Treatment of Acute Lymphoblastic Leukemia by Activation of Patient's Immune Cells by a Bispecific Antibody

MILAN, June 13, 2014 /PRNewswire/ --

Dr Nicola Gökbuget will explain also on behalf of Max Topp, the results of two abstracts that will be presented during the 19^th Congress of EHA about the treatment of ALL. 

Abstract S722 

Acute lymphoblastic leukemia  (ALL) is a rare type of blood cancer which is mainly treated by intensive chemotherapy. If the disease is resistant to initial treatment or reoccurs (relapse) the chance to survive is unfortunately very poor. Often the leukemia cells then become resistant to chemotherapy.

The bispecific antibody Blinatumomab was designed to connect with one side to a surface marker on the leukemia cells (CD19) and with the other side to attract T-cells of the patient. These T-cells kill the leukemia cells.

The treatment was given to patients with relapsed/refractory B-precursor ALL (r/r ALL) as a 4 week continuous infusion, followed by two weeks break and another four weeks of treatment. The goal was to achieve a complete remission (CR), which means that no leukemia cells are detected my microscopy in the bone marrow or at other sites of the body.

189 patients with r/r ALL in an unfavourable setting were treated. The CR rate was 43%.  In patients with prior stem cell transplantation the CR rate was 45%. The most frequent side effects were fever, headache and low white blood cell counts associated with fever.

Overall it was demonstrated that Blinatumomab as a single agent therapy was effective in r/r ALL including patients with resistance to prior treatment approaches.

Abstract S1314 

In acute lymphoblastic leukemia (ALL) response to therapy is usually measured by microscopic analysis of the bone marrow. The detection level for leukemic cells by this method is 5%. With molecular biologic tests the sensitivity is increased and 0.01% leukemia cells can be detected. This low level of leukemia cells is called minimal residual disease (MRD).

In a clinical trial with the bispecific antibody Blinatumomab (abstract 4572) 189 patients with relapsed/refractory (r/r) ALL were treated. 43% achieved a complete remission (CR), which means that no leukemia cells were detectable with microscopy. One explorative goal of the trial was the measurement of MRD in patients with CR. MRD evaluation was conducted in a central laboratory. With MRD detection it could be demonstrated that 82% of the patients with CR showed a low level of MRD (<0.01%) and 70% had no detectable MRD.

Patients with low MRD after first therapy usually have a higher chance to maintain complete remission. It will be analysed whether this is also relevant in r/r ALL and whether MRD detection allows to discriminate good risk patients better than conventional remission evaluation.

Presenter: Dr Nicola Gökbuget

Affiliation: Head of Study Center, University Hospital, Department of Medicine II, Frankfurt, Germany

Topic: Treatment of acute lymphoblastic leukemia by activation of patient's immune cells by a bispecific antibody.

Abstract S722 will be presented by Dr Max Topp on Saturday June 14, 2014, 16:15 - 16:30 at Room Brown 1+2 (SW - Level 2)

Abstract S1314 will be presented by Dr Nicola Gökbuget on Sunday June 15, 2014, 09:00 - 09:15 at Room Brown 1+2 (SW - Level 2)

About the EHA Annual Congress 

Hematology is a specialty that covers everything to do with blood: its origin in the bone marrow, diseases of blood and their treatments. The latest data on research and developments will be presented. The topics range from stem cell physiology and development, to leukemia, lymphoma, myeloma - diagnosis and treatment; red blood cells -, white blood cells- and platelet disorders; thrombosis and bleeding disorders.