The U.S. Food and Drug Administration has approved Faslodex (fulvestrant) as a first-line treatment for patients with hormone-receptor positive (HR+), human epidermal growth factor receptor 2 negative (HER2-) advanced breast cancer, therapy developer AstraZeneca announced.
The approval, which is for postmenopausal women who have not received prior endocrine therapy, was based on positive results from the Phase 3 FALCON trial (NCT01602380).
“We’re pleased that the landmark FALCON trial results demonstrated the efficacy of Faslodex as initial monotherapy treatment for women who are living with HR+, HER2- advanced breast cancer,” Jamie Freedman, AstraZeneca’s executive vice president and head of the Oncology Business Unit, said in a press release. “This approval, building on more than 15 years of clinical experience, means more patients can have the opportunity to receive Faslodex earlier in the treatment journey.”
The randomized, double-blind, multicenter FALCON study included 462 postmenopausal women with HR+, HER2– metastatic or locally advanced breast cancer. Participants were randomized to receive either intramuscular Faslodex or Arimidex (anastrozole), which is the current standard of care.
In the study, patients taking Faslodex experienced a median of 16.6 months until disease progression compared with 13.8 months in the Arimidex group. This represented a 20% reduction in the risk of disease progression or death compared with the standard treatment.
The most common side effects reported with Faslodex were joint pain, hot flashes, fatigue, and nausea.
“This study provides evidence that using fulvestrant as the first option for previously untreated hormone receptor-positive advanced breast cancer will prolong the time before the disease advances and alternative therapies are required,” said Matthew Ellis, MD, PhD, director of the Lester and Sue Smith Breast Center, part of the NCI-designated Dan L. Duncan Comprehensive Cancer Center at Baylor College of Medicine.
Faslodex is an estrogen receptor (ER) antagonist that binds to the receptor and targets it for destruction. In a certain type of breast cancer, called hormone-receptor positive, estrogen can promote the progression of cancer. Faslodex inhibits the growth of cancer cells by blocking the effects of estrogen. Contrary to selective estrogen receptor modulators (SERM) like tamoxifen, Faslodex blocks the ER on all tissues, not only the breast.
Faslodex has been approved by the FDA since 2002 for the treatment of HR+ advanced breast cancer in postmenopausal women who failed anti-estrogen therapy such as tamoxifen. It is also approved in combination with Ibrance (palbociclib), a cyclin-dependent kinase (CDK) inhibitor, for HR+, HER2– breast cancer in women who failed endocrine therapy. With the new approval, Faslodex can now be used as a first-line therapy for advanced HR+, HER2– breast cancer.