Abstract: Clinical trials frequently include multiple end points that mature at different times. The initial report, typically based on the primary end point, may be published when key planned co-primary or secondary analyses are not yet available. Clinical Trial Updates provide an opportunity to disseminate additional results from studies, published in JCO or elsewhere, for which the primary end point has already been reported. The European Stop Kinase Inhibitors (EURO-SKI) study is the largest clinical trial for investigating the cessation of tyrosine kinase inhibitors (TKIs) in patients with chronic myeloid leukemia in stable deep molecular remission (DMR). Among 728 patients, 434 patients (61%; 95% CI, 57 to 64) remained in major molecular response (MMR) at 6 months and 309 patients of 678 (46%; 95% CI, 42 to 49) at 36 months. Duration of TKI treatment and DMR before TKI stop were confirmed as significant factors for the prediction of MMR loss at 6 months. In addition, the type of BCR::ABL1 transcript was identified as a prognostic factor. For late MMR losses after 6 months, TKI treatment duration, percentage of blasts in peripheral blood, and platelet count at diagnosis were significant factors in multivariate analysis. For the entire study period of 36 months, multiple logistic regression models confirmed duration of treatment, blasts, and transcript type as independent factors for MMR maintenance. In addition to the duration of treatment, transcript type as well as blasts in peripheral blood at diagnosis should be considered as important factors to predict treatment-free remission.

Abstract: The nucleoside analogue cytarabine (AraC) has served as the backbone of acute myeloid leukemia (AML) treatment for nearly forty years. About one-third of expressed genes are abnormally spliced in AML yet alternative exon usage (AEU) plays a role in the plasticity of tumor cells and may influence the response to treatment. Here the exon expression profiles of the erythroleukemia K562 cell line were compared to that of its AraC-resistant variant K562/AraC through Affymetrix HTA2 exon arrays. 5140 exon events harbored by 2583 genes distinguished the 2 cell lines. Among these, the skipping of TET2 exon 2 was identified in K562 cells sensitive to AraC whereas TET2 gene expression remained unchanged at the whole transcript level. The results were confirmed by exon-specific RTPCR (ESPCR). Microarray analysis did not evidenced any significant change in mRNA splicing for the 10 remaining exons of the TET2 gene. TET2 is a dioxygenase that catalyzes the conversion of 5-methylcytosine (5-mC) to 5-hydroxymethylcytosine (5-hmC) and promote DNA demethylation. TET2 somatic mutations occur in about 25% AML, distributing across the whole coding sequence without obvious hot spots. These mutations decrease TET2 enzymatic activity by truncating the protein or affecting its catalytic activity. TET2 exon 2 is spliced in a mutually exclusive manner with exon 1 yet it is used as an alternative promoter (https://fasterdb.lyon.unicancer.fr/). However, TET2 exon 2 is not translated into protein and its role in TET2 regulation is still unknown. Having found that AraC sensitive cells harbor the spliced TET2 isoform, we investigated whether or not skipping of TET2 exon 2 correlate with disease outcome in AML patients treated with AraC-based intensive chemotherapy (AraC-IC). The discovery cohort included 106 consecutive AML patients treated with AraC-IC (median age 57.91, 64 males). RNA was extracted from bone marrow MNCs and assayed for TET2 exon 2 skipping through real-time quantitative ESRTPCR (qESRTPCR) amplification of E1E3 (spliced) and E2E3 (unspliced) TET2 isoforms. TET2 exon 2 skipping was quantified by calculating the ratio E1E3/E2E3. For statistical analysis, the ratio E1E3/E2E3 was dichotomized using median value as the cutoff value. Skipping of TET2 exon 2 was associated with a significantly lower