2031, date not disclosed
Kesimpta expected to lose US exclusivity
Company guidance. Novartis 20-F: US compound patent 2031 (already expired in Europe). Multiple sclerosis; sales grew 37% in 2025.
When does Kesimpta go off patent?
In the US, biosimilars can launch from 2031. Kesimpta is sold by Novartis. Novartis 20-F: US compound patent 2031 (already expired in Europe). Multiple sclerosis; sales grew 37% in 2025.
Kesimpta'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 |
|---|---|---|
| Key US patent | Kesimpta, per Novartis | 2031 |
| FDA biologic exclusivity | Listed under Arzerra's 2009 licence for the same antibody | None listed |
| Europe compound patent | Ofatumumab | Expired |
Novartis lists 2031 as the US expiry of Kesimpta's key patent; in Europe the compound patent has already expired. Kesimpta uses the same antibody as Arzerra, a leukemia drug first approved in 2009, and is listed under the same FDA licence, so its US protection rests on patents. Alvotech is developing a biosimilar, licensed to Advanz for Europe; we found no US filing. Sales grew 37% in 2025.
Sources: Novartis 20-F 2025 · FDA Purple Book
| Year | Worldwide | US | Growth |
|---|---|---|---|
| 2021 | $0.37B | – | – |
| 2022 | $1.09B | $0.92B | +194% |
| 2023 | $2.17B | $1.53B | +99% |
| 2024 | $3.22B | $2.18B | +49% |
| 2025 | $4.43B | $2.94B | +37% |
Novartis did not report a US figure for 2021. Worldwide net sales as reported, with the US share. Sources: Novartis 20-F 2025 · Novartis 20-F 2023 · Novartis 20-F 2022
Early development Alvotech is developing a Kesimpta biosimilar, licensed to Advanz for Europe in 2025. We found no US filing.
| Company (product) | Stage |
|---|---|
| Alvotech | Early development. Europe partner: Advanz |
Checked October 2026. Sources: Pearce IP: Alvotech and Advanz
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 | $2.94B | $1.00B34% | $0.31B11% | $0.13B4% |
| Median | $2.94B | $1.92B65% | $1.13B38% | $0.78B27% |
| Slowest past case | $2.94B | $2.75B93% | $2.23B76% | $1.87B64% |
An illustration, not a forecast: it applies the past-cliff benchmarks to Kesimpta's 2025 US sales, held flat until copies arrive in 2031. Year 1 is the first full year with copies on sale.
Kesimpta is 8.1% of Novartis's 2025 revenue ($4.4B of $54.5B). With Entresto, Xolair, Cosentyx and Kisqali, the drugs tracked here add up to 46% of Novartis's revenue losing US exclusivity by 2031.
Bars show each company's tracked drugs as a share of its total 2025 revenue. Kesimpta is highlighted.
Company guidance. Novartis 20-F: US compound patent 2031 (already expired in Europe). Multiple sclerosis; sales grew 37% in 2025.