Patients In Complete Hematologic Remission Research Articles

S111: REPEATED INFUSIONS OF ESCALATING DOSES OF EXPANDED AND ACTIVATED AUTOLOGOUS NATURAL KILLER CELLS IN MINIMAL RESIDUAL DISEASE-POSITIVE PH+ ACUTE LYMPHOBLASTIC LEUKEMIA PATIENTS. A GIMEMA PHASE 1 TRIAL

Background: Due to age and co-morbidities, many Philadelphia-positive acute lymphoblastic leukemia (Ph+ ALL) patients are ineligible to undergo high-dose chemotherapy or allogeneic transplant as consolidation treatment. Our group reported the promising results of the chemo-free scheme D-ALBA based on dasatinib/blinatumomab in induction/consolidation, underlying the potential role of immunotherapy in this setting (Foà et al, NEJM 2020;383:1616-23). Considerable interest has been raised by natural killer (NK) cells. We developed a GMP protocol for NK cell ex vivo expansion in the presence of IL-2 and IL-15, and report the results of a phase 1 protocol of adoptive immunotherapy with activated and expanded autologous NK cells for Ph+ ALL patients in complete hematologic remission (CHR) but with persistent/recurrent minimal residual disease (MRD) ≥60 years or ineligible for other post-CHR treatment modalities. Aims: The primary endpoint was to determine the maximum tolerated dose of NK cells and the recommended dose for subsequent studies. Secondary endpoints were the assessment of safety and tolerability of the treatment, the immunologic modifications induced by the procedure and the clinical response to treatment. Methods: The planned 6 patients were enrolled: 5 in 1st CHR and 1 in 2nd CHR. Patients underwent repeated infusions (maximum 5) of escalating doses of NK cells, ranging from 1x106 to 5x107/kg of body weight (BW). No conditioning therapies were administered before the infusion; patients were allowed to continue tyrosine kinase inhibitors. Patients underwent a comprehensive MRD monitoring by Q-RT-PCR with a one-year follow-up. Immunophenotypic analysis on the NK cell product was performed before and after the expansion. Intracellular cytokine production and PBMC cytotoxic activity against K562 cells, allogeneic and autologous blasts were evaluated after expansion and at time 0 and 7 days from each NK cell infusion. Results: NK cells presented a 12.3-fold ex vivo expansion. Expanded cells showed an increased expression of activating receptors and measurable cytotoxicity against primary allogeneic and autologous blasts. One patient received a maximum NK cell dose of 5x106 cells/kg, 2 patients 1x107 cells/kg and 3 5x107 cells/kg/BW. No patient experienced infusion-related toxicities. Two adverse events were recorded (grade 1 and 2), both judged not treatment-related, that resolved after TKI suspension. The higher cell dose infusion resulted in a significantly increased expression of natural cytotoxicity receptors, a greater cytokine production by NK, T and NKT cells, and in an increased capacity of PBMC to lyse K562 cells. These modifications appear persistent over time. At a 1-year follow-up from the last infusion, 5/6 patients are alive in CHR (Table 1). The MRD levels reduced over time and 4/6 patients reached a complete molecular response (CMR) or a positive-not-quantifiable (PNQ) status during the study period. At a median follow-up of 30.8 months from the last infusion, the 5 patients who received the NK treatment in 1st CHR are still in CMR or PNQ, though 1 patient required additional treatment. The patient in 2nd CHR at the time of the infusions showed a rise in MRD and died of disease progression. Image:Summary/Conclusion: This phase 1 study demonstrates that autologous NK cells can be efficiently expanded ex vivo from MRD-positive Ph+ ALL patients in CHR. The infusion of these expanded cells is safe and induces a marked in vivo host immune response, suggesting that this approach represents a tolerable and feasible model worthy of being investigated in larger clinical studies.

P353: FORTY MONTHS UPDATE OF THE GIMEMA LAL2116 (D-ALBA) PROTOCOL AND ANCILLARY LAL2217 STUDY FOR NEWLY DIAGNOSED ADULT PH+ ALL

Background: The outcome of adult Philadelphia-positive acute lymphoblastic leukemia (Ph+ ALL) patients greatly improved since the introduction of tyrosine kinase inhibitors (TKIs). A further improvement was achieved with a chemo-free induction/consolidation strategy based on the sequential administration of dasatinib followed by blinatumomab - the D-ALBA GIMEMA LAL2116 trial - with overall survival (OS) and disease-free survival (DFS) rates of 95% and 88% at 18 months (Foa et al, NEJM 2020). Aims: To provide an updated follow-up of the D-ALBA trial and to document the long-term management of previously enrolled patients. Methods: In the D-ALBA trial, after the primary endpoint, patients were followed for 12 months. Data on subsequent treatment and survival are being collected in the ancillary study GIMEMA LAL2217. Results: As reported, 63 patients were enrolled (median age 54 years, 24-82; no upper age limit); the median follow-up is 40 months (0.9-62.5). Since enrollment in the D-ALBA trial, 9 relapses have been documented: 4 hematologic (1 major protocol deviation and 1 in an 82-year old woman who rapidly went off study), 4 at CNS and 1 nodal; median time to relapse was 4.4 months (1.9-25.8). Six deaths were recorded (3 post-allogeneic transplant) in 1st complete hematologic remission (CHR). Of the 58 patients who started blinatumomab, 29 continued treatment with TKI: 21 with dasatinib (85% after receiving all 5 cycles of blinatumomab), 2 switched to imatinib due to intolerance (all after the 5 cycles of blinatumomab) and 5 switched to ponatinib for a molecular minimal residual disease increase or medical decision (66% had received all 5 cycles of blinatumomab). Twenty-nine patients were allografted, including 6 patients in 2nd CHR: 9 from a sibling, 13 from an unrelated donor, 6 from a haploidentical donor and 1 from a cord blood. Six transplants were performed in 2nd CHR. Before transplant, 8 patients received 2 and 3 cycles of blinatumomab, respectively, 5 4 cycles and 6 5 cycles (2 patients were allografted after 1 cycle). Among grafted patients, 6 deaths occurred, 3 of which in cases transplanted in 2nd CHR; thus, the transplant-related mortality in 1st CHR is 10%. When considered in a covariate model, transplant did not impact on both OS and DFS; similar results were obtained also considering allograft only in 1st CHR. It must, however, be underlined that the allografted population was enriched in cases who did not achieve a molecular response (23 pts). Further investigation is ongoing on this aspect. In the updated follow-up, the estimated 48 months OS is 78% (95% CI: 66-92%) and the DFS is 75% (95% CI: 64-87%). DFS was significantly better in patients achieving a molecular response upon induction than in those who did not (100% vs 67%, p=0.016, Fig. 1A), with no events recorded in the group of complete molecular responders and positive-not-quantifiable cases. Furthermore, we confirmed the inferior DFS for patients carrying an IKZF1plus genotype compared to that of cases with no IKZF1 deletions/IKZF1 deletions alone (85% vs 47%, p=0.012, Fig. 1B). Image:Summary/Conclusion: In the updated analysis of the D-ALBA trial and the ancillary GIMEMA LAL2217 study, with a median OS of 40 months, we confirm the reported very favorable outcome. Among the few relapsed cases, we observed a rather high incidence of CNS involvements. These results represent the scientific rationale for the ongoing phase 3 GIMEMA LAL2820 trial, where dasatinib has been substituted by ponatinib, CNS prophylaxis has been increased, and transplant allocation is based on genomic features and minimal residual disease monitoring.

