Fulvestrant or Exemestane After Adjuvant Therapy for Advanced Breast Cancer
Posted: Tuesday, November 23, 2021
Fulvestrant may improve clinical outcomes for patients with estrogen receptor–positive locally advanced or metastatic breast cancer who have previously been treated with adjuvant nonsteroidal aromatase inhibitors (NSAIs). In particular, fulvestrant increased progression-free survival and tripled the overall response rate compared with exemestane. These findings were presented by Jiayu Wang, MD, of the National Cancer Center, Cancer Hospital, Beijing, and colleagues during the European Society for Medical Oncology (ESMO) Congress 2021 (Abstract 235P) and published in the Annals of Oncology.
This randomized, open-label, multicenter, parallel-group study enrolled postmenopausal women with recurrent estrogen receptor–positive/HER2-negative metastatic or advanced breast cancer who had previously been treated for at least 2 years with NSAIs (n = 144). Patients were randomly assigned to receive either fulvestrant (500 mg on days 0, 14, and 28, then continuing every 28 days) or exemestane (25 mg daily).
Fulvestrant was found to increase progression-free survival for women treated with fulvestrant (8.5 months) compared with exemestane (5.6 months, P = .014). Additionally, the overall response rate appeared to be more than three times higher with fulvestrant (19.48%) than with exemestane (5.97%, P = .018). The time to treatment failure was also found to be increased in the fulvestrant group compared with the exemestane group (8.4 months vs. 5.5 months, respectively, P = .008). There were no differences found in adverse events between the groups. Patients with ESR1 mutations had similar responses to fulvestrant as to exemestane.
The study authors concluded: “Fulvestrant [at] 500 mg was associated with a statistically significant increase in progression-free survival compared with exemestane and was generally well tolerated. There were no significant differences in progression-free survival between the two groups irrespective of ESR1 status.”
Disclosure: The study authors reported no conflicts of interest.