A new study published in the American Journal of Hematology has established a novel approach to assess treatment response in patients diagnosed with myelodysplastic syndromes (MDS), chronic myelomonocytic leukemia (CMML), or acute myeloid leukemia (AML).

The new response category, called peripheral blood complete remission (PB-CR), uses data from the differential blood count and clinical parameters. Hence, PB-CR not only combines the criteria for morphologic CR but also eliminates the need for bone marrow assessments.

The study’s findings revealed a significant enhancement in median overall survival for patients achieving PB-CR, with a duration of 22.8 months in comparison with 10.4 months for those who did not achieve PB-CR. The hazard ratio for overall survival was 0.366 (P <.0001).

“These data could change clinical practice and raise the current evidence level in future expert opinions and guidelines. We propose and anticipate the rapid and widespread adoption of PB-CR as a new response type in clinical practice, the incorporation of PB-CR as secondary endpoint in randomized clinical trials, the assessment of whether these findings hold true for other treatments, as well as the consideration of PB-CR in future response criteria,” the study’s authors said.

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Notably, even among the subset of patients who reached morphologic CR, those who additionally met the PB-CR criteria showed a median adjusted overall survival of 32.6 months compared with 21.7 months for those without PB-CR.

According to the study’s authors, the PB-CR criteria could be particularly relevant in cases where (1) a bone marrow evaluation is not conducted due to decisions made by the treating physician and/or the patient’s preference, (2) a bone marrow evaluation yields inconclusive results, and (3) additional information is needed alongside bone marrow evaluations.

Moreover, the use of the PB-CR criteria could serve as critical information for patients who may have previously been considered nonresponders and removed from therapy. Achieving PB-CR, with or without a bone marrow evaluation, and with or without achieving CR/CR with incomplete count recovery, identifies patients who have experienced a clinically meaningful response and should therefore continue treatment.

However, the study’s authors advised that the lack of achieving PB-CR should not be used to identify patients who no longer require or benefit from treatment.

The study enrolled 1,441 patients diagnosed with MDS, CMML, or AML included within the Austrian Myeloid Registry. The researchers used Cox proportional hazards models and a deep neural network to analyze the study cohort.


Pleyer L, Vaisband M, Drost M, et al. Cox proportional hazards deep neural network identifies peripheral blood complete remission to be at least equivalent to morphologic complete remission in predicting outcomes of patients treated with azacitidine—a prospective cohort study by the AGMT. Am J Hematol. Published online August 7, 2023. doi:10.1002/ajh.27046