Two medicines, side by side
Abiraterone vs letrozole
Abiraterone is labeled for prostate cancer; letrozole for breast cancer. Their labels share no use, so they are not alternatives to each other. Drugs@FDA records approvals of abiraterone since 2011 and of letrozole since 1997. Pharmacies paid $0.774 per abiraterone acetate 250 mg tablet and $0.145 per letrozole 2.5 mg tablet (NADAC, October 7, 2026); the strengths differ, so the two prices are not like for like. In FDA's classes, abiraterone is a cytochrome p450 17a1 inhibitor and letrozole an aromatase inhibitor.
Check it at the source: the abiraterone FDA label on DailyMed (effective March 28, 2025); the letrozole FDA label on DailyMed (effective June 11, 2026).
Highlights of the abiraterone record
Abiraterone (Zytiga) · label of March 28, 2025
Used for
From the label: indicationsZYTIGA is indicated in combination with prednisone for the treatment of patients with Metastatic castration-resistant prostate cancer (CRPC) Metastatic high-risk castration-sensitive prostate cancer (CSPC) ZYTIGA is a CYP17 inhibitor indicated in combination with prednisone for the treatment of patients with metastatic castration-resistant prostate cancer (CRPC). […]
On the market
- Earliest approval on file
- April 28, 2011
- Generic labelers
- 23 labelers
- Pharmacy cost
- $0.774 per tablet
Supply and safety
- Shortage
- No current entry
- Recalls
- 0
Highlights of the letrozole record
Letrozole (Femara) · label of June 11, 2026
Used for
From the label: indicationsFemara is an aromatase inhibitor indicated for: Adjuvant treatment of postmenopausal women with hormone receptor positive early breast cancer. ( 1.1 ) Extended adjuvant treatment of postmenopausal women with early breast cancer who have received prior standard adjuvant tamoxifen therapy. ( 1.2 ) First and second-line treatment of postmenopausal women with hormone receptor positive or unknown advanced breast cancer. […]
On the market
- Earliest approval on file
- July 25, 1997
- Generic labelers
- 19 labelers
- Pharmacy cost
- $0.145 per tablet
Supply and safety
- Shortage
- No current entry
- Recalls
- 1
Source: FDA drug labels via openFDA (Abiraterone label of March 28, 2025, Letrozole label of June 11, 2026); NDC Directory, Drugs@FDA, NADAC, FDA shortages and recalls (October 8, 2026)
How do abiraterone and letrozole differ on the record?
In FDA's classes, abiraterone is a cytochrome p450 17a1 inhibitor and letrozole an aromatase inhibitor.
How each works, in its label's words: Abiraterone, “Abiraterone acetate (ZYTIGA) is converted in vivo to abiraterone, an androgen biosynthesis inhibitor, that inhibits 17 α-hydroxylase/C17,20-lyase (CYP17).”; Letrozole, “The growth of some cancers of the breast is stimulated or maintained by estrogens.”
Half-life, in each label's words: Abiraterone, “Elimination In patients with metastatic CRPC, the mean terminal half-life of abiraterone in plasma (mean ± SD) is 12 ± …”; Letrozole, “Letrozole’s terminal elimination half-life is about 2 days and steady-state plasma concentration after daily 2.5 mg …”
Generics: abiraterone since 2018; letrozole since 2008 (Drugs@FDA).
| Abiraterone | Letrozole | |
|---|---|---|
| Labeled for | Prostate cancer | Breast cancer |
| Pharmacologic class | Cytochrome P450 17A1 Inhibitor | Aromatase Inhibitor |
| How it works (label) | Abiraterone acetate (ZYTIGA) is converted in vivo to abiraterone, an androgen biosynthesis inhibitor, that inhibits 17 α-hydroxylase/C17,20-lyase (CYP17). | The growth of some cancers of the breast is stimulated or maintained by estrogens. |
| Half-life (label) | Elimination In patients with metastatic CRPC, the mean terminal half-life of abiraterone in plasma (mean ± SD) is 12 ± 5 hours. | Letrozole’s terminal elimination half-life is about 2 days and steady-state plasma concentration after daily 2.5 mg dosing is reached in 2-6 weeks. |
| Earliest approval on file (Drugs@FDA) | April 28, 2011 | July 25, 1997 |
| First generic approved | October 31, 2018 | December 24, 2008 |
| Generic labelers (NDC) | 23 labelers | 19 labelers |
| Pharmacy cost (NADAC, each one's most listed form; strengths differ) | $0.774 per tablet (Abiraterone acetate 250 mg tablet) | $0.145 per tablet (Letrozole 2.5 mg tablet) |
| 12-month price change | -27% | +12% |
| Boxed warning | No | No |
| Shortage now | No current entry | No current entry |
| Recalls recorded | 0 | 1 |
| FAERS reports (a report is not proof of cause; counts follow how widely a medicine is used) | 40,909 | 61,238 |
| DEA schedule | none | none |
Source: Drugs@FDA, FDA NDC Directory, CMS NADAC of October 7, 2026, FDA shortages and recalls, FAERS via openFDA (FDA files October 8, 2026)
What next?
- Alternatives to abiraterone
- every medicine labeled for the same conditions