Higher Dose of Faslodex® More Effective for Advanced Breast Cancer

Among postmenopausal women with advanced, estrogen receptor-positive breast cancer that has progressed or recurred after prior hormonal therapy, a 500 mg dose of FaslodexR (fulvestrant) appears to be more effective than the originally approved 250 mg dose. These results were published in the Journal of Clinical Oncology. As a result of these findings, the 500 mg dose was recently approved by the U.S. Food and Drug Administration (FDA).

Each year roughly 200,000 U.S. women are diagnosed with breast cancer. Many of these breast cancers will be hormone receptor-positive, meaning that they are stimulated to grow by the circulating female hormones estrogen and/or progesterone. Treatment of hormone receptor-positive breast cancer often involves hormonal therapies that suppress or block the action of estrogen.

Faslodex—a type of hormonal therapy known as an estrogen receptor antagonist—blocks the actions of estrogen. It’s used for the treatment of metastatic, hormone receptor-positive breast cancer in postmenopausal women who experience cancer progression or recurrence after prior hormone therapy. Until recently, a standard dose of Faslodex was 250 mg.

In order to assess the effects of a higher dose of Faslodex, researchers conducted a Phase III clinical trial known as CONFIRM (Comparison of Faslodex in Recurrent or Metastatic breast cancer). The study compared the 250 mg dose of Faslodex to a 500 mg dose among 736 women in 17 countries.

Compared with the lower dose, the higher dose of Faslodex delayed cancer progression. Median time to cancer progression was 6.5 months among patients treated with the 500 mg dose and 5.5 months among patients treated with the 250 mg dose.After one year 34% of patients treated with the 500 mg dose were alive and free of cancer progression compared with 25% of patients treated with the 250 mg dose.No new safety concerns were identified with the 500 mg dose. The most common side effects included nausea, bone pain, back pain, and injection site pain.

The results of this study indicate that the 500 mg dose of Faslodex improves progression-free survival without increasing side effects. Based on these findings, the FDA approved the 500 mg dose for postmenopausal women with hormone receptor-positive, metastatic breast cancer that has progressed after antiestrogen therapy.

Reference: Di Leo A, Jerusalem G, Petruzelka L et al. Results of the CONFIRM Phase III trial compared fulvestrant 250 mg with fulvestrant 500 mg in postmenopausal women with estrogen receptor-positive advanced breast cancer. Journal of Clinical Oncology [early online publication]. September 20, 2010.

View the original article here

Arimidex and Faslodex Combined Show Promise in Metastatic Breast Cancer

The combination of anastrozole (ArimidexR) and fulvestrant (FaslodexR) prolonged overall survival and progression-free survival in postmenopausal women with previously untreated hormone receptor-positive metastatic breast cancer compared to Arimidex alone, according to the results of a study published in the New England Journal of Medicine. ?

Each year roughly 200,000 U.S. women are diagnosed with breast cancer. Many of these breast cancers are hormone receptor-positive, meaning that they are stimulated to grow by the circulating female hormones estrogen and/or progesterone. Treatment of hormone receptor-positive breast cancer often involves hormonal therapies that suppress or block the action of estrogen.?

Arimidex is a type of hormone therapy known as an aromatase inhibitor and works by suppressing the production of estrogen in postmenopausal women. Faslodex is a type of hormonal therapy known as an estrogen receptor antagonist and works by binding to estrogen receptors and degrading them. Both drugs are approved for the treatment of postmenopausal women with metastatic breast cancer. ?

To evaluate the drugs in combination, researchers conducted a trial involving 694 women who were randomly assigned to receive Arimidex alone or Arimidex and Faslodex combined. All women in the study had cancer that was hormone-receptor positive and none of them had been previously treated with chemotherapy, immunotherapy, or hormone therapy to stop the spread of disease. ?

The results indicated that the combination was superior to the single agent therapy. The median progression-free survival was 15 months in the combination group, compared to 13.5 months in the Arimidex alone group. Overall survival was also longer in the combination group—47.7 months compared to 41.3 months in the single agent group. Of note, not all patients assigned to anastrozole subsequently received fulvestrant.? Furthermore, another study looking at the combination of anastrozole and fulvestrant failed to show superiority over anastrozole alone.?

Both groups had mild to moderate side effects such as joint pain and hot flashes. Although the rate was higher in the combination group, it was not statistically significant. ?

The researchers concluded that the combination of Arimidex and Faslodex was superior to Arimidex alone for the treatment of hormone-receptor positive metastatic breast cancer—even though the dose of Faslodex was below the current standard dose. However, the results of this study have to be reconciled with the less favorable results from the other study that evaluated this combination. ?Many oncologists continue to believe that the optimal hormonal therapy approach for women newly diagnosed with metastatic breast cancer remains uncertain.?

Reference:?

Mehta RS, Barlow WE, Albain KS, et al. Combination anastrozole and fulvestrant in metastatic breast cancer. New England Journal of Medicine. 2012; 367:435-444.?

Posted August 6, 2012

View the original article here