Shire under a £1bn shadow

FEARS about competition and cost pressures sent Shire Pharmaceuticals' shares plunging to a two-year low, a 32% setback that wiped more than £1bn from its market value.

US-owned Barr Laboratories has produced its own version of Adderall, which was specially developed by Shire for children suffering from hyperactivity, and there are worries about Barr's products gaining market share.

Shire has countered the Barr move by producing a one-shot-a-day version of Adderall, which is Shire's lead drug, contributing a third of revenues.

Although Shire has launched three other drugs, the process of researching and trialling other drugs could mean extra expenditure in the short term.

However, chief executive Rolf Stahel said that in the medium- to long-term the group has excellent prospects for its portfolio of drugs that can treat HIV, cancer, epilepsy and hypotension.

Pre-tax profit before exceptionals was $295.4m (£208m) in the year to last December against $204.2m the year before. The shares fell 240p to 520p.