Background: In several phase II and III topotecan studies the large number of patients with stable disease is striking. Since no severe organ toxicity has been described for topotecan, long-term therapy with topotecan seems to be reasonable. In this summary we present evidence, that long-term topotecan therapy can be managed without cumulative hematological and non-hematological toxicity.
Patients and methods: Thirty-three patients with recurrent ovarian cancer, who were treated with at least 7 courses of topotecan, were evaluated in this retrospective study (patient database from SmithKline Beecham, Germany). Most of the patients had more than 2 previous courses of chemotherapy. The starting dose was between 1.0 and 1.5 mg/m2 topotecan administered for 5 days every 3 weeks as an i.v. infusion. All patients were evaluated for toxicity, 32 patients for response.
Results: The 33 patients received 343 courses of topotecan, an average of more than 10 courses per patient. The highest number of courses given to a single patient was 33. The hematotoxicity was in the expected range, but toxicity was not cumulative. The number of interventions for growth factors and blood cell transfusions were constant over the whole therapy. Dose reductions were conducted in more than 75% of the patients as early as in course two. There was no grade 3 or 4 non-hematological toxicity. Alopecia was the only toxicity to be cumulative. Remissions were observed in 12 out of 32 eligible patients. The remissions were achieved after an average of 4.3 courses (range 2-7). The median time to progression was 33 weeks.
Conclusion: Long-term therapy with topotecan is reasonable and can be conducted without cumulative hematological toxicity.