IL-15 Super Agonist ALT-803 to Treat Relapse Of Hematologic Malignancy After Allogeneic SCT

This is a multi-center, phase I/II clinical trial for patients who have relapsed more than 60 day after allogeneic transplant for a hematologic malignancy. The study consists of two phases. The dose finding phase is a modified version of a phase I trial and the extended phase is a modified version of a phase II trial. The primary objective of the dose finding phase is to determine the maximum tolerated, minimum efficacious dose (MTD/MED) of a interleukin-15 (IL-15) super agonist complex (ALT-803) when given once weekly for 4 weeks in the outpatient setting. The study will follow a standard 3+3 design of dose escalation for toxicity with an added feature of stopping early if efficacy is confirmed. There are six dose levels of ALT-803 for to determine the MTD/MED: 1, 3, 6, 10, 20, and 30 mcg/kg. Once the MTD/MED for ALT-803 is determined, this cohort will be used in the extended phase. The primary goal of this extended phase is to study the potential efficacy of ALT-803 in this patient population. Efficacy will be measured using rates of remission induction. An optimal Simon's two-stage design will be used in this phase. Stage 1 will enroll 14 patients (including the 6 patients treated at the MTD/MED during the dose finding phase). If 3 or more of these 14 patients respond to ALT-803, the trial will move to stage 2 and enroll an additional 23 patients. If 2 or fewer respond, the study will terminate enrollment early.