Predictive factors of response and survival in myelodysplastic syndrome treated with erythropoietin and G-CSF: the GFM experience.

We analyzed prognostic factors of response, response duration, and possible impact on survival of epoetin alpha, epoetin beta, or darbepoetin alpha (DAR) with or without granulocyte colony-stimulating factor in 403 myelodysplastic syndrome (MDS) patients. Sixty-two percent (40% major and 22% minor) and 50% erythroid responses were seen, and median response duration was 20 and 24 months according to IWG 2000 and 2006 criteria, respectively. Significantly higher response rates were observed with less than 10% blasts, low and int-1 International Prognostic Scoring System (IPSS), red blood cell transfusion independence, serum EPO level less than 200 IU/L, and, with IWG 2006 criteria only, shorter interval between diagnosis and treatment. Significantly longer response duration was associated with major response (IWG 2000 criteria), IPSS low to INT-1, blasts less than 5%, and absence of multilineage dysplasia. Minor responses according to IWG 2000 were reclassified as "nonresponders" or "responders" according to IWG 2006 criteria. However, among those IWG 2000 minor responders, response duration did not differ between IWG 2006 responders and nonresponders. Multivariate adjusted comparisons of survival between our cohort and the untreated MDS cohort used to design IPSS showed similar rate of progression to acute myeloid leukemia in both cohorts, but significantly better overall survival in our cohort, suggesting that epoetin or DAR treatment may have a favorable survival impact in MDS.

High molecular response rate of polycythemia vera patients treated with pegylated interferon alpha-2a.

V617F JAK2 mutation is a reliable molecular marker of polycythemia vera (PV), potentially useful to monitor the effect of treatments in this disease. In a phase 2 study of pegylated (peg) IFN-alpha-2a in PV, we performed prospective sequential quantitative evaluation of the percentage of mutated JAK2 allele (%V617F) by real-time polymerase chain reaction (PCR). The %V617F decreased in 24 (89%) of 27 treated patients, from a mean of 49% to a mean of 27% (mean decrease of 44%; P < .001), and no evidence for a plateau was observed. In one patient, mutant JAK2 was no longer detectable after 12 months. In 3 patients homozygous for the mutation, reappearance of 50% of wild-type allele was observed during treatment. The results seem to confirm the hypothesis that IFN-alpha preferentially targets the malignant clone in PV and show that %V617F assessment using a quantitative method may provide the first tool to monitor minimal residual disease in PV. This trial was registered at www.clinicaltrials.gov as #NCT00241241.