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Background Tyrosine kinase inhibitors (TKI) can be safely discontinued in chronic phase chronic myeloid leukemia (CP‐CML) patients who had achieved a sustained deep molecular response. Based on the results of discontinuation trials, recommendations regarding patient selection for a treatment‐free remission (TFR) attempt had been proposed. The aims of this study were to evaluate the rate of patients eligible for TKI discontinuation and molecular recurrence‐free survival (MRFS) after stop according to recommendations. Methods Over a 10‐year period, newly diagnosed CP‐CML patients and treated with first‐line TKI in the nine French participating centers were included. Eligibility to treatment discontinuation and MRFS were analyzed and compared according to selection criteria defined by recommendations and first‐line treatments. Results From January 2006 to December 2015, 398 patients were considered. Among them, 73% and 27% of patients received imatinib or either second or third generation tyrosine kinase inhibitors as frontline treatment, respectively. Considering the selection criteria defined by recommendations, up to 55% of the patients were selected as optimal candidates for treatment discontinuation. Overall 95/398 (24%) discontinued treatment. MRFS was 51.8% [95% CI 41.41–62.19] at 2 years and 43.8% [31.45–56.15] at 5 years. Patients receiving frontline second‐generation TKI and fulfilling the eligibility criteria suggested by recommendations had the lowest probability of molecular relapse after TKI stop when compare to others. Conclusion One third of CP‐CML patients treated with TKI frontline fulfilled the selection criteria suggested by European LeukemiaNet TFR recommendations. Meeting selection criteria and second‐generation TKI frontline were associated with the highest MRFS., Tyrosine kinase inhibitors (TKI) can be safely discontinued in chronic phase chronic myeloid leukemia patients who had achieved a sustained deep molecular response. Several recommendations regarding the optimal selection of the patients before stop have been proposed. Based on these recommendations, we estimate that one third of the patients treated with frontline TKI will meet these criteria. Moreover, patients treated with frontline second generation TKI and selected as optimal candidate according to these recommendations have the highest probability of molecular recurrence‐free survival when compared to others.

International audience; PurposeTo assess the incidence of BCR‐ABL kinase domain (KD) mutation detection and its prognostic significance in chronic phase chronic myeloid leukemia (CP‐CML) patients treated with tyrosine kinase inhibitors (TKIs).Patients and MethodsWe analyzed characteristics and outcome of 253 CP‐CML patients who had at least one mutation analysis performed using direct sequencing. Of them, 187 patients were early CP (ECP) and 66 were late CP late chronic phase (LCP) and 88% were treated with Imatinib as first‐line TKI.ResultsOverall, 80 (32%) patients harbored BCR‐ABL KD mutations. A BCR‐ABL KD mutation was identified in 57% of patients, who progressed to accelerated or blastic phases (AP‐BP), and 47%, 29%, 35%, 16% and 26% in patients in CP‐CML at the time of mutation analysis who lost a complete hematologic response, failed to achieve or loss of a prior complete cytogenetic and major molecular response, respectively.Overall survival and cumulative incidence of CML‐related death were significantly correlated with the disease phase whatever the absence or presence of a mutation was and for the latter the mutation subgroup (T315I vs P‐loop vs non‐T315I non‐P‐loop) (P

Background: Tyrosine Kinase Inhibitors (TKIs) discontinuation in patients who had achieved a deep molecular response (DMR) offer now the opportunity of prolonged treatment-free remission (TFR). Patients and Methods: Aims of this study were to evaluate the proportion of de novo chronic-phase chronic myeloid leukemia (CP-CML) patients who achieved a sustained DMR and to identify predictive factors of DMR and molecular recurrence-free survival (MRFS) after TKI discontinuation. Results: Over a period of 10 years, 398 CP-CML patients treated with first-line TKIs were included. Median age at diagnosis was 61 years, 291 (73%) and 107 (27%) patients were treated with frontline imatinib (IMA) or second- or third-generation TKIs (2&ndash, 3G TKI), respectively. With a median follow-up of seven years (range, 0.6 to 13.8 years), 182 (46%) patients achieved a sustained DMR at least 24 months. Gender, BCR-ABL1 transcript type, and Sokal and ELTS risk scores were significantly associated with a higher probability of sustained DMR while TKI first-line (IMA vs. 2&ndash, 3G TKI) was not. We estimate that 28% of CML-CP would have been an optimal candidate for TKI discontinuation according to recent recommendations. Finally, 95 (24%) patients have entered in a TFR program. MRFS rates at 12 and 48 months were 55.1% (95% CI, 44.3% to 65.9%) and 46.9% (95% CI, 34.9% to 58.9%), respectively. In multivariate analyses, first-line 2&ndash, 3G TKIs compared to IMA and TKI duration were the most significant factors of MRFS. Conclusions: Our results suggest that frontline TKIs have a significant impact on TFR in patients who fulfill the selection criteria for TKI discontinuation.