response rate: 65% vs 92%, p = 0.001 but with a significantly lower relapse rate: 39% vs 85%: p 〈 10-4. Univariate analysis (27 months median follow-up) showed that in addition to age and cytogenetic risk, TET2 exon 2 skipping significantly influenced DFS; the higher the level of E1E3 isoform expression, the better the outcome [HR=0.27 (95% confidence interval (CI):0.13-0.53), p 〈 10-4]. The favorable effect of TET2 exon 2 skipping on DFS remained in the 49 patients with normal karyotype: HR=0.31 (CI: 0.12-0.84), p=0.022. Multivariate analysis showed that age [HR=1.83 (CI:1.03-3.24), p=0.039] , cytogenetics [HR=3.03 (CI:1.55-5.96), p=0.001], and TET2 exon 2 skipping [HR=0.38 (CI:0.19-0.77), p=0.007] were independent prognostic factors for DFS. The validation cohort included 103 patients with normal karyotype treated with AraC-IC (median age 61.12, 63 males). Skipping of TET2 exon 2 was associated with a lower response rate: 87.5% vs 91.1% (NS) and a significantly lower relapse rate: 3% vs 66%: p 〈 10-4. Univariate analysis showed that in addition to age, FLT3 internal tandem duplication (FLT3-ITD), nucleophosmin (NPM1) exon-12 gene mutation, TET2 exon 2 skipping significantly influenced DFS, EFS, and OS. In multivariate analysis, TET2 exon 2 skipping was the sole prognostic factor for DFS [HR=0.07 (CI: 0.02-0.3), p 〈 10-4], EFS [HR=0.32 (CI: 0.14-0.74), p=0.008] , and OS [HR=0.42 (CI: 0.19-0.90), p=0.025]. As an additional control, the prognostic effect of TET2 exon 2 skipping was evaluated in a series of 36 AML unfit for IC and treated with hydroxyurea, azacitidine, decitabine, low dose AraC, or supportive care only. TET2 exon 2 skipping possessed no significant impact on the response rate, the relapse rate, OS, DFS, and EFS in this population. In conclusion TET2 exon 2 skipping is associated with a low relapse rate and possesses a strong favorable prognostic impact in AML treated with AraC-CTI. The mechanism linking this alternative exon usage with resistances to AraC are currently investigated while our results suggest that the determination of TET2 exon 2 splicing status might assist risk stratification. Disclosures Nicolini: Novartis: Consultancy.

Abstract: ATP binding cassette (ABC) transporters are a superfamily of highly conserved membrane proteins that transport a wide variety of substrates across cell membranes and confer drug resistance against a wide range of chemotherapeutic agents. We recently found that WT1, which is regularly overexpressed in AML and interact with the splicing machinery, modifies the splicing of ABC transporters A2, A3, A5, and C2. For ABCA3, WT1 knock-down in three AML cell line coupled with Affymetrix HTA2 exon arrays analysis confirmed by exon-specific PCR revealed that WT1 influences the skipping of exon 19. ABCA3 belongs in the ABC subclass and induces a significant reduction in cytotoxicity observed following exposure to DNR, mitoxantrone, etoposide, Ara-C and vincristine. The ABCA3 domain encoded by exon 19 (amino acid 805-847) is localized at the junction of the first nucleotide-binding domain and the second transmembrane domain, and is involved in ATP hydrolysis. In silico, skipping of exon 19 deletes a sequence of 32 amino acids rich in positively charged residues and is thereby assumed to increase drug efflux through increased ATP hydrolysis. The effects of the skipping of exon 19 on chemoresistance and DNR efflux are currently investigated while for the present study, we hypothesized that skipping of exon 19 of ABCA3 might negatively influence outcome in AML patients. Analyzing 132 bone marrow AML samples harvested at diagnostic confirmed the statistically significant correlation between WT1 expression and ABCA3 splicing in vivo (p 〈 10-4, Spearman Rank Correlation). This correlation was specific because it was not observed in 37 control samples deriving from bone marrow donors or in the AML cases with 2 TET2 alternative exon