m. More than four weeks must have elapsed since any prior systemic therapy at the time the time of randomization, and patients' toxicities must have recovered to a grade 1 or less (except for alopecia or vitiligo). Patients must have stable or progressing disease after prior treatment. Patients may have undergone minor surgical procedures within the past 3 weeks, as long as all toxicities have recovered to grade 1 or less or as specified in the eligibility criteria.