Nilotinib (NIL) 600 mg daily has demonstrated its superiority over Imatinib 400 mg daily in terms of response and incidence of deep molecular response in the front-line chronic phase (CP) CML setting. In this observational study we have retrospectively analyzed the outcome of in- and out-study 202 patients (pts) treated in this setting with NIL 600 mg front-line, in "real-life" conditions. All pts with newly diagnosed adult CP-CML receiving NIL 300 mg BID alone front-line between 10/2007 and 06/2020, were eligible for this study. Data were retrospectively collected according to the current French regulations with pts' information. All pts were assessed and followed according to ELN recommendations 2003, 2006, and 2009 along treatment and to the recommendations from the French group of CML (D. Rea et al., Cancer 2018) in case of TFR. In this regard, a TKI was resumed if loss of MMR. All BCR-ABL1 assessments were performed in the 3 reference laboratories, standardised and expressed in % (IS) with ≥32,000 copies of ABL1 as control. The primary endpoints were the rate of molecular responses in the long-term and the (vascular) safety of Nilotinib. Secondary endpoints were the kinetics of molecular response, survival and safety of Nilotinib. Survival (OS, PFS & EFS) was defined according to ELN (J. Guilhot et al. Blood 2012). Two hundred and two patients were reported with 44% females and 56% males with a median age at diagnosis of 50.4 (17.5-83) years, and 26% of them had cardiovascular risk factors at onset (tobacco abuse 11%, hypercholesterolemia 9.3%, diabetes 1.45%, none with past history of cardiovascular events [CVE]). ELTS scores were high in 14%, intermediate in 31% and low in 55% of pts. Twenty-four (12%) pts harboured additional chromosomal abnormalities at diagnosis. The median follow-up after NIL initiation was 61.5 (1-147.5) months. At last follow-up 113 pts (55%) are not on NIL anymore for toxicities, TFR or resistance reasons. Twenty-eight (14%) pts present an arterial event on NIL (18% PAOD, 14% angina pectoralis, 7% myocardial infarction, 14% stroke, 47% others such as atrial fibrillation, cardiomyopathy...), that occurred after a median of 26 (0.6-98.5) months on NIL. Forty-six (22.5%) pts reached TFR criteria and stopped NIL after a median of 58.5 (27-126) months. The cumulative incidence (CI) rates of MMR at 1, 2 and 5 years were 64 (57-71)%, 79.4 (75.45-83.35)% and 95 (92-98.5)% respectively. For MR4, those were 35.5 (29-42)%, 60 (52-67)% and 82 (74.5-89)% respectively; and for MR4.5, were 14 (9-19)%, 31 (24-28)% and 62 (54-70.5)% respectively. The CI of sustained MR4.5 (i. e. patients eligible for TFR: MR4.5 ≥2 years) was observed in 30 (23-37)% at 3 years, 45.5 (36-55)% at 5 years and 52.5 (41.5-64)% at 6 years (Figure). The CI of patients entering TFR was 16.75 (10.5-23)% at 5 years and 51.94 (37.31-66.57)% at 10 years with a survival without MMR loss of 70.7 (58- 86)% at 1 year and 65.26 (50.6-84)% at 5 years. Nine (4.5%) pts progressed towards accelerated phase (4 pts) or BC (2 lymphoid, 3 myeloid) responsible for 5 deaths at latest follow-up. Among NIL resistant patients screened, 15 were harbouring ABL1 mutations (5 Y253H, 3 E255K, 3 T315I, 1 M244V, 1 G250E, 1 F359V, 1 V299L). Overall, 10 patients died (5 from CML, 5 from unrelated causes). The probability of OS was 95.75 [95%CI: 92.9-98.7]% at 2 years and 94.8 [91.5-98.3]% at 5 years, for PFS it was 94.92 [91.7-98.2]% at 2 years and 89.5 [84.7-94.6]% at 5 years, and EFS it was 78 [72.3-84]% at 2 years and 60.25 [53.3-68.1]% at 5 years. Regarding sustained MR4.5, univariate analysis showed that female gender (HR=2.46 [1.50-4.02], p NIL first-line efficiently limits progression of newly diagnosed CP-CML patients and provides high rates of sustained MR4.5, allowing TFR in a substantial proportion of pts. However, the onset of arterial occlusive events, especially in the elderly is a matter of concern in the choice of this compound at treatment initiation. Disclosures Nicolini: Incyte: Research Funding, Speakers Bureau; Novartis: Research Funding, Speakers Bureau; Sun Pharma Ltd: Consultancy. Cony-Makhoul:BMS: Speakers Bureau; Incyte Biosciences: Speakers Bureau; Pfizer: Consultancy; Novartis: Consultancy; BMS: Consultancy. Dulucq:Incyte: Speakers Bureau; Novartis: Speakers Bureau. Cayuela:Novartis: Speakers Bureau; Incyte: Speakers Bureau. Rea:Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees; BMS: Membership on an entity's Board of Directors or advisory committees; Pfizer: Honoraria, Membership on an entity's Board of Directors or advisory committees; Incyte: Honoraria, Membership on an entity's Board of Directors or advisory committees. Mahon:ARIAD: Honoraria; Pfizer: Honoraria; Novartis Pharma: Honoraria, Research Funding; BMS: Honoraria. Etienne:Pfizer: Consultancy, Speakers Bureau; Incyte: Consultancy, Speakers Bureau; Bristol-Myers Squibb: Consultancy, Research Funding, Speakers Bureau; Novartis: Consultancy, Research Funding, Speakers Bureau.