Sorafenib As Maintenance Therapy Post Allogeneic Stem Cell Transplantation for FLT3-ITD Positive AML: Results from the Randomized, Double-Blind, Placebo-Controlled Multicentre Sormain Trial

▪Introduction: Most patients with FLT3-ITD-positive AML, who relapse after allogenic stem cell transplantation (allo-SCT) die from their disease. Whether prophylactic FLT3-ITD inhibition with sorafenib can prevent AML relapse and improve outcome of patients in complete hematological remission (CHR) after allo-SCT is unknown and was tested in the SORMAIN trial.Methods: This randomized, double blind, placebo-controlled study was done at 14 centers in Germany and Austria. Patients with FLT3-ITD+ AML, aged 18 years or older, who had undergone allogenic stem cell transplantation from a HLA-matched sibling donor, 10/10 or 9/10 HLA-matched unrelated donor, and who were in confirmed CHR at the time of screening between day +30 and day +100 post allo-SCT, were included. Patients were randomly assigned (1:1) to receive either sorafenib (starting dose: 2 x 1 tbl. [2 x 200mg] qd, increasing every 14d to up to 2 x 2 tbl. [2 x 400mg] qd according to tolerability) or placebo (2 x 1 or 2 tbl. qd) for up to 24 months. Randomization was done centrally. In case of drug related adverse events, study medication could be interrupted, stepwise reduced to a minimum of 2 x 1 tbl. qd, temporarily withheld and recommenced at a lower dose level. FLT3-ITD diagnostics was done centrally at baseline and at time of relapse. In relapsing patients, off-label compassionate use of sorafenib was possible. The primary endpoint was relapse-free survival (RFS) as defined by either hematological relapse or death from any cause. The secondary endpoint was overall survival (OS). We here report the final RFS analysis. The OS results will be unblinded only prior to the ASH meeting and will be reported there. The SORMAIN study was terminated prior to full recruitment because of slow accrual. SORMAIN was registered with the European Clinical Trials Database (EudraCT 2010-018539-16) and the German Clinical Trials Register (DRKS00000591).Results: Between October 29, 2010, and May 17, 2016, 83 patients (41 males, 42 females) were randomized and included in the primary analysis (placebo, n=40; sorafenib, n=43). Median age was 54 years (IQR 47.75 - 61.33) for the entire study population and not significantly different between sorafenib and placebo groups. With a median follow up of 41.8 months after randomization (IQR 24.1 - 42.5), median RFS was 30.9 months (lower bound of 95% CI 5.2 months) in the placebo group versus not reached in the sorafenib group, corresponding to a 2-year RFS of 53,3 % (95% CI 36.5-67.5) in the placebo versus 85.0 % (69.5-93.0) in the sorafenib group (hazard ratio [HR] 0.39, 95% CI; 0.18 -0.85; P=0.0135) (Fig. 1). Overall, sorafenib was well tolerated. The most common grade 3-4 adverse event in both groups was acute GvHD (seven [ 17.5%] in the placebo group vs. nine [20.9%] in the sorafenib group.Conclusion: Sorafenib maintenance therapy after allo-SCT is feasible and significantly reduces the risk of relapse or death in patients with FLT3-ITD positive AML. OS results will be presented at the meeting. DisclosuresBurchert:Bristol Myers Squibb: Honoraria, Research Funding; Bayer: Research Funding; Pfizer: Honoraria; AOP Orphan: Honoraria, Research Funding; Novartis: Research Funding. Bug:Amgen: Honoraria; Neovii: Other: Travel Grant; Novartis Pharma: Honoraria, Research Funding; Astellas Pharma: Other: Travel Grant; Jazz Pharmaceuticals: Other: Travel Grant; Celgene: Honoraria; Janssen: Other: Travel Grant. Finke:Riemser: Consultancy, Honoraria, Research Funding; Novartis: Consultancy, Honoraria, Other: travel grants, Research Funding; Neovii: Consultancy, Honoraria, Other: travel grants, Research Funding; Medac: Consultancy, Honoraria, Other: travel grants, Research Funding. Stelljes:Pfizer: Consultancy, Honoraria, Research Funding; MSD: Consultancy; JAZZ: Honoraria; Amgen: Honoraria; Novartis: Honoraria. Rollig:Bayer: Research Funding; Janssen: Research Funding. Wäsch:Pfizer: Honoraria. Lang:Novartis: Membership on an entity's Board of Directors or advisory committees, Other: Travel, Research Funding. Ehninger:Cellex Gesellschaft fuer Zellgewinnung mbH: Employment, Equity Ownership; GEMoaB Monoclonals GmbH: Employment, Equity Ownership; Bayer: Research Funding. Serve:Bayer: Research Funding. Kroeger:Neovii: Honoraria, Research Funding; JAZZ: Honoraria; Sanofi: Honoraria; Celgene: Honoraria, Research Funding; Riemser: Honoraria, Research Funding; Novartis: Honoraria, Research Funding. Götze:JAZZ Pharmaceuticals: Honoraria; Novartis: Honoraria; Takeda: Honoraria, Other: Travel aid ASH 2017; Celgene: Honoraria, Research Funding. Schmid:Jazz Pharma: Honoraria, Other: Travel grant, Speakers Bureau. Wolf:BMS: Honoraria, Research Funding; Pfizer: Honoraria; Novartis: Honoraria, Research Funding; AOP Orphan: Honoraria, Research Funding. Thiede:AgenDix: Other: Ownership; Novartis: Honoraria, Research Funding. Haferlach:MLL Munich Leukemia Laboratory: Employment, Equity Ownership. Bethge:Miltenyi Biotec GmbH: Consultancy, Honoraria, Research Funding; Neovii GmbH: Honoraria, Research Funding.

