The goal of this study is to study the safety and tolerability of a novel combination of medications in relapsed or refractory AML: tagraxofusp and gemtuzumab ozogamicin. If the combination is found to be safe, then further studies will be done to determine whether this combination is effective for AML.~The first part of this study is called phase 1A. This part of the study is done to determine the optimal dose of tagraxofusp that can be given with gemtuzumab. The main purpose of phase 1A is to test different doses of the study drug, starting with the lowest dose and determining the optimal dose.~In phase 1B (the second part of the study), this dose will be given along with gemtuzumab to a larger group of patients to further test the safety and tolerability of this combination. The results of phase IB will also be used to determine whether the combination of tagraxofusp, when given at the optimal dose, and gemtuzumab are effective in treating AML. Substances (biomarkers) found in the blood and bone marrow will be drawn from patients in the course of this study to better understand whether the combination is effective against AML.
This is an open-label Phase Ia/Ib clinical study of tagraxofusp-erzs, a novel cytokine-drug conjugate that links interleukin-3 with a truncated diphtheria toxin, in combination with gemtuzumab ozogamicin for patients with relapsed/refractory AML.~The primary objective of the study is to determine the recommended phase 2 dose (RP2D) of tagraxofusp-erzs in combination with gemtuzumab ozogamicin in this patient population. Then, once RP2D is determined, to determine the safety and tolerability of combination gemtuzumab and tagraxofusp-erzs when administered at the RP2D.