DLTs are defined as the following occurring in Cycle 1 for which a causal relationship with study drug cannot be ruled out: febrile neutropenia, Grade 4 neutropenia persisting for more than 7 days, or neutropenia requiring hematopoietic stimulating agents, Grade 4 thrombocytopenia, or thrombocytopenia requiring platelet transfusion, Grade 4 anemia, or anemia requiring blood transfusion, Grade 3 non-hematological toxicity (except abnormal clinical laboratory values of no clinical significance, any events which can be managed and controlled to Grade 2 or less by maximal medical management, infusion reactions of Grade 3 or higher are NOT considered DLTs because they are stochastic and idiosyncratic events, not related to dose), Grade 4 non-hematological toxicity, and/or when the second treatment with farletuzumab ecteribulin is postponed more than 14 days from the scheduled day due to toxicity. DLTs will be determined by discussion between the investigator, sponsor, and medical expert.