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The risk and clinical significance of cardiac iron overload due to chronic transfusion varies with the underlying disease. Cardiac iron overload shortens the life expectancy of patients with thalassemia, whereas its effect is unclear in those with myelodysplastic syndromes (MDS). In patients with sickle cell anemia (SCA), iron does not seem to deposit quickly in the heart. Our primary objective was to assess through a multicentric study the prevalence of cardiac iron overload, defined as a cardiovascular magnetic resonance T2*<20 ms, in patients with thalassemia, SCA, or MDS. Patient inclusion criteria were an accurate record of erythrocyte concentrates (ECs) received, a transfusion history >8 ECs in the past year, and age older than 6 years. We included from 9 centers 20 patients with thalassemia, 41 with SCA, and 25 with MDS in 2012-2014. Erythrocytapharesis did not consistently prevent iron overload in patients with SCA. Cardiac iron overload was found in 3 (15%) patients with thalassemia, none with SCA, and 4 (16%) with MDS. The liver iron content (LIC) ranged from 10.4 to 15.2 mg/g dry weight, with no significant differences across groups (P = 0.29). Abnormal T2* was not significantly associated with any of the measures of transfusion or chelation. Ferritin levels showed a strong association with LIC. Non-transferrin-bound iron was high in the thalassemia and MDS groups but low in the SCA group (P<0.001). Hepcidin was low in thalassemia, normal in SCA, and markedly elevated in MDS (P<0.001). Two mechanisms may explain that iron deposition largely spares the heart in SCA: the high level of erythropoiesis recycles the iron and the chronic inflammation retains iron within the macrophages. Thalassemia, in contrast, is characterized by inefficient erythropoiesis, unable to handle free iron. Iron accumulation varies widely in MDS syndromes due to the competing influences of abnormal erythropoiesis, excess iron supply, and inflammation.

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Background:Preclinical findings suggest that imatinib mesylate (IM) and metronomic cyclophosphamide (MC) combination provides synergistic antiangiogenic activity on both pericytes and endothelial cells.Methods:We have designed a 3+3 dose-escalating phase I trial with a fixed dose of MC (50 mg two times daily) plus IM (400 mg per day; 300 and 400 mg two times daily). Enrolled patients had IM- and sutininib-refractory advanced gastrointestinal stromal tumours (GIST) (n=17), chordoma (n=7) and mucosal melanoma (n=2). Dose-limiting toxicities were monitored for the first 6 weeks. Progression-free survival (PFS) and response assessment are based on RECIST 1.0 guidelines. Pharmacokinetics of IM were measured before and after exposure to MC.Results:No dose-limiting toxicity was observed. Fourteen patients of the expanded cohort received 400 mg two times daily of IM with MC. Apart from a case of possibly related acute leukaemia occurring after 4 years of treatment, we did not see unexpected toxicity. No drug–drug pharmacokinetic interaction was observed. There was no objective response. We have observed long-lasting stable disease in chordoma patients (median PFS=10.2 months; range, 4.2–18+) and short-term stable disease in heavily GIST pretreated patients (median PFS=2.3 months; range, 2.1–6.6).Conclusion:This combination is feasible and may warrant further exploration in refractory GIST or chordoma patients.

Iron overload resulting from transfusion dependency in some patients with chronic anaemia can be prevented by chelation. Deferasirox is an oral alternative to the well studied but inconvenient deferroxamine therapy. The pharmacokinetic parameters of this new drug suggest potential interindividual variability and patients might benefit from pharmacologic drug monitoring. We developed an liquid chromatography coupled with tandem mass spectrometry (LC-MS-MS) method to quantify deferasirox in plasma. After protein precipitation, samples were injected onto an XTerra RP18 column with a gradient of acetonitrile and formiate buffer (4 mM, pH 3.0) with 5% methanol. Detection by electrospray ionization mass-spectrometry was performed using the multiple reaction monitoring mode. Sixty-three samples from patients treated with deferasirox were then analyzed to evaluate pharmacokinetic/pharmacodynamic relationships. Calibration curves were linear from 0.5 to 40 microg/mL. Interday and intraday precision were lower than 8.9% and 7.3%, respectively. Bias did not exceed 12.7%. Plasma iron overload did not interfere with analysis. Plasma drug concentrations of patients treated by deferasirox were compared with plasma ferritin, considered as a marker of treatment efficacy. No statistically significant correlation was observed, though higher ferritin concentrations (>1000 microg/L, n = 30) were observed in patients with lower mean deferasirox concentration (9.5 +/- 9.1 microg/mL). This simple method is suitable for routine monitoring of deferasirox concentrations in plasma as it requires very few steps and has a short runtime. It allows evaluation of patient compliance, drug-drug interactions, and further investigations of pharmacokinetic/pharmacodynamic relationships.

