Abstract
Background: EPO continues to be a primary therapeutic choice for the treatment of anemic patients with low to intermediate-1 risk MDS. Initially, without standardized response criteria, ER rates were modest. Recently, a meta-analysis of EPO monotherapy studies in MDS demonstrated a significant improvement in ER rates with the application of standardized International Working Group criteria (IWGc) for response evaluation (Moyo V et al. 2006 ASCO Annual Meeting Proceedings Part I. Vol 24, No. 18S (June 20 Supplement), 2006: 6572). This meta-analysis was expanded to determine the impact of higher doses of EPO or the addition of granulocyte or granulocyte-macrophage colony stimulating factor (G- or GM-CSF) to EPO on ER rates (defined as major + minor response).
Methods: A systematic review and data extraction of studies from PubMed, ASCO and ASH proceedings from 1990–2006 in MDS patients treated with EPO monotherapy or EPO + G-/GM-CSF combination therapy was performed. Pooled estimates of ER rates were calculated in studies defining ER rates without IWGc application (non-IWGc) for EPO monotherapy at Standard (std) dose (30,000–40,000 Units per week) in comparison to studies that defined ER rates using IWGc, where EPO was used at std dose or high dose (60,000–80,000 Units per week) or in combination with G-/GM-CSF.
Results: A total of 23 studies were evaluated in this analysis. As shown in the table below the IWGc studies using EPO at std dose or high dose or in combination with G-/GM-CSF demonstrated significantly higher ER rates than the non-IWGc studies (p<0.001 for all comparisons). Among the IWGc studies, those using a higher dose of EPO alone had significantly higher ER rates as compared to studies using std dose EPO monotherapy (p<0.001) or EPO + G-/GM-CSF combination (p=0.018). In addition, among the studies using EPO combinations, those using EPO + G-CSF (Total studies-3, evaluable N= 96) showed ER rates of 55.2% as compared to 42.8% (p=0.142) for the EPO + GM-CSF combination (Total studies-3, evaluable N= 56).
Conclusions: The findings from this present meta-analysis confirm the impact of IWGc on ER rates for EPO therapy previously observed. Further improvement in ER rates was observed with the use of higher doses of EPO alone or the combination of EPO + G-/GM-CSF. Increasing the EPO dose appeared to have a greater impact on ER than the addition of G-/GM-CSF.
| . | Non-IWGc . | . | IWGc . | . |
|---|---|---|---|---|
| Study Group | EPO Std Dose | EPO Std Dose | EPO High dose | EPO + G-/GM-CSF |
| Starting EPO Dose Units/week | 30,000–40,000 | 30,000–40,000 | 60,000–80,000 | 30,000–40,000 |
| No. of Studies | 8 | 5 | 4 | 6 |
| No.of Evaluable Patients | 262 | 393 | 196 | 152 |
| ER Rates (%)(95% CI) | 32.1 (26–38) | 47.8 (43–53) | 63.3 (57–70) | 50.7 (42–59) |
| . | Non-IWGc . | . | IWGc . | . |
|---|---|---|---|---|
| Study Group | EPO Std Dose | EPO Std Dose | EPO High dose | EPO + G-/GM-CSF |
| Starting EPO Dose Units/week | 30,000–40,000 | 30,000–40,000 | 60,000–80,000 | 30,000–40,000 |
| No. of Studies | 8 | 5 | 4 | 6 |
| No.of Evaluable Patients | 262 | 393 | 196 | 152 |
| ER Rates (%)(95% CI) | 32.1 (26–38) | 47.8 (43–53) | 63.3 (57–70) | 50.7 (42–59) |
Disclosures: This abstract discusses the use of epoetin alfa in myelodysplastic syndromes, which is not currently not a labeled use of epoetin alfa.; Victor Moyo, Behin Yektashenas, and Suneel Mundle are full-time employees of Ortho Biotech Clinical Affairs, LLC.; Patrick Lefebvre and Ahmed Bourezak are paid consultants of Ortho Biotech Clinical Affairs, LLC.; Victor Moyo, Behin Yektashenas, and Suneel Mundle own stock in Johnson and Johnson.
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