Fourth-quarter earnings at Shire have more than tripled, while revenues climbed 46% to $724.5 million, helped by a much better-than-expected performance from Vyvanse, the follow-up to the UK firm’s old attention deficit hyperactivity disorder drug Adderall XR.

Net income reached $212.1 million, though the figure was boosted by a $114.8 million one-time gain from its recent sale of eight drugs to Spain's Almirall. Saleswise, Adderall XR (mixed amphetamine salts) continued to keep growing and rose 21% to $277.7 million, but it was the revenues from Vyvanse (lisdexamfetamine dimesylate), launched in July last year, that raised most eyebrows.

Analysts have been downgrading Shire in their droves recently, claiming that the Basingstoke-based firm’s forecasts for the drug had been too high and that the launch was going slower than expected. However fourth-quarter revenues from Vyvanse reached $65.9 million, way beyond the estimates from the investment community and specifically 85% higher than predicted by Morgan Stanley.

Vyvanse is vital to Shire’s fortunes seeing as Adderall XR will face generic competition in 2009, but as well as switching patients to the new drug, the firm is doing well at positioning Vyvanse as a new drug with significant advantages over the older treatment and other ADHD products. Incidentally, Shire’s ADHD patch product Daytrana (methylphenidate) had fourth-quarter sales of $23.0 million, up 51%.

Shire stated that the launch of Vyvanse “has been tracking in line with other blockbuster central nervous system drug launches”, with over 900,000 prescriptions being written. As of last week, it had achieved a US ADHD market share of 6.3% based on daily prescription volume.

Chief executive Matthew Emmens said “we are confident about the medication’s future growth supported by new clinical studies and expected additional indications”. In particular, the firm is hoping to get US approval for Vyvanse as a treatment for adults at the end of April, noting that the latter target group represents “the largest and fastest growing segment of the ADHD market with a total of 9.9 million patients, of which 7.5 million are untreated”. Shire is expecting Vyvanse sales to be in the region of $350-$400 million this year and will be relying far less on the coupons and wholesaler discounts used at the launch.

There is, however, much more to Shire than ADHD drugs. Fourth-quarter sales of Elaprase (idursulfase) for Hunter syndrome reached $57.4 million, up 197%, while turnover from Fosrenol (lanthanum carbonate) for high blood phosphate levels was up 40% to $26.2 million. Replagal (agalsidase alfa), for the treatment of Fabry disease, contributed $38.9 million to the coffers, up 25%, while the ulcerative colitis therapy Pentasa (mesalamine) was up 27% to $48.7 million.

Commenting on the results, Deutsche Bank analyst Brian White issued a research note saying that “with Adderall XR generating substantial revenues and with a strong 2008 performance this will provide Shire with a windfall of revenues in 2009”. He added that even with this windfall, Shire is providing guidance for continued positive revenue growth through to 2010, “which demonstrates the strength in the new product portfolio and the confidence in the launch of Vyvanse".