Shire has hit the acquisition trail and is spending $4.20 billion to buy the US rare disease specialist ViroPharma.

The Ireland-headquartered group is paying $50 per share, which represents a 27% premium on ViroPharma's closing share price on November 8. The deal gives Shire access to the hereditary angioedema drug Cinryze (C1 inhibitor [human]), which complements its own HAE drug Firazyr (icatibant).

Last year, Cinryze sales reached $321 million in the USA and for this year, North American revenues are forecast $395-$405 million. ViroPharma also sells Plenadren (hydrocortisone modified release) for adrenal insufficiency and Buccolam (midazolam), which treats prolonged seizures in infants, children and adolescents.

In terms of pipeline, two products are in Phase II - maribavir for the treatment of cytomegalovirus infection in transplant patients and VP20621 for the prevention of recurrent Clostridium difficile infection. ViroPharma also has an option to acquire Meritage Pharma, which is conducting Phase II trials with oral budesonide for eosinophilic oesophagitis.
 
Shire, which recently announced job cuts in the UK, says it will review these programmes to ensure its R&D resources are "appropriately deployed". Chief executive Flemming Ornskov said the acquisition "will immediately benefit Shire and is entirely consistent with our clear strategic objective of strengthening our rare disease portfolio". 
 
He added that his company "is uniquely positioned to drive the continued success of Cinryze for the benefit of patients through our knowledge of the rare disease space, our international infrastructure and our biologics manufacturing expertise". Mr Ornskov concluded by saying that Shire has conducted "a thorough and collaborative due diligence process over the last few months", and the acquisition "is expected to create a $2 billion rare disease revenue base and delivers further strong growth prospects".

The news has gone well with investors and Shire shares were up 3.5% to £28.94 at 9.50 this morning (UK time). Savvas Neophytou, an analyst at Panmure Gordon, said that  the broker views acquisition "in the same league as the BioChem Pharma, TKT and New River Pharmaceuticals transactions that transformed the group". He said the price paid represents "an eye watering multiple ", but declared that it is "strategically very sound".