Five-Day Azacitidine Regimen Shows Superior Survival Outcomes in Lower-Risk MDS Patients
核心洞察
A decade-long multicenter trial of 247 patients demonstrated that five-day azacitidine significantly improved event-free survival and overall survival compared to three-day azacitidine or decitabine regimens in lower-risk myelodysplastic syndrome.
The five-day azacitidine regimen achieved overall response rates of 48% in transfusion-dependent patients and 70% in transfusion-independent patients while maintaining a favorable safety profile without increased toxicity.
These findings establish five-day azacitidine as the optimal shorter-duration hypomethylating agent regimen for lower-risk MDS (搜索), offering improved outcomes with reduced side effects compared to traditional seven-day protocols.
Patients with lower-risk myelodysplastic syndromes (搜索) experienced significantly improved survival outcomes when treated with a five-day azacitidine regimen compared to shorter three-day courses of azacitidine or decitabine, according to final results from a decade-long multicenter trial presented at the 67th American Society of Hematology Annual Meeting.
The study, led by researchers at The University of Texas MD Anderson Cancer Center, enrolled 247 patients across multiple centers to compare three different shortened hypomethylating agent regimens: three-day decitabine, three-day azacitidine, and five-day azacitidine. The trial addressed a critical clinical need, as traditional seven-day azacitidine and five-day decitabine regimens approved for higher-risk MDS (搜索) often cause excessive myelosuppression in lower-risk patients.
Superior Survival Outcomes Across Patient Groups
The five-day azacitidine regimen demonstrated the most consistent survival benefits across both transfusion-dependent and transfusion-independent patient populations. Among the 151 transfusion-dependent patients, five-day azacitidine significantly improved event-free survival compared to three-day azacitidine (HR = 0.41; 95% CI, 0.19-0.9) and showed superior overall survival compared to three-day decitabine (HR = 0.46; 95% CI, 0.26-0.82).
In the 96 transfusion-independent patients, the survival advantages were even more pronounced. Five-day azacitidine significantly improved event-free survival compared to both three-day azacitidine (HR = 0.25; 95% CI, 0.09-0.71) and three-day decitabine (HR = 0.28; 95% CI, 0.1-0.77). Overall survival was also significantly better compared to three-day decitabine (HR = 0.13; 95% CI, 0.04-0.45).
"For patients with lower-risk MDS (搜索), a five-day duration of azacitidine was safe and effective, showing improved event-free survival and overall survival compared to three-day durations of azacitidine or decitabine," said Ian Bouligny, M.D., assistant professor of Leukemia at MD Anderson and lead investigator. "We've seen firsthand how this approach improves outcomes and enhances the overall treatment experience for our patients in clinic."
Strong Response Rates with Favorable Safety Profile
The five-day azacitidine regimen achieved overall response rates of 48% in transfusion-dependent patients and 70% in transfusion-independent patients. Among transfusion-independent patients, the five-day regimen showed numerically superior response rates compared to three-day azacitidine (54%) and three-day decitabine (50%).
Response duration analysis revealed that transfusion-independent patients treated with five-day azacitidine maintained responses for a median of 28.9 months, compared to 15.3 months for three-day azacitidine (P = .05). Many patients were able to avoid blood or platelet transfusions after treatment without excess toxicity.
Safety analysis showed that grade 3 or worse thrombocytopenia occurred significantly more frequently in patients receiving decitabine (45%) compared to three-day azacitidine (27%; P = .04), and numerically more often than in those receiving five-day azacitidine (31%). Investigators observed no increased toxicity with the five-day regimen compared to the shorter alternatives.
Implications for Clinical Practice
The findings address substantial variability in clinical practice regarding optimal dosing and duration of hypomethylating agents for lower-risk MDS (搜索). Prior to recent approvals of luspatercept-aamt and imetelstat, clinicians commonly used shortened hypomethylating agent regimens, but without standardized protocols.
"Five-day azacitidine produced the most consistent survival benefit, and in my view, this makes sense because we're giving a higher dose of an effective drug," Bouligny explained. The results were particularly notable given that some investigators had anticipated stronger performance from the decitabine arm based on previous studies suggesting higher response rates with three-day decitabine compared to three-day azacitidine.
The study's use of event-free survival as the primary endpoint represents an important methodological advance, as many previous clinical trials for lower-risk MDS (搜索) focused primarily on transfusion independence. By demonstrating that five-day azacitidine significantly improves survival and alters the natural course of lower-risk MDS, the investigators showed how these drugs can change the disease's natural history.
Future Directions and Oral Formulations
Researchers are currently investigating an oral formulation of azacitidine-cedazuridine (搜索), which could provide additional convenience for patients. "We are excited to identify the optimal azacitidine dosing schedule in lower-risk MDS (搜索)," Bouligny noted. "We are eager to see how these results translate to improved outcomes with a convenient oral formulation for our patients with lower-risk MDS in the near future."
The study results will help inform optimal doses and durations of azacitidine-cedazuridine (搜索) in lower-risk MDS (搜索) and could serve as a starting point for future combination strategies. However, questions remain about how five-day azacitidine compares with newer therapies such as luspatercept-aamt or imetelstat, which would help determine optimal sequencing of these agents in clinical practice.