ALBERT

Description: Abstract 3084 With modern intensive chemotherapy, 78% to 93% of adult patients with acute lymphoblastic leukemia (ALL) achieve complete remission (CR). However, the disease-free survival rate is only 30% to 40% due to the high rate of relapse. A part of relapsed patients can achieve second remission (CR2) with salvage therapy, and allogeneic hematopoietic stem cell transplantation (HSCT) in CR2 will be the only curative strategy. Prognosis after relapse in adult patients with ALL is considered to be extremely poor, but reports as to the outcome after relapse have been limited. To elucidate the outcome of relapsed patients and prognostic factors after relapse, we retrospectively collected and analyzed clinical data from 69 institutions in Japan on patients with Philadelphia-chromosome (Ph) negative ALL, aged 16–65 years, who relapsed after first CR (CR1) between 1998 and 2008. A total of 332 patients were included in this study. The median age of them was 35 years, and 165 patients were male. Median duration of CR1 was 290 days (range 15–7162 days), and median follow-up time after relapse was 319 days (range 3–3689 days). Fifty-eight and 4 of them relapsed after allogeneic and autologous HSCT in CR1, respectively. The overall survival (OS) rate was not significantly different between patients who relapsed after allogeneic HSCT in CR1 and those who relapsed after chemotherapy only (50.0% vs. 43.4% at 1 year and 10.6% vs. 16.3% at 5 year, respectively). Among 270 patients who relapsed after chemotherapy only, 234 patients received salvage chemotherapy after relapse, and 123 patients achieved CR2 (52.5%). Sixty-two patients out of those 123 patients underwent allogeneic HSCT in CR2. Median duration between the achievement of CR2 with salvage chemotherapy and allogeneic HSCT in CR2 was 76 days. OS rate was significantly better in patients who underwent allogeneic HSCT in CR2 following salvage chemotherapy than those who did not (74.1% vs. 55.1% at 1 year and 44.7% vs. 11.6% at 5 year, respectively) by a landmark analysis limiting patients who were surviving without disease at 76 days after the achievement of CR2. In multivariate analysis of factors that included allogeneic HSCT in CR2 following salvage chemotherapy as a time-dependent covariate, lower white blood cell count at relapse (less than 10000/μl) and allogeneic HSCT in CR2 were associated with better OS rate among patients who achieved CR2 following salvage chemotherapy. Forty-six patients underwent allogeneic HSCT in non-CR after receiving salvage chemotherapy. A part of them survived long, and 5 year OS rate was 20.9%. In conclusion, the prognosis of adult patients with relapsed Ph-negative ALL is poor. Allogeneic HSCT after first relapse could improve the prognosis. Disclosures: No relevant conflicts of interest to declare.

Description: Abstract 4334 BACKGROUD We designed a multicenter study (JALSG ALL 97) including an intensified consolidation program with dose-escalated doxorubicin (DOX) in order to improve outcome in adults with acute lymphoblastic leukemia (ALL) in pre-imatinib era. We reported here the efficacy and prognostic factors of mainly Philadelphia chromosome (Ph)-negative patients. METHODS From May 1997 to December 2001, patients (age ranges 15 - 64 years) with previously untreated ALL (excluding mature B-cell ALL) were consecutively registered in this study. We modified the standard induction program with five drugs; vincristine (VCR), daunorubicin, cyclophosphamide, prednisolone (PSL) and L-asparaginase and the maintenance program with daily 6-mercaptopurine, weekly methotrexate (MTX) and monthly pulses of VCR and PSL used in CALGB 8811 study. Consolidation therapy included eight courses featuring dose-intensified DOX and intermediate-dose MTX. The total dose of DOX in consolidation phase was 330 mg/m2. For patients with Ph or t(4;11), allogeneic stem cell transplantation (HSCT) was recommended during their first complete remission (CR), if donors were available; whereas for patients without Ph or t(4;11) there was no criteria for choosing HSCT. The 5-year