usages found WT1-independent ex vivo. In the 106 patients treated with intensive chemotherapy (IC), skipping of ABCA3 exon 19 was associated with a significantly lower response rate: 39/55 (70.9%) vs 44/51 (86.3%, p = 0.045, Pearson’s chi-squared test). In complete remitters, skipping of ABCA3 exon 19 was associated with a significantly higher relapse rate: 77.1% vs 52.6% (p=0.026, Pearson’s chi-squared test). Median follow-up was 25 months. The 25 allografted patients were censored at the time of allograft. By univariate analysis ABC-A3 exon skipping of exon 19 significantly affected OS (HR=4.50 (95% confidence interval: 2.10-9.63), p 〈 10-4), DFS (HR=3.76 (95% confidence interval: 1.87-7.42), p 〈 10-4), and EFS (HR 3.73 (95% confidence interval: 1.38-5.13), p=0.004); higher the level of exon 19 skipping, poorer the outcome. In multivariate analysis, age, cytogenetic, and ABC A3 exon 19 skipping were identified to be independent prognostic factors for OS, EFS and DFS. Age and ABC-A3 exon exclusion were identified to be independent prognostic factor for OS in the 49 patients with normal karyotype. In order to confirm these results we investigated the prognostic impact of ABC A3 exon 19 skipping in a validation cohort of 108 additional AML case with normal cytogenetics. FLT3 internal tandem duplication (FLT3-ITD) and nucleophosmin (NPM1) exon-12 gene mutation were identified in 37 (34.3%) and 66 cases (61.1%). In the 86 patients treated with IC, the CR rate was 89,5% without significant difference between patients with or without exon 19 skipping. The relapse rate was higher in cases with exon 19 skipping (47,1% vs 23.5%) but the difference was not statistically significant. The 29 allografted patients were censored at the time of allograft. Median follow-up was 12 months. By univariate analysis ABC-A3 exon skipping of exon 19 significantly affected DFS (HR=2.03 (95% confidence interval: 1.22-3.39), p=0.007, and EFS (HR 1.62 (95% confidence interval: 1.06-2.48), p=0.027); higher the level of exon 19 skipping, poorer the outcome. In multivariate analysis, age, FLT3-ITD, ABC A3 exon 19 skipping but not NPM1 mutation were identified to be independent prognostic factors for EFS while FLT3-ITD and ABC A3 exon 19 skipping were independent prognostic factors for DFS. In conclusion ABC-A3 missplicing possesses a strong prognostic impact in AML indicating that besides whole gene transcription, quantitative analysis of alternative splicing might represent a promising tool for assessing AML aggressiveness at the time of diagnostic in patients with normal or abnormal karyotype. Disclosures Nicolini: Novartis: Consultancy.

Abstract: 6503 Background: Ponatinib is a potent, oral, pan-BCR-ABL inhibitor active against the native enzyme and all tested resistant mutants, including the uniformly resistant T315I mutation. Methods: The PACE (Ponatinib Ph+ALL and CML Evaluation) trial started Sept 2010. Pts with refractory CML (CP, AP or BP) or Ph+ALL resistant or intolerant (R/I) to dasatinib or nilotinib or with T315I received 45 mg ponatinib once daily. The trial is ongoing; enrollment completed Sept 2011. Data as of 17 Jan 2012 are reported. Results: 449 pts were enrolled, 5 of whom were ineligible (post-imatinib, non-T315I) but treated. Median age was 59 (18-94) yrs; 53% male. Diagnoses were: 271 CP-CML (R/I=207; T315I=64); 79 AP-CML (R/I=60; T315I=19); 94 BP/ALL (R/I=48; T315I=46). Median time from diagnosis to ponatinib was 6 yrs. Prior TKIs included imatinib (96%), dasatinib (85%), nilotinib (66%), bosutinib (7%); 94% failed ≥2 prior TKIs, 59% failed ≥3 prior TKIs. 83% had a history of resistance to dasatinib or nilotinib; 12% were purely intolerant. In CP, best response to most recent dasatinib or nilotinib was MCyR 25%. Frequent mutations confirmed at entry: 29% T315I, 8% F317L, 4% E255K, 4 % F359V, 3% G250E. Median follow-up was 6.6 months. Response rates are presented in the table. Overall, 64% remained on therapy (77% CP). Most frequent reasons for discontinuation were progression (12%) and AE (10%). Most common drug‑related AEs were thrombocytopenia (33%), rash (33%), dry skin (26%). Conclusions: Ponatinib has substantial activity in heavily pretreated pts and those with refractory T315I. Response rates continue to improve with longer follow-up. Multivariate analyses of predictors of outcome will be presented. [Table: see text]

