Predicting outcome of patients with MDS after failure of AZA: validation of the North American MDS consortium scoring system

The advent of Hypomethylating Agents (HMAs) has changed the management of Myelodysplastic Syndrome (MDS) in recent years. The HMAs azacitidine (AZA) and decitabine are commonly used as disease-modifying treatment for MDS.

These drugs have produced favorable hematological responses with regards to delaying the onset of Acute Myeloid Leukemia (AML) and improving Overall Survival (OS). Nevertheless, these effects are temporary and are not curative. Worse still, there is a great deal of variation in the results with AZA in terms of improving OS and patients’ prognoses become poor if they fail with AZA. Thomas Prebet et al. from the Le Groupe Francophone des Myélodysplasies (GFM) report that the OS could fall between a median 3.4 months for secondary AML and 5.6 months for higher-risk MDS in this scenario.

Prebet et al. conducted a retrospective analysis of 223 MDS patients who had undergone at least one cycle of AZA treatment in order to ascertain the factors that could affect patient outcomes after treatment failure with HMA therapy. This study was published in Haematologica in October 2016.

As part of the analysis, the investigators compared their findings with those of the North American MDS consortium which were published by Nazha et al. in Haematologica in June 2016.

According to this publication, Nazha et al. state the following factors could affect the outcomes in MDS after failure with HMA therapy:

• Age
• ECOG PS
• Bone marrow blast counts
• Cytogenetics
• Platelet counts
• RBC transfusion-dependency

In the analyses by Prebet et al., the key variables affecting patient outcome were age and cytogenetics, as well as the type of treatment employed after the AZA failure.

In addition to the identification of the variables affecting patient outcomes, the authors attempted to validate the scoring system created by the North American MDS consortium. According to the North American MDS consortium, a score below 2.5 equates to a low-risk group and patients with such a score have a median OS of 11 months. High-risk patients have scores of 2.5 and above which correlates to a median OS of 4.5 months.

The results of the analysis by Prebet et al. were consistent with the North American MDS consortium’s scoring system:

• The median OS was 13 months for patients with a low-risk score
• The median OS for patients with a high-risk score was 5 months (P<0.001).

In summary, the investigators concluded that this scoring system was suitable for ascertaining patients’ outcomes after failure with AZA.