The response definitions proposed by the European Leukemia Net (ELN) have been recently modified. We evaluated the new criteria for de novo imatinib (400 mg/d) chronic phase chronic myeloid leukemia (CP-CML) patients. Response status according to the 2009 and 2013 criteria were determined in 180 unselected patients. Outcome of the subgroups of patients were then compared. The 180 patients were classified as optimal responders (OR2009; n = 113, 62.7%), suboptimal responders (SOR2009; n = 47, 26.1%) and failures (FAIL2009; n = 20, 11.1%) according to the 2009 ELN criteria and optimal responders (OR2013; n = 77, 42.7%), warnings (WAR2013; n = 59, 32.7%), and failures (FAIL2013; n = 44, 24.4%) according to the 2013 ELN criteria. No difference in terms of outcome was observed between OR2009 patients who became WAR2013 when compared with OR2013 patients. When compared with FAIL2009 patients, SOR2009 patients who became WAR2013 had better EFS, FFS, PFS, and OS. No difference was observed in PFS or OS in SOR2009 patients who became FAIL2013. The 2013 ELN response status criteria have improved patients classification in terms of response status. However, in our patient population this improvement is related to a better definition of failure rather than that of optimal response for CP-CML patients treated with IM frontline therapy. Am. J. Hematol. 90:37–41, 2015. © 2014 Wiley Periodicals, Inc.

Sustained imatinib treatment in chronic myeloid leukemia patients can result in complete molecular response allowing discontinuation without relapse. We set out to evaluate the frequency of complete molecular response in imatinib de novo chronic phase chronic myeloid leukemia patients, to identify base-line and under-treatment predictive factors of complete molecular response in patients achieving complete cytogenetic response, and to assess if complete molecular response is associated with a better outcome. A random selection of patients on front-line imatinib therapy (n=266) were considered for inclusion. Complete molecular response was confirmed and defined as MR 4.5 with undetectable BCR-ABL transcript levels. Median follow up was 4.43 years (range 0.79–10.8 years). Sixty-five patients (24%) achieved complete molecular response within a median time of 32.7 months. Absence of spleen enlargement at diagnosis, achieving complete cytogenetic response before 12 months of therapy, and major molecular response during the year following complete cytogenetic response was predictive of achieving further complete molecular response. Patients who achieved complete molecular response had better event-free and failure-free survivals than those with complete cytogenetic response irrespective of major molecular response status (95.2% vs. 64.7% vs. 27.7%, P=0.00124; 98.4% vs. 82.3% vs. 56%, P=0.0335), respectively. Overall survival was identical in the 3 groups. In addition to complete cytogenetic response and major molecular response, further deeper molecular response is associated with better event-free and failure-free survivals, and complete molecular response confers the best outcome.

International audience

In chronic myeloid leukemia (CML), cytogenetic abnormalities found in addition to the t(9;22) translocation may impact the response to therapy. Loss of the Y chromosome is generally overlooked in this context, owing to its relatively frequent occurrence in healthy elderly patients. In this multicenter retrospective study, the outcome after imatinib treatment of 30 CML patients with karyotype showing Y chromosome loss (Y-) was compared to 30 Y+ control males diagnosed and treated at the same time in the same institutions. Y- patients had significantly delayed cytogenetic and molecular responses, lower event-free survival and shorter overall survival than Y+ patients. The negative impact of this abnormality was particularly marked when it occurred in a sub-clone (clonal evolution) rather than in all mitoses. These data indicate that loss of the Y chromosome should be taken into account in the prognostic evaluation of chronic myelogenous leukemia patients.