Very Long Term Follow-up Data of Pediatric Acute Promyelocytic Leukemia Treated with Upfront Arsenic-Trioxide Based Regimens

Combination of all-trans retinoic acid (ATRA) and arsenic trioxide (ATO) is currently considered the standard of care in the management of acute promyelocytic leukemia (APL). While APL is considered a highly curable malignancy there is recognition that the outcome in pediatric patients is inferior to that reported in young adults. There have been concerns raised in the past on the potential long term side effects of the use of ATO, especially in a pediatric population. There is limited long term follow up data on the use of ATO in the pediatric population. At our center we have been using ATO based regimens to treat pediatric and adult patients with APL since 1998 and hence we undertook this retrospective analysis to evaluate the long term clinical outcomes and toxicity profile in the pediatric cohort.Data on all consecutive pediatric patients (age ≤18yrs) diagnosed with APL and treated in the Department of Haematology, Christian Medical College, Vellore, from January, 1998 to December, 2017 were included in this retrospective analysis. Of the total 73 patients with age ≤ 18yrs diagnosed during this period, 5 refused treatment and were discharged against medical advice. Treatment in the remaining 68 patients consisted of single agent ATO until 2015 (n=57), as reported previously by us (Mathews et al. Blood 2016). From 2015 combination of ATO, ATRA ± an anthracycline in induction and consolidation was administered in a risk adjusted manner (n=11). The median age was 2 years (range: 2-18) with equal gender distribution (50% each). Sixty two (91.2%) achieved complete hematologic remission (CR), 5 (7.4%) early deaths occurred from intracranial hemorrhage (n=3), neutropenic sepsis (n=1) and pulmonary thrombo-embolism (n=1), one patient did not achieve CR at the end of induction. The median time to CR was 45 days (range: 25- 62). Other acute ATO-related toxicities were low grade, transient and not associated with any mortality (transaminitis = 12 [17.6%]; ATRA like syndrome = 6 [8.8%]). With a median follow-up of 71 months, the 5 year OS and EFS of pediatric cohort (n=68) was 78.9±5.2% and 61.8±6.4% respectively (Fig 1). Among the 62 patients in CR, 21 (33.9%) relapsed at a median of 18 months (range: 5-126) from the initial diagnosis; 16 bone marrow, 3 bone marrow+CNS and 2 molecular relapses; an additional 2 patients died in remission (one viral encephalitis and another data not available). Nineteen out of 21 (90.5%) patients who relapsed received ATO based re-induction while 2 refused treatment and were discharged at request. Out of the 19 treated patients, all attained second CR. CR was consolidated with an autologous SCT (n=10) or ATO based chemotherapy (n=9). The OS and EFS of the 19 relapsed patients was 72.9±10.4% and 68±10.8% respectively.On long term follow up of this pediatric cohort (median follow up 71 months; 18 (26.5%) > 10 years follow up and 37 (54.5%) > 5 years follow up) there were no long term renal, hepatic, metabolic complications or second malignancies noted.Our results indicate the high efficacy and long term safety of ATO based regimens in the treatment of children with APL. Even among the relapse pediatric APL patients treated with upfront ATO, salvage chemotherapy with ATO based regimen followed by autologous stem cell transplantation is associated with excellent long term survival and is not associated with any major long term complications. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Testing for minimal residual disease in adults with acute lymphoblastic leukemia in Europe: a clinician survey

BackgroundIn acute lymphoblastic leukemia (ALL), the presence of minimal residual disease (MRD) after induction/consolidation chemotherapy is a strong prognostic factor for subsequent relapse and mortality. Accordingly, European clinical guidelines and protocols recommend testing patients who achieve a complete hematological remission (CR) for MRD for the purpose of risk stratification. The aim of this study was to provide quantitative information regarding real-world clinical practice for MRD testing in five European countries.MethodsA web-based survey was conducted in March/April 2017 in France, Germany, Italy, Spain, and the UK. The survey was developed after consultation with specialist clinicians and a review of published literature. Eligible clinicians (20 per country; 23 in Spain) were board-certified in hemato-oncology or hematology, had at least five years’ experience in their current role after training, had treated at least two patients with B-cell precursor ALL in the 12 months before the survey or at least five patients in the last five years, and had experience of testing for MRD in clinical practice.ResultsMRD testing is now standard practice in the treatment of adult ALL across the five European countries, with common use of recent treatment protocols which specify testing. Respondents estimated that, among clinicians in their country who conduct MRD testing, 73% of patients in first CR (CR1) and 63% of patients in second or later CR (CR2+) are tested for MRD. The median time point reported as most commonly used for the first MRD test, to establish risk status and to determine a treatment plan was four weeks after the start of induction therapy. The timing and frequency of tests is similar across countries. An average of four or five post-CR1 tests per patient in the 12 months after the first MRD test were reported across countries.ConclusionsThis comprehensive study of MRD testing patterns shows consistent practice across France, Germany, Italy, Spain, and the UK with respect to the timing and frequency of MRD testing, aligning with use of national protocols. MRD testing is used in clinical practice also in patients who reach CR2 + .

Multicenter Total Therapy Gimema LAL 1509 Protocol for De Novo Adult Ph+ Acute Lymphoblastic Leukemia (ALL) Patients. Updated Results and Refined Genetic-Based Prognostic Stratification

