The UK Supreme Court has ruled in favor of US drugmaker Eli Lilly in a patent dispute with generics producer Actavis, now owned by Israel’s Teva, over the cancer drug Alimta. The highest court of the land found that Actavis’ alternative salt forms of the drug directly violate Lilly's patent for Alimta in combination with vitamins in the UK, France, Italy and Spain.

The Supreme Court’s ruling, which overturns a lower court in favor of Actavis, gives the US company until 2021 to protect European sales of the blockbuster under the relevant patent.

In a statement, Lilly’s counsel said it was pleased with the court’s key conclusions that the Alimta vitamin regimen patent would be infringed by competition from generic products in the respective countries up to 2021, when the relevant patent expires.

According to analysts, the drug generates altogether about $1.2 billion for Lilly outside the US. The scope of the UK ruling affects about $300 million in sales in the countries where it applies. A Lilly spokesperson told the journal Fierce Pharma the company may seek damages for losses related to the infringement.

Actavis launched its pemetrexed product, Armisarte, in June 2015. The drug is  recommended for treatment of advanced non-small cell lung cancer and mesothelioma.

Lilly’s patent infringement battles have met with mixed results up to now. In 2015, it lost a fight with Actavis in Germany and earlier this year a case against Teva in the US. Other US cases are said to be pending.