Purpose to evaluate the relevance of the 2013 ELN response status criteria for de novo imatinib (400 mg/d) chronic phase chronic myeloid leukemia (CP-CML) patients. Patients and Methods Response status according to the 2009 and 2013 criteria were determined in 180 unselected patients. Outcome of the subgroups of patients were then compared. Results One hundred and eighty patients were included in this study. The median age at diagnosis was 58.1 years (range, 19.8-88.9) and 112 (62.2%) were male. Sokal risk scores were low in 50 patients (27.7%), intermediate in 74 (41.1%), high in 38 (21.1%) and unknown in 18 patients (10%). Ten patients (5.5%) had clonal evolution at diagnosis. With a median follow up of 5.4 years, the 180 patients were classified as optimal responders (OR2009) (n=113, 62.7%), suboptimal responders (SOR2009) (n=47, 26.1%) and failures (FAIL2009) (n=20, 11.1%) according to the 2009 ELN criteria and optimal responders (OR2013) (n=77, 42.7%), warnings (WAR2013) (n=59, 32.7%) and failures (FAIL2013) (n=44, 24.4%) according to the 2013 ELN criteria. All the patients classified as failures according to the 2009 criteria were classified as failures by the 2013 criteria. Results are presented in table 1. No difference was observed in event-free (EFS), progression-free (PFS) and overall (OS) survivls between OR2009 and SOR2009 or between OR2013 and WAR2013. PFS and OS were not different between SOR2009 and FAIL2009 whereas a significant difference was observed between WAR2013 and FAIL2013 in PFS and OS (p=.003 and p=.024 respectively). No difference in terms of outcome was observed between OR2009 patients who became WAR2013 when compared to OR2013 patients. When compared to FAIL2009 patients, SOR2009 patients who became WAR2013 had better EFS, FFS, PFS and OS. No difference was observed in PFS or OS in SOR2009 patients who became FAIL2013. Conclusion The 2013 ELN response status criteria have improved patients classification in terms of response status. However this improvement is related to a better definition of failure rather than that of optimal response for CP-CML patients treated with IM frontline therapy. Disclosures: Etienne: Ariad Pharmaceuticals: Membership on an entity’s Board of Directors or advisory committees; Novartis: Consultancy, Membership on an entity’s Board of Directors or advisory committees, Speakers Bureau; Bristol Myers Squibb: Consultancy, Membership on an entity’s Board of Directors or advisory committees, Speakers Bureau; Pfizer: Membership on an entity’s Board of Directors or advisory committees. Dulucq:Novartis: Membership on an entity’s Board of Directors or advisory committees. Nicolini:Ariad Pharmaceuticals: Membership on an entity’s Board of Directors or advisory committees, Speakers Bureau; Pfizer: Membership on an entity’s Board of Directors or advisory committees, Speakers Bureau; Novartis: Consultancy, Membership on an entity’s Board of Directors or advisory committees, Speakers Bureau; Teva: Speakers Bureau; Bristol Myers Squibb: Speakers Bureau. Mahon:Novartis: Consultancy, Membership on an entity’s Board of Directors or advisory committees, Speakers Bureau; Bristol Myers Squibb: Consultancy, Membership on an entity’s Board of Directors or advisory committees, Speakers Bureau; Pfizer: Membership on an entity’s Board of Directors or advisory committees; Ariad Pharmaceuticals: Membership on an entity’s Board of Directors or advisory committees.

Les patients atteints de LMC decouvrent la chronicite de leur maladie au travers de la prescription du traitement oral. A partir de ce moment se mettent en place les determinants de leurs pratiques d’observance: de la ritualisation, la banalisation a l’oubli ou l’arret prolonge. L’etude socioanthropologique de l’experience relatee par les patients explore ici la complexite du phenomene d’observance, de la consultation medicale a la vie quotidienne des malades.

