The overall outcomes of patients with lower-risk myelodysplastic syndrome (MDS) was similar with either a 5- or 7-day dosing schedule of azacitidine, according to a phase 2 study published in the journal Cancer.

Although 7-day uninterrupted dosing of azacitidine is used for patients with lower-risk MDS, its efficacy and safety compared with 5-day dosing has been confirmed. The aim of this study was to compare the 5- and 7-day dosing schedules for the treatment of patients with lower-risk MDS.

The multicenter, phase 2 trial randomly assigned 55 patients with low or intermediate-1 risk MDS as determined by the International Prognostic Scoring System (IPSS) to receive either 5- or 7-day dosing of azacitidine. The study was stopped early due to low accrual rate. The primary endpoint was overall response rate (ORR) and secondary endpoints included cytogenic response rate (CyR) and safety.

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At baseline, the median age was 59 and 49% of patients were female. The majority of patients had an intermediate-1 risk score by IPSS. The IPSS-revised score assigned 3.6% of patients as very low risk, 34.5% as low, 40.0% as intermediate, 20.0% as high, and 1.8% as very high. There were 60% of patients with an abnormal karyotype, and most patients had a good or intermediate cytogenetic risk. There were 14.5% of patients who had previously received an erythropoiesis-stimulating agent.

There was no significant difference in ORR between arms, with rates of 48.0% and 39.3% with the 5- or 7-day dosing schedule, respectively. There were 35.3% of patients who achieved red blood cell transfusion independence with the 5-day schedule compared with 40.0% with the 7-day schedule.

CyR was significantly higher with the 7-day schedule at 53.8% compared with 8.3% with the 5-day schedule (P =.027). Overall survival was similar between the groups.

The overall rate of adverse events (AEs) was also similar between the arms, but there were a greater number of grade 3 or higher events of thrombocytopenia and febrile neutropenia with the 7-day schedule.

The authors concluded that “the 5-day azacitidine in lower-risk MDS showed comparable efficacy to a 7-day regimen in terms of similar overall response and other outcomes, despite significantly higher rates of CyR in the 7-day regimen.”

Disclosures: This study was supported by Celgene, now part of Bristol-Myers Squibb. Please see the original reference for a full list of disclosures.


Park S, Park SY, Le J-H, et al. Five‐day versus 7‐day treatment regimen with azacitidine in lower risk myelodysplastic syndrome: A phase 2, multicenter, randomized trial. Cancer. Published online October 8, 2022. doi: