Bristol Myers accuses AstraZeneca of infringing patent on cancer blockbuster Opdivo—again

After clashing with oncology rivals over checkpoint inhibitor patents multiple times in the past, Bristol Myers Squibb is going after rival AstraZeneca once more.

In a new lawsuit in Delaware federal court, BMS claims AZ infringed a patent covering its blockbuster checkpoint inhibitor Opdivo.

Specifically, BMS claims AZ's Imfinzi infringes its so-called '899 patent, which BMS was awarded in 2016. The patent covers a method of treating cancer by using an anti-PD-L1 antibody to limit interactions between proteins PD-1 and PD-L1.

This is not the first time that BMS has sued AstraZeneca for alleged infringement. In 2017, Imfinzi’s approval year, BMS alleged infringement on the same patent.

That lawsuit was ultimately dismissed, so it appears BMS is pressing its case once again with the latest action.

The two drugs are major moneymakers. Last year, Opdivo brought in $8.25 billion for BMS, while AZ garnered $2.8 billion with Imfinzi over the same period.

BMS and AZ didn't immediately respond to requests for comment.

Aside from legal activity over the '899 patent, BMS in March sued AZ for allegedly stepping on eight Opdivo patents issued between 2017 and 2019.

And in January, the company targeted AZ’s CTLA-4 inhibitor Imjudo, which BMS claims treaded on two of its Yervoy patents.

The company hasn't just tussled with AZ. Bristol also went after Merck & Co. in a separate patent case and ultimately scored a $625 million payout plus royalties, which BMS split 75/25 with its partner Ono Pharmaceutical.

And in November 2020, Bristol and Ono revealed a patent licensing deal (PDF) with Roche.