London — French pharmaceutical firm Sanofi agreed to buy US biotech company Synthorx for $2.5bn, almost triple its market value, accelerating a push into cancer under new CEO Paul Hudson.

Sanofi will pay $68 a share in cash for Synthorx, the companies said on Monday. Shares of the unprofitable San Diego-based company closed at $25.03 on Friday, having surged 40% last week.

The deal underscores the Paris-based drug maker’s efforts to build its portfolio of innovative therapies in the fast-growing and lucrative cancer field. It was unveiled a day before Hudson outlines his pipeline and acquisition priorities, along with his initial plans for the consumer-health, diabetes and other units. The purchase marks Sanofi’s first multibillion acquisition since early 2018.

Investors are counting on Hudson to fire up Sanofi’s research operations and step up the search for novel products to reduce its reliance on Dupixent, a medicine for severe eczema and asthma. Hudson, the former pharma head at Novartis, is credited with launching key medicines at his previous job before becoming CEO of Sanofi in September.

The purchase is the latest sign of big pharma’s increasing bet on oncology medicines with drug makers including Roche, Bristol-Myers Squibb and Merck leading the pack. Big premiums have become the norm as companies place riskier bets on acquiring potentially lucrative treatments from biotech start-ups.

Another company in catch-up mode, GlaxoSmithKline, paid about $5.1bn earlier this year for Tesaro, the maker of a promising cancer medicine called Zejula. The UK drug maker’s new CEO, Emma Walmsley, has doubled the number of experimental cancer drugs in human testing to 16. Three of those could reach the market next year.

Synthorx’s main drug, known as THOR-707, is being explored as a treatment for multiple types of solid tumours, together with immune checkpoint inhibitors and other future combinations.

Sanofi shares fell as much as 1% on Monday in Paris, while Synthorx rose to just below the offer price in premarket US trading.

The French drug maker earlier this year said it would accelerate 17 drug programmes, almost half in cancer, and drop more than a dozen others under development. Analysts at HSBC wrote in August that more deals would be the fastest way to build up Sanofi’s stable of medicines and profile in cancer. Sanofi and partner Regeneron Pharmaceuticals won approval last year for an immune-oncology drug — Sanofi’s first — for a deadly form of skin cancer.

In another sign of rising deal activity in the biotech sector, Astellas Pharma last week agreed to buy Audentes Therapeutics for about $3bn, paying a 110% premium to advance into the gene therapy realm.

Sanofi shares have climbed about 11% since Hudson was named CEO in June, closing at €83.56 on Friday. The stock had declined almost 16% over the previous four years.