A feasibility study of the efficacy and tolerability of the combination of Exemestane with the COX-2 inhibitor Celecoxib in post-menopausal patients with advanced breast cancer

Background This was a feasibility study of the combination of Exemestane and the cyclooxygenase-2 (COX-2) inhibitor Celecoxib in advanced breast cancer. Patients and methods Post-menopausal women with histologically proven, hormone receptor positive, advanced breast cancer who had progressive disease, normal blood counts, liver and renal function were eligible. Exemestane was given at a dose of 25 mg daily and Celecoxib at a dose of 400 mg bd. Responses were assessed according to RECIST criteria and toxicity was accessed according to CTC. The primary end-point was the percentage of patients who had neither discontinued therapy nor progressed at 6 months (‘treatment successes’). Results Fifty-three eligible patients were enrolled. Of 30 patients with target lesions, 4 (13%) had a complete response (CR), 12 (40%) a partial response (PR) and 5 (17%) stable disease (SD). The best response in 18 of the 23 patients with no target lesions at baseline was stable disease. The clinical benefit (CR, PR + SD) for the whole group was therefore 39/53 (74%). The ‘treatment success’ rate was 60%. There were two non-malignant deaths which may have been associated with treatment. Conclusion The combination of Exemestane and Celecoxib shows promising activity and tolerability and these results support the use of this combination in phase III clinical trials of short duration treatments.