It is the third time in three years that a US court upheld the patent on Alimta.
In March 2014, the US Court for the Southern District of Indiana upheld the validity of the vitamin regimen patent.
The same court again ruled in Lilly's favor regarding infringement of the vitamin regimen patent in August 2015.
If Eli Lilly gets favorable ruling on all remaining challenges, it will have exclusivity on the drug until May 2022. The Alimta compound patent remains in force through 24 January 2017.
Lilly senior vice president and general counsel Michael Harrington said: "We are pleased with today's ruling by the Court of Appeals, affirming the earlier district court's decisions, finding the Alimta vitamin regimen patent is valid and would be infringed.
"The significant scientific research that Lilly performed in support of the vitamin regimen patent deserves intellectual property protection, which has been confirmed in every validity challenge to date.”
The US Food and Drug Administration approved Alimta in combination with cisplatin (another chemotherapy drug) for the initial treatment of advanced nonsquamous non-small cell lung cancer (NSCLC).
Alimta can suppress bone marrow function, which could result in low blood cell counts.
Image: Eli Lilly and Company's global headquarters, in Indianapolis, Indiana, United States. Photo: courtesy of Guanaco152003.