Updated Phase III Survival Data for Faslodex (Fulvestrant) in Breast Cancer
Overall survival not significantly different between 500-mg and 250-mg doses (Dec. 5)
Updated overall survival (OS) results for Faslodex (fulvestrant, AstraZeneca) in patients with hormone receptor-positive advanced breast cancer whose disease progressed or recurred following prior endocrine therapy have been reported at the 35th CTRC–AACR San Antonio Breast Cancer Symposium.
The new data — from the phase III CONFIRM (COmparisoN of Faslodex In Recurrent or Metastatic Breast Cancer) trial — showed a 19% relative reduction in the risk of death (hazard ratio [HR]: 0.81). No adjustments were made for multiplicity; therefore, these findings cannot be considered statistically significant. The median OS for Faslodex 500 mg and 250 mg was 26.4 months and 22.3 months, respectively.
Faslodex 500 mg increased progression-free survival (PFS; the study’s primary endpoint), with a relative risk reduction of 20% (HR: 0.80; P = 0.006) compared with Faslodex 250 mg. Median PFS with Faslodex 500 mg was 6.5 months compared with 5.5 months with the 250-mg dose.
Faslodex 500 mg is indicated for the treatment of hormone receptor-positive metastatic breast cancer in postmenopausal women with disease progression following antiestrogen therapy.
The CONFIRM trial was a phase III, randomized, double-blind, parallel-group, multicenter study that compared Faslodex 500 mg (n = 362) with Faslodex 250 mg (n = 374) in postmenopausal women with estrogen receptor-positive advanced breast cancer whose disease progressed or recurred following prior endocrine therapy. Eligible patients were randomly assigned to receive Faslodex 500 mg or 250 mg and were assessed for tumor progression every 12 weeks. The primary objective was to compare the efficacy of the two treatment groups in terms of PFS.
The initial survival analysis conducted after a minimum follow-up of 18 months showed no statistically significant difference in OS (HR = 0.84; P = 0.091). The median OS was 25.1 months with Faslodex 500 mg and 22.8 months with Faslodex 250 mg. The updated OS analysis, conducted after a minimum follow-up of 50 months, showed a 19% relative reduction in the risk of death (HR: 0.81). These data were considered to be non-significant. The Kaplan-Meier estimate showed a median survival period of 26.4 months versus 22.3 months for the 500-mg and 250-mg doses, respectively.
Metastatic breast cancer occurs when cancer cells spread beyond the initial tumor site to other parts of the breast or body; it is the most advanced stage of breast cancer (stage four). Metastatic breast cancer may be diagnosed as a distant recurrence after treatment of early breast cancer or as a progression of earlier-stage disease. There is no cure for metastatic breast cancer; the goal of treatment is to delay disease progression.
Source: AstraZeneca; December 5, 2012.