Decitabine versus hydroxyurea in advanced chronic myelomonocytic leukemia shows survival differences linked to baseline counts.

This randomized controlled trial (RCT) evaluated 120 patients with advanced proliferative chronic myelomonocytic leukemia (CMML). The study compared decitabine against hydroxyurea as the comparator intervention. Follow-up duration was 35.1 months. The primary outcome assessed overall survival, while secondary outcomes included the hazard of death and persistence of monocytes > 1 × 10/L, WBC > 10 × 10/L, or bone marrow blast excess.

Median overall survival from landmark analysis was 35.1 months in patients with cMo ≤ 0.94 ×10/L AND iGRAN ≤ 0.40 ×10/L versus 15.3 months in others. This difference had a p-value of 0.013. The hazard of death increased with persistence of monocytes > 1 × 10/L or WBC > 10 × 10/L after 6 cycles, with a hazard ratio of 5.38 (p = 0.0003). Higher absolute cMo and iGRAN counts independently predicted poorer overall survival. The effect size for the specific comparison of decitabine versus hydroxyurea was not reported for the landmark survival analysis.

Safety data regarding adverse events, serious adverse events, discontinuations, and tolerability were not reported in the provided evidence. A key limitation noted is that whether mitigation of myeloproliferation improves prognosis of CMML independently of bone marrow response is unknown. The study suggests that biomarkers integrating blood counts and flow cytometry may predict CMML prognosis irrespective of treatment. Practice relevance is restrained by the uncertainty regarding whether the observed survival differences are driven by the intervention or baseline prognostic factors.