ALBERT

Description: Second-generation tyrosine kinase inhibitors (2G-TKI), nilotinib or dasatinib used after imatinib failure can induce complete cytogenetic response (CCR) in 50% of chronic myeloid leukemia (CML) patients. BCR-ABL transcript levels reduction in the initial months of treatment has been associated improved outcome. Aims to evaluate the predictive value of early molecular responses, at 3 and 6 months after treatment with 2G-TKI in CML patients with imatinib failure or intolerance; to correlate these responses with CCR, overall survival (OS), progression-free survival (PFS) and event free survival (EFS). Methods Between September 2007 and August 2012, 71 consecutive patients with CML resistant or intolerant to imatinib were treated with dasatinib (n= 50) or nilotinib (n=21). BCR-ABL transcripts were measured in peripheral blood using real-time quantitative PCR (RQ-PCR) at 3 months intervals. Results were expressed as BCR-ABL/ABL ratio, with conversion to the international scale (IS). Major molecular response (MMR) was defined as a transcript level ≤ 0.1% (IS). Cytogenetic analysis was performed at baseline, 3, 6, 12 and 18 months after starting therapy with 2G-TKI. BCR-ABL mutation analysis by direct sequencing was investigated in resistant patients. Probabilities of OS, PFS and EFS were calculated using Kaplan-Meier method. An event was defined as the loss of CHR, CCR, progression to advanced phases, death or 2G-TKI discontinuation. The CCR probabilities according to molecular responses were calculated by c2 method and cumulative incidence, considering as competitive event death or progression. Results 71 patients were analyzed, median age of 47 years (15-81); Disease status before 2G-TKI was: 50 (71%) CP; 13 (18%) AP and 8 (11%) BC. Responses: 59/71 (83%) obtained CHR; 38/55 (69%) CCR and 37/60 (62%) MMR. At 3 months of therapy, 81.5% (44/54) had a BCR-ABL ratio ≤10% and at 6 months 66% (33/50) had ≤ 1%. At 3 months, CCR was obtained 65% (19/29) pts with ≤10% RQ-PCR and 16% (1/6) with 〉10% RQ-PCR (p= 0.06). At 6 months, CCR was 100% (12/12) in pts with RQ-PCR ≤ 1% and 14% (1/7) in those with 〉1% (p〈 0.0001). The probability to achieve RQ-PCR 〈 10% at 3 month was 43% (95% CI 32-54%). During treatment 3 (4%) progressed to AP and 5 (7%) to BC. The 5-year probability of OS was 78% (95% CI: 68-88%) albeit by disease status was 86% in CP, 92% in AP and 12% in BC (p〈 0.0001). OS was inferior in pts with RQ-PCR 〉 10% at 3 months (60 vs 84%, p= 0.03) and 〉1% at 6 months (68 vs100%, p= 0.006). PFS was 68% in 5-year, and was lower in BC pts (p〈 0.0001) and pts with RQ-PCR 〉1% at 6 months (p= 0.004). EFS was 53% and lower in BC pts (p〈 0.0001), in pts with RQ-PCR 〉 10% at 3 months (p= 0.005) and 〉 1% at 6 months (p〈 0.0001). RQ-PCR at 3 and 6 months were also predictive of a worse survival when patients in CP were analyzed separately. 2G-TKI was discontinued in 44% (31/71) due to: resistance (n=18), intolerance (n=5), death (n= 3), HSCT (n=3) and loss of follow-up (n=2). Eleven BCR-ABL mutations were detected in 36 pts; 3 previously 2G-TKI (L387M-1, E255K-1, M351T-1) and 9 after therapy (T315I-5, M244V-2, E255V-1, Y253H-1). OS by mutation was 45% with any mutation and 88% with no mutation (p= 0.05). Conclusion BCR-ABL transcript levels at 3 and 6 months can identify patients with worse prognosis and less chance to obtain CCR with 2G-TKI after imatinib treatment. Disclosures: No relevant conflicts of interest to declare.

