(Bloomberg) -- Novartis AG agreed to buy Chinook Therapeutics Inc. for as much as $3.5 billion to add two promising treatments in advanced tests for a rare kidney disease.

Most Read from Bloomberg

• Oil Traders Are Daring to Defy Market Kingpin Saudi Arabia

• UBS Completes Credit Suisse Takeover to Create Bank Titan

• As Fed Signals Rate Pause, Powell Will Have to Placate Hawks

• Jeff Bezos Has Gained $10 on Mystery Purchase of One Amazon Share

• Goldman’s Low US Recession Odds Get It Wrong, Bond Investors Say

The Swiss drug company will pay $40 a share in cash for Seattle-based Chinook, 67% more than Friday’s close, it said in a statement Monday. Another $4 a share could be paid later if the medicines achieve certain regulatory milestones.

Chief Executive Officer Vas Narasimhan had been more active in slimming Novartis down rather than boosting its drug pipeline through acquisitions. The two Chinook medicines could pay off quickly if they’re successful, with one expected to report key results as early as this year.

Companies from AstraZeneca Plc to Amgen Inc. have acquired other developing treatments for rare diseases because they command higher prices. Investors had been expecting a pipeline-boosting transaction since Novartis sold its stake in rival Roche Holding AG, giving it financial firepower.

Chinook’s two treatments target a progressive, rare kidney disease called IgAN that mostly affects young adults and currently lacks targeted treatment options. The most advanced one is also in development for other rare kidney diseases. The purchase would be the Swiss company’s largest since it bought Medicines Co. for about $9.7 billion in 2020.

Novartis shares rose as much as 1.5% in Zurich trading.

CEO Narasimhan decided last year to spin off Novartis’s Sandoz division, creating the largest European generic and biosimilar drug company by sales. Novartis is also considering selling some ophthalmology assets and it has cut jobs and combined its pharma and cancer units.

Novartis said it expects to complete the deal in the second half of 2023.

(Updates with shares in fifth paragraph. A previous version of this story corrected where Chinook is based in second paragraph.)

Most Read from Bloomberg Businessweek

• America’s Long, Tortured Journey to Build EV Batteries

• Will Argentina Ditch the Peso for the Dollar?

• The Netflix Effect Chills Foreign Content Creators

• Giorgia Meloni Seeks to Cement Power by Remaking Corporate Italy

• Payrolls, Prices, Productivity and Profits Hold the Answer to the Puzzling US Economy

©2023 Bloomberg L.P.