Patients were allowed a maximum of 2 cycles at each dose level of to achieve a response. Patients who achieved a CR or CRi during the first 2 cycles were eligible for extension treatment every 3 weeks at a dose of 5 or 10 µg/kg. Although formal MTD was never exceeded at the doses tested, planned dose levels between 80 μg/kg and 250 μg/kg were never tested.