September 2027
Lynparza US compound patent expires
None of the four generic filers challenges this patent, so this is the earliest the FDA can approve them.
When does Lynparza go off patent?
In the US, generics can launch from 2027. Lynparza is sold by AstraZeneca and Merck. Merck 10-K: US basic patent 2027. AstraZeneca and Merck have sued generic filers since 2023. Sales as reported by AstraZeneca; Merck books $1.5B of alliance revenue.
Lynparza'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 small-molecule drug, so copies are generics. Generic launches usually take most of the US volume within months.
| Patent or protection | Covers | Expiry |
|---|---|---|
| US 7,449,464 | Olaparib itself and the drug product | 8 September 2027 |
| Tablet and formulation patents | The drug product | 31 December 2029 |
| Later use patents | Methods of treatment | 25 October 2041 |
| Europe | Key patents, per AstraZeneca | 2027 to 2029 |
| Japan and China | Key patents, per AstraZeneca | 2029 |
Lynparza's compound patent runs to September 2027, and none of the four generic filers challenges it, so that is the earliest the FDA can give final approval. Tablet patents run to 2029 and use patents to 2041. Natco won tentative approval in July 2026, AstraZeneca settled with Sandoz in April 2026, and the cases against Natco, Cipla and Zydus have no trial date yet. Outside the US, key patents run to 2027 to 2029 in Europe and 2029 in Japan and China.
Sources: FDA Orange Book data files · AstraZeneca 20-F 2025 · Merck 10-K 2025
| Year | AstraZeneca (Merck books its alliance share separately) | US | Growth |
|---|---|---|---|
| 2021 | $2.35B | $1.09B | – |
| 2022 | $2.64B | $1.23B | +12% |
| 2023 | $2.81B | $1.25B | +7% |
| 2024 | $3.07B | $1.33B | +9% |
| 2025 | $3.28B | $1.43B | +7% |
Net sales as reported, with the US share. Sources: AstraZeneca 20-F 2025 · AstraZeneca 20-F 2023
Tentatively approved Four generic makers have filed. None challenges the compound patent, which expires in September 2027, so that is the earliest the FDA can give final approval. Natco won tentative approval in July 2026. AstraZeneca settled with Sandoz in April 2026; the cases against Natco, Cipla and Zydus have no trial date yet.
| Company (product) | Stage |
|---|---|
| Natco / Alembic | Tentatively approved Jul 2026; in litigation |
| Sandoz | Filed with the FDA; settled Apr 2026, terms confidential |
| Cipla | Filed with the FDA; in litigation, sued Jul 2026. Second filing sued Jul 2026 |
| Zydus | Filed with the FDA; in litigation |
Checked October 2026. Sources: Merck 10-Q, Q2 2026 · AstraZeneca H1 2026 (6-K) · Natco: tentative approval
Among past small-molecule drugs facing unrestricted generics, US sales in the first full year after copies arrived were a median 18% of the last full year before (range 0% to 48%, 10 drugs), and 6% by the third year (8 drugs). Where settlements limit generic volumes, as with Revlimid, the decline is slower. 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 2028) | Year 2 | Year 3 |
|---|---|---|---|---|
| Fastest past case | $1.43B | $0.00B0% | $0.00B0% | $0.01B1% |
| Median | $1.43B | $0.26B18% | $0.10B7% | $0.08B6% |
| Slowest past case | $1.43B | $0.69B48% | $0.35B25% | $0.25B17% |
An illustration, not a forecast: it applies the past-cliff benchmarks to Lynparza's 2025 US sales, held flat until copies arrive in 2027. Year 1 is the first full year with copies on sale.
Lynparza is 5.6% of AstraZeneca's 2025 revenue ($3.3B of $58.7B). With Farxiga, Imfinzi, Tagrisso, Calquence and Ultomiris, the drugs tracked here add up to 57% of AstraZeneca's revenue losing US exclusivity by 2035.
Lynparza is 2.2% of Merck's 2025 revenue ($1.4B of $65.0B). With Januvia, Keytruda and Gardasil, the drugs tracked here add up to 63% of Merck's revenue losing US exclusivity by 2028.
Bars show each company's tracked drugs as a share of its total 2025 revenue. Lynparza is highlighted.
None of the four generic filers challenges this patent, so this is the earliest the FDA can approve them.