Abstract: 6596 Background: Omacetaxine mepesuccinate (“omacetaxine”) is a first-in-class, reversible, transient inhibitor of protein elongation that facilitates tumor cell death without depending on BCR-ABL signaling. Clinical activity was shown in two phase 2, open-label, multicenter studies of patients with treatment-resistant CML who had failed at least prior imatinib, many of whom were also resistant to or intolerant of dasatinib and/or nilotinib. Methods: A subset of data from the phase 2 studies included patients in chronic phase who were resistant/intolerant to ≥2 approved TKIs. Omacetaxine 1.25 mg/m 2 was given subcutaneously twice daily: ≤14 consecutive days/28-day cycle for induction, ≤7 days/cycle as maintenance. Patients had never achieved or lost response to ≥2 TKIs (R group), were intolerant of ≥2 TKIs (I), or resistant to 1 and intolerant of another (R/I) were evaluated. Results: Of 81 patients (median age, 58 years), 69 were R, 7 I, and 5 R/I. Major cytogenetic response occurred in 13 (19%) in the R group (median duration not reached), 2 (29%) I (median duration 7.4 months), and 1 (20%) R/I (duration 17.7 months). For all patients, cycles of exposure and study duration were 7 cycles and 9.1 months (R); 4 cycles, 7.3 months (I); and 2 cycles, 2.3 months (R/I). Median overall survival in months were 33.9 (R), not reached (I), and 25.0 (R/I). Of 66 (81%) patients with treatment-related grade 3/4 adverse events (AEs), the most common were thrombocytopenia in 44 R, 6 I, and 4 R/I patients and neutropenia in 32 R, 4 I, and 1 R/I. Fifteen patients had an AE leading to discontinuation (10 R, 2 I, 3 R/I), primarily disease progression. There were 9 deaths (the most common were disease progression, sepsis), 8 I, 1 R/I; 2 were considered related to treatment (both sepsis). Conclusions: This subset analysis of patients with chronic-phase CML and prior therapy with ≥2 TKIs shows that omacetaxine provides efficacy and tolerability across TKI-R, I, and R/I groups. Interpretation of the I and the R/I group data was limited by small sample sizes. Support: Teva Pharmaceutical Industries Ltd.

Abstract: Ponatinib is a potent oral pan–BCR-ABL tyrosine kinase inhibitor (TKI) with activity against native and mutant BCR-ABL. The efficacy and safety of ponatinib (45 mg once daily) in pts with CP-CML were evaluated in the phase 2 PACE trial. Objectives To review the management of treatment-related AEs (TRAEs) that emerged during therapy with ponatinib in the PACE trial. Methods A total of 270 CP-CML pts (267 in efficacy population) resistant or intolerant to dasatinib or nilotinib or with the T315I mutation were enrolled in this ongoing, phase 2, international, open-label clinical trial. The primary endpoint was major cytogenetic response (MCyR) at any time within 12 mos. Safety monitoring included collection of AEs, and the following variables were evaluated: incidence, severity, time to onset, duration, and management. Select TRAEs are discussed. Data as of 01 Apr 2013 are reported, with a median follow-up of 20 (0.1–28) mos. Minimum follow-up for pts remaining on study was 18 mos. Results Median age was 60 (18-94) yrs; median time from diagnosis to first dose was 7 (0.5-27) yrs; 93% had ≥2 prior TKIs, 60% ≥3. Ponatinib demonstrated significant activity in CP-CML pts: 56% MCyR, 46% CCyR, and 36% MMR. At the time of analysis, 60% of pts remained on study. The most frequent reasons for discontinuation were AEs (14%) and progression (8%). The