Phase II study of fulvestrant 250 mg/month in patients with recurrent or metastatic endometrial cancer: a study of the Arbeitsgemeinschaft Gynäkologische Onkologie.

Abstract Objectives The aim of this study is to evaluate the activity and toxicity of fulvestrant, a pure estrogen receptor antagonist in patients with advanced or recurrent endometrial cancer, expressing estrogen and/or progesterone receptors (ER/PR). Methods Eligible patients with advanced or recurrent endometrial cancer not amenable to curative surgery and/or radiotherapy were treated with fulvestrant at a dose of 250mg by IM injection every 4weeks for at least 12weeks. Therapy was continued until disease progression, death, intolerable side effects or end of study. Response was assessed in patients with at least one target lesion according to WHO-criteria. Results Thirty-five patients were enrolled in this study and received at least one injection of fulvestrant (intention to treat-population, ITT). Twenty six patients received the intended 3 injections of fulvestrant (per protocol population, PP). There was no complete response but 4 partial responses (11.4% ITT) and 8 stable diseases. The median time to progression was 2.3months (ITT). Overall survival was 13.2months (ITT). Treatment was well tolerated. Conclusions Fulvestrant at a dose of 250mg IM every 4weeks has marginal activity and good tolerability in patients with ER and/or PR positive advanced or recurrent endometrial cancer. A loading dose strategy and the use of 500mg/4weeks might improve the efficacy of this treatment.