overall survival (OS), the 5-year disease-free survival (DFS), and the prognostic factors were evaluated. RESULTS There were 404 eligible patients (median age, 38 years), of whom 256 were Ph-negative and 116 were Ph-positive. Of the eligible patients, 298 patients (74%) achieved CR. With a median follow-up time of 5.8 years, the estimated 5-year OS rate was 32% (95%CI: 27.1-36.9), and the 5-year DFS was 33% (95%CI: 26.8 - 38.2). The CR rates in Ph-negative and Ph-positive patients were 81% (n=208) and 56% (n=65), respectively. The 5-year OS in Ph-negative and Ph-positive patients were 39% and 15%, respectively. In Ph-negative patients, multivariate Cox analysis showed that older age, PS and WBC count were the independent prognostic factors for OS. The 5-year OS rates for patients younger than 35 years and a WBC count less than 30 × 109/L (risk group 1), for patients younger than 35 years and a WBC count above 30 × 109/L (risk group 2), for patients older than 35 years and a WBC count less than 30 × 109/L (risk group 3), and for patients older than 35 years and a WBC count above 30 × 109/L (risk group 4), were 51%, 29%, 33%, and 27%, respectively (P=0.0005). Of the 208 Ph-negative patients who achieved CR, 60 patients (29%) were underwent allogeneic-HSCT during their first CR (37 from a related donor and 23 from an unrelated donor), resulting that 8 (13%) died in remission, 16 (27%) relapsed, and 36 (60%) remained in continuous CR. The 5-year OS rate for the 60 patients was 63 %. Among them, the 5-year OS rates for the 31 patients of the risk group 1 (standard risk group) and for other 29 patients (high risk group) were 73% and 54%, respectively. Among 148 patients who did not receive allogeneic-HSCT during first CR, six (4 %) died in remission, 105 (71%) relapsed, and 37 (25%) remained in continuous CR. The 5-year OS rates for the 148 patients, for patients with standard risk, and for patients with high risk were 37%, 44% and 33%, respectively. CONCLUSION Result of this study was in the range of those reported by most large cooperative groups, but showed little improvement of adult Ph-negative ALL therapy. The prognostic factors for long term outcome of Ph-negative patients were similar to those in previous reported. This study also suggested that allogeneic-HSCT for Ph-negative patients in first CR might have contributed to the improvement of the outcome. Disclosures: No relevant conflicts of interest to declare.

Description: The majority of acute promyelocytic leukemia (APL) cases are characterized by the presence of a promyelocytic leukemia–retinoic acid receptor alpha(RARA) fusion gene. In a small subset, RARA is fused to a different partner, usually involved in regulating cell growth and differentiation. Here, we identified a novel RARA fusion transcript, BCOR-RARA, in a t(X;17)(p11;q12) variant of APL with unique morphologic features, including rectangular and round cytoplasmic inclusion bodies. Although the patient was clinically responsive to all-trans retinoic acid, several relapses occurred with standard chemotherapy and all-trans retinoic acid. BCOR is a transcriptional corepressor through the proto-oncoprotein, BCL6, recruiting histone deacetylases and polycomb repressive complex 1 components. BCOR-RARA was found to possess common features with other RARA fusion proteins. These included: (1) the same break point in RARA cDNA; (2) self-association; (3) retinoid X receptor alpha is necessary for BCOR-RARA to associate with the RARA responsive element; (4) action in a dominant-negative manner on RARA transcriptional activation; and (5) aberrant subcellular relocalization. It should be noted that there was no intact BCOR found in the 45,-Y,t(X;17)(p11;q12) APL cells because they featured only a rearranged X chromosome. These results highlight essential features of pathogenesis in APL in more detail. BCOR appears to be involved not only in human congenital diseases, but also in a human cancer.

Description: Key Points We conducted a phase 2 study of ATO followed by autologous HCT for relapsed APL. This sequential treatment is effective and feasible.