most common hematologic TRAE was thrombocytopenia (41% any grade, 32% grade 3/4). The incidence by time to initial onset is shown below (Figure). Pts experienced thrombocytopenia for a median total duration of 166 days (64% of whom had 〉 1 event) and typically required dose modification: 13% drug withdrawn, 40% dose reduced, 29% dose interrupted only, 17% no dose modification. Among pts with thrombocytopenia, 27% required a platelet transfusion. Thirteen percent of CP-CML pts experienced treatment-related neutropenia and thrombocytopenia. The most common nonhematologic TRAE was rash (39% any grade, 4% grade 3/4), which includes erythematous, macular, and papular rash. Pts experienced rash for a median total duration of 65 days (46% of whom had 〉 1 event) and most did not require dose modification: 0% drug withdrawn, 15% dose reduced, 11% dose interrupted only, 73% no dose modification. One additional pt discontinued due to grade 2 treatment-related exfoliative rash. Pancreatitis was observed (7% any grade, 6% grade 3/4). Median duration was 5 days. Pts were typically managed with dose modification: 5% drug withdrawn, 58% dose reduced, 32% dose interrupted only, 5% no dose modification. Treatment-emergent cardiovascular events were observed in 8% of pts and treatment-emergent cerebrovascular or peripheral vascular events in 11%. Cardiovascular events were considered treatment-related in 4%; cerebrovascular or peripheral vascular events were also considered treatment-related in 4%. The median time to initial onset was 9 mos for cardiovascular and 11 mos for cerebrovascular or peripheral vascular events. The median duration was 6 and 97 days, respectively. Management of pts with cardiovascular AEs: 20% drug withdrawn, 10% dose reduced, 40% dose interrupted only, 30% no dose modification. Management of pts with cerebrovascular or peripheral vascular AEs: 8% drug withdrawn; 8% dose reduced; 17% dose interrupted only; 67% no dose modification. Conclusions Ponatinib has robust antileukemic activity in heavily pretreated CP-CML pts (93% of whom received ≥2 prior TKIs). Treatment-related thrombocytopenia and pancreatitis generally occurred early in therapy and were manageable with dose modification. Treatment-related rash generally occurred early in therapy, was mild-to-moderate in severity, managed without the need for dose modification, and rarely led to discontinuation. Management of treatment-related arterial thrombotic events varied; pts with predisposing cardiovascular risk factors should be monitored closely and managed accordingly. ClinicalTrials.gov ID: NCT01207440 aIncidence = (number of pts with initial onset during time interval) / (number of pts dosed during time interval [N] excluding those who previously experienced the event) X 100 Disclosures: Le Coutre: Novartis: Research Funding; Novartis, BMS, Pfizer: Honoraria. Kim:BMS, Novartis, IL-Yang: Consultancy; BMS, Novartis, Pfizer, ARIAD, IL-Yang: Research Funding; BMS, Novartis, Pfizer, IL-Yang: Honoraria; BMS, Novartis, Pfizer: Speakers Bureau; BMS, Pfizer: Membership on an entity’s Board of Directors or advisory committees. Pinilla-Ibarz:Novartis, Ariad: Research Funding; Novartis, Ariad, BMS and Pfizer: Speakers Bureau. Paquette:Ariad, BMS, Novartis: Consultancy; Ariad, BMS, Novartis: Honoraria; Ariad, BMS, Novartis: Speakers Bureau. Chuah:Novartis, BMS: Honoraria. Nicolini:Novartis, ARIAD, Teva: Consultancy; Novartis, BMS: Research Funding; Novartis, BMS, Teva, Pfizer, ARIAD: Honoraria; Novartis, BMS, TEva: Speakers Bureau; Novartis, ARIAD, Teva, Pfizer: Membership on an entity’s Board of Directors or advisory committees. Apperley:Novartis: Research Funding; Ariad, Bristol Myers Squibb, Novartis, Pfizer, Teva: Honoraria. Talpaz:Ariad, BMS, Sanofi, INCYTE: Research Funding; Ariad, Novartis: Speakers Bureau; Ariad, Sanofi, Novartis: Membership on an entity’s Board of Directors or advisory committees. DeAngelo:Ariad, Novartis, BMS: