(Adds details of Roche-Shire patent fight)
ZURICH, March 28 (Reuters) - A Tokyo court has ruled that Shire's claim against Swiss drugmaker Roche's new Hemlibra haemophilia medicine should be dismissed, Roche's Japanese subsidiary Chugai said on Wednesday, helping to clear up legal uncertainty over the prospective blockbuster medicine.
Chugai, which is 60 percent Roche-owned and which developed Hemlibra, said it expected no change to its financial prospects due to the ruling.
"Tokyo District Court rendered a decision in favor of Chugai's claim," Chugai said on its website. "(Shire's) claim shall be dismissed in its entirety."
Hemlibra is approved in the United States and Europe for patients who have developed resistance, or inhibitors, to standard treatments that include infusions of clotting factors that help stop bleeding in sufferers of haemophilia A.
Shire is also seeking a U.S. injunction aimed at stopping some patients from getting Helimbra as it tries to protect its own haemophilia products facing pressure from Roche's new drug.
Roche is pressing ahead with plans to expand its medicine's approvals to patients who have not developed inhibitors and contends Shire's patent claims are without merit.
The patent dispute underscores Hemlibras potential to take business from Shire, with some analysts estimating Roches roughly $450,000-per-year drug will hit $5 billion in annual sales by muscling in on older drugs for the genetic disease whose sufferers blood does not clot properly.
Shares in Shire have reacted negatively as Hemlibra, also known as ACE910, succeeded in trials ahead of its U.S. Food and Drug Administration approval last year. It was approved this year in Europe.
(Reporting by John Miller. Editing by Jane Merriman)