Introduction: Management of Ph+ ALL has changed since the introduction of tyrosine kinase inhibitors (TKI). We previously reported the preliminary findings of the GIMEMA LAL 1509 total therapy protocol, based on dasatinib plus steroids administration as induction therapy (Chiaretti et al, ASH 2014). The updated results on overall survival (OS), disease-free survival (DFS) and the impact of a genetic-based prognostic stratification are hereby provided.Methods: Steroids were administered from day -6 to day 31. Dasatinib (140 mg/day) was given between days 1 and 84. Patients reaching a complete molecular response (CMR, i.e. BCR/ABL1 to ABL1 ratio=0) at the end of induction (day 85) continued Dasatinib. Patients in complete hematologic remission (CHR), but not in CMR, underwent chemotherapy (clofarabine-cyclophosphamide) and/or an allogeneic transplant (HSCT), according to eligibility and donor availability. Dasatinib was administered until disease progression. Molecular testing was used to identify the presence of the BCR/ABL1 transcript on bone marrow samples, to define the fusion protein and to quantify BCR/ABL1 levels at baseline and follow-up (FU). Mutational screening was performed in relapsed cases, based on material availability. SNP array analysis was carried out using the Cytoscan HD arrays (Affymetrix, Santa Clara, CA) to identify genomic aberrations.Results: 60/63 enrolled patients were eligible. Median age was 41.9 years (range 18.7-59.1), 34 were males and 26 females; median WBC count was 12.5 x 109/l (range 1.4-178.0); the p190 fusion product was detected in 33 patients, p210 in 18 and p190/p210 in 9. Median FU is 28.4 months (range 4.2-43.7). After the steroid pre-phase, 38 patients (63%) had a blast reduction ≥75%. At day 85, 58 patients were in CHR (97%), while 2, in CHR at day 57, lost it: both harbored the p210 fusion transcript. They both returned into CHR following chemotherapy. A sustained CMR was obtained in 11 patients (18.6%): 72% had a p190 fusion transcript. No deaths in induction occurred. Among the CMR patients, only 1 experienced a hematologic relapse, which carried a T315I mutation. Of the 46 non-CMR cases, 14 relapses occurred, 8 of which in p210+ patients. Overall, there have been 12 deaths in CHR. OS is 58.3% (95%CI: 44.4-76.3) at 36 months and DFS at 30 months is 48.9% (95%CI: 36.8.0-64.9). A better DFS was observed in patients who obtained a CMR compared to cases with minimal residual disease (MRD) at day 85 (75% vs 44%, p=0.06), and in p190+ vs p210+ patients (57.1% vs 39.6%, p=ns). Mutational screening, performed in 7/15 cases at hematologic relapse detected mutations in 5: 3 T315I and 2 V299L, of which 1 with a concomitant F317I and F317L. SNP array analysis, performed in 39 cases with available DNA, showed that the most frequent aberrations were deletions of IKZF1 (85%), PAX5 (38%), CDKN2A/B (33%), MLLT3 (33%), RB1 (28%) and JAK2 (28%). While IKZF1 deletions alone did not impact on CHR or CMRachievement and DFS, a significantly worse DFS (p=0.01) and increased cumulative incidence of relapse (CIR, p=0.024) were observed in cases harboring deletions of IKZF1 plus CDKN2A/B and PAX5 (DFS: 40% vs 65% at 18 months; CIR: 40% vs 14% at 18 months (Fig. 1A and B). The relevance of this finding was further refined by stratifying patients according to the fusion protein: the impact of IKZF1 plus CDKN2A/B and PAX5 deletions is prognostically relevant in p190+, but not in p210+ patients, possibly because of the worse outcome of the latter group (Fig. 2). Finally, this analysis identified a set of genes specifically deleted in CMR cases; investigations are ongoing on additional cases to validate their potential role in predicting response to TKI.Conclusions: In this updated analysis of the GIMEMA 1509 trial, we confirm the effectiveness of a chemo-free induction in inducing CHR in almost all adult Ph+ ALL patients (97%) and CMR in a subgroup of cases (18.6%). OS and DFS at 36 months and 30 months, approaching 60% and 50%, are encouraging. More importantly, CMR achievement at day 85 is associated with extremely promising results, being 75% at 30 months, underlying that CMR should be regarded as a primary endpoint in Ph+ ALL. We confirm that p210+ patients may require an intensified approach, given the lower rate of CMR achievement and the higher relapse rate. Finally, we provide evidence that a broader genetic characterization at diagnosis allows a more refined prognostic stratification of Ph+ ALL patients. [Display omitted] [Display omitted] [Display omitted] DisclosuresMartinelli:Pfizer: Consultancy; Ariad: Consultancy; AMGEN: Consultancy; BMS: Consultancy, Speakers Bureau; ROCHE: Consultancy; MSD: Consultancy; Novartis: Consultancy, Speakers Bureau. Foà:Roche: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau.

First Results of the Multicenter Total Therapy Gimema LAL 1509 Protocol for De Novo Adult Philadelphia Chromosome Positive (Ph+) Acute Lymphoblastic Leukemia (ALL) Patients

▪Introduction: Ph+ ALL management has changed since the introduction of tyrosine kinase inhibitors (TKI). In the GIMEMA LAL 1509 protocol for adult Ph+ ALL, Dasatinib was administered in combination with steroids as induction treatment, and chemotherapy and/or allogeneic transplantation (HSCT) was given if patients did not reach a sustained complete molecular response (CMR) after induction.Methods: Steroids were administered from day -6 to day 31. Dasatinib (140 mg/day) was given between days 1 and 84. Patients reaching a confirmed CMR (i.e. BCR/ABL to ABL ratio=0) at the end of induction (day +85), continued Dasatinib for 6 additional months. Patients in complete hematologic remission (CHR), but not in CMR, were stratified according to HSCT eligibility: those with a promptly available donor underwent directly a HSCT; if the donor was not readily available, a consolidation cycle with clofarabine and cyclophosphamide was administered. HSCT non-eligible patients received two cycles of clofarabine and cyclophosphamide of 5 and 3 days, respectively. Dasatinib was administered until disease progression. Molecular testing was used to identify the presence of a BCR/ABL transcript, define the fusion protein and quantify BCR/ABL levels at baseline and at follow-up. Mutational screening was performed in relapsed cases.Results: Sixty of the 64 enrolled patients were eligible. Median age was 41.9 years (range: 18.7-59.1), 34 were males and 26 females; the median WBC count was 12.5 x 109/l (range 1.4-178.0); the p190 fusion product was detected in 33 patients, p210 in 18 and p190/p210 in 9. Median follow-up is 17.6 months (range 4.1-31.6). After the steroid pre-phase, 38 patients (63%) had a blast reduction ≥75%. At day 85, 58 patients achieved a CHR (97%) and 2 were non-responders (1 hematologic relapse and 1 disease progression): notably, both had a p210 fusion transcript. A CMR was obtained in 11 patients (18.6%): of these, 72% had a p190 fusion transcript. Overall, 24% of p190+ patients and 11% of p210+ or p190/210+ cases obtained a CMR. As previously reported in other GIMEMA trials, no deaths in induction occurred. Among the CMR patients, only 1 experienced a hematologic relapse and harbored a T315I mutation. Among the 46 non-CMR cases, 17/27 eligible patients underwent a HSCT, while 9 did not; 5 relapses occurred in the non-transplanted group, while 1 was observed in the HSCT group. Of the 19 HSCT non-eligible patients, 14 received the planned therapy: in this group, 2 relapses occurred. At 24 months, the overall survival (OS) is 69.1% (95%CI: 55.3-86.3), with a disease-free survival (DFS) at 18 months of 61.6% (95%CI: 47.6.0-79.8). A better DFS was observed in patients who obtained a CMR at day +85. Dasatinib exerted a rapid blast clearance, that was highly significant (p<0.0001) between the onset and day +22, and between day +22 and +45; a significantly more rapid clearance (p=0.0005, p=0.0013 and p=0.001 at days +22, +45 and +57, respectively) was observed in patients who achieved a CMR at day +85, underlining the heterogeneous sensitivity of Ph+ ALL blasts to TKI. Importantly, a significantly greater clearance was observed in p190 (n=33) vs p190/210 and p210 (n=27) cases (p=0.0008, p=0.0032, p=0.0031, p=0.0016, p=0.007 at diagnosis, days +22, +45, +57, and +85, respectively). Mutational screening was performed in 6/12 patients who relapsed and mutations were detected in 5: 3 T315I and 2 V299L, of which 1 with a concomitant F317L. Overall, 12 relapses (5 in the p190 and 7 in the p210 subgroup) and 7 deaths in CR occurred, 5 of which in allografted patients. The median time to relapse was 6.7 months (range 0.3-22.5).Conclusions: We confirm that a chemo-free induction approach for adult Ph+ ALL patients results in a very high CHR rate (97%), with no deaths in induction. In this Dasatinib-based protocol, a sustained CMR is achieved after induction in >18% of cases, suggesting that a subset of patients may be spared further intensive treatment. We witnessed an increase in p190/p210-p210+ cases compared to earlier studies; these patients showed a worse prognosis as underlined by a lower susceptibility to TKI, lower blast clearance and greater incidence of relapses (58%). At this first analysis, OS and DFS are at least comparable to those obtained in previous GIMEMA studies, despite the higher incidence of p210+ patients – which accounted for 45% of cases in this cohort – and which may require an intensified approach. DisclosuresMartinelli:Pfizer: Consultancy; BMS: Consultancy, Speakers Bureau; Novartis: Consultancy, Speakers Bureau; ARIAD: Consultancy.