Description: Clinical characteristics of Japanese patients with t(8;21) acute myeloid leukemia (AML) have not been well described. From January 2000 to December 2005, a total of 147 Japanese adult de novo AML (FAB: M2) patients were newly diagnosed with t(8;21) AML (n=46) or without t(8;21) AML (n=101) in collaborating hospitals. Patients with t(8;21) (median age, 49.5 years; range, 18–86 years) were significantly younger than AML(M2) patients without t(8;21) (median age, 60 years; range 17–90 years) (p

Description: Abstract 1703 The majority of acute promyelocytic leukemia (APL) cases are characterized by the presence of a PML-RARA fusion gene. In a small subset, RARA is fused to a different partner including PLZF, NPM1, NuMA, STAT5b, PRKAR1A and FIP1L1. Here we identified a novel RARA fusion transcript, BCOR-RARA in a t(X;17)(p11;q12) variant of APL. The patient was a 45-year-old man. Although the patient was clinically responsive to ATRA, repeated standard chemotherapy with ATRA did not effect a cure. The bone marrow promyelocytes had unique morphologic features, including rectangular and round cytoplasmic inclusion bodies. They were more granular than those of AML M2 but less granular than the classical t(15;17) APL. Flow cytometric analysis revealed strong expression of CD13, CD33, CD56, weak expression of CD11c and lack of HLA-DR and CD7. The karyotype analysis detected a novel chromosomal translocation described as 45,-Y, t(X;17)(p11.2;q12)[19]/ 46,XY[1]. FISH analysis indicated one intact and two split signals of RARA and two intact signals of PML. To amplify unknown chimeric fusion transcripts, we performed 5'-RACE. The sequence revealed that BCL6 co-repressor, BCOR cDNA from exons 9 to 12 to be fused to RARA exon 3. By RT-PCR, we confirmed full length chimeric fusion transcripts spanning from the start codon to 4,948 nt of BCOR cDNA (NM_001123384) fused to RARA cDNA from exon 3 to the stop codon. The chimeric cDNA had an in-frame codon from BCOR through RARA, creating a 1,931 amino acid fusion protein. One of the consistent features in all known RARA fusion partners is self-association. To determine whether BCOR-RARA self-associate, we performed co-immunoprecipitation assays. These results showed that BCOR-RARA is able to self-associate both through the region of BCOR-S and the ankyrin repeat domain of BCOR. In addition, BCOR-RARA associated with BCL6. RXR recruitment is a critical determinant of transforming potential of oligomeric RARA fusion proteins. To investigate how BCOR-RARA associates with RARE in vitro, we performed EMSA. These results showed that BCOR-RARA/RXRA complex associates with RARE in an alternative manner compared to RARA and PML-RARA. Deregulation of RARA transcriptional activations has a central role in pathogenesis of APL. Therefore, we evaluated ATRA-induced transcriptional activation of 4× RAREs with a reporter assay in HepG2 cells. Without ATRA, BCOR-RARA repressed the reporter activity. With addition of ATRA, BCOR-RARA induced transcriptional activation very weakly. Subsequently, we evaluated dominant-negative effects of the samples in the RARA/RXRA pathway. In contrast to BCOR, BCOR-RARA clearly inhibited ATRA-induced RARA transcriptional activation as well as PML-RARA. Furthermore, we asked which domains are sufficient for the dominant-negative effects with the deletion mutants. The results indicated that the region spanning from 999 to 1,409 aa of BCOR-RARA has pivotal roles in the dominant-negative effects. Correct protein function is highly dependent on intracellular localization. To investigate subcellular localization of BCOR-RARA, we performed immunofluorescence analysis in 293T cells. In BCOR-RARA-expressing cells, BCOR-RARA localized as two patterns; (I) diffusely in the nucleus as well as PML-RARA in 82% of the cells, (II) diffusely in the nucleus and aggregately in the cytoplasm in 18% of the cells. The subcellular localization of BCOR-RARA was clearly distinguishable from the punctuate pattern as shown in the nucleus of BCOR-expressing cells. Moreover, co-immunofluorescence analysis between BCOR-RARA and BCL6 indicated that the subcellular localization of BCOR-RARA/BCL6 is distinct from BCOR/BCL6. BCOR-RARA was found to possess common features with other RARA fusion proteins. These included: (I) the same break point in RARA cDNA; (II) self-association; (III) RXRA is necessary for BCOR-RARA to associate with the RARA responsive element; (IV) action in a dominant-negative manner on RARA transcriptional activation; (V) aberrant subcellular relocalization. It should be noted that there was no intact BCOR found in the 45,-Y,t(X;17)(p11;q12) APL cells because they featured only a rearranged × chromosome. These results highlight essential features of pathogenesis in APL in more detail. BCOR appears to be involved not only in human congenital diseases but also in a human cancer. Disclosures: No relevant conflicts of interest to declare.

