ASH 2015

Promising new strategy for treating children with acute lymphocytic leukaemia

Dr Elizabeth Raetz - University of Utah, Salt Lake City, USA

Now you’ve been looking at a classification system, you’ve been looking at genes and something else, response rate, in children with ALL. What were you doing here, in fact?

This is a study that was conducted a while ago, so it was conducted from 2003 to 2011, so now we’re analysing the data. We had a protocol that was designed to classify each child newly diagnosed with leukaemia into a certain risk group that we would then use to determine what would be the best intensity of their treatment.

So what were you looking at, in fact?

We looked at known cytogenetic markers that we knew to be prognostically significant. We had a battery of those and then we also looked at, for the first time in one of our protocols that we acted on, minimal residual disease response as well as their morphological response during induction treatment.

So you were looking at the way the kids were responding, you were also looking at their genetic patterns.

The features.

What did you find?

It was interesting. So we found if we looked at our two risk groups of patients, standard risk based on age and white count, and high risk based on age and white count, within that high risk population we found if they had favourable cytogenetics and they responded very rapidly in terms of their MRD at day 8 and day 29, that they really had outstanding outcomes. They had a five year event free survival of 94.9%.

So some of these children might otherwise have gone on to have chemotherapy, perhaps quite aggressive chemotherapy?

Right. They all received a traditional protocol for high risk ALL but what these findings help us with is we know in the future since that minor subgroup does better than the whole high risk group overall we don’t need to intensify their chemotherapy any further. They’re really doing quite well with the standard chemotherapy protocol so we hope that we can avoid any potential additive toxicities that further intensification might provide.

So what are your recommendations coming out of this to clinicians?

For clinicians it’s children have this combination, high risk patients have this combination of very good cytogenetic findings and good MRD responses, our recommendation is they continue on a traditional high risk treatment protocol and not have further intensification.

And a brief take-home message, then? What would you say that is?

To me this study suggests the power of systematically analysing a large number of children. We will learn then that there are novel biologic subtypes and we can learn that those patients can have their treatment recommendations refined in the future.