Treatment of Adult Patients with the Modified Protocol of the International Consortium on Acute Promyelocitic Leukemia (IC-APL)

IntroductionAcute promyelocytic leukemia (APL) with PML/RARA rearrangement is currently classified by the WHO as part of the group of acute myeloid leukemia with recurrent genetic abnormalities. Therapeutic improvements in chemotherapy protocols containing trans-retinoic acid (ATRA) have achieved complete response rates close to 90% and long-term relapse free survival curves of 85%.The treatment protocol of the International Consortium on Acute Promyelocytic Leukemia (IC-APL), which started in 2006, sought to improve rates of complete remission and survival in developing countries through a risk-based protocol and the implementation of daunorubicin instead of idarubicin. Recently the results of that multicenter study were published.MethodsA retrospective cohort of patients with APL was studied at the Acute Leukemia Clinic of the Department of Hematology and Oncology, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico; from January 2007 to June 2013.All APL patients were recruited from 2006 to 2013. Diagnosis of APL was established based on the recommendations of the 2000 WHO and subsequently 2008.The original IC-APL chemotherapy scheme was administered. Some minor modifications to the original protocol were made: we did not search for minimal residual disease neither identify the PML / RARA isoforms at diagnosis and prophylactic intrathecal chemotherapy in high-risk patients was applied (4-6 dose cytarabine 60mg and methotrexate 12.5mg), monthly, once the consolidation therapy was finished. Patients who relapsed received rescue therapy and autologous HCT. Allogeneic HCT was performed in advaced stages.ResultsOf the 18 patients evaluated 11 were women (61.1%). The median age at diagnosis was 40 years, (range 21-74 years). It should be noted that 16.6% had more than 65 years. The risk classification showed 27.8% of cases as low risk, 55.6% intermediate and 16.7% of high risk.At diagnosis 22.2% of patients met the criteria for disseminated intravascular coagulation. Morphological characteristics of BMA were analyzed; in 17 patients (94.1%) BMAs were classified as classic and in one patient it was considered variant-type. Sixteen patients underwent immunophenotyping at diagnosis, 100% of which reported a classic pattern immunophenotype CD34 (-) HLA-DR (-), CD13 (+) CD33 (+), myeloperoxidase (+). The t (15, 17) (q22, q21) was demonstrated by either FISH or karyotype in 94.4% of patients and in one patient the PML/RARA rearrangement could only be demostrated by PCR.Of the 18 patients, 17 achieved complete hematologic remission (94.4%) at a median of 42 days (range 34-158 days). One patient died during induction and this patient presented multiple comorbidities.No serious complications were seen in 66.7% of patients during induction, 22.2% had grade 3-4 infection and 11.1% non-hematologic adverse events and one patient had subarachnoid hemorrhage and vasculitis.The rates of severe neutropenia and fever during induction was 61.1%. ATRA syndrome was identified in 22.2% of patients.Only 15 patients in complete hematologic remission could be analyzed by FISH or cytogenetics, of which 100% were in complete cytogenetic remission.In the 17 patients who achieved complete remission, 14 received all the programmed consolidation chemotherapy. The incidence of febrile neutropenia during consolidation was 29.4%, contrasting with 61.1% after induction. No deaths during consolidation phase were seen.Bone marrow relapse was documented in 5.9%. This patient underwent autologous HCT and subsequently died of disease progression.Of all patients, two died (11.1%), one in bone marrow aplasia after induction (5.5%) and the other in disease progression post-autologous HCT (5.5%). Median survival has not been reached.ConclusionsAs far as we know this is the first reported series of patients treated with the modified-IC-APL protocol after the original publication in 2013. Longer follow-up is required for survival analysis (median not reached). Implementation of quantitative RT-PCR analysis for minimal residual disease and timely detection of molecular relapse is desirable. DisclosuresNo relevant conflicts of interest to declare.

Minimal Residual Disease In Adult AML

BackgroundThe achievement of complete hematologic remission (CR) is used as predictor for treatment response in patients with myeloid leukemia (AML).However <5% blasts in the bone marrow does not reflect the presence of tumor burden precisely. Minimal residual disease (MRD) in the first complete remission (CR1) may play a critical rule in assessment of treatment response and prediction of subsequent relapse. Patients and MethodsLeukemia associated immunophenotyping (LAIP) for 73 patients with denovo AML monitored at diagnosis , day 14 and day28 post-induction by multiparametric flow cytometry (MFC). ResultsCR achieved in 60(82%) patients and 13(18%) patients did not. Among the 60(80%) patients who achieved CR 9 (15%) were MRD negative and 51(85%) were MRD positive at day14. Significant association between MRD detection and disease free survival (DFS) using 0.01% cut off value (P=.015). Day 28 post induction show highly significant association between MRD and DFS using 0.01% cut off value (P=0.001) as 38(63%) patients were MRD negative and (27%) were positive.Significant association between MRD detection and overall survival (50 month) at day 14 and day 28 (P=0.02, P=0.001) respectively using cut off value 0.01%. MRD was positive in 63(86%) at day 14 and (37%) at day 28. ConclusionMRD detection at day28 and d14 at the end of induction in patients in CR may have a prognostic significance on clinical outcome and may thus be a useful marker for risk stratification. Disclosures:No relevant conflicts of interest to declare.

The Pretransplantation Serum Cytokine Profile in Allogeneic Stem Cell Recipients Differs from Healthy Individuals, and Various Profiles are Associated with Different Risks of Posttransplantation Complications

Cytokines play a key role in regulation of normal and malignant hematopoiesis, angiogenesis, and inflammation. Serum levels of several cytokines are altered in patients with hematologic malignancies, and pretransplant cytokine levels seem to have a prognostic impact in patients treated with allogeneic stem cell transplantation. However, the cytokine system constitutes an interacting functional network, and it may therefore be more relevant to look at serum cytokine profiles rather than the serum levels of single cytokines in allotransplanted patients. We therefore investigated the pretransplantation serum levels of 35 cytokines in a group of 44 consecutive allogeneic stem cell transplantation patients, mainly with a primary diagnosis of acute leukemia. Serum samples were collected before the start of myeloablative conditioning therapy when all patients were in complete hematologic remission. Unsupervised hierarchical clustering analysis identified three major patient groups/subsets. These groups differed especially in the levels of hepatocyte growth factor and granulocyte-colony stimulating factor, and one of the groups was characterized by low early treatment-related morbidity and high levels of hepatocyte growth factor and granulocyte-colony stimulating factor. The degree of weight gain/fluid retention after conditioning therapy did not differ between the patient subsets, but fluid retention showed a significant correlation with pretransplantation serum levels of basic fibroblast growth factor. We conclude that the pretransplantation serum cytokine profile shows a considerable variation even between patients in complete hematologic remission and is associated with clinicopathologic features.

