Regeneron Stock Jumps 13% to 52-Week High as Sanofi Dupixent Windfall Powers a Blockbuster Third Quarter

Shares of Regeneron Pharmaceuticals surged more than 13% on Friday to a 52-week high after the biotechnology company reported third-quarter profit and revenue far above Wall Street's expectations, driven by a jump in profits from its partnership with Sanofi.

Regeneron stock rose $109.12, or 13.33%, to close at $927.89, its highest close in a year. The shares had closed at $818.77 on Thursday. The stock's 52-week high is $935.35.

Volume reached about 2.9 million shares, nearly four times the three-month average of about 734,000. Regeneron's market value rose to about $96 billion.

The rally made Regeneron one of the best-performing large health care stocks on a day when the S&P 500 fell 1.8%.

Earnings crush estimates

Regeneron reported adjusted earnings of $20.07 per share, well ahead of analysts' expectations of $16.06 and up 70% from $11.83 a year earlier.

Revenue rose 36% to $5.12 billion, beating forecasts of $4.54 billion. Net income rose 33% to $1.95 billion.

It was the third consecutive quarter of double-digit growth in both revenue and earnings, the company said.

"This was an outstanding quarter for Regeneron," Chief Executive Leonard Schleifer said, noting that Dupixent, Eylea HD and Libtayo each achieved record net sales.

Sanofi windfall

The biggest driver was Regeneron's collaboration with Sanofi on Dupixent, a blockbuster drug for eczema, asthma, COPD and other conditions.

Sanofi sells Dupixent worldwide and shares the profits with Regeneron. Collaboration revenue from Sanofi reached $2.7 billion, up 68% from a year earlier.

Regeneron finished repaying a balance of development costs owed to Sanofi in the second quarter. The third quarter was the first period in which Regeneron recorded its full share of the partnership's profits, giving its results a significant boost.

Partnership expanded

Regeneron and Sanofi also expanded their alliance in October to cover four next-generation, long-acting immunology antibodies.

Under the deal, Sanofi will pay Regeneron $1 billion upfront, to be booked as revenue in the fourth quarter, and up to $7 billion more tied to development, regulatory and commercial milestones.

Eye drug transition

Not every product grew. Sales of Regeneron's older eye drug, Eylea, continued to decline as patients shift to newer treatments and face competition from cheaper rivals.

But the company's newer, longer-lasting version, Eylea HD, posted record sales, helping offset the decline.

Regeneron also raised its full-year 2026 guidance for adjusted gross margin on net product sales to about 86%, from 84% to 85%.

Strong October

Friday's gain capped a strong month for Regeneron. The stock rose about 26% in October, while the S&P 500 lost about 1%.

Over the past 52 weeks, the shares have gained about 44%, recovering from a low of about $591.

Regeneron trades at about 20.5 times trailing earnings.

ETF impact

The rally also lifted health care and biotech exchange-traded funds that hold large positions in Regeneron, including the Health Care Select Sector SPDR Fund.

What's next

Investors will watch the fourth quarter, when Regeneron will book the $1 billion upfront payment from Sanofi, as well as progress in its pipeline of about 50 clinical programs.

The company's ability to keep growing as Eylea sales decline will remain a key focus for investors.