Eli Lilly has won a patent case in the Court of Appeal in London over its blockbuster Alimta lung cancer drug, boosting prospects for future sales and dealing a blow to generic challenger Actavis, now renamed Allergan.
 

Alimta generated worldwide sales of $2.79 billion for Lilly last year, making the medicine its biggest-selling product. Shares in the U.S. drugmaker jumped 5 percent on Thursday.
 

The verdict, which reverses a 2014 decision by the English High Court, will also apply to France, Italy and Spain under a legal system of corresponding declarations.
 

The London appeals court ruled Actavis's plan to market certain alternative salt forms of Alimta -- known generically as pemetrexed -- after the basic patent on the medicine expires in December 2015 would indirectly infringe another Lilly patent.
 

The additional patent is valid to 2021 and covers the administration of two nutrients, folic acid and vitamin B12, that are given to patients before and while they receive Alimta to prevent side effects.
 

Lilly said that the latest ruling "increases the likelihood that the vitamin regimen patents for Alimta will provide exclusivity in the UK, France, Italy and Spain through June 2021".
 

Bernstein analyst Tim Anderson estimated Alimta sales in the four countries totaled between $400 million and $500 million in 2014, and the drug's high margins meant continuing revenue streams to 2021 would boost earnings per share (EPS)significantly.
 

"By our estimate, this could boost Lilly’s EPS by nearly 10 percent annually from 2016 to 2020," he wrote in a note.
 

Analysts at Cowen also increased earnings estimates for the company and raised their price target for the stock to $90 from $85.
 

Lilly shares have enjoyed a strong run recently on growing hopes for its experimental drug solanezumab, an Alzheimer's disease treatment once considered a dud.
 

Litigation over Alimta patents is continuing in the United States, where the consensus view is currently that Lilly is likely to prevail.
 

In Germany, by contrast, the argument has gone against Lilly, following a decision in March by an appeal court there that Actavis would not infringe Lilly's patent if it sold its product after December 2015.