According to a recent clinical trial, immunotherapy is a safe and effective treatment option for infants with leukaemia.

Children with an aggressive form of acute lymphoblastic leukaemia (ALL) have a significantly improved survival rate following immunotherapy with blinatumomab, which has increased from 66 per cent to 93 per cent. They experienced fewer treatment-related side effects as well.

Based on the findings, blinatumomab will now be the accepted worldwide standard of care for infants with this severe form of leukaemia.

The findings of the study were published in the New England Journal of Medicine, A specific flaw in the DNA of leukaemia cells is present in three babies diagnosed with acute lymphoblastic leukaemia (ALL) per year in the Netherlands.

This so-called KMT2A rearrangement leads to an aggressive form of ALL with a poor prognosis. The prognosis for these infants has not improved in recent decades despite intensifying chemotherapy.

Intensive chemotherapy works very well for half of the babies. But in the other half of the children, the disease returned within two years, or children died from the disease or sometimes from the side effects of the therapy. 90% of recurrences - when cancer comes back - occur during the two-year course of therapy.

Immunotherapy with the drug blinatumomab is already offered to some adults and older children with ALL. It was still unclear whether this treatment is also well tolerated and effective in babies.

Blinatumomab binds to leukaemia cells on one side and to immune cells on the other side. This connects the immune cells to the leukaemia cells and clears them up.

Researchers at the Princess Maxima Center for pediatric oncology in the Netherlands led an international clinical trial looking at the safety and effectiveness of blinatumomab in babies with ALL. Between 2018 and 2021, 30 children in 9 countries were treated with blinatumomab.

This was added to the existing chemotherapy treatment, the so-called Interfant-06 protocol. The team compared the outcomes with those of 214 children who had been treated in previous years with the Interfant-06 standard therapy: the same treatment, without blinatumomab.

The survival rate of babies who received one month of immunotherapy in addition to chemotherapy was significantly higher: 93% of them were still alive two years after diagnosis, compared with 66% of children who had only been treated with chemotherapy in the past.

This brings the survival of babies with a KMT2A rearrangement in their leukaemia cells to the level of the average survival of older children with this form of blood cancer.

Two years after diagnosis, 18% of babies treated with blinatumomab saw their cancer come back or died from their disease. This also indicates a strong improvement compared with babies treated within the Interfant-06 protocol, without immunotherapy. In that group, 51% had a recurrence or death during the two-year treatment with chemotherapy.

The results of the international clinical trial were published on April 26 in the prestigious New England Journal of Medicine. 

Dr. Inge van der Sluis, a paediatric oncologist and clinical pharmacologist at the Princess Maxima Center for pediatric oncology, led the clinical study. She said, 'It's fantastic to see that we have made such progress for babies with ALL: the addition of immunotherapy to chemotherapy leads to much better survival and fewer side effects.

We were already familiar with this immunotherapy from studies in other patient groups. This is the first time that we tested blinatumomab as a first-line treatment and for the first time in such young children.

"This was a small study, but with a clear enough result that all babies with this form of leukaemia are now receiving immunotherapy as part of standard treatment. We want to confirm the effect of blinatumomab in a larger study with more children. We also want to see whether babies benefit from two courses of blinatumomab and a reduction in chemotherapy, in order to improve their quality of life even further.'"