Description: Abstract 1077 (Background) Studies focused on elderly APL are limited. The European APL study group reported in their APL 93 trial that lower survival rate in elderly APL was mainly due to an increase of early deaths and toxicity of chemotherapy (Ades et al, 2005). On the other hand, PETHEMA group reported in their LPA96 and 99 studies that ATRA combined with anthracycline monochemotherapy resulted in low toxicity and high compliance, and that survival rate is similar to younger patients (Miguel A et al, 2004). We analyzed clinical features and outcomes of elderly APL patients with APL who were treated with ATRA and intensive chemotherapy and compared with those of younger patients in long term follow-up of the JALSG-APL97 Study. (Methods) Patients with newly diagnosed APL were continuously registered from May 1997 to June 2002, and induction therapy was composed of ATRA and chemotherapy including idarubicin and cytarabine. The dose and duration of chemotherapy were based on initial leukocyte count. After completion of 3 courses of consolidation chemotherapy, patients negative for the PML-RARA transcript were randomly allocated either to receive 6 courses of intensified maintenance chemotherapy or to observation. Elderly patients were treated with the same schedule to younger patients (Asou et al, 2007). Clinical features as well as relapse rate (RR), overall survival (OS) and disease-free survival (DFS) were assessed in elderly group with aged 60 or more in comparison with younger group. Clinical outcomes were updated on January, 2009 and the median follow up period is 7.3 years. (Results) Of 302 patients registered in this study, 283 patients were assessable. The median age was 48 years (range, 15–70 years), with 237 patients in younger group (median age, 44 years) and 46 patients in elder group (median age, 63 years). Significantly lower platelet count (less than 10 × 109/L), higher incidence of ECOG performance status 3 to 4, lower albumin level (〈 3.5g/dl) were observed in elderly group compared to younger group (P = 0.04, P = 0.02 and P 〈 0.001, respectively), while clinical characteristics including gender, initial leukocyte count, APL cells in peripheral blood, DIC score, frequency of variant type (M3v), expression of CD-phenotype, past history of chemotherapy and/or radiotherapy and number of infectious complications at diagnosis, did not differ between two groups. The CR rates and early mortality during induction therapy including to hemorrhagic complications were similar between two groups (89% vs. 96%, P = 0.06; 11% vs. 4%, P = 0.08), whereas induction death due to differentiation syndrome in elderly group is higher compared with younger group (4% vs. 0%, P = 0.03). The cumulative incidence of non relapse mortality (NRM) during the third consolidation chemotherapy was significantly higher in elderly group (9% vs. 1%., P = 0.04). All of the mortality occurred during consolidation therapy was associated with infection. Although OS was lower in elderly groups at 10 year compared with younger group (65% vs. 87%, P 〈 0.001), DFS and RR were similar between two groups (65% vs. 67%, P = 0.70; 13% vs. 26%, P = 0.15, respectively). (Conclusion) The present study demonstrated that efficacy of ATRA combined with chemotherapy in elderly APL was similar to younger APL. Nevertheless, lower OS at 10 year in elderly APL was observed in this study. One of the reasons was an increase of NRM, especially induction death due to differentiation syndrome and infection death during consolidation chemotherapy. Thus, reduction of intensity of post remission chemotherapy should be considered in elderly patients. Non-myelosuppressive agents such as arsenic trioxide and/or tamibarotene should be incorporated into the post remission therapy for elderly patients with APL. Disclosures: No relevant conflicts of interest to declare.

