Sanofi S.A., FR0000120578

Sanofi expands Regeneron alliance while Sanofi stock gains 1.52 percent

Published on 10/01/2026 at 13:10 | Editorial responsibility: Rafael Müller, Editor-in-Chief AD HOC NEWS

Sanofi pays USD 1.00 billion upfront, with up to USD 7.00 billion in milestones. Sanofi stock costs EUR 73.98 on October 1, 2026 versus EUR 72.87.

Modern pharmaceutical sterile fill-and-finish manufacturing facility interior with glass vial-filling machines and cleanroom workers in white suits — Sanofi FR0000120578 photorealistic sterile fill-and-finish facility with vial-filling machines and cleanroom workers, Illustration mit AI erstellt.

Sanofi (ISIN FR0000120578) is expanding its Regeneron alliance with four next-generation antibodies, while Sanofi stock was trading at EUR 73.98 at Lang & Schwarz on October 1, 2026 at 1:04 p.m. CEST, up 1.52 percent versus the prior close of EUR 72.87. The agreement announced by Sanofi on October 1, 2026 covers long-acting immunology treatments and includes a USD 1.00 billion upfront payment.

Four antibodies extend the alliance

The expanded agreement adds the clinical-stage IL-13 antibody REGN20423, one IL-4xIL-13 bispecific and two other preclinical antibodies. The companies will co-develop and co-commercialize all four programs, share costs and divide future profits equally worldwide, according to Reuters on October 1, 2026.

Regeneron will receive up to USD 7.00 billion in additional development, regulatory and commercial milestone payments. The existing Dupixent profit-sharing agreement remains unchanged, while the companies also settled earlier collaboration-related litigation.

Q2 growth raises the strategic stakes

Sanofi's second-quarter 2026 net sales rose 17.80 percent year over year to EUR 11.60 billion, while business earnings per share increased 33.30 percent, according to ScanX News in its report on September 18, 2026. Dupixent sales exceeded EUR 5.00 billion in the quarter, rising 37.00 percent year over year, with more than 1.5 million patients receiving the medicine.

The new deal therefore targets a measurable concentration risk: the next wave of growth must eventually complement Dupixent. REGN20423 is already in a phase 1 study for atopic dermatitis, while the other three antibodies are expected to enter clinical studies in 2027, leaving development and regulatory execution as the main uncertainties.

Stock gains as market value reaches EUR 88.1 billion

Sanofi is listed on Euronext Paris under ticker SAN and is a CAC 40 constituent. Its market capitalization stood at EUR 88.1 billion on October 1, 2026, and the Euronext Paris market page identifies the company as a pharmaceutical group through its Sanofi listing data.

At Lang & Schwarz, the intraday quote of EUR 73.98 was EUR 1.11 above the EUR 72.87 prior close of September 30, 2026, equivalent to a plus 1.52 percent daily move. The further course of trading is shown by the continuously updated real-time quote of Sanofi stock.