Shire has come to an agreement with regulators in the USA to conduct more trials on the hypotension drug ProAmatine to preserve its marketing approval.

In August 2010, the US Food and Drug Administration said it wanted to withdraw ProAmatine (midodrine) which was approved in the USA in 1996 under the accelerated approvals process. However, according to the agency, neither Shire nor any generic firm (the drug went off-patent in 2003) has since demonstrated ProAmatine's clinical benefit.

Shire completed two post-marketing trials as required and submitted the results to the FDA in 2005, but the agency requested additional studies.  The firm disagrees with the agency and "believes that these trials, together with 15 years of clinical experience, have established the clinical efficacy of ProAmatine and provide the necessary data to support the full approval".

Nowadays, the Irish company has "no financial interest in midodrine, and no longer manufactures, distributes or markets the brand name version". However it is still the holder of the New Drug Application for the treatment and has "worked diligently with the FDA to develop a path forward that would allow the NDA to maintain its marketing authorisation thus allowing the generic versions of ProAmatine to remain available for patients who critically need this medicine and who have no alternative treatments".

It is against this background that Shire has reached an agreement with the FDA's Center for Drug Evaluation and Research to conduct two additional trials. They are expected to begin as soon as possible with an anticipated completion by the end of 2014 and generic midodrine will remain available while the studies are conducted.

"The timeframe outlined in the proposal for additional clinical trials is consistent with Shire's original request and we are appreciative that we have come to agreement with CDER on this path forward," said the firm's R&D chief Jeffrey Jonas.