Current status of hematopoietic cell transplantation in the treatment of systemic amyloid light-chain amyloidosis

Systemic amyloid light-chain (AL) amyloidosis is a protein conformation disorder caused by clonal plasma cell dyscrasias. Symptoms result from fibrillar extracellular deposits in various tissues. The deposits disrupt organ function and ultimately lead to death. The prognosis is poor and depends mostly on the severity of cardiac involvement. The treatment is derived from the therapy of multiple myeloma with the main goal being to reach a complete hematological remission (CR). High-dose melphalan (HDM) and autologous hematopoietic cell transplantation can induce CR rates in about 40%. The main concern was the high transplant-related mortality of up to 40% due to organ dysfunction, which could be reduced to <12% by careful patient selection in experienced centers. However, >50% of patients in CR survive longer than 10 years, suggesting that HDM has the potential to change the natural course of the disease. As there is evidence that 'graft-versus-plasma-cell-dyscrasia' effects are active in AL amyloidosis, allogeneic hematopoietic cell transplantation might be an option for younger patients with preserved organ functions who have relapsed after HDM.

Long-term follow-up of patients with chronic myeloid leukemia having received autologous stem cell transplantation

Prior to introduction of imatinib mesylate, the median survival of chronic myeloid leukemia (CML) patients was approximately 60months and the standard treatment with interferon-alpha (IFN-α) resulted in major cytogenetic responses of 20-25%. As an alternative treatment approach besides allogeneic transplantation, intensive chemotherapy followed by autologous hematopoietic stem cell transplantation (autoHSCT) was investigated at that time with the rationale of debulking disease burden and mobilization and transplantation of Philadelphia chromosome-negative (Ph-) stem cells. In the era of tyrosine kinase inhibitors as state-of-the-art therapy for CML, the concept of autoHSCT has attracted only little interest and long-term follow-up and outcome data after autoHSCT in CML patients is scarce. In this long-term analysis, we report on 21 CML patients, mobilized in early chronic phase and transplanted with largely Ph- grafts, who received IFNα as maintenance therapy. Imatinib mesylate was administered upon cytogenetic relapse or disease progression while on IFN-α. The 10-year survival was 61% and 11 patients (52%) were alive at a median follow-up of 12.5years (range 0.3-13.8) with eight patients in complete hematologic remission (CHR) and three of eight in major molecular remission (MMR). While all patients in MMR and two of five patients in CHR received imatinib, it is noteworthy that three patients remaining in CHR only received IFN-α maintenance after autoHSCT. With the limitations of a small patient population, this is the longest follow-up analysis demonstrating that autoHSCT in CML is very efficient to debulk the disease, restore Ph-negative hematopoiesis, and is able to induce major and sustained molecular responses in the majority of patients with substantial long-term survival rates.

A Randomized Phase II Study Comparing Imatinib and the Combination of Imatinib and Pegylated Interferon Alpha-2b in Newly Diagnosed Non-High Risk Chronic Myeloid Leukemia (CML) Patients in Complete Hematological Remission After Imatinib Induction Therapy.

Abstract 3280Poster Board III-1 Background:Imatinib mesylate (IM) 400 mg once daily (OD) is the current standard first-line therapy for CML. Several biological and clinical observations suggest that combining IM with interferon alpha (IFNa) may improve the outcome of treatment. Aim:To compare the effects of standard-dose IM to combination of IM and IFNa in newly diagnosed chronic phase CML patients with an intermediate or low Sokal risk score. The primary end point was to compare the major molecular response (MMR) rate after 12 months between the treatment arms (intention-to-treat analysis). Patients and therapies:In a Nordic CML Study Group (NMCLSG: Denmark, Finland, Norway and Sweden) and Israel multicenter study we randomized 114 newly diagnosed CML patients in complete hematological remission following 3 months of IM 400 mg OD induction therapy. The study arms were IM (Glivec, Novartis) and the combination of IM and IFNa 2b (PegIntron, Schering-Plough). IM dose was fixed at 400 mg OD. IFNa was started at 30 μg/week but could be escalated to 50 μg/week or reduced down to 15 μg/week depending on tolerability. Molecular response was evaluated by blood RQ-PCR for BCR-ABL1 and was expressed on the international scale (IS). Results:As of August 17, 2009, 79 patients were evaluable for primary endpoint and 47 of these were in MMR (59%) The rate of complete cytogenetic response (CCgR) was 68/79 (86%). Nineteen patients (17%) were considered as treatment failures (grade 4 nonhematological adverse event, refusal, loss of CCgR, progression to advanced phase, protocol violation or other reason). Conclusions:A final analysis will be performed when we have complete data on all randomized patients. The comparison by treatment arm on molecular and cytogenetic responses as well as other relevant data (treatment failures, patients off-treatment for protocol violations, refusal or toxicity) will be presented on site.Supported by European LeukemiaNet, WP 4. Disclosures:Simonsson:Novartis: Consultancy, Honoraria, Research Funding; BMS: Consultancy, Honoraria, Research Funding. BjÖreman:BMS: Consultancy, Honoraria. Mustjoki:BMS: Honoraria. StrÖmberg:Novartis: Honoraria; BMS: Honoraria. Weiss Bjerrum:Novartis: Consultancy, Honoraria; BMS: Consultancy, Honoraria. Gruber:Novartis: Research Funding. Nagler:Novartis: Consultancy. Porkka:Novartis: Consultancy, Honoraria, Research Funding; BMS: Consultancy, Honoraria, Research Funding.

Long-Term Follow-up of Patients with Chronic Myeloid Leukemia Having Received Autologous Stem Cell Transplantation.

