3. Participation in another clinical trial and any concurrent treatment with any investigational drug or anti-tumor therapy or radiotherapy within 21 days prior to randomization (or 28 days for those therapies with a schedule of administration every 4 weeks and except for nitrosoureas, mitomycin which may not be used up to 6 weeks prior to the first cycle provided that patients do not have residual signs of any toxicity). No wash-out is required for hormonotherapy which has to be discontinued before the first cycle.