Alimta, known generically as pemetrexed, had worldwide sales of $2.49 billion last year, making it Lilly’s second biggest-selling product.

The setback follows a win for Lilly in the UK appeals court in June and highlights the complexity of legal arguments over patents that cover the administration of vitamins given alongside Alimta.

Lilly said the latest court ruling was that its vitamin regimen patent would not be infringed by Actavis marketing pemetrexed trometamol with instructions to dilute the product only with dextrose solution.

In June, the appeals court said Lilly’s patent would be indirectly infringed by the sale of certain alternative salt forms of pemetrexed with instructions to dilute them with saline solution, but it left open the question of dextrose solution.

The UK court rulings also apply to France, Italy and Spain under a legal system of corresponding declarations, and Lilly said it planned to appeal the latest decision.

In major European countries, the basic compound patents for Alimta expired in December 2015 but its vitamin regimen patents run until June 2021.