Market exclusivity for Shire's VYVANSE upheld on appeal
This article was originally published in Scrip
The US Court of Appeals for the District of Columbia Circuit has confirmed that Shire Pharmaceuticals' attention deficit hyperactivity disorder (ADHD) product VYVANSE retains its New Chemical Entity exclusivity status until February 23rd 2012. Consequently, generic manufacturers, including Actavis which had originally sued the US FDA in the District Court of Columbia, cannot submit an ANDA to FDA until February 23, 2011.
VYVANSE is lisdexamfetamine, a prodrug of dextroamphetamine, the active ingredient of Shire's earlier ADHD drug, Adderall. In its original suit, Actavis had claimed that FDA was wrong to grant exclusivity to the drug because the active moiety of VYVANSE is actually the older drug dextroamphetamine rather than lisdexamfetamine. After seeking public comments, FDA stuck to its guns, and the district court upheld FDA's position.
The Hatch-Waxman Amendments under which the five-year exclusivity is granted stipulate that the status can be granted to drugs “no active ingredient [...] of which” has been approved in a prior new drug application. Actavis maintained in its suit that because lisdexamfetamine eventually becomes dextroamphetamine in the body it should not be granted 5-year exclusivity. However, the appeal court ruled that the FDA's conclusion – that the entire pre-ingestion drug molecule is responsible for the drug’s activity (including distribution, metabolism, excretion, and toxicity) – is valid, and certainly not contrary to what Congress had intended when it voted on the Amendments.