Lintuzumab-Ac225 in Older Acute Myeloid Leukemia (AML) Patients

Low dose cytarabine administered at 20 mg subcutaneously every 12 hours for the first 10 days (Days 1 to 10) of every cycle. Cycle 1 can last up to 52 days (depending on the schedule of study drug dosing) in order to allow for recovery from Lintuzumab-Ac225. Cycles 2-12 will last 28 days each.

In Phase 1 the starting dose level was 1.0 μCi/Kg of Lintuzumab-Ac225 and 15 μg/Kg unlabeled HuM195 divided into 2 equal fractionated doses (0.5 μCi/Kg and 7.5 μg /Kg + 0.5 μCi/Kg and 7.5 μg /Kg) with the first fraction administered approximately 4-7 days after 1 cycle of low dose cytarabine and the second fraction administered 4-7 days after the first fraction, followed by up to 11 more cycles. In Phase 2 the dose will be 4.0 μCi/Kg Lintuzumab-Ac225 and 25 μg/Kg unlabeled HuM195 divided into 2 equal fractions with the first fraction given on Day 1 and the second fraction given on Day 5-8.

40 mg by mouth daily one day prior to treatment with Lintuzumab-Ac225 and continuing for 10 days following administration of the 2nd divided dose.

25 mg by mouth daily, administered 10 days after second dose of 225Ac-HuM195 and continued for 12 months.