28 March 2031
Extended Dupixent US patent expires
Sanofi plans to defend exclusivity beyond this date. Biosimilars are in early development.
When does Dupixent go off patent?
In the US, biosimilars can launch from 2031. Dupixent is sold by Sanofi and Regeneron. Extended US patent runs to 28 March 2031. Sanofi plans to defend exclusivity beyond that.
Dupixent's US exclusivity date is based on company guidance. The date comes from the company's own filings or guidance. Secondary patents, new formulations or litigation can still move it. It is a biologic, so copies are biosimilars. Biosimilars are harder to make and usually erode sales more gradually than generics.
| Patent or protection | Covers | Expiry |
|---|---|---|
| US compound patent (with term extension) | Dupilumab itself | March 2031 |
| US regulatory exclusivity | FDA 12-year biologic exclusivity | March 2029 |
| Later-filed US patents | Uses and other inventions (pending) | To 2045 |
| EU compound patent (with SPC) | Dupilumab itself (Europe) | September 2032 |
The US compound patent, extended for regulatory delay, runs to March 2031, two years after the 12-year biologic exclusivity ends. Sanofi says later-filed patents could extend coverage as far as April 2045 if granted, and plans to defend exclusivity beyond 2031. In Europe the compound protection runs to September 2032, or March 2033 with a pediatric extension, and in Japan to May 2034. Regeneron shares profits and separately reports its share.
Sources: Sanofi 20-F 2025
| Year | Worldwide | US | Growth |
|---|---|---|---|
| 2023 | €10.71B | €8.14B | – |
| 2024 | €13.07B | €9.54B | +22% |
| 2025 | €15.71B | €11.54B | +20% |
Worldwide net sales as reported, with the US share, in EUR as the company reports them, so growth is not distorted by exchange rates. Source: Sanofi 20-F 2025 (Sanofi-booked sales)
In clinical trials Biosimilars are in early development. Chong Kun Dang has approval to start a first trial in Europe and the UK, and Samsung Bioepis added the drug to its pipeline in January 2026.
| Company (product) | Stage |
|---|---|
| Chong Kun Dang | In clinical trials. Phase 1 approved in the EU and UK (Jan 2026) |
| Samsung Bioepis | Early development |
| CSPC | In clinical trials. Clinical trials approved in China |
Checked October 2026. Sources: Pearce IP: Chong Kun Dang · Pearce IP: Samsung Bioepis pipeline
Among past biologics facing biosimilars, US sales in the first full year after copies arrived were a median 65% of the last full year before (range 34% to 93%, 7 drugs), and 27% by the third year (9 drugs). Biosimilars usually take share more gradually than generics. Every drug is different: settlements, how many copies launch, and pricing all change the curve. See the erosion benchmarks →
| Scenario | 2025 US sales | Year 1 (about 2032) | Year 2 | Year 3 |
|---|---|---|---|---|
| Fastest past case | €11.5B | €3.92B34% | €1.23B11% | €0.49B4% |
| Median | €11.5B | €7.54B65% | €4.43B38% | €3.07B27% |
| Slowest past case | €11.5B | €10.8B93% | €8.73B76% | €7.34B64% |
An illustration, not a forecast: it applies the past-cliff benchmarks to Dupixent's 2025 US sales, held flat until copies arrive in 2031. Year 1 is the first full year with copies on sale.
Dupixent is 36% of Sanofi's 2025 revenue (≈$17.8B of $49.3B). Total net sales €43.6B. Sanofi books Dupixent's global sales.
Dupixent is 37% of Regeneron's 2025 revenue ($5.2B of $14.3B). Dupixent is Regeneron's Sanofi collaboration revenue ($5.2B), mostly its share of Dupixent profits.
Bars show each company's tracked drugs as a share of its total 2025 revenue. Dupixent is highlighted.
Sanofi plans to defend exclusivity beyond this date. Biosimilars are in early development.