USA – Gene therapies: Industry asks for clarification on FDA’s sameness guidance

Biotech companies and industry groups are raising questions about the US Food and Drug Administration’s (FDA) recent draft guidance on interpreting sameness of gene therapy products under its orphan drug regulations.
 
The draft guidance, issued for comment in January, explains how FDA intends to determine the sameness of two gene therapies intended for the same use or indication for the purposes of awarding orphan drug designation and exclusivity. (RELATED: FDA finalizes 6 gene therapy guidances, unveils a new draftRegulatory Focus 28 January 2020).
 
While current regulations “do not elaborate on how the ‘same drug’ definition applies specifically to gene therapy products,” FDA explains that it will consider the principal molecular structural features of the gene therapies to make its determination.
 
The draft guidance provides three examples of situations where it would consider two gene therapies intended for the same use or indication to be different drugs: based on whether they express different transgenes and have or use different viral vectors, whether they express different transgenes and whether they have or use vectors from a different viral class. The agency also explains that for gene therapies that express the same transgene and have or use the same vector, it will also consider other features of the products, such as regulatory elements and the cell type that is transduced, to inform its decision on their sameness…