Description: The use of all-trans retinoic acid (ATRA) has markedly improved therapeutic outcome in patients with acute promyelocytic leukemia (APL). Non-cross resistance between ATRA and chemotherapeutic drugs has contributed to not only a high complete remission (CR) rate but also a decrease in the relapse rate, leading to the significant improvement in disease-free survival (DFS) and overall survival (OS) rates. However, it is not clear whether maintenance chemotherapy actually prevents relapse in APL patients treated with ATRA and chemotherapy. If short-term therapy without maintenance shows identical DFS rates as compared to long-term therapy with maintenance, it would be beneficial for quality of life of patients as well as to medical costs. In these aspects, to determine an efficacy of maintenance/intensification chemotherapy, this study was designed to compare the DFS and OS rates in previously untreated adult patients with APL who showed absence of PML-RARα fusion transcript at the end of consolidation therapy and were randomly allocated to either maintenance therapy or observation. Of 302 registered, 283 patients were assessable and 267 (94%) achieved a CR. Predicted 6-year OS and DFS rates were 83.7% and 69.2%, respectively. The PML-RARα fusion gene was amplified using bone marrow samples at the diagnosis and after consolidation therapy by the reverse transcriptase-polymerase chain reaction analysis. The detection limit of PML-RARα fusion transcript in this assay was 10-4. Among 235 patients who completed 3 courses of consolidation chemotherapy, five (2.1%) were positive for the PML-RARα fusion transcript. Three of them subsequently relapsed and another one patient received allogeneic hematopoietic stem cell transplantation. On the other hand, 230 patients (97.9%) showed no PML-RARα transcript in the bone marrow cells at the end of consolidation. Of these, 175 patients were randomly assigned to receive moderately intensive and intermittent maintenance chemotherapy (n=89) or to observation (n=86). Predicted 6-year DFS was 63.2% for the chemotherapy group and 81.8% for the observation group, showing no statistically significant difference (p=0.102). Predicted 6-year OS in patients assigned to observation was 98.7% and was significantly higher than 85.9% in those allocated to maintenance therapy (p=0.013). These results indicate no benefit from adding maintenance chemotherapy in APL patients who are negative for PML-RARα fusion transcript after 3 courses of intensive consolidation.

Description: Abstract 3608 CD56 expression is reportedly associated with an adverse prognosis in patients with acute promyelocytic leukemia (APL) (Murray et al, 1999, Ferrara et al, 2000), but the prognostic significance of CD56 has not been elucidated in multivariate analysis. Recently, however, Spanish group demonstrated that CD56 expression was a significant adverse prognostic factor for relapse in APL treated with ATRA combined anthracycline-based regimens in multivariate analysis (Montesinos et al, 2011). We tried to evaluate the significance of CD56 in APL on more intensive regimen composed by ATRA, anthracycline and cytosine arabinocide (Ara-C). Newly diagnosed APL patients were registered to the JALSG APL97 from May 1997 to June 2002. The detail of the treatment protocol was previously reported (Asou et al, 2007). In brief, induction therapy was composed of ATRA and chemotherapy including idarubicin and Ara-C. The dose and duration of induction therapy were based on initial white blood cell (WBC) count. After 3 courses of consolidation therapies, patients were randomly allocated either to receive 6 courses of intensified maintenance chemotherapy or to observation. Leukemia blasts were stained by anti-CD45 monoclonal antibody (mAb), gated by CD45 expression and analyzed by flow cytometer. Cells were additionally stained by fluorescein conjugated mAb against each surface antigen including CD56. Surface markers were defined as positive if more than 20% of APL cells expressed a specific antigen. Clinical characteristics were compared by the chi-square test or the Fisher's exact test for categorical data and the Wilcoxon rank-sum test for continuous data. Overall survival (OS) and event-free survival (EFS) were estimated by the Kaplan-Meier method and the log-rank test. Cumulative incidence of relapse (CIR) was compared by the Gray test for comparisons. Multivariate analyses were also performed. Clinical outcomes were renewed on March 2010 and the median follow up period is 7.5 years. Among 302 patients enrolled, 239 patients were assessable. Twenty three patients (9.6%) were CD56-positive (CD56+) APL. CD56 expression was significantly associated with lower platelet count, serious DIC and expressions of CD2, 7, 34, HLA-DR. (P = 0.04, 0.04, 0.03, 0.04,

