Orphan Drug Exclusivity and Monoclonal Antibodies

Are you thinking of making a monoclonal antibody and hoping that your product is different enough than another already approved to gain 7 years of Orphan Drug Exclusivity (ODE)?  Think again – or better yet just read FDA’s final guidance on the issue released earlier this week.  The full guidance, “Interpreting Sameness of Monoclonal Antibody Products Under the Orphan Drug Regulations”, may be found here.

Monoclonal antibodies may have similar functions and features, but could also appear somewhat different.  The above-referenced guidance gives specific advice on how FDA will, on a case-by-case basis, determine whether one monoclonal antibody is the same as another, under the provisions of the Orphan Drug Act and its implementing regulations.  The purpose of this is to establish whether a second period of ODE could be awarded, or (if the products are considered to be the same) to determine that the first period of ODE blocks approval of the “similar” monoclonal antibody.

The science behind the determination is beyond the scope of this blog, but please review the guidance document for an understanding of the various factors FDA will use in making its decision.  The information will certainly answer many questions relative to sameness for ODE purposes, but since FDA will decide each case on its own merit, I am certain that the gamesmanship will be alive and well on this stage.  The ultimate determination if the products are deemed the same from a structural standpoint will be if the new product is clinically superior.