated dermal safety studies were not needed for new topical drugs.
As such, the draft guidance advises sponsors that dedicated dermal safety studies “are not generally needed,” and recommends assessing local skin reactions in clinical studies.
FDA also recommends that sponsors use static scales to measure skin reactions, including erythema, edema and erosion, as well as patient reported outcomes for other reactions, such as pruritus or burning.
Additionally, FDA says sponsors should “characterize suspected adverse reactions of allergic or photoallergic contact dermatitis using diagnostic patch testing or photopatch testing with the individual ingredients (active and inactive) as well as the product.”
FDA notes that the guidance does not address how to assess other cutaneous adverse reactions, nor does it cover safety assessments for transdermal systems, nonprescription drug ingredients or generic drug development. FDA also says the guidance does not discuss phototoxicity as the issue is addressed in the International Council for Harmonisation S10 Photosafety Evaluation of Pharmaceuticals guideline.
FDA