Consultancy. Abruzzese:BMS, Novartis: Consultancy. Rea:BMS, Novartis, Pfizer, Ariad, Teva: Honoraria. Baccarani:ARIAD, Novartis, BMS: Consultancy; ARIAD, Novartis, BMS, Pfizer, Teva: Honoraria; ARIAD, Novartis, BMS, Pfizer, Teva: Speakers Bureau. Muller:Novartis, BMS, ARIAD: Consultancy; Novartis, BMS: Research Funding; Novartis, BMS, ARIAD: Honoraria. Gambacorti-Passerini:Pfizer: Research Funding; Pfizer, BMS: Honoraria. Lustgarten:ARIAD: employees of and own stock/stock options in ARIAD Pharmaceuticals, Inc Other, Employment. Yanase:ARIAD: employees of and own stock/stock options in ARIAD Pharmaceuticals, Inc. Other, Employment. Turner:ARIAD: Employment. Haluska:ARIAD: employees of and own stock/stock options in ARIAD Pharmaceuticals, Inc Other, Employment. Deininger:BMS, ARIAD, NOVARTIS: Consultancy; BMS, NOVARTIS, CELGENE, GILEAD: Research Funding; ARIAD, NOVARTIS: Advisory Boards, Advisory Boards Other. Hochhaus:Ariad, Novartis, BMS, MSD, Pfizer: Research Funding; Novartis, BMS, Pfizer: Honoraria. Hughes:Novartis, BMS, ARIAD: Honoraria, Research Funding. Goldman:ARIAD: Honoraria. Shah:Ariad, Bristol-Myers Squibb: Consultancy, Research Funding. Kantarjian:ARIAD, Novartis, BMS, Phizer: Research Funding. Cortes:Ariad, Pfizer, Teva: Consultancy; Ariad, BMS, Novartis, Pfizer, Teva: Research Funding.

Abstract: Background: Allogeneic SCT is considered standard treatment for patients with advanced phase CML (accelerated phase, blast crisis), de novo Ph+ ALL, or patients in chronic phase (CP) resistant or intolerant to at least 2 tyrosine kinase inhibitors (TKI). Ponatinib is FDA and EMA approved for the treatment of CML or Ph+ ALL in patients with the BCR-ABL1 T315I mutation or for whom no other TKI therapy is indicated. In patients harboring the T315I mutation, ponatinib currently represents a suitable alternative treatment option to allogeneic SCT. However, differences in outcomes between patients treated with ponatinib and allogeneic SCT have not been analyzed. Objective: To compare overall survival (OS) among CML and Ph+ ALL patients with the BCR-ABL1 T315I mutation treated with ponatinib (in PACE) versus allogeneic SCT (in the EBMT database). Methods: Data from a Phase II trial of ponatinib (PACE trial; Cortes et al., New Engl J Med 2013; NCT01207440) and European Bone Marrow Transplant (EBMT) registry were pooled to conduct an indirect comparison of ponatinib with allogeneic SCT. Both ponatinib and allogeneic SCT cohorts comprised patients with the T315I mutation age 18 years or older in any phase of CML or with Ph+ ALL. All patients harbored the T315I mutation detected by Sanger sequencing, DHPLC, PCR-RFLP, or other equivalent tests. Allogeneic SCT patients in their second CP phase were excluded, and no patients in the EBMT database were treated with ponatinib prior to receiving allogeneic SCT. The date of intervention (ponatinib or SCT) served as the index date. Baseline demographic and clinical characteristics were compared between the two intervention groups. OS was compared between the two groups using adjusted Kaplan-Meier (KM) survival curves and multivariate Cox proportional hazards models; all comparisons were adjusted for age (as a continuous variable), gender, geographic region (Europe, Asia, and Australia vs. North America), time from CML diagnosis to intervention, and CML phase or Ph+ ALL at intervention to control confounding by these variables. Results were presented overall and stratified by phase of CML or Ph+ ALL. Results: A total of 184 (128 ponatinib, 56 allogeneic SCT) patients were included in the analysis: 90 were in CP-CML, 26 were in accelerated phase (AP-CML), 41 were in blast phase (BP-CML), and 27 had Ph+ ALL. On average, ponatinib patients were older than allogeneic SCT patients on the date of intervention (median age 53 vs. 45 years, p=0.006). In addition, a larger proportion of patients in the ponatinib group were from