SoftBank Group Corp. has quietly built a ¥550 billion ($5 billion) stake in Roche Holding AG, placing a bet on the pharmaceutical company’s strategy of using data to develop drugs, according to people familiar with the matter.

The Japanese conglomerate is now one of Roche’s largest investors, according to data compiled by Bloomberg.

Roche’s sales have recently been boosted by its COVID-19 testing business. The company’s diagnostics unit reacted swiftly to the coronavirus pandemic, but the pharmaceuticals division, where aging cancer medicines face increasing competition, has had a more difficult time.