Adverse Events. (A-B) Distribution of all grades of the most common toxicities considered at least possibly related to the drug administration; (A) Arm B, 4 mg and (B) Arm C, 5.5 mg. (C-D) Incidence of hematological toxicity across individual cycles, highlighting lack of any cumulative hematological toxicity; (C) Arm B, 4 mg and (D) Arm C, 5.5 mg.