Abstract 4268Before the introduction of imatinib mesylate, the median survival of chronic myeloid leukemia (CML) patients was approximately 60 months and the standard treatment with interferon-alpha (IFN-α) resulted in major cytogenetic responses of 20-25 %. As an alternative treatment approach at that time, intensive chemotherapy followed by autologous hematopoietic stem cell transplantation (autoHSCT) was investigated with the rational of debulking disease burden and mobilisation and transplantation of Philadelphia chromosome-negative (Ph-) stem cells. In the era of tyrosine kinase inhibitors (TKIs) as state-of-the-art therapy for CML, the concept of autoHSCT has attracted only little interest and long-term follow-up and outcome data after autoHSCT in CML patients is scarce.In this long-term analysis, we report on 21 CML patients, mobilized in early chronic phase (ECP) and transplanted with largely Ph- grafts, who received interferon alpha (IFNα) as maintenance. Imatinib mesylate was given upon cytogenetic relapse or disease progression after IFN-α. The 10-year survival was 61% and 11 patients (52%) were alive at a median follow-up of 12.5 years (range 0.3 - 13.8) with 8 patients in complete hematologic remission (CHR) and 3 of 8 in major molecular remission (MMR). While all patients in MMR and 2 of 5 patients in CHR received imatinib, it is noteworthy that three patients remaining in CHR only received IFN-α maintenance after autoHSCT.With the limitations of a small patient population, this is the longest follow-up analysis demonstrating that autoHSCT in CML is very efficient to debulk the disease and able to induce major and sustained molecular responses in the majority of patients with substantial long-term survival rates. Disclosures:Waller:Hospira UK Ltd: Consultancy.

Report of a Phase II Trial of Single-Agent BiTE® Antibody Blinatumomab in Patients with Minimal Residual Disease (MRD) Positive B-Precursor Acute Lymphoblastic Leukemia (ALL).

Abstract 840▪▪This icon denotes an abstract that is clinically relevant. Introduction:In patients with B-precursor ALL, presence of MRD after induction therapy or at any time point later predicts a hematological relapse, despite continued intensive chemotherapy or/and an allogeneic hematological stem cell transplantation (HSCT). Blinatumomab (MT103) targets the CD19 antigen, and is a member of a novel class of bispecific BiTE® antibodies that redirect T cells for lysis of target cells. A phase II study was conducted in collaboration with the German Multicenter Study Group on Adult Lymphoblastic Leukemia (GMALL) in patients with MRD-positive B precursor ALL. Methods:B–precursor ALL patients in complete hematological remission with either persistent or reappeared MRD at any time after consolidation I of front-line therapy were included. One treatment cycle of blinatumomab is a 4-week continuous i.v. infusion, which can be followed by allogeneic HSCT or in case of response by repeated consolidation cycles of blinatumomab with 2-week treatment-free intervals. The dose level at enrollment is 15 μg/m2/day. In patients, who do not respond within four cycles of treatment, the dose can be increased to 30 μg/m2/day. Molecular response is assessed by quantitative PCR of either individual rearrangements of immunoglobulin/TCR-genes or specific genetic aberrations such as bcr/abl or MLL-AF4. Results:Nineteen patients have been treated to date and 16 patients are already evaluable for response. Thirteen of 16 evaluable patients went into molecular complete remission (CR) already after one cycle of blinatumomab. Three patients had a stable MRD level. Of note, 10 of the responding 13 patients had never achieved a molecular CR before blinatumomab treatment despite multiple treatment cycles including tyrosine kinase inhibitors in case of Ph-positive ALL. Two patients in molecular CR had an extra-medullary relapse one in testis and one in cerebro-spinal fluid, both representing immunological niches with limited accessibility for T cells. One patient with stable MRD level had a medullary relapse. All other patients are still relapse-free. None of the patients with molecular CR has shown a medullary relapse to date. The maximum follow-up of molecular CR has been 12 months. Most common adverse events (AEs) included lymphopenia, pyrexia, leucopenia and hypoimmunoglobulinemia. Only one patient had to be discontinued because of a fully reversible epileptical seizure. All other AEs resolved during treatment. Overall, treatment with blinatumomab was well tolerated. Response data of all 21 patients will be presented at ASH. Conclusions:Treatment with blinatumomab converted MRD-positive B–precursor ALL into molecular CR in 13 of 16 evaluable patients with refractory disease as indicated by persistent MRD after intensive chemotherapy. This amounts to a response rate of 81% providing thus the rationale for introducing blinatumomab as a novel agent in the treatment of B–precursor ALL. Disclosures:Zugmaier:Micromet: Employment, Equity Ownership. Goekbuget:Micromet: Consultancy, Research Funding. Kufer:Micromet: Employment, Equity Ownership, Patents & Royalties. Klinger:Micromet: Employment, Equity Ownership. Degenhard:Micromet: Employment, Equity Ownership. Baeuerle:Micromet: Employment, Equity Ownership. Schmidt:Micromet: Employment, Equity Ownership. Nagorsen:Micromet: Employment, Equity Ownership. Riethmueller:Micromet: Consultancy, Equity Ownership. Bargou:Micromet: Consultancy, Equity Ownership, Patents & Royalties.

First Results of the GRAAPH-2005 Study in younger Adult Patients with De Novo Philadelphia Positive Acute Lymphoblastic Leukemia