Introduction Imatinib has indeed revolutionized the treatment of chronic myelogenous leukemia (CML) since more than 15 years now, especially in CP. The first patients (pts) in this setting were treated with this compound within the IRIS phase III trial from Novartis, started in January 2000. Regular updates of the results of this study have been presented during various meetings until year 7, and academic studies have recently reported the outcomes of IM first-line CP CML pts after 66 months follow-up. However, little is known about the very long-term outcomes (>8 years) of such first-line pts and these data might be of interest while generic forms of IM will be soon launched in this setting. In this study, we aimed to look at long-term outcomes in terms of efficacy and toxicities in first-line CP CML pts treated with branded form of IM (Glivec®). Methods This is a comprehensive retrospective analysis of first-line CP CML pts treated with IM first-line 400 mg daily since diagnosis and followed in 2 university reference centers for CML between 2000 and 2015, inside or outside academic or industrial clinical trials. All living pts have given their agreement for participation in this retrospective analysis. Pts have been analyzed in intention-to-treat, CML was defined according to ELN criteria [CP, accelerated phase (AP) and blast crises (BC)], Sokal, Euro and EUTOS scores have been calculated as published. Molecular biology tests have been performed according to ELN guidelines and BCR-ABL1/ABL1 were expressed as % on the international scale and 3 ELN conversion factors have been applied successively along time according to material exchanges performed with the central European laboratory in Mannheim. Cytogenetic and molecular responses have been defined according to the ELN criteria. Overall survival (OS) was calculated from the date of IM initiation until death at any time and for any reason; until progression to AP or BC at any time for progression-free survival (PFS); and until death, progression to AP or BC, failure on IM or IM treatment discontinuation for any cause including treatment-free remission (TFR), for event-free survival (EFS). The cut-off date for this analysis was the 20th of July 2,015. Results At time of analysis, 120 pts could be analyzed, with a median follow-up of 85.5 (1-194) months, 70 (58%) were males, with a median age of 55 (11-85) at IM initiation. Sokal score was high for 24(20%) pts, intermediate for 58 (49%), low for 34 (30.5%), unknown in 4 (0.5%) pts. Four (3.5%) pts had a variant Ph chromosome, 7 (6%) with additional chromosomal abnormalities, and 2 a masked Ph chromosome, 6 harbored atypical BCR-ABL1 transcripts excluded from analysis. Early molecular response (M3) was achieved in 86 (72%) pts, unreached in 20 (16%) pts, and unknown for 15 (12.5%) pts. It was predictive of Major Molecular Response (MMR) at 12 months (p=0.01, OR 5.35, 95%CI [1.3-31.94]), for MR4 rates at 24 months (p=0.03, OR 7.35 95%CI [1-328]) and for EFS (p=0.006) but not for OS and PFS in a multivariate Cox model analysis. MMR was achieved in 42% of evaluable pts at 12 months. Eutos, Euro and Sokal scores had no impact on OS, PFS and EFS. Five pts progressed to BC (1 myeloid, 4 lymphoid) within the 5 first years and died after allogeneic stem cell transplantation. The PFS rates were 97.5% at 2 years, 92% at 5 years, 88.6% at 10 and 14 years, EFS rates were 76% at 2 years, 60% at 5 years, 45% at 10 years and 21% at 14 years (figure 1), OS rates were 98% at 2 years, 95% at 5 years, 87% at 10 and 14 years. Figure 1: PFS and EFS in pts on IM first-line. (Dashed lines represent 95%CI). MR4.5 was achieved in 58 (48.5%) pts after a median of 46 (3-191) months and TFR strategy (or trial) was proposed in 28 pts (23.5%) and successful in 15 (12.5%) pts. At latest follow-up, after a median of 85.5 (4-180) months, 64 (53.5%) pts are still on IM, and 44 (37%) have switched to an alternative therapy for intolerance (17 pts, 14%) or resistance (16 pts, 13.5%, 7 with a BCR-ABL mutation) to IM and 11 for other causes (pregnancy, secondary tumors…). Overall, at latest follow-up, 10/120 pts died, 5 of CML progression and 5 from other causes. Conclusions After a very long median follow-up of more than 85 months, IM still consistently provides high rates of remission and survival, without disease progression and severe long-term toxicities. In addition, half of the pts reached the MR4.5 level, ≥2 years stable in 23.5% of the pts offering the possibility of a treatment-free strategy. Figure 1. Figure 1. Disclosures Nicolini: Bristol-Myers Squibb: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Ariad Pharmaceuticals: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau. Mahon:Novartis: Consultancy, Honoraria; ARIAD: Consultancy; Pfizer: Consultancy; Bristol-Myers Squibb: Consultancy, Honoraria. Etienne:Novartis: Consultancy, Honoraria; BMS: Honoraria.

Imatinib mesylate induces a complete cytogenetic response (CCR) in many patients with chronic myeloid leukemia (CML). However, the ultimate goal of therapy for CML is complete elimination of Philadelphia chromosome positive cells or BCR-ABL rearrangements. We studied molecular responses in CML patients in CCR after imatinib treatment.Real-time quantitative reverse transcriptase polymerase chain reaction analysis were used to monitor BCR-ABL levels in 59 CCR patients. Negative results were confirmed by two different techniques performed in two different laboratories. Patients were considered in complete molecular remission if they had four undetectable analyses from two separate samples taken three months apart.The median follow-up was 41 months (17-53). The median BCR-ABL/ABL ratio at the time of CCR was 0.3 % (0-9.88). Patients were split into two groups: group A (n=43) comprised patients with a detectable BCR-ABL/ABL ratio throughout the follow-up and group B (n=16) included those with an undetectable level of BCR-ABL/ABL (10(-5)) i.e. in complete molecular remission. No relapses were observed in group B, while 13 group A patients lost their CCR. The probability of losing CCR in this group was 33.2 %+/-18.0. By Cox regression analysis the best factor for predicting the probability of achieving molecular remission was having a CCR at 6 months (p=0.038) or at 3 months (p=0.024).Molecular remission after imatinib treatment, i.e. BCR-ABL/ABL10-5 in peripheral blood, is not a rare event, particularly in patients achieving CCR at 6 months.