Description: Chronic myeloid leukemia (CML) patients with imatinib failure are usually treated with second generation tyrosine kinase inhibitors (TKI). In case of dasatinib or nilotinib intolerance or resistance patients with HLA matched donor are submitted to allogeneic hematopoietic stem cell transplantation (HSCT) or switch treatment to a different TKI. Aims to evaluate complete hematological response (CHR), cytogenetic and molecular responses, overall, progression free and event free survival (OS, FPS and EFS) in CML patients in third line therapy that previously used 2 TKI. BCR-ABL mutations was also evaluated in this population Patients and methods between July 2008 and August 2012 26 CML patients were evaluated: 10 patients (pts) treated with dasatinib (38,5%) and 16 with nilotinib (61,5%) in third line therapy. OS, PFS and EFS were calculated with Kaplan-Meier method and Log-Rank was used for comparison, from the date of the third TKI start. The events for PFS were progression to accelerated phase (AP) or blast crisis (BC) and death. For EFS, were considered loss of CHR, loss of complete cytogenetic response (CCR), TKI discontinuation for failure or intolerance, progression or death. Patients were censored in HSCT date or TKI discontinuation for cytogenetic and molecular responses evaluation, but not for OS. Mutational analysis was done with Sanger sequencing. Results 13 male (50%) and 13 female patients with median age 54 years (22-75) and median follow-up of 32 months were analyzed (1-59). Previous response to imatinib: only one patient has achieved CCR. Status before third TKI start: 19 (73%) less than partial cytogenetic response (PCyR); 2 (7,7%) PCyR; 4 (15,5%) CCR;and 1 (3,8%) clonal evolution. 8/18 (42%) patients presented the following mutations: F317L (2), E255V (1), Y253H (1), M351T (1), M244V (1) e F359V (2). The median time of the third TKI treatment was 171 days (15-1140). Responses to third line TKI: CHR 17/19 (89%) in CP; 3/3 AF; 0/4 BC; CCR: 3/19 in CP (2 pts at 3 months and one in the 12º month); 1/3 AP; 0/4 BC; MMR: 4/19 in CP; 1/3 AP; 0/4 in BC. Nine lost CHR (45%) (8 in CP and one in AP). At 3 months, 1/21 pts (4.5%) achieved MMR; 2/13 (15%) at 6 months, while at 12 months 1/11 (9%) had MMR. At 3 months 11/21 had a BCR-ABL/ABL(IS) 〉10% and at 6 months 10/13 〉1%. Three patients progressed to advanced phases (11,5%) ; 6 (23%) died (4 due to LMC, 1 acute myocardial infarction and 1 from graft vs host disease after HSCT; one lost follow-up. Third line treatment was discontinued in 12 (46%) pts: 6 for resistance, 2 death; 2 intolerance and resistance; 1 intolerance and one loss of follow-up. OS, PFS and EFS were 69%, 68% e 30% respectively(figure 1). OS was inferior in AP and BC in comparison with CP (0% vs 50% vs 90% - p〈 0,0001)(figure 2). In summary responses may be obtained with dasatinib or nilotinib after 2 TKI failure, but they are not durable in advanced phases. Besides the results, that is an alternative for disease stabilization until the identification of a suitable donor or for patients with no performance status for HSCT. Disclosures: No relevant conflicts of interest to declare.

Description: Several studies demonstrated the prognostic significance of an early molecular response in chronic myeloid leukemia (CML) patients (pts) treated with imatinib in first line or other tyrosine kinase inhibitors. Aims: The aim of this study was to evaluate the impact of early molecular responses, at 3 and 6 months after treatment with imatinib in CML pts and correlate these responses with CCR, MMR, overall survival (OS) and event free survival (EFS). Patients and Methods Between February 2006 and June 2012, 95  adult pts with newly diagnosed CML in chronic phase (CP) received imatinib 400mg/daily. CP was defined using WHO 2008 criteria. All pts received a short course of hydroxiurea until imatinib was available. Cytogenetic analysis was performed at diagnosis, 3, 6, 12 and 18 months after starting therapy and then every 12-24 months thereafter. BCR-ABL transcripts were measured in peripheral blood at 3-month intervals using quantitative RT-PCR (RQ-PCR). Results were expressed as BCR-ABL/ABL ratio, with conversion to the international scale (IS). Major molecular response (MMR) was defined as a transcript level ≤ 0.1% (IS). Statistical analysis: OS was measured from imatinib start until date of death or last visit. An event was defined as death from any cause. EFS was measured from imatinib start until the first event (loss of complete hematological response (CHR); complete cytogenetic response (CCR), progression to advanced phase, death or imatinib discontinuation) or last visit. OS and EFS rates were calculated using Kaplan-Meier method and log-rank test to compare its curves. The MMR probabilities according to molecular responses at 3 and 6 months were calculated by c2 method and cumulative incidence, considering as competitive event death or progression, before the event. Results 95 pts were analyzed, 57 (60%) male, with a median age of 47 years (17-79); Sokal score: high, intermediate and low was 30, 38.6 and 31.4% respectively; EUTOS scores was 81.5% low and 18.5% high. The median time from diagnosis until imatinib therapy was 1 month (0-5) and the follow-up was 39 month (3-89). Responses: 88% achieved CHR; 50% CCR and 53% MMR. One patient progressed to advanced phase during follow-up, while on imatinib treatment. 