"This study means that doctors have another option in treating women with metastatic breast cancer," said William Gradishar, MD, professor of medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois. "In particular, the once-a-month dosing may be helpful in patients for whom compliance with prescriptions has been an issue."

The study -- Evaluation of Faslodex versus Exemestane Clinical Trial (EFECT) -- represents the first phase 3 clinical trial of this treatment in this patient population, Dr. Gradishar said.

For the EFFECT study, Dr. Gradishar and colleagues enrolled 693 patients who had disease progression after taking a nonsteroidal aromatase inhibitor. Of these patients, 351 were randomly assigned to receive fulvestrant intramuscular injections at a 500-mg loading dose on day 1 and then at 250 mg on day 14 and on day 28; thereafter, these patients received 250 mg monthly. The 342 women randomized to oral exemestane received 25 mg once daily.

The therapy was continued until disease progression or death.

Time to disease progression, the primary endpoint of the study, was 3.7 months in both arms of the study (P = .65), Dr. Gradishar said in his plenary oral presentation on December 15^th.

Objective responses were seen in 7.4% of patients on fulvestrant and 6.75 of patients on exemestane (P = .7364), but clinical benefit -- the combination of response plus stable disease for at least 24 weeks -- was achieved by 32.2% of patients on fulvestrant compared with 31.5% of the patients on exemestane (P = .8534).

The median duration of clinical benefit was 9.3 months for patients on fulvestrant and 8.3 months for patients taking exemestane, Dr. Gradishar said.

Duration of clinical benefit was determined through a retrospective analysis of the data, and as such, a statistical value was not estimated.

"Both regimens were well tolerated," Dr. Gradishar said. About 2% of patients on fulvestrant and 2.6% of patients on exemestane withdrew from the trial due to adverse events. About 1.1% and 0.6% of patients in each group, respectively, experienced a drug-related serious event. No patient in either arm died due to drug-related serious events.

"The fulvestrant loading dose offers an effective and well-tolerated treatment option for postmenopausal women with advanced breast cancer who have progressed or recurred on nonsteroidal aromatase inhibitor therapy," he said.

"This study confirmed the efficacy of fulvestrant in patients who have progressed on a nonsteroidal aromatase inhibitor," he said.


[Presentation title: Fulvestrant Versus Exemestane Following Prior Non-Steroidal Aromatase Inhibitor Therapy: First Results From EFECT, A Randomized, Phase III Trial in Postmenopausal Women With Advanced Breast Cancer. Abstract 12]

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