Shire to face generic competition for Adderall XR from Actavis

Shares in UK drugmaker Shire (LSE: SHP) fell around 9% to £17.82 in early trading this morning, after the company revealed over the weekend that the US Food and Drug Administration has responded to Adderall XR (mixed amphetamine salts) citizen petition, saying that all Abbreviated New Drug Applications have to establish bioequivalence using partial area under the curve measurements at five hours and beyond five hours for both d- and l- amphetamine. The FDA response is consistent with its recent decisions on other long acting ADHD products, the company noted.

However, the US regulator also informed Shire that it has approved an ANDA filed by Actavis, a unit of US generics firm Watson Pharmaceuticals (NYSE: WPI), for generic Adderall XR, a drug for the treatment of attention-deficit hyperactivity disorder. The FDA has not approved any other Adderall XR ANDAs.

Shire, the UK’s third-largest pharmaceutical company, believes that it will remain competitive in the Adderall XR marketplace through the distribution of branded Adderall XR and through its two authorized generic partners, Teva and Impax. While recognizing that there will be multiple dynamics affecting the overall market following the approval of the Actavis generic, Shire continues to believe that it will deliver good, full year 2012 earnings growth.