Letrozole
As of the edition of 20 October 2026, Letrozole is a small molecule: marketed, first approved in 1996 (FR); acts on CYP19A1; US protection ends in 2031.
Sources: FDA Orange Book and Purple Book, other approval registers, ClinicalTrials.gov, ChEMBL.
The drug
- Status
- Marketed; latest approval 2006
- Kind
- Small molecule
- Brand name
- Femara
- First approved
- 24 July 1996 (FR)
- Approvals on record
- 10 in 7 regions
- Holder of the most recent approval
- Novartis; 5 holders in all
- Registered trials
- 536, 67 stopped early
- Disease areas
- Cancer; Skin and connective tissue; Urinary and reproductive; Pregnancy and women's health; Hormones; Nutrition and metabolism
US protection
US protection ends in 2031.
The last listed US drug-substance patent ends in 2031. The application that gives this date is held by Novartis.
This is the US only, and it is not the date generics or biosimilars can enter.
The exact date and the listings behind it
In the product8 listings count towards this date. The exact date and each listing are in the product.
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Companies that need a new molecule because of this drug
1 company on route B because of this drug.
Companies on route B for this drug
In the product1 company is on route B because of Letrozole.
See the 1 company on route B for this drug, with the facts behind eachRequest access. Nothing is shown until you do.
Target
| Gene | Protein | UniProt |
|---|---|---|
| CYP19A1 | Aromatase | P11511 |
Registered trials
| Phase | Trials | Completed | Active | Stopped early |
|---|---|---|---|---|
| Phase not stated | 71 | 36 | 13 | 2 |
| Phase 1 | 62 | 34 | 12 | 13 |
| Phase 2 | 234 | 101 | 73 | 29 |
| Phase 3 | 118 | 55 | 33 | 12 |
| Phase 4 | 51 | 22 | 7 | 11 |
| All trials | 536 |
Who has held its approvals
| Company | Role | Years |
|---|---|---|
| Novartis | Applicant and Lead sponsor of trials | 1997 to now |