Abstract 1669 Most epidemiologic studies performed in chronic myelogenous leukemia (CML) relate that the disease occurs preferentially in males with a sex ratio of ∼1.2. In addition, CML can be diagnosed in young adults and masculine fertility is a matter of concern, particularly because tyrosine kinase inhibitors (TKI) may impact on spermatogenesis by a selective inhibition of Src kinases, PDGF-R and c-kit. Sperm cryopreservation is recommended by some authors at diagnosis in males that would expect to have children later on. In a retrospective analysis we have analysed the spermograms of 62 chronic phase (CP) and 2 onset blast crisis (BC) CML males referred to our 3 centres between 2001 and 2012, collected at diagnosis before TKI treatment, and we have compared the results obtained to those of 15 healthy volunteer donors from the cryopreservation bank database, after informed consent. In 10 patients we could collect some data for patients being on imatinib mesylate (IM). CML patients had a median age of 31 (16–48) years, significantly younger than that in the control group of healthy donors: 37 (34–45) years (p=0.001). Sokal scores were 24% high, 27% intermediate and 49% low for evaluable patients (13 patients unknown or not available). The median BCR-ABLIS value at diagnosis was 77.65%. Patients had a median duration of 26 (0–38) days of hydroxyurea prior to commencing any TKI and 65% of evaluable patients had HU before TKI. None of the patients got interferon prior to TKI. The semen cryopreservation was performed within a median of 10 (2–102) days after CML diagnosis and after a median abstinence of 5 (0.5–30) days. The median volume of semen obtained in CML patients was 2.95 (0.5–14.9) ml and 3 (1.4–5.3) ml for normal donors (p=0.3). Williams test showed 72 (0–87)% of necrospermia in patients versus 18 (4–32)% in donors (p=0.00003). The median number of spermatozoa obtained was not different in patients [46 (0.03–200) 106/ml] than that in donors [74 (19.2–253) 106/ml] (p=0.24), as well as the number of spermatozoa per ejaculate observed (p=0.49). The motility of spermatozoa at 30 minutes after collection was not different between patients (median = 47.5%) and donors (median = 50%) (p=0.12), however higher numbers of atypical spermatozoa were observed in patients [median = 77.5 (16–100)%] rather than in donors [median = 45% (22–89)%], p=0.008, and the multiple abnormalities index (MAI) was significantly higher in patients [median = 1.99 (1.14–2.7)] than that in donors [median = 1.33 (1.09–1.55)], p=0.00006. There was no correlation between age at diagnosis, Sokal index and the number of spermatozoa per ml obtained (p=0.7 and 0.21 respectively). Ten CP CML patients had spermograms after a median of 1440 (9–1456) days of IM treatment and the results obtained were compared to i) the results of each individual patient at CP diagnosis and ii) to the results of healthy comparators. In comparison to the characteristics observed at diagnosis, the semen volume (median = 3.1 ml), Williams test (median = 65%), the motility at 30 minutes (median = 37.5%) and the MAI (median = 1.71) were not different (p=ns for all), however, the numbers of spermatozoa (median = 14.9 106/ml and = 37.05 ml per ejaculate) collected on IM were significantly lower (p=0.014 and p=0.045 respectively). The different parameters evaluated on IM were compared to those of normal controls and showed significant alterations. The semen volume was not different (p=0.94), neither the motility of spermatozoa (p=0.24), but the Williams test was highly perturbed on IM [median 65 (24–79)% versus 18 (4–32)% in donors] p=0.00003, as well as the numbers of spermatozoa as 106 per ml, collected on IM [median 14.9 (0.67–179)) versus normal [74 (19.2–253)], p=0.0036 or as 106 per ejaculate collected on IM [median 37.5 (2.68–572.8)) versus normal [149 (30–535.3)], p=0.026. Atypical forms were significantly more abundant on IM [median = 80 (68–90)%] versus healthy controls [median = 45% (22–89)], p=0.0058. Finally, the MAI was severely altered on IM [median = 1.71 (1.61–1.98)] versus normal individuals [median = 1.33 (1.09–1.55)], p=0.00013. In conclusion, this work demonstrates the existence of significant sperm alterations in young males with CML at diagnosis of undetermined origin, prior to any treatment. These alterations persist on IM treatment and little is know about the impact of second generation TKI. Thus the most appropriate approach remains a matter of debate in thus setting. Disclosures: Nicolini: Novartis, Bristol Myers-Squibb, Pfizer, ARIAD, and Teva: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Huguet:Novartis, BMS: Speakers Bureau. Michallet:Novartis, Pfizer, Teva, Genzyme, Janssen Cilag, BMS, Merck, Pfizer, Gilead, Alexion: Consultancy, Speakers Bureau. Etienne:Novartis, Pfizer, speaker for Novartis, BMS: Consultancy.