21 (22%) pts discontinued imatinib due to intolerance (47.6%); resistance (42.9%), death (4.8%) and Allo-HSCT (4.8%). At 3 months from the start of therapy, 30/64 (46.8%) achieved CCR, 15/64 (23.4%) partial cytogenetic response and 20/64 (31.2%) less than partial; by RQ-PCR, 72.3% (68/94) achieved at 3 months BCR-ABL transcripts ≤10% and 27.7% (26/94) 〉 10%. At 6 months 55.2% (48/87) had BCR-ABL transcripts ≤ 1% and 44.8% (39/87) 〉1%. The OS was 97% (95%CI: 95-99%) and EFS 63% (95%CI: 52-75%).There was no significant difference in OS and EFS in pts with RQ-PCR 〉 10% vs ≤ 10% at 3 months (figure 1), but pts with BCR-ABL transcripts 〉 10 and 〉1-10% at 6 months had an inferior EFS in comparison with pts with  BCR-ABL transcripts ≤ 1%  (41%,50%,89% respectively - p= 0.005), (figure 2). The CI showed that CCR pts at 3 months reached MMR earlier at 24 month (54% vs 18%, p=0.03), as well as CCR pts at 6 months, albeit no significance statistically (52% vs 37%, p= 0.16). For RQ-PCR at 3 months, pts with BCR-ABL transcripts 0-1% had a probability of 88% to achieve MMR, 1-10% had 52% and 〉10% 42%, p〈 0.0001 (figure 3). In conclusion, our results show that early molecular responses are predictive of achieving MMR and BCR-ABL transcripts

Description: Abstract 3289 Poster Board III-1 Imatinib dose escalation has been used in sub-optimal response and therapeutic failure to imatinib in conventional doses. The aim of this study was to evaluate the efficacy of imatinib dose increase in CML patients in CP who did not achieve the best response to imatinib 400 mg QID. Patients and methods: All CML patients in CP treated in our institution with imatinib 400mg between March 2002 and December 2008 were evaluated. Imatinib was escalated to 600–800mg in cases with sub-optimal response or failure, according to Leukemia Net or IRIS Trial criteria. All survival curves were calculated from date of dose increase: overall survival (OS) until death or last follow-up, event free survival (EFS) until loss of complete hematological response (CHR) or major cytogenetic response (MCyR), progression to accelerated phase (AP) or blast crisis (BC) or death from any cause. Transformation free survival (TFS) was calculated from dose increase until progression to AP, BC or death. Results: 137 patients in CP were treated with imatinib 400 mg. Dose was escalated in 55 (40%) patients due to loss or failure to achieve CRH (13 = 24%); progression to BC (2 = 3.5%); no CCR (11 = 20%); loss of RCC (5 = 9%); CCR without major molecular response (MMR) after 18 months of imatinib (24 = 43.5%). Males: 37, females 18 cases. Median age: 44 (16–74) years. Twenty-eight patients (49%) were treated with imatinib as first line therapy and 51% had used IFN previously. Median time between diagnosis and imatinib start was 4.5 (0–94) months. Responses: 94% achieved CHR; 58% CCR and 34% MMR. After dose increase, 31 (56%) responded: 58% of the patients with previous sub-optimal molecular response achieved MMR. Among those who benefited from dose increase, only 3 cases lost the response: one with hematological resistance and two with cytogenetic resistance (2 lost CCR and one CHR). Seven out of 16 patients who increased dose due to cytogenetic failure (loss of response, failure and sub-optimal response) achieved response: one had partial cytogenetic response (PCyR) and 6 CCR. Five patients with hematological failure presented response: CHR (2), CCR (1), PCyR (1) and MMR (1). Patients with BC (2 cases) did not respond to dose escalation. TFS was 89% and 67% in 2 and 5 years, respectively. EFS was 71% and 64% in 2 and 5 years respectively. When stratified by the type of failure, EFS was 100%, 49% and 34% in the group with molecular sub-optimal response with median time of 22 (4–41) months, cytogenetic 17 (1.2–42) and hematological failure 7.7 (0.2–57), respectively (P

Description: Introduction The majority of chronic myeloid leukemia (CML) patients (pts) in chronic phase (CP), present satisfactory response to imatinib treatment. However, 25-30% of these pts exhibit suboptimal response or treatment failure. The probability of achieving optimal response may be related with several factors. The human organic cation transporter 1 (hOCT1, SLC22A1), an influx transporter, is responsible for the uptake of imatinib into chronic myeloid leukemia (CML) cells The aim of this study was to analyze hOCT-1 levels at diagnosis of CML patients and correlate with cytogenetics and molecular responses. Methods hOCT-1 expression was evaluated in 58 newly diagnosed CML pts. Pts were treated with imatinib 400-600mg in first line. Samples were collected from peripheral blood at diagnosis and RNA was obtained from total leucocytes. For cDNA synthesis, 3 ug of RNA was used. hOCT-1 expression was evaluated by real-time PCR with TaqMan probe SLC22A1 (Applied Biosystems) and endogenous GAPDH control. The results were analyzed using 2-ΔΔCT. Cytogenetic analysis was performed at diagnosis, 3, 6, 12 and 18 months after starting therapy and then every 12-24 months