EORTC 10941: A phase II study of liarozole in postmenopausal patients with'Chemotherapy-Resistant' or 'Potentially Hormone Sensitive' metastatic breast cancer

Liarozole is an imidazole compound that inhibits enzymes involved in steroi d hormone aromatisation and retinoid metabolism. The IDBBC branch of the EO RTC has performed a series of phase II studies of the agent in four groups of postmenopausal women with metastatic breast cancer. This paper reports t he results of the first two groups: 'Chemotherapy Resistant' (unrestricted ER status, 1 or 2 prior chemotherapy regimens, 0-2 prior hormonal therapies ) and 'Potentially Hormone Sensitive' (ER positive or unknown, 1 or 2 prior hormonal therapies with a substantial disease free interval or progression free survival, and no history of chemotherapy for metastatic disease). Lia rozole was administered at 150-300 mg orally bid. The objective response ra te was 12% in the 'Chemotherapy Resistant' group (n=34), and 22% in the 'Po tentially Hormone Sensitive' group (n=37), with median response durations o f 9 and 14 months, respectively. Median time to treatment failure was only 2 months in both groups, due largely to the significant percentage (24%) of patients who ceased treatment following excessive mucocutaneous and gastro intestinal toxicity. This adverse event profile will limit its use in breas t cancer. Results of the 'ER negative' and 'Tamoxifen Refractory' groups wi ll be reported in a future paper.