Abstract 1684 The early assessment of molecular responses to tyrosine kinase inhibitors (TKI) used as a front line therapy for chronic phase chronic myeloid leukemia (CML) might represent an attractive surrogate marker for survival and help to discriminate poor prognosis patients (pts). So, we studied in a retrospective bicentric institutional analysis a series of 142 de novo CP CML pts diagnosed between 2000 and 2011, receiving imatinib (IM) 400 mg daily (n=85 pts), second generation TKI (TKI2) (n=57 pts) with 37 dasatinib (DAS) pts 100 mg daily and 20 nilotinib (NIL) pts 600–800 mg daily as front-line therapy, enrolled or not in clinical trials. All pts were assessed for their cytogenetic and molecular responses (local RQ-PCR for BCR-ABL, expressed as BCR-ABL/ABL ratios (IS) in %). Failure to TKI was defined as progression to accelerated phase or blast crisis, death, loss of complete hematologic response, loss of complete cytogenetic response, confirmed loss of major molecular response (MMR), discontinuation of TKI because unacceptable toxicity, primary cytogenetic resistance. The definition of progression included the same variables except the two last. Pts were considered in MMR with a BCR-ABL/ABL ratio ≤0.1% (IS). There were 87 males (61%) and 55 females with a median age of 55 years (21–83) at diagnosis. Six pts (4%) had an additional clonal abnormality, 4 a masked Philadelphia (Ph) chromosome, and 4 a variant Ph. Three pts had an atypical BCR-ABL transcript, all in IM400 group. Sokal scores were low for 37 (26%), intermediate for 61 (43%) and high for 43 (31%) (1 NA), and Euro scores were low for 49 (35%), intermediate for 78 (55%), and low for 14 (10%) (1 NA). These scores were similarly balanced in the IM400, NIL and DAS groups. The median time between diagnosis and TKI was 1 (0.9–1.28) month, not significantly different between TKI groups. The median follow-ups were 56, 37, and 19 months for IM400, NIL and DAS groups respectively. Fifteen percent, 6%, and 14% of pts achieved MMR at 3 months (M3) (p=ns); 31%, 37%, and 40% at M6 (p=ns); 55%, 70% and 71% at M12 (p=ns); 67%, 90% and 87% at M18 (p=ns) in IM400, NIL and DAS groups respectively, taken into account the limited numbers of pts at latest time-points in the 2 TKI2 arms. Twenty-three pts achieved 4-log molecular response MR4 in IM400, 10% in NIL and 11% in DAS at latest follow-ups. Four pts died, 3 in blast crisis in IM400 group and 1 for unrelated reason to disease or treatment in NIL group. A multivariate analysis adjusted on progression-free survival (PFS) performed, did not identify any significant parameter including age, gender, Sokal and Hasford scores, ACA, type of transcript, interval between diagnosis and TKI start. The progression-free survival (PFS) was 94 (83–100)% for pts achieving M3 MMR vs 86 (74–100)% if MMR occurred at later time points vs 86 (73–100)% for pts that never achieved MMR (p=0.02). There was no difference for PFS between the 3 TKI (log-rank p=0.9). None of the M3 MMR switched to another treatment, whereas 10 % of other pts did so for resistance (n= 10, 1 and 2 for IM400, NIL and DAS respectively), 9% for intolerance (n=10, 1 and 4), and 3% for other reasons (n=4, 0 and 0) with no difference between the 3 drugs (p=0.74). The failure-free survival (FFS) was 95% for M3 MMR pts vs 65% for pts with MMR occurring at later time points, versus 0% if MMR has not been achieved (p In conclusion, this academic retrospective study suggests that the achievement of M3 MMR represents a major prognostic factor for progression-free and failure-free survival in CP CML pts on TKI. Disclosures: Nicolini: consultant for Novartis Pharma France and Bristol Myers Squibb: Consultancy. Michallet:consultant for Novartis Pharma France and Bristol Myers Squibb: Consultancy. Mahon:consultant for Novartis Pharma France and Bristol Myers Squibb: Consultancy. Etienne:consultant for Novartis Pharma France and Bristol Myers Squibb: Consultancy.

