Last reviewed · How we verify
ARIMIDEX (anastrazole)
ARIMIDEX (anastrazole) is a Aromatase inhibitor Small molecule drug developed by AstraZeneca. It is currently in Phase 3 development for Hormone receptor-positive early-stage breast cancer in postmenopausal women (adjuvant therapy), Metastatic hormone receptor-positive breast cancer in postmenopausal women, Extended adjuvant therapy following tamoxifen in postmenopausal women with early-stage breast cancer.
Anastrozole is a non-steroidal aromatase inhibitor that blocks the conversion of androgens to estrogen in postmenopausal women.
Anastrazole, also known as Arimidex, is a small molecule inhibitor of the cytochrome P450 19A1 enzyme, specifically targeting aromatase. It is used to treat conditions such as early-stage breast carcinoma, hormone receptor positive tumor, and breast cancer, particularly in patients with hormone receptor positive tumors.
-
Baseline phase 3 → approval rate
+58.3pp
Industry-wide phase 3 drugs reach approval ~58.3% of the time (BIO/Informa 2023 industry benchmark across all therapeutic areas). -
Oncology Phase 3 boost
+3.0pp
Oncology Phase 3 trials have higher approval rates (~61%) than the cross-industry average due to clearer endpoints and FDA oncology pathway. -
Big-pharma sponsor
+3.0pp
AstraZeneca is a top-20 pharma sponsor — historical approval rates run ~3pp above average due to scale, regulatory experience, and trial-design quality.
| Regulator | Country | Likely year | Lag vs FDA |
|---|---|---|---|
| FDA | US | 2028–2030 | — |
| EMA | EU | 2029–2031 | +0.7 yr |
| MHRA | GB | 2029–2031 | +0.7 yr |
| Health Canada | CA | 2029–2032 | +0.9 yr |
| TGA | AU | 2029–2032 | +1.2 yr |
| PMDA | JP | 2029–2032 | +1.5 yr |
| NMPA | CN | 2030–2033 | +2.3 yr |
| MFDS | KR | 2029–2032 | +1.4 yr |
| CDSCO | IN | 2029–2033 | +1.8 yr |
| ANVISA | BR | 2030–2033 | +2.3 yr |
Hover any row for the lag rationale. Lag estimates are reduced when the drug has FDA Breakthrough or EMA PRIME designation (sponsors file globally in parallel).
Estimate based on the BIO/Informa industry phase transition rates plus per-drug modifiers for therapeutic area, sponsor type, FDA designations, mechanism, and trial design. Per-jurisdiction lags from Tufts CSDD international approval studies. Not investment, clinical or regulatory advice. Methodology: /methodology#likelihood.
At a glance
| Generic name | ARIMIDEX (anastrazole) |
|---|---|
| Sponsor | AstraZeneca |
| Drug class | Aromatase inhibitor |
| Target | Aromatase (CYP19A1) |
| Modality | Small molecule |
| Therapeutic area | Oncology |
| Phase | Phase 3 |
Mechanism of action
Anastrozole selectively inhibits the aromatase enzyme, which catalyzes the final step of estrogen synthesis in peripheral tissues. By reducing circulating estrogen levels, it suppresses estrogen-dependent growth of hormone receptor-positive breast cancer cells. This mechanism is particularly effective in postmenopausal women where peripheral aromatization is the primary source of estrogen.
Approved indications
- Hormone receptor-positive early-stage breast cancer in postmenopausal women (adjuvant therapy)
- Metastatic hormone receptor-positive breast cancer in postmenopausal women
- Extended adjuvant therapy following tamoxifen in postmenopausal women with early-stage breast cancer
Common side effects
- Hot flashes
- Arthralgia/joint pain
- Fatigue
- Headache
- Vaginal dryness
- Osteoporosis/bone loss
- Elevated cholesterol
Key clinical trials
- A Study of Elacestrant Versus Standard Endocrine Therapy in Women and Men With ER+,HER2-, Early Breast Cancer With High Risk of Recurrence (PHASE3)
- Testing Whether Hormone Therapy With Ribociclib is as Effective as Chemotherapy Followed by Hormone Therapy With Ribociclib for the Treatment of High Anatomic Stage Breast Cancer With Low Recurrence Risk, The RxFINE-Low Trial (PHASE3)
- Hormone Therapy With or Without Combination Chemotherapy in Treating Women Who Have Undergone Surgery for Node-Negative Breast Cancer (The TAILORx Trial) (PHASE3)
- A Study of LOXO-783 in Patients With Breast Cancer/Other Solid Tumors (PHASE1)
- Tamoxifen Citrate, Letrozole, Anastrozole, or Exemestane With or Without Chemotherapy in Treating Patients With Invasive RxPONDER Breast Cancer (PHASE3)
- Ribociclib And Endocrine Treatment of Physician's Choice for Locoregional Recurrent, Resected Hormone Receptor Positive HER2 Negative Breast Cancer (PHASE2)
- A Study of Tersolisib (LY4064809/STX-478) With Other Anti-Cancer Treatments in Participants With Advanced Breast Cancer With a Genetic Change (PIK3CA) (PHASE3)
- A Study of the Impact of Endocrine Therapy on Surgical Outcomes in People With Breast Cancer (PHASE2)
Primary sources
Every claim on this page is sourced from regulatory or scientific primary sources. See our editorial policy for full methodology.
| Source | Used for |
|---|---|
| ClinicalTrials.gov | Trial enrolment, design, endpoints, results |
Competitive intelligence
For the full competitive landscape — auto-detected comparators, recent regulatory actions across the set, upcoming PDUFA, patent timeline, sponsor landscape:
- ARIMIDEX (anastrazole) CI brief — competitive landscape report
- ARIMIDEX (anastrazole) updates RSS · CI watch RSS
- AstraZeneca portfolio CI
Frequently asked questions about ARIMIDEX (anastrazole)
What is ARIMIDEX (anastrazole)?
How does ARIMIDEX (anastrazole) work?
What is ARIMIDEX (anastrazole) used for?
Who makes ARIMIDEX (anastrazole)?
What drug class is ARIMIDEX (anastrazole) in?
What development phase is ARIMIDEX (anastrazole) in?
What are the side effects of ARIMIDEX (anastrazole)?
What does ARIMIDEX (anastrazole) target?
Related
- Drug class: All Aromatase inhibitor drugs
- Target: All drugs targeting Aromatase (CYP19A1)
- Manufacturer: AstraZeneca — full pipeline
- Therapeutic area: All drugs in Oncology
- Indication: Drugs for Hormone receptor-positive early-stage breast cancer in postmenopausal women (adjuvant therapy)
- Indication: Drugs for Metastatic hormone receptor-positive breast cancer in postmenopausal women
- Indication: Drugs for Extended adjuvant therapy following tamoxifen in postmenopausal women with early-stage breast cancer
Primary sources · FDA · ClinicalTrials.gov · EMA · SEC EDGAR · ChEMBL · Wikidata · full sourcing