Clinical Trial

Disease: Acute Myeloid Leukemia, AML, (NCT05662904)

Disease info:

Leukaemia is cancer of the white blood cells. White blood cells help your body to fight infection. Blood cells form in the bone marrow. In leukaemia, the bone marrow produces abnormal white blood cells, which outnumber healthy blood cells, thus compromising the function of blood. In acute myeloid leukaemia (AML), there are too many of a specific type of white blood cell called a myeloblast.

AML is the most common type of acute leukaemia in adults. This type of cancer usually gets advances quickly if it is not treated. 

The estimated number of new cases of acute myeloid leukaemia is 4.3 per 100,000 men and women per year. The estimated number of deaths is 2.8 per 100,000 men and women per year. These rates are age-adjusted and based on 2012-2016 cases and deaths.
Official title:
Genetic Ablation of CD33 in Hematopoietic Stem Cells to Broaden the Therapeutic Index of CD33-directed Immunotherapy in Patients With Acute Myeloid Leukemia (AML)

Principal Investigator: Tim Sauer, Dr. med., University Hospital Heidelberg 


German Cancer Research Center


University Hospital Heidelberg

University Hospital Dresden


Dresden, Germany

Heidelberg, Germany

Study start:
Dec. 1, 2022
Gene editing method:
Type of edit:
Gene knock-out
Delivery method:
Not disclosed - Ex-vivo
Safety updates:


IND Enabling Pre-clinical
Phase I Safety
Phase II Safety and Dosing
Phase III Safety and Efficacy

Status: Not yet recruiting


CRISPR/Cas9-mediated inactivation of CD33 in hematopoietic stem cells (HSC) may broaden the therapeutic index of CD33-directed immunotherapy for patients with AML by rendering healthy hematopoietic stem and progenitor cells (HSPC) resistant to escalating doses and/or shorter dosing intervals of the CD33-specific antibody-drug conjugate (ADC) Gemtuzumab-ozogamicin (GO).

In this proof of concept trial, we will develop a platform for genome editing of CD34+ HSC and demonstrate the feasibility, safety and efficacy of this approach for targeted therapy of AML.

Upon implementation, the platform shall be used for innovative clinical trials in diverse types of cancer. Outside of leukemias, autologous HSC could be used to ease the procedure.

Patients with relapsed AML after allogeneic hematopoietic stem cell transplantation will be transplanted with CD33-deleted CD34+ HSC derived from the initially matched family donor.

Upon HSC engraftment, patients will be treated with escalating doses of the anti-CD33 antibodydrug conjugate Gemtuzumab-Ozogamicin (GO). A conditioning regimen containing GO (d-14, d-11, d-8),Fludarabine 30 mg/m2 (d-6 to d-3) and Melphalan 140mg/m2 (d-2) is used prior to transplantation.

The clinical trial will be conducted at two trial sites in the University Hospitals in Heidelberg and Dresden.

25 patients will be assessed for eligibility and 12 patients will be allocated into the trial.

Last updated: Jun. 5, 2023
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