thereafter if CCR was achieved. BCR-ABL transcripts were measured in peripheral blood at 3-month intervals using quantitative RT-PCR (RQ-PCR). Results were expressed as BCR-ABL/ABL ratio, with conversion to the international scale (IS). Major molecular response (MMR) was defined as a transcript level ≤ 0.1%. Results 58 CML pts, 60% male, median age of 46 years (19-87) were evaluated, 71% in chronic phase (CP), 21% in accelerated phase (AP) and 5% in blast crisis (BC). The mean and median of hOCT-1 transcript levels in the total group was 2.03 and 0.961 respectively (0.008–19.039) and CP pts was 1.86 and 1.00 (0.008-10.34).The median duration of imatinib treatment was 27 months (1-109) and 96.6% achieved complete hematological response, 79.3% complete cytogenetic response and 69% major or complete molecular response. The regression analysis showed correlation between higher transcript levels of hOCT-1 and BCR-ABL transcripts

Description: Abstract 1681 Recently the European LeukemiaNet has developed a new scoring system (European Treatment and Outcome Study [EUTOS] score) for newly diagnosed chronic myeloid leukemia (CML) in chronic phase (CP) treated with imatinib. The EUTOS score classifies patients in high or low risk on the basis of the percentage of basophils in the peripheral blood and the spleen size at diagnosis, with significant correlations with the achievement of an 18-month complete cytogenetic response (CCyR) and progression-free survival (PFS). The aim of this work was to evaluate EUTOS score in CML-CP treated in our center with imatinib as a predictive factor for overall survival (OS), event-free survival (EFS) and PFS. Patients and methods: Between February 2003 and May 2012 consecutive patients with newly diagnosed CML-CP were treated with imatinib 400 mg daily (n= 144) or imatinib 600–800 mg daily (n= 14) were included in the analysis. The criteria recommended by European LeukemiaNet (ELN) were used for the definitions of CCyR and the progression to accelerated phase (AP) or blast phase (BP). The EUTOS score was defined by (7×basophils) plus (4×spleen size) at diagnostic. A EUTOS score of more than 87 indicates high risk, and less than or equal to 87 low risk. EFS was measured from the start of imatinib treatment to the date of any of the following events: death from any cause at any time, loss of complete hematologic response, loss of CCyR, or progression to AP or BP. PFS was measured from the start of treatment to the date progression to AP or BP, last follow-up, or death from any cause. Survival probabilities were estimated by the Kaplan-Meier method and compared by the log-rank test whereas it was applied cumulative incidence for the probability to achieve CCyR. Results: A total of 158 patients were treated, 94 (59.5%) male. The median age at Imatinib was 47 years (17–86 years). The median time from diagnosis to TKI therapy was 2 (0–6) months, with 153 (96.8%) receiving previous treatment with Hydrea. The median follow-up was 29 (1–110) months. The median splenomegaly size was 4 (0–29) cm and the median basophil percentage was 2.5% (0–18%). According to the Sokal score, 43 (34,4%) patients, 46 (36,8%), and 36 (28,8%) were in low, intermediate, and high Sokal score category, respectively (33 not available). Concerning the Hasford score, 60 (48,3%), 50 (40,4%) and 14 (11,3%) were in low, intermediate and high risk categories (34 NA). A total of 137 (86,8%) patients were in the low EUTOS score category and 21 (13,2%) in the high risk category. The cumulative probability of achieving a CCyR and MMR at 36 months for all patients was 78% and 64%, respectively. Patients who had not achieved CCyR after 6 months (51/153 – 33%) had a 2% risk of subsequent progression, which increased to 12% after 12 months, 14% in 18 months and 19% after 24 months. EFS, PFS, and OS rates for the whole group were 60%, 89%, and 92%, respectively. Patients with a low EUTOS score had higher rates of cumulative CCyR compared with patients with high EUTOS score (82% vs. 53%, p= 0.06) (figure 1). There were no differences in the cumulative CCyR rates in patients stratified by Sokal or Hasford scores (and 0.21 and P=0.82, respectively). Patients with CCyR at 18 months had a higher EFS (81% vs. 18%, p〈 0.0001) and PFS rates (96% vs. 82%, p= 0.03). There was no difference in PFS (figure 2) and OS rates between patients with low and high EUTOS score. However, patients with high and intermediate Sokal score had an inferior PFS rates in comparison with low risk group (77%, 84% and 100%, respectively, p= 0.02). There was a superior EFS rates in low risk in comparison with high EUTOS score (63% vs. 36%, p= 0.01) (figure 3), whereas the overall survival there was no difference (91% vs. 100%). Sokal scores EFS rates were 68%, 60% and 40% for low, intermediate and high risk groups respectively (p= 0.03). In conclusion, similarly to the original report, EUTOS score seems to predict CCyR, but not PFS in our population. However, EFS was significantly better in the low than high risk group. The score can discriminate patients with poor outcome, with lower probability of achieving responses to first line imatinib therapy. Disclosures: No relevant conflicts of interest to declare.

