Medicago’s novel vaccine technology has proven attractive to Japanese drug company Mitsubishi Tanabe Pharma , which has reached an agreement to buy a majority stake the vaccine developer in a deal valued at up to $357 million Canadian.

Quebec City-based Medicago has its largest manufacturing facility in Research Triangle Park. Under the definitive agreement announced Friday morning, Mitsubish will acquire all of the shares in Medicago other than those shares currently held by minority owner Philip Morris Investments. When the deal is completed, Mitsubish will own 60 percent of the company and Philip Morris will own 40 percent.

The transaction has already received the unanimous approval of Medicago’s board of directors.

Mitsubishi and Medicago are already well acquainted. The companies last year entered a vaccine collaboration deal that would pay Medicago up to $33 million, plus royalties for developing and bringing to market a new rotavirus vaccine. That deal also included the opportunity to develop and commercialize at least three new vaccines to be determined at a later date.

Medicago, has developed proprietary technology that can make vaccines from tobacco leaves. The technology makes virus-like particles, or VLPs, that mimic the structure of a virus and prompt an immune response from the body. But because the particles are not the actual virus, they cannot infect people and they are unable to replicate.

Medicago RTP plant which was designed to play a role in manufacturing vaccine in response to pandemic viral outbreaks. The facility plant was built with under a $21 million U.S. government contract set for scalable manufacturing facilities that can respond to virus outbreaks.

“Mitsubishi Tanabe Pharma’s capabilities in biopharmaceutical research, development, and commercialization along with its financial stability offer us the ideal opportunity to realize the full potential of our platform,” Medicago CEO Andy Sheldon said in a statement. “These resources provide us the ability to foster the development of innovative vaccines with the financial stability to expand our Quebec, Canadian, U.S. and global operations.”

The companies said the transaction is expected to close later this year.