North America than in the allogeneic SCT group (43.8% vs. 26.8%, p=0.030). Median time from diagnosis to intervention was longer for patients treated with ponatinib compared with those treated with allogeneic SCT in CP-CML (58 vs. 32 months, p=0.029), but not significantly different in AP-CML (80 vs. 49 months, p=0.075) nor Ph+ ALL (17 vs. 10 months, p=0.212). This period was nominally shorter for the ponatinib cohort in BP-CML (26 vs. 43 months, p=0.340). Over 93% of patients in both treatment cohorts in all disease phases reported previous use of imatinib. Adjusted median OS was significantly longer in CP-CML patients treated with ponatinib as opposed to allogeneic SCT patients (KM median: not reached [NR] vs. 103.3 months, p=0.013), with a hazard ratio (HR) of 0.37 (95% CI: 0.16, 0.84, p=0.017). Median OS was not significantly different between the two treatment groups in patients with AP-CML (NR vs. 55.6 months, p=0.889; HR=0.90 [95% CI: 0.20, 4.10, p=0.889] ). However, among patients with BP-CML, ponatinib was associated with significantly shorter OS compared with allogeneic SCT: median 7.0 vs. 10.5 months (p=0.026), HR=2.29 (95% CI: 1.08, 4.82, p=0.030). Ph+ ALL patients treated with ponatinib had nominally shorter median OS than allogeneic SCT (6.7 vs. 32.4 months, p=0.119; HR=2.77 [95% CI: 0.73, 10.56, p=0.136]). See Figures 1a-1d for adjusted KM survival curves. Conclusion: AllogeneicSCT remains a potential curative therapy for patients with BP-CML. However, ponatinib was associated with significantly longer OS than allogeneic SCT in patients with CP-CML that harbor the T315I mutation and could represent a promising therapeutic alternative in this setting, although follow-up remains short to date. OS was similar between intervention groups in AP-CML and longer for allogeneic SCT patients in BP-CML and Ph+ ALL. Disclosures Nicolini: 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; Bristol-Myers Squibb: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Basak:MSD: Consultancy, Honoraria; Astellas: Honoraria; Sanofi: Honoraria; Pierre-Fabre: Honoraria. Kim:Pfizer: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; BMS: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Il-Yang: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau. Pinilla-Ibarz:BMS: Consultancy, Speakers Bureau; Novartis: Consultancy; ARIAD: Consultancy; Pfizer: Consultancy, Speakers Bureau. Apperley:ARIAD: 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: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; BMS: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Hughes:Novartis: Honoraria, Research Funding; BMS: Honoraria, Research Funding; ARIAD: Honoraria, Research Funding. Niederwieser:Novartis: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Mauro:Ariad: Consultancy; Pfizer: Consultancy; Novartis Pharmaceutical Corporation: Consultancy, Research Funding; Bristol-Myers Squibb: Consultancy. Chuah:Bristol-Myers Squibb: Honoraria; Novartis: Honoraria; Chiltern International: Honoraria. Hochhaus:Pfizer: Honoraria, Research Funding; Novartis: Honoraria, Research Funding; Bristol-Myers Squibb: Honoraria, Research Funding; ARIAD: Honoraria, Research Funding. Martinelli:Novartis: Consultancy, Speakers Bureau; MSD: Consultancy; Pfizer: Consultancy; Ariad: Consultancy; ROCHE: Consultancy; BMS: Consultancy, Speakers Bureau; AMGEN: Consultancy. DerSarkissian:ARIAD: Research Funding. Kageleiry:ARIAD: Research Funding. Yang:ARIAD: Employment. Huang:ARIAD: Employment, Equity Ownership. McGarry:ARIAD: Employment, Equity Ownership. Cortes:Pfizer: Consultancy, Research Funding; BMS: Consultancy, Research Funding; BerGenBio AS: Research Funding; Teva: Research Funding; Novartis: Consultancy, Research Funding; Ariad: Consultancy, Research Funding; Astellas: Consultancy, Research Funding; Ambit: Consultancy, Research Funding; Arog: Research Funding; Celator: Research Funding; Jenssen: Consultancy.