Antibody drug gives new hope to children who relapse from blood cancer

April 22, 2013

Researchers at Children's Cancer Institute have shown that a new antibody-based drug has the potential to improve the survival rate for children who relapse from one of the most common types of paediatric blood cancers: acute lymphoblastic leukaemia.

Currently, the survival rate for children who have this disease is more than 80 per cent. However, if a child relapses this rate can drop to less than 20 per cent.

Professor Richard Lock, Head of the Leukaemia Biology Program at Children’s Cancer Institute has co-authored a study that was funded by the National Cancer Institute (USA) through the Pediatric Preclinical Testing Program (PPTP). The findings were recently published in the prestigious journal Clinical Cancer Research, and there are plans in place to trial the drug both in Australia and internationally by the end of 2013.

“Antibodies and antibodies with drugs attached to them are being used increasingly for cancer treatment,” says Professor Lock. “SAR3419 is an anti-CD19 antibody with a drug linked to it that targets a protein present on the surface of almost all acute lymphoblastic leukaemia cells, but not on the cells that replenish our normal complement of blood cells. SAR3419, developed by Sanofi, is already in clinical trials for the treatment of adult cancer. However, in our experiments using a laboratory model of paediatric acute lymphoblastic leukaemia, we found that SAR3419 combined with a three-drug regimen of standard drugs, has the potential to prevent children from relapsing with the disease.

“The combination we used specifically targeted the leukaemia cells when tested on aggressive or drug-resistant acute lymphoblastic leukaemia,” explains Professor Lock. “It significantly delayed disease dissemination and progression into the major organs and prevented leukaemia relapse in those organs.

“What is so exciting about this drug is that it has the potential to not only improve the survival rate of children who have relapsed, but since it acts as a ‘magic bullet’, it only targets the cancer cells, leaving the healthy cells untouched.”

Dr David Ziegler, paediatric oncologist with the Sydney Children’s Hospital and Balnaves Foundation Young Researcher’s Fund recipient, whose specific research interest is in the translation of novel targeted therapeutics from the laboratory to the bedside, is currently working with Children’s Cancer Institute in developing a clinical trial for this new drug.

“These results are so exciting that we are working as quickly as possible to make sure we can take this discovery from the laboratory and make it directly available for children with leukaemia who need more effective treatments,” says Dr Ziegler. “Our patients and their parents can’t afford to wait years to have new treatments developed. We plan to start a clinical trial of this new therapy for children with leukaemia by the end of this year.”