3770 Background: Second generation tyrosine kinase inhibitors such as dasatinib (Sprycel®, Bristol-Myers Squibb) induce significantly higher levels of cytogenetic and molecular responses than imatinib when given as frontline therapy for chronic phase chronic myelogenous leukemia (CP-CML) (DASISION trial, Kantarjian et al., NEJM 2010). Dasatinib is associated with the occurrence of pleural effusions (PE). The cumulative incidence of all grades PE in DASISION trial was reported to be 10% by 12 months and 14% by 24 months. Aims: To analyse efficacy of dasatinib first line and to test risk factors associated with the occurrence of PE. (EudraCT 2008–006854–17). Methods: Newly diagnosed CP-CML patients (pts) were assigned to dasatinib 100 mg/d. Dasatinib Cmin levels were assessed 24+/−2h after intake by tandem mass spectrometry after 2 weeks of therapy and every 3 months during 12 months thereafter. Pts with high Cmin values (Cmin ≥ 3 nM) at day 15 were randomized between dasatinib dose reduction or not. As the trial is still recruiting, the effect of randomization (treatment adaptation) was not analysed. For the purpose of this study, patients with at least 12 months follow-up were analysed for efficacy and all enrolled patients were analysed for safety. Molecular assessments were expressed as BCR-ABL/ABL (IS) in %. Results: Efficacy. In March 2012, 125 pts out of 191 pts enrolled in the trial had at least 12 months follow-up. Sokal scores were high for 18%, intermediate for 36% and low for 46% of pts. The median age was 52 (18–89) years. The rates of complete cytogenetic responses (CCyR) at 3, 6, and 12 months were 74%, 87%, and 97% respectively on evaluable samples, and 60%, 82%, and 95% when results were analysed according to the intention-to-treat principle taking into account missing values. The cumulative incidences of major molecular response (MMR) by 3, 6, 9 and 12 months were 21%, 46%, 56%, and 62% respectively. Of note 11 pts (9%) did not have a BCR-ABL (IS) ≤10% at 3 months. None of these patients reached a MMR by 12 months compared to a 68% (95% CI: 60–77) cumulative incidence of MMR in the other 114 pts. At 12 months, molecular response 4.5 (MR4.5) rate was 25%, including 80% of the pts with undetectable BCR-ABL transcript (sensitivity 4 to 5 log). Safety. 12 pts out of 191 (6.3%) presented a PE corresponding to a cumulative incidence of 9% by 24 months. 95 pts had at least one high Cmin value during the pharmacokinetic follow-up and 10 pts developed PE as compared to 2 out of the 96 remaining pts (p= 0.018). Cumulative incidence of PE by 24 months was 13.4% in high Cmin group as compared to 4.8% in low Cmin group (p=0.04). We next analysed whether the measurement of dasatinib Cmin at day 15 could predict the risk to develop a PE. Fifty pts (26%) had a high Cmin value at day 15 (group A) and 141 had a low Cmin (group B). The cumulative incidence of PE by 24 months was 17.4% in group A compared to 6.9% in group B (p=0.021) (fig 1). We next search for clinical factors influencing Cmin value at day15 of dasatinib 100 mg/d. Median Cmin values were significantly higher in patients aged 50 and over as compared to younger patients (2.5 nM versus 1.6 nM, p=0.0032). As expected, age 50 and over was also associated with an increased risk of pleural effusion. Conclusion: Current data demonstrate efficacy of dasatinib 100 mg/d similar or even better to that reported in other frontline trials such as the DASISION trial. We provide evidences suggesting that a high Cmin (>3nM) at day 15 and/or age 50 and over identify patients treated with dasatinib 100 mg/d with a high risk of PE. The benefit of dasatinib dose reduction is randomly tested for this group of patients in the OPTIM-Dasatinib trial and may be a major issue in elderly patients. Disclosures: Rousselot: BMS, Novartis: Research Funding. Nicolini:BMS, Novartis: Consultancy, Research Funding. Coiteux:Novartis, BMS: Speakers Bureau. Gardembas:Novartis: Speakers Bureau. Roy:Novartis, BMS: Speakers Bureau. Dartigeas:Roche: Consultancy. Guilhot:ARIAD: Honoraria. Mahon:Novartis Pharma: Consultancy, Honoraria, Research Funding; Bristol-Myers Squibb: Consultancy, Honoraria; Pfizer: Consultancy.

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