ALBERT

Description: Key Points FOXP1 is downregulated in germinal centers, inversely to BCL6, whereby it regulates a network of genes, half of which are also BCL6 targets. In transgenic mice, constitutive FOXP1 expression impairs GC formation and function, which might contribute to B-cell lymphomagenesis.

Description: Background: The trombopoietin receptor agonists (TRAs) romiplostim and eltrombopag are effective and safe in the treatment of chronic immune thrombocytopenia (ITP). However, when no response is achieved or when adverse events occur with one TRA the value of the sequential use of romiplostim and eltrombopag has not been clearly established. Here we have evaluated the efficacy and tolerance of using eltrombopag after romiplostim in ITP. Methods: Fifty-one primary ITP patients (aged 18 years or more) who had been sequentially treated first with romiplostim and then with eltrombopag in the Spanish Eltrombopag Registry were retrospectively evaluated. In accordance with the usual standards, complete response was defined as a platelet count of 100x109/L and a response as a platelet count of 30x109/L or a count of at least twice the initial (pre-treatment) value. This study was performed in accordance with the standards of the Helsinki declaration and approved by the Hospital Universitario de Burgos Ethics Committee. Results: The median age of our cohort was 49 [range, 18–83] years. There were 32 women and 19 men. According to the standard definition, patients were allocated to newly diagnosed (n=2), persistent (n=5) and chronic (n=44) ITP groups. The median number of therapies prior to administration of eltrombopag was 4 [range, 2–9], including splenectomy (39%), rituximab (33%) and romiplostim (100%). The median duration of romiplostim use before switching to eltrombopag was 12 (IQR 5–21) months. The reasons for switching from the romiplostim to eltrombopag were: lack of efficacy of romiplostim (n=25), patient's preference (n=16), platelet-count fluctuation (n=6), and side-effects (n=4). The initial response rate to eltrombopag was 41/51 (80.5%), including 67% (n=34) of cases with complete remission. After a median follow-up of 13 months with eltrombopag, 39 patients maintained their response. When eltrombopag was used for patients who were refractory to the maximum romiplostim dose the initial response rate of eltrombopag was 25%. However, 83% of patients who relapsed after their initial response to romiplostim responded to eltrombopag. Sixteen romiplostim responders requested their physicians to switch them to eltrombopag because they preferred an oral drug. The efficacy was maintained after switching in all 16 patients. In the platelet-count fluctuation group, the initial response rate was also 100%. All 4 patients who were switched to eltrombopag because they experienced side-effects of romiplostim achieved complete remission with eltrombopag and their adverse events were resolved. 16 / 51 (33%) patients experienced one or more adverse event during treatment with eltrombopag. The frequency of grade 3–4 adverse events during treatment with eltrombopag was 9.8%. Conclusion: The use of eltrombopag after romiplostim for treating ITP is effective and safe. The reason for discontinuing romiplostim was associated with the response to eltrombopag. Disclosures No relevant conflicts of interest to declare.

Description: Background Bortezomib-based combinations, including alkylating agents (VMP or CyBorD) or immunomodulatory drugs (VTD or RVD) have been established as regimens widely used in newly diagnosed MM patients. Bendamustine is a bifunctional alkylating agent effective in