The GRAAPH-2005 International study for adults with newly diagnosed chromosome Philadelphia positive (Ph+) acute lymphoblastic leukemia (ALL) was designed to compare an imatinib-based induction regimen with an imatinib-HyperCVAD induction regimen and to evaluate the role of imatinib prior to stem cell transplantation (SCT).The protocol enrolled patients > 18 years and < 60 years. Among 118 enrolled patients from May 2006 onwards, 83 had a follow-up long enough to allow at least induction and consolidation evaluation. Median age was 42 years; 60% were male. A 7-day prephase steroid regimen (prednisone 60 mg/m2/day) allowed identification of the BCR/ABL transcript. In arm A (imatinib-based), imatinib 800 mg was given days 1–28, only combined with vincristine (2 mg at days 1, 8, 15, 22) and dexamethasone (40 mg at days 1–2, 8–9, 15–16, and 22–23). In arm B (imatinib-HyperCVAD), imatinib 800 mg was given days 1–14 of each course, combined with adriamycin (50 mg/m2 at day 4), cyclophosphamide (300 mg/m2/12h at day 1, 2, 3), vincristine (2 mg at days 4 and 11), and dexamethasone (40 mg at days 1–4 and 11–14) in the induction course, and combined with high-dose methotrexate (1 g/m2 at day 1) and high-dose cytarabine (3 g/m2/12h at days 2 and 3) in the salvage/consolidation course. Salvage/consolidation course was similar for patients initially following arm A. Four intrathecal infusions (methotrexate + cytarabine + methylprednisolone) were included within induction/consolidation courses. Complete hematological remission (CR) rate at the end of the two courses of induction/consolidation was 100% with arm A (42 patients of whom 2 after salvage course) and 95% with arm B (39/41 patients; all after induction course): overall 97.5% vs 70% in the pre imatinib era (LALA-94 trial). One patient died during the first course and 2 during the second course (of which 1 in CR after the induction course). Overall, median number of days to response was 37 (range, 28–136 days). Minimal residual disease (MRD) was centrally evaluated by quantitative RT-PCR at the end of induction (MRD-1) and at the end of salvage/consolidation chemotherapy (MRD-2). Molecular disease was undetectable in 11% at the time of MRD-1 and in 18% at the time of MRD-2, and at a level < 0.1% in 40% at the time of MRD-1 and in 60% at that of MRD-2. Although this did not translate into significant difference in terms of survival, monitoring of MRD (< 0.1%) documented that arm B was capable of inducing a deeper marked clearance of leukemic cells than arm A at the end of salvage/consolidation chemotherapy: 35% in arm A and 45% in armB (p = 0.3) for MRD-1, and 48% in arm A and 72% in arm B (p = 0.05) for MRD-2. After the two phases of induction/consolidation, patients received intensification by allogeneic SCT using related or unrelated donor stem cells or autologous SCT when a donor was not available and MRD < 0.1%. In absence of potential SCT, they underwent repeated cycles of imatinib-HyperCVAD regimen. Of the 61 patients with enough follow-up after induction/consolidation courses, 52 (85%) actually received SCT: 41 allogeneic SCT (of which 25 from related- and 16 from unrelated-donor) and 11 autologous SCT. Overall survival (OS) was 62% at 2-year (68% and 54% in arm A and arm B, respectively; p = 0.3), which differ significantly from the 29% observed in the pre imatinib era (LALA-94 trial). Disease-free survival (DFS) was 43% at 2-year (54% and 32% in arm A and arm B, respectively; p = 0.7). After a median follow-up of 12.6 months (95% CI, 10.6–15 months), 18 relapses (22%) were observed. Eighteen patients have died after induction/consolidation phase: 8 patients with progressive disease and 10 patients in CR (1 from septic shock waiting for allogeneic SCT, and 9 from toxicity during allogeneic SCT).The preliminary data of this study suggest that an imatinib-based regimen induces a high rate of hematological CR, similar to a more intensive (HyperCVAD) regimen. However the rate of molecular response has a tendency to be lower with imatinib-based regimen. The combination of imatinib with chemotherapy allows a majority of patient to have consolidation with SCT.

Generation of functional dendritic cells (DC) in adult acute lymphoblastic leukemia: rationale for a DC-based vaccination program for patients in complete hematological remission

The capacity to generate effective dendritic cells (DC) from adult acute lymphoblastic leukemia (ALL) patients in complete remission (CR) and off-therapy was investigated. Monocyte-derived DC cultured in the presence of granulocyte-macrophage colony-stimulating factor, interleukin (IL)-4 and tumor necrosis factor (TNF)-α expressed maturation markers, produced IL-12 and loaded apoptotic bodies to a similar extent to normal DC. Patients' circulating T and NK lymphocytes were normally represented and, after stimulation, were capable of producing TNF-α and interferon-γ to a similar extent to control lymphocytes. DC loaded with leukemia-derived apoptotic bodies increased their ability to stimulate both allogeneic and autologous lymphocytes, and to generate specific anti-leukemic CD3 + cells. These findings offer a rationale for the design of DC-based vaccine programs for adult ALL patients in CR with the aim of controlling/eradicating the disease.

Extramedullary blast crises in CML patients in complete hematological remission treated with imatinib mesylate

Extramedullary blast crises in CML patients in complete hematological remission treated with imatinib mesylate

Detection of minimal residual disease in B chronic lymphocytic leukemia (CLL).

In the absence of specific chromosomal translocations the best method for detecting minimal residual disease (MRD) in B cell malignancies is based on the uniqueness of immunoglobulin (Ig) genes rearrangement. We here report a very sensitive method for assessing MRD in complete hematological remission (CHR) chronic lymphocytic leukemia (CLL) patients as defined by the international workshop on CLL (IWCLL). Twelve CLL patients in CHR and complete phenotypic remission (CPR) were included in the study. Eight of them received Fludarabine (FDR), one was treated by Chop regimen, and the remaining 3 were rescued by polychemotherapy followed by autologous bone marrow transplantation (ABMT). DNA extracted from peripheral blood lymphocytes (PBL) of each patient was amplified with VH family specific and framework 3 primers in 5' and a consensus JH primer in 3', before treatment and sequentially after the CPR completion. When no clonal rearrangement could be detected by this assay, the CDR3 sequence specific probe of the clone was used as the 3' primer, associated to the VH family specific primer in 5'. PCR products were analyzed by classical procedures in agarose and/or acrylamide gels. Mixtures of leukemic cells and normal PBL showed detection of a single leukemic cell among more than 10(5) normal cells. Four out of the 12 patients achieved molecular remission (MR) when employing CDR3 amplification. All 3 autografted patients were in MR, whereas only one out of the 9 patients treated by chemotherapy alone achieved MR. When using a clone specific probe, a clonal signal was observed in all cases but one (ABMT). Results presented here confirm that MR may be achieved in a few cases of B-CLL. Further studies are needed to determine the exact relationship between MRD and clinical outcome.

Red Cell Distribution Width (RDW) as a Marker of Disease Activity in Patients with Hairy Cell Leukemia

Red cell distribution width (RDW) was examined in 18 patients with hairy cell leukemia (HCL) treated with 2-chlorodeoxyadenosine (2-CdA), in 5 patients treated with Interferon alpha (IFN-alpha) and in 9 patients subjected to splenectomy. Out of 18 patients treated with 2-CdA one patient was excluded of the study because of association of HCL with acquired sideroblastic anemia. In the remaining 17 patients the mean value of RDW before therapy was 18.8% (range 13.5% to 25.0%) and dropped after successful therapy after 6 to 12 months to the mean value of 13.6% (range 11.2% to 17.9%) and after 18 months to 13.4% (range 12.6% to 14.7%) (p = 0.00015 and p = 0.00049 respectively). The hemoglobin level increased from the mean value of 119 g/l (range 99 g/l to 157 g/l) before therapy to the mean value of 145.9 g/l (range 127 g/l to 172 g/l) after 6 to 12 months and after 18 months to 147.8 g/l (range 132 g/l to 168 g/l) (p = 0.000017 and p = 0.00036 respectively). The same trend was observed in the group of patients treated with IFN-alfa. The RDW decreased from the mean value of 21.3% (range 18.8% to 28.7%) to the mean value of 15.3% (range 12.4% to 16.7%), (p = 0.031). The hemoglobin level increased in this group of patients from the mean value of 115 g/l (range 98 g/l to 127 g/l) to the mean value of 136 g/l (range 127 g/l to 146 g/l) (p = 0.031). In 9 patients in complete hematologic remission 34 to 293 months after splenectomy the mean value of RDW was 13.9% (range 13.0% to 15.5%). Increased RDW in HCL is associated with active disease and is reversible after successful therapy. This phenomenon has not been reported in the literature yet. Preliminary results show that the increase of RDW may be due to the dyserythropoiesis.