KYOTO (Kyodo) -- Japanese Nobel laureate in medicine Tasuku Honjo on Friday filed a lawsuit against Ono Pharmaceutical Co., seeking about 22.6 billion yen ($211 million) in patent royalties from the company that sells the cancer treatment drug Opdivo developed based on the discovery of his research team.
The complaint, filed with the Osaka District Court, said Ono Pharmaceutical made a verbal proposal in 2014 to pay Honjo 40 percent of the patent royalties due from a U.S. drugmaker if he cooperated on a lawsuit between the two companies.
Honjo, a distinguished professor at Kyoto University and 2018 Nobel Prize winner, agreed to help the Japanese drugmaker, but the company broke its promise and paid only 1 percent of the royalties after the two firms reached an out-of-court settlement, according to the complaint.
The royalties he is now seeking correspond to the difference between the 40 percent of the fees Ono Pharmaceutical earned from the U.S. drugmaker from 2017 to 2019 and the actual sum Honjo was paid.
The discovery of the protein PD-1 by Honjo and his team in 1992 later led to the development of Opdivo, a drug that triggers the immune system to attack cancer cells.
Honjo is planning to donate most of the royalties he may receive through the suit to a fund at Kyoto University designed to support young researchers.
Honjo signed a contract with Ono Pharmaceutical in 2006 on how to split revenue between them. But a new round of negotiations started in 2011, with the scientist claiming that he had signed the deal at an unfair rate as the university did not have a good support system pertaining to intellectual property at the time.
He could file a separate lawsuit over this contract in the future.
Ono Pharmaceutical in 2018 proposed a donation of up to 30 billion yen to the university, instead of paying the 40 percent of the patent royalties, but Honjo declined the offer.
"I've been very patient for the past 10 years or so. It's about time to bring this to an end, otherwise there's no merit in it for the university," Honjo said during a press conference on June 5, when he announced his plan to seek about 22.6 billion yen in patent royalties through a lawsuit.
"There have been frequent cases of companies taking advantage of academic people's ignorance," he said. "I hope my case becomes a precedent and helps young researchers to be recognized (by society)."