Abstract 2299 Before the imatinib era and besides allogeneic hematopoietic stem cell transplantation (HSCT), interferon alpha (IFN) was an alternative therapeutic option to treat chronic myeloid leukemia (CML). In very rare situations, some patients achieved a complete molecular remission (CMR) defined as the absence of detectable BCR-ABL transcript using qualitative PCR available at that time.We previously reported the outcome of patients with CML in complete cytogenetic remission after cessation of IFN (J Clin Oncol., 2002, 20:214-220.). Here, we update this experience with a long outcome after discontinuation of IFN. The main criteria for IFN discontinuation was the achievement of a sustained CMR lasting for at least two years. Twenty-one patients (9 males, 12 females; median age 39 years) were eligible for this study. One, 2 and 18 pts belonged to respectively high, intermediate and low risk group according to the Sokal score.All patients were treated with IFN (median dose 56ui/week) during a median time of 7.5 years (2.4-14) and 4 of them received an autologous HSCT. The median time to achieve CMR was 54 month (5-140). The median follow up after discontinuation of IFN treatment was 8 years (mean 9, range 5–18). Quantitative PCR was used to quantify BCR-ABL and evaluate residual disease. We distinguished two groups of patient according to the molecular pattern: group 1 (n=12) regards patients with sustained CMR confirmed by quantitative PCR. One patient belonging to this group relapsed and progressed suddenly after 5 years of IFN discontinuation and was treated with allogeneic HSCT. Group 2 (n=9) regards patients who are not in CMR with leukemic cells detectable by RQ-PCR. Six of them exhibit a fluctuation of BCR-ABL detection assessed by RQ-PCR. For the 3 other patients with a median follow up of 6 years after discontinuation, RQ-PCR became clearly positive after a median time of 2 years with a level of residual disease that corresponds to the definition of major molecular response (3 log reduction of BCR-ABL). No progression was observed in this group. So we conclude that the persistence of leukemic cells at low level after discontinuation of IFN treatment does not automatically lead to CML relapse. This long term follow up after IFN discontinuation raises the question of the need of a complete eradication of residual leukemic cells to cure the disease Disclosures: No relevant conflicts of interest to declare.

Loss of the Y chromosome (-Y) in bone marrow cells frequently occurs in elderly patients. It is thus unclear whether loss of the Y chromosome, when found in Philadelphiapositive cells, should be overlooked, or whether it represents a clonal evolution (a criterion of cytogenetic acceleration of the disease) or an additional cytogenetic abnormality (ACA), considered of little importance in patients treated with imatinib mesylate (IM). We have collected diagnostic characteristics, clinical, cytogenetic and molecular evolution data from 29 patients diagnosed with CML from 1991 to April 2007 in 6 participating centres, who presented a loss of the Y chromosome at diagnosis (n=20) or during evolution (n=9) and who were treated with imatinib in first (n=19) or second (n=10) line. They were compared to patients with a Philadelphia chromosome as sole anomaly, diagnosed at similar dates in the same centres, thus benefitting from the same management. Age and Sokal score at diagnosis were similar. In both -Y and control groups, two thirds of patients had received prior treatment (mostly interferon, hydroxyurea and aracytine). Median follow-ups were respectively 54 months (range: 7–146) and 58 months (range: 13–149), censored if therapy was changed for a second generation tyrosine-kinase inhibitor or bone marrow transplantation. The time to achieve complete cytogenetic remission (CCR) (22 months vs 7, p=0.02) and major molecular response (MMR) (not reached vs 30 months, p=0.0015) were significantly higher in -Y patients. Acceleration (8/29 vs 1/29, p=0.003), acutisation (4/29 vs 1/29, p=0.1) and death (3/29 vs 1/29) were more frequent in the -Y group, but owing to the rare occurrence of these events, statistical significance was clear for acceleration only. Interestingly, prognosis (time to CCR, MMR and occurrence of acceleration) was worse if loss of the Y chromosome was present in a subclone (suggesting a clonal evolution) rather than all mitoses (ACA) and also when it was observed at diagnosis rather than during the evolution of the disease. Consequently, survival was significantly reduced (55 months vs not reached, p=0.009) in those patients for whom -Y was present in a subclone at diagnosis. In conclusion, loss of the Y chromosome in Philadelphia-positive cells is an important finding since it affects the prognosis of CML patients, especially, but not exclusively, when present at diagnosis in a subclone. In this case, loss of the Y chromosome even predicts a decreased survival after imatinib treatment.