Eli Lilly has won a key round in its legal battle with Teva Pharmaceutical Industries to protect patents on its osteoporosis blockbuster Evista.

A US district court in Indiana has upheld Lilly’s method-of-use patents on Evista (raloxifene) for osteoporosis (the drug is also indicated for the prevention of breast cancer for certain postmenopausal women). The ruling means that Teva cannot launch its generic version of the drug until March 2014.

The ruling comes after the judge granted a temporary restraining order preventing the Israeli drugmaker from selling its copycat version of Evista. The court now says that Teva failed to demonstrate "the obviousness, enablement and inequitable conduct" of four patents.

However the court did declare two particle-size patents invalid and Lilly said it "is reviewing this aspect of the ruling to determine whether or not to appeal”. In turn, Teva stated that it definitely plans to appeal the decision.

Robert Armitage, Lilly's general counsel, said “we have always been very confident that these patents are valid and enforceable” and the court ruling “sends a clear message on the strength of those patents”. He added that “protection of intellectual property rights is extremely important to the biopharmaceutical industry”.

Sales of Evista are also important to Lilly, though second-quarter revenues from the drug were down 10% to a still-healthy $251.3 million.

Astellas sues Teva
Meantime, Teva has been sued by Astellas Pharma for patent infringement of Vesicare (solifenacin) for overactive bladder, The Japanese firm is asking that Teva’s Abbreviated New Drug Application to sell a generic of the treatment not be approved until its patents run out in 2018.

Vesicare is co-marketed in the USA with GlaxoSmithKline and posted North American sales of $339 million in the fiscal year ended in March.