Phase 2
Completed N=297
A Study of Abiraterone Acetate Plus Prednisone With or Without Exemestane in Postmenopausal Women With Estrogen Receptor-Positive (ER+) Metastatic Breast Cancer Progressing After Letrozole or Anastrozole Therapy
Metastatic ER+ Her2- Breast Cancer · Postmenopausal
Source: ClinicalTrials.gov NCT01381874 ↗
Enrolled (actual)
297
Serious AEs
19.8%
Results posted
Jul 2018
Primary outcomePrimary: Progression-Free Survival (PFS) — 3.68; 3.65; 4.47 Months — p=0.437
Summary
The purpose of this study is to assess the safety and efficacy of oral abiraterone acetate plus oral prednisone and oral abiraterone acetate plus oral prednisone plus oral exemestane, each compared with oral exemestane alone, in postmenopausal women with estrogen receptor-positive (ER+) metastatic (spreading) breast cancer that has relapsed after treatment with letrozole or anastrozole.
Outcome Measures
| Outcome | Result | p-value |
|---|---|---|
| PRIMARY Progression-Free Survival (PFS) |
3.68; 3.65; 4.47 | 0.437 |
| PRIMARY Overall Survival (OS) |
NA; 26.41; NA | 0.807 |
| SECONDARY Overall Response Rate (ORR) |
6.3; 5.8; 12.1 | 1.000 |
| SECONDARY Clinical Benefit Rate |
12.7; 9.6; 22.7 | 0.603 |
| SECONDARY Duration of Response |
6.47; 4.86; 6.93 | — |
| SECONDARY Change From Baseline in Serum Endocrine Biomarkers (Estradiol and Estrone) at End of Treatment |
1.53; -3.35; -1.04; -34.20; -28.09; -30.60 | — |
| SECONDARY Change From Baseline in Serum Endocrine Biomarkers (Progesterone and Testosterone) at End of Treatment |
-4.80; 8.98; 12.34; -0.09; -0.51; -0.48 | — |
Eligibility Criteria
Inclusion Criteria
- Female patients must be postmenopausal
- ER+, Human epidermal growth factor receptor 2 (Her2) negative metastatic breast cancer
- Disease must have been sensitive to anastrozole or letrozole therapy prior to disease progression
- No more than two prior lines of therapy in the metastatic setting, of which no more than one was chemotherapy
- Eastern Cooperative Oncology Group (ECOG) performance status score of <=1
- Patients with disease confined only to bone may be included, but patients with purely sclerotic lesions may not participate in the study
Exclusion Criteria
- Prior treatment with exemestane, ketoconazole, aminoglutethimide, or a CYP17 inhibitor. Prior treatment with ketoconazole for <= 7 days is permitted and topical formulations of ketoconazole are permitted
- Potential patients must not have taken anastrozole, letrozole, fulvestrant, or any chemotherapy for at least 2 weeks (bevacizumab for at least 3 weeks) before randomization
- Anticancer immunotherapy or investigational agent within 4 weeks before randomization, or anticancer radiotherapy (except palliative) or anticancer endocrine therapy within 2 weeks before randomization
- Serious or uncontrolled nonmalignant disease, including active or uncontrolled infection
- Clinical or biochemical evidence of hyperaldosteronism or hypopituitarism
- Any condition that, in the opinion of the investigator, would compromise the well-being of the patient or that could prevent, limit, or confound the protocol-specified assessments
Data sourced from ClinicalTrials.gov (NCT01381874). Outcome figures and adverse-event rates are extracted automatically from the registry's posted results and are provided for clinician reference, not as a substitute for the primary publication. Informational only — not medical advice.