Will Shire's acute HAE drug OK shift dynamic for ViroPharma's prophylactic?

The US FDA's approval on 25 August of Shire's hereditary angioedema (HAE) drug Firazyr (icatibant) as the first and only self-administered subcutaneous treatment for acute attacks has not only opened the gate for the medicine to claim a favourable chunk of the US market in that indication, but also could have an impact on the prophylactic setting.