US drugmaker Eli Lilly has lost the latest round in an ongoing legal fight in the UK over patents relating to the administration of vitamins given alongside its blockbuster lung cancer drug Alimta (pemetrexed disodium).

The UK High Court ruled that Lilly’s Alimta vitamin regimen patent would not be infringed by Actavis marketing its pemetrexed trometamol in the UK, France, Italy and Spain with instructions to dilute the product only with dextrose solution.

The decision was based on Actavis complying with its stated marketing plan, as well as certain circumstances not changing over the remaining life of the patent in force until June 2021. The compound patents for Alimta expired in major European countries in December 2015.

In June 2015, the court ruled that Lilly’s patent would be indirectly infringed by certain alternative salt forms of pemetrexed with instructions to dilute the product with saline solution. However, it left open the question of whether an alternative salt form with instructions to dilute only in dextrose solution would infringe.

Lilly said it will seek permission to appeal the decision. The drugs firm has also applied for permission to appeal the direct infringement aspect of last June’s ruling. The request is still pending.

In Germany, Lilly has been granted permission to appeal a decision by the Düsseldorf Court of Appeal that its patent would not be infringed by a generic competitor planning to market pemetrexed dipotassium in the country. The appeal is scheduled to be heard in mid-2016.

Lilly has also recently received a preliminary injunction against a different generics firm to restrict marketing of a copycat pemetrexed product.