Fulvestrant: A Further Treatment Option for Patients with Metastatic Uterine Cancer?

Fulvestrant for the treatment of endometrial cancer

INTRODUCTION

About one third of patients with endometrial cancer (EC) relapse and face a limited prognosis, if surgery or radiotherapy are not feasible. The remaining therapeutic options are chemotherapy and endocrine therapy.

AREAS COVERED

This review summarizes the development of the first selective estrogen receptor (ER) down-regulator fulvestrant. This article provides its mechanism of action, pharmacokinetics and the available preclinical and clinical data. Furthermore, this review provides an overview of the market of treatments for recurrent or metastatic EC (RMEC) while also taking into account studies of fulvestrant in metastatic breast cancer.

EXPERT OPINION

Even if fulvestrant showed only marginal activity in two phase II trials, it shouldn't be abandoned but instead further developed in EC. Firstly, the dose of fulvestrant used in these trials was too low from today's point of view. Secondly, the available literature on other endocrine agents is full of limitations and does not provide a gold standard. Furthermore, given the activity of mTOR inhibitors in EC, there may also be synergistic effects, given the cross-regulation of ER and the PI3K/AKT/mTOR pathway. The authors suggest that a prospective, phase II trial in ER positive RMEC would help to further explore the efficacy and tolerability of fulvestrant together with a mTOR inhibitor.

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

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 250 mg by IM injection every 4 weeks for at least 12 weeks. 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 2.3 months (ITT). Overall survival was 13.2 months (ITT). Treatment was well tolerated.

CONCLUSIONS

Fulvestrant at a dose of 250 mg IM every 4 weeks 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 500 mg/4 weeks might improve the efficacy of this treatment.