Description: Abstract 2036 BACKGROUND: There are limited numbers of studies focusing on the role of hematopoietic stem cell transplantation (HSCT) as a salvage treatment for acute promyelocytic leukemia (APL) after relapse in the all-trans-retinoic acid (ATRA) era. We retrospectively analyzed the outcomes of APL patients who underwent allogeneic or autologous HSCT during second complete remission (CR2) and compared them with those in APL patients who did not receive HSCT. PATIENTS & METHODS: A total of 302 adult patients with previously untreated de novo APL were registered in the Japan Adult Leukemia Study Group (JALSG) APL97 study between 1997 and 2002, and treated with ATRA and chemotherapy (Asou et al., 2007). Of 283 assessable patients with t(15;17) and/or PML-RARA, 267 (94.3%) achieved CR and 67 (23.7%) relapsed. Except for 2 patients unable to complete the follow-up survey, 65 relapsed patients received salvage treatment with ATRA alone (n=17), ATRA plus chemotherapy (n=33), chemotherapy alone (n=6), tamibarotene alone (n=7), allogeneic HSCT (n=1), unknown (n=1), and 58 of these patients (89%) achieved CR2. Of the patients who achieved CR2, 27 received HSCT (21 allogeneic and 6 autologous) during CR2, 30 did not receive HSCT, and 1 was not assessable. All 6 patients who underwent autologous HSCT were confirmed of having achieved molecular CR. We compared the survival rates of patients with CR2 achievement who received HSCT (HSCT group) or did not receive HSCT (no-HSCT group). Survival was calculated from the date of CR2 to death or last visit. Probabilities of survival were estimated using the Kaplan-Meier method and compared by the log-rank test. RESULTS: Median age at first relapse was significantly lower in the HSCT group (36 years; range: 22 – 60) than in the no-HSCT group (53 years; range: 16 – 72) (P = 0.006). Median first CR duration was 21.6 months (range: 5.5 – 80.8) in the HSCT group and 17.6 months (range: 5.9 – 90.5) in the no-HSCT group (P = 0.75). Among patients in the no-HSCT group, 6 underwent allogeneic (n = 4) or autologous (n = 2) HSCT during CR3 or more. Five-year survival rate in the HSCT and no-HSCT groups were 70.4% and 77.4%, respectively (P = 0.86). Six patients died within 5 years of CR2 in the HSCT group. The causes of death included complications of allogeneic HSCT (n = 4) and relapse after HSCT (n = 2; 1 autologous, 1 allogeneic). In contrast, 7 patients in the no-HSCT group died of complications of allogeneic HSCT after second relapse or later (n = 4), disease progression (n = 2), and ischemic heart disease (n = 1). Among younger patients (aged ≤39 years), there was no statistically significant difference in 5-year survival between the HSCT group (100.0%) and the no-HSCT group (82.5%) (P = 0.10). In contrast, among older patients (aged ≥40 years), 5-year survival rate was significantly higher in the no-HSCT group (78.0%) than in the HSCT group (40.5%) (P = 0.04) (using the time-dependent covariates). Within the HSCT group, 5-year survival rate was significantly better in younger patients (n = 15) (100.0%) than in older patients (n = 12) (50.0%) (P = 0.006). Among the 27 patients in the HSCT group, there was no significant difference in 5-year survival between patients who underwent allogeneic HSCT (76.2%) and those who underwent autologous HSCT (83.3%) (P = 0.69). However, the 5-year cumulative incidence of relapse was significantly higher in patients who underwent autologous HSCT (58.3%) than those who underwent allogeneic HSCT (11.3%) (P = 0.01). After second relapse, 3 of 4 patients who underwent autologous HSCT at CR2 achieved CR3 through treatment with arsenic trioxide (ATO), tamibarotene or high-dose cytarabine. CONCLUSIONS: This study indicates that allogeneic HSCT is recommended in younger APL patients (aged ≤39 years) during CR2, while autologous HSCT is accompanied by frequent relapses. Our retrospective study also revealed that outcomes were significantly better in elderly patients who did not receive HSCT than those who did during CR2. This may result from a high HSCT-related mortality rate among elderly patients, and suggests a need for appropriate salvage treatment after relapse. We can now use ATO for salvage therapy routinely, allowing for further improvement of relapsing APL outcomes, even for patients not eligible for HSCT. Disclosures: Takeshita: Takeda: Research Funding; Novaltis: Research Funding. Naoe:Kyowa-Hakko Kirin.: Research Funding; Dainipponn-Sumitomo Pharma.: Research Funding; Chugai Pharma.: Research Funding; Novartis Pharma.: Honoraria, Speakers Bureau; Zenyaku-Kogyo: Research Funding; Otsuka Pharma.: Research Funding.