Dupixent powers Sanofi, pipeline must catch up
- Dupixent is the center of the story, with EUR 15.7 billion in 2025 sales and more than 30% patient growth.
- Sanofi has sold control of Opella, turning itself into a more focused biopharma and vaccines company.
- New launches are starting to matter, led by ALTUVIIIO at EUR 1.2 billion and Beyfortus at EUR 1.8 billion in 2025 sales.
- The Opella deal brought in EUR 10.4 billion, which management says it has put toward acquisitions and pipeline building.
- The main worry is not today’s sales, it is whether the pipeline can replace Dupixent when exclusivity fades later.
- Finn’s view is cautious because the growth story is real, but setbacks, reimbursement headwinds, and vaccine confusion still matter.
A cleaner drug company, with one giant engine
Sanofi has made its choice. It is no longer trying to be a mix of prescription drugs, vaccines, and consumer health. After selling control of Opella, it is a more focused science company built around specialty medicines and vaccines.
The bull case starts with Dupixent. The drug reached EUR 15.7 billion in 2025 sales, and Sanofi said patient count grew by more than 30% over the past year. New products also help. ALTUVIIIO reached EUR 1.2 billion in 2025 sales, and Beyfortus reached EUR 1.8 billion.
The extra cash from Opella gives Sanofi room to act. Management said the EUR 10.4 billion received from the divestment has been used for business development and deals, including Blueprint, Vicebio, and the proposed Dynavax deal. That supports the plan to build more medicines and vaccines before Dupixent loses exclusivity.
The bear case is clear. Sanofi still has to prove that its pipeline can carry the company later. Tolebrutinib failed in PPMS, a form of multiple sclerosis, and the Regeneron reimbursement rolloff is expected to hurt business operating income by EUR 400 million in 2026 and about EUR 700 million in 2027. That is why the stock can look reasonably valued while Finn still stays measured on the full story.
Prescription drugs and vaccines now drive it
Sanofi makes money by selling patented medicines and vaccines around the world. Its largest profit pool is specialty pharma, especially Dupixent, which treats several immune and inflammatory diseases. Vaccines add a second pillar, led by RSV and flu products.
The model works best when Sanofi can launch new products, win new approved uses for existing drugs, and keep pricing pressure under control. A drug with patent protection can earn strong margins, but that protection does not last forever. This is why pipeline quality matters so much.
The Opella sale changed the shape of the company. Consumer health is no longer the main focus. The cash raised gives Sanofi more flexibility, but it also raises the bar. Investors need those deals to become real products, not just expensive promises.
The biggest break point is concentration. Dupixent is huge, and still growing, but the company must build enough around it to avoid a hard slowdown later.
What Sanofi sells
Dupixent
Dupixent is Sanofi’s biggest growth driver. It reached EUR 15.7 billion in 2025 sales, helped by wider use across diseases and more than 30% patient growth over the past year.
Vaccines, including Beyfortus and flu
Vaccines generated EUR 7.9 billion in 2025 sales. Beyfortus is the key newer product, while Fluzone High-Dose, Flublok, Efluelda, and Supemtek support the flu business.
ALTUVIIIO
ALTUVIIIO is a hemophilia medicine that reached blockbuster status with EUR 1.2 billion in 2025 sales. Sanofi says patients are switching from both factor and nonfactor medicines.
Ayvakit
Ayvakit came through the Blueprint Medicines acquisition and targets rare immunology disease. It reached $725 million in annual pro forma sales, slightly ahead of Blueprint’s early 2025 expectations.
Beyfortus
Beyfortus protects infants from RSV. It reached EUR 1.8 billion in 2025 sales, but new U.S. childhood vaccine rules could confuse doctors and parents in the near term.
Older-adult vaccine pipeline
Sanofi is adding to vaccines for older adults through Vicebio and the proposed Dynavax deal. Dynavax would add HEPLISAV-B, an adult hepatitis B vaccine, plus a shingles candidate.
Mostly biopharma, with vaccines beside it
The mix uses Sanofi’s 2025 full year sales from the Q4 2025 call. Total sales were EUR 43.6 billion, with vaccines at EUR 7.9 billion and the remaining sales treated as biopharma after the Opella separation.
What could break the story
Dupixent replacement risk
High impact · Medium oddsDupixent is Sanofi’s core growth engine today. That is good while demand rises, but it creates a future cliff risk when exclusivity fades. The pipeline has to produce enough large products before that point.
Pipeline execution setbacks
High impact · Medium oddsSanofi needs its research engine to deliver. The failure of tolebrutinib in PPMS shows that not every important study will work. Mixed or failed late-stage data would make the post-Dupixent plan less convincing.
Regeneron reimbursement rolloff
Medium impact · High oddsSanofi expects the end of Regeneron development reimbursements to hurt business operating income. The headwind is now projected at EUR 400 million in 2026 and about EUR 700 million in 2027. That can pressure margin even if sales keep growing.
Beyfortus adoption confusion
Medium impact · Medium oddsBeyfortus is a strong launch, but U.S. childhood vaccine rule changes could confuse the market. If doctors, payers, or parents slow decisions, near-term uptake may fall short of expectations. This matters because Beyfortus is one of the key new launch stories.
Policy and tax pressure
Medium impact · Medium oddsSanofi faces several outside pressures. The U.S. Inflation Reduction Act can affect drug pricing, tariffs could affect imported medicines, and France has passed tax changes that raise the local burden. Each item may be manageable alone, but together they can limit upside.
In one breath
What is Sanofi best known for?
Sanofi is best known for Dupixent, vaccines, and specialty medicines. Dupixent is the main driver today, with EUR 15.7 billion in 2025 sales.
Why did Sanofi sell Opella?
Sanofi sold control of Opella to focus on biopharma and vaccines. The deal brought in EUR 10.4 billion, which management says it has redeployed into deals and pipeline building.
Is Sanofi only a vaccines company?
No. Vaccines are important, with EUR 7.9 billion in 2025 sales, but most sales come from biopharma. Dupixent and other prescription medicines are the larger part of the company.
What is the biggest risk for Sanofi stock?
The biggest risk is that the pipeline does not grow fast enough to offset a future Dupixent slowdown. Investors should also watch margin pressure from the Regeneron reimbursement rolloff.