Description: Abstract 1701 Mutations within the BCR-ABL domain are the most frequent mechanism of imatinib (IM) resistance. The second generation inhibitors (SGI) are indicated for imatinib intolerance or resistance and the initials trials showed similar response rates in IM resistant patients after IM failure, independent of mutation status, with exception of T315I. The aim of this work was to report the frequency of BCR-ABL mutations in chronic myeloid leukemia (CML) patients of a Latin American population and to evaluate the clinical impact of the presence and type of mutations in overall survival (OS), progression free survival (PFS) and in the response to second generation inhibitors (SGI). Methods: retrospective analysis of 17 centers from Latin America. A total of 529 CML patients with mutation analysis performed in samples collected between 2002 and 2011 were included. Mutations were detected by direct sequencing from bone marrow or peripheral blood samples, collected from CML patients. After imatinib resistance, patients were treated with SGI (69%) or other treatments. Overall survival (OS) was calculated from date of mutation detection until last follow-up or death, and progression-free survival (PFS) from date of mutation detection until progression to accelerated phase or blast crisis, last follow-up or death. Survival curves were calculated using the log-rang test (SPSS 14.0 software).Results: the median age of patients at diagnosis was 45 years (5–87). 81% were in chronic phase (CP), 13% in accelerated phase (AP), 6% in blast crisis (BC). According to Sokal score, patients were stratified in low (36%), intermediate (30%) and high risk (34%); 36% had previously used Interferon. The median time from diagnosis until Imatinib treatment was 8 months (0–310) and from Imatinib start until mutation detection was 31 months (1–104). Mutations were found in 188 patients, in the following sites: P-loop (75/40%), nucleotide contact site (34/18%), catalytic domain (44/23%), A-loop (11/6%) and others (24/13%). The most frequent mutations detected were: T315I (30/16%), F359V/C/I (27/14%), M244V (18/9.6%), E255K/V (17/9%), G250E (17/9%), Y253H/F/Y (15/8%), M351T/L (12/6%); Ten patients presented concomitant mutations. On dasatinib treatment 29 mutations (27% T315I) were detected whereas 18 during nilotinib (16.5% T315I). Overall survival in the total group was 61% (95%CI: 51–71%) with a median time of 12 months. There was a significant difference in OS and PFS between non-mutated and mutated patients (76% vs 44% and 64% vs 44% respectively (P= 0.008 and P= 0.001). There was no difference in survival comparing P-loop mutations and others, excluding T315I. Patients with T315I mutations had a poorer outcome in comparison with other mutations (OS 21% vs 62%; PFS 35% vs 55%) (P= 0.04 and 0.06, respectively). In the group with BCR-AL mutations, OS was superior in patients that received a SGI in comparison with other treatments after resistance (50% vs 36% P= 0.007). One hundred patients (19%) died due to: disease progression (72), infections (8), graft versus host disease (2), central nervous system bleeding (2), cardiac failure (1), second neoplasia (1). 14 causes were not reported. Conclusions: Patients with BCR-ABL mutations had an inferior OS and PFS. T315I mutations were associated to a poor outcome. Treatment with SGI prolonged survival of patients after imatinib failure. Disclosures: Pagnano: Novartis: Speakers Bureau; Bristol Myers Squibb: Speakers Bureau. Boquimpani:Novartis: Speakers Bureau; Bristol Myers Squibb: Speakers Bureau. Pasquini:Novartis: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Bristol Myers Squibb: Speakers Bureau. Spector:Novartis: Membership on an entity's Board of Directors or advisory committees.