Phase II trial of goserelin and exemestane combination therapy in premenopausal women with locally advanced or metastatic breast cancer

A promising option as the treatment of choice for premenopausal patients with locally advanced or metastatic breast cancer (MBC) could be the combination of a luteinizing hormone-releasing hormone analog and an aromatase inhibitor. However, no prospective studies on the efficacy of goserelin with exemestane in locally advanced or MBC premenopausal breast cancer patients have been reported. We present the phase II trial of goserelin plus exemestane in a total of 44 premenopausal women with locally advanced or MBC. All patients received a subcutaneous injection of 3.6mg goserelin every 4 weeks along with 25mg exemestane daily. The primary end point was progression-free survival (PFS). The second end point included overall survival (OS), objective response rate (ORR), duration of response (DOR), and clinical benefit rate (CBR) based on complete response (CR), partial response (PR), or stable disease (SD) for ≥6 months. The median PFS was 13 months (range: 2-42 months). The median DOR was 8 months (range: 2-40 months). Two patients achieved CR (4.5%), and 15 patients experienced PR (34.1%). Fifteen patients (34.1%) had SD ≥6 months. The ORR was 38.6%, and the CBR was 65.9%. Primary progressive disease occurred in 15 patients (34.1%). Five patients (11.4%) died during the study period. Because a few patients have died, the median OS has not been reached. Drug therapy was well tolerated. The most frequent grade-3 adverse events were arthralgia (18.2%), skin rash (6.8%), and myalgia (4.5%). No participants withdrew from the study due to drug toxicity. This study suggested that goserelin and exemestane might be highly effective and well-tolerated regimens in premenopausal women with hormone-responsive, locally advanced or MBC.