LONDON, Nov 17 (Reuters) - An experimental lupus drug fromAstraZeneca significantly improved the symptoms of lupusin a mid-stage clinical trial, boosting prospects for a medicinethe company believes could become a major seller.
Only one new drug -- GlaxoSmithKline's Benlysta --has been introduced for lupus in half a century, underlining thedifficulties of tackling the disease that causes the immunesystem to attack joints and organs.
AstraZeneca's sifalimumab works in a different way toBenlysta by targeting interferon, a protein involved ininflammation.
In a Phase IIb study, details of which will be presented atthe American College of Rheumatology (ACR) annual meeting,sifalimumab improved symptoms at all doses. However, there wasan increase in patients reporting Herpes zoster, particularly atthe highest dose.
Sifalimumab is one of two drugs for lupus being developed byAstraZeneca's biotech unit MedImmune. The other is anifrolumab,which blocks interferon more comprehensively. Early data, alsobeing presented at the ACR meeting, suggests this second drugmay be more effective.
Bing Yao, head of respiratory, inflammatory and autoimmunemedicine at MedImmune, said the company would decide which ofthe two drugs to take into final-stage Phase III trials aftergetting Phase IIb results on anifrolumab next year.
In May, AstraZeneca predicted the lupus medicines couldeventually generate annual sales of around $1 billion. It madethe forecast as part of a long-term sales projection in itsdefence against an unsuccessful $118 billion takeover bid byPfizer.
AstraZeneca will give a further update on its new drugs atan investor day on Nov. 18, just eight days before Pfizer isallowed to make a new bid under British takeover rules. (Reporting by Ben Hirschler; Editing by Mark Potter)