Regulatory briefs: Shire to dump ProAmatine after FDA moves; Kowa gets first European approval for pitavastatin

In what can come as no surprise after the US Food and Drug Administration's threats to withdraw market approval of Ireland-based drugmaker Shire's low blood pressure therapy ProAmatine (midodrine; The Pharma Letter August 17), the company has said it will take the product off the US market, effective September 30.

In its announcement this week, the FDA said that neither Shire nor generic marketers of midodrine had complied with a request for post-marketing studies that had been required under the accelerated approval that was granted on the drug back in 1996. The agency has been accused of being lax about following up on P-M studies, and this muscle-flexing action could just have back-fired in that a drug that had been considered necessary for the condition of orthostatic hypotension just won't be available at all. It also seems very unlikely that the generics firms will be prepared to invest in expensive post-marketing studies for an off-patent product that never generated total sales of more than around $257 million.

Shire noted that it acquired ProAmatine as a part of the acquisition of Roberts Pharma in 1999 and contends that it conducted and completed the post-marketing trials that the FDA required. The FDA, however, viewed these trials as inconclusive and required that additional studies be conducted for ProAmatine to maintain its marketing authorization. As a result, Shire elected to withdraw the product and notified the FDA in November 2009 and health care professionals earlier this year of this decision. Shire's withdrawal of the NDA was not related to any concerns regarding the safety of ProAmatine. Moreover, sales of the drug are negligible, representing less that 0.1% of Shire's turnover.