Phase II study of elliptinium acetate salvage treatment of advanced breast cancer

Elliptinium acetate (Celiptium) is an intercalating agent belonging to the ellipticine family. This agent has demonstrated clinical activity as salvage treatment in breast cancer using a weekly regimen. However, its clinical use was hampered by important toxicities such as xerostomia and immune-mediated haemolytic reactions due to development of anti-elliptinium IgM antibodies. We have studied 83 patients previously treated for metastatic breast cancer using elliptinium acetate with a different schedule: 80 mg/m2 daily for 3 consecutive days every 21 days. In 80 evaluable patients, an objective response (complete + partial response) was obtained in 5 of 30 patients with visceral metastases (13%), in 6 of 21 patients with soft tissue metastases (29%), and in 3 of 20 patients with mixed metastases (15%). The overall objective response rate was 14/80 (18%, 95% confidence interval = 10-26%). Moderate to severe xerostomia occurred in 10% of patients, while no anti-elliptinium antibodies or haemolytic reactions were detected using this schedule. No significant haematological toxicity, as usually reported with this drug, was observed. Elliptinium acetate has modest but definite activity as salvage treatment of breast cancer. The 3-week schedule seems as active as and less toxic than the weekly schedule.