- six sequential doses established in the absence of limiting toxicity, as follows: 7.5 - 8.0 - 8.5 - 9.0 - 9.5 - 10.0 mg/m2. Steps 9.5 mg / m² and 10 mg / m will be discussed after approval by an independent committee in charge of the studyContinuation of Topotecan at conventional dose can be done thanks to clinical data based on efficacy and tolerance