(Bloomberg) -- SoftBank Group Corp. has quietly built a $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.

Shares of the Basel, Switzerland-based company have risen 8.8% in the last 12 months, compared with a 14.7% gain in the MSCI World Pharma Biotech & Life Sciences index over the same period.

The drugmaker has a dual-class share structure with separate voting and non-voting shares. The founding families own 50.1% of the voting class, while cross-town rival Novartis AG holds one-third. It’s unclear which types of shares SoftBank holds.

SoftBank believes Roche’s Genentech division, which focuses on data-based drug discovery and development, is highly undervalued, one of the people said, all of whom asked not to be identified because the information is private. Roche last year hired Aviv Regev, a computational and systems biologist who was a core member of the Harvard University-affiliated Broad Institute, to lead the Genetech research unit.

Roche is also developing a new pill for Covid-19 and an Alzheimer’s disease treatment. In June, the U.S. approved Biogen Inc.’s Alzheimer’s drug Aduhelm, which was seen as a positive sign for the Roche medicine.

SoftBank has been increasingly focused on biotech and health care. It invested in Pacific Biosciences of California Inc., AbCellera Biologics and Sana Biotechnology. In February, Bloomberg News reported that SoftBank was planning to spend billions investing in public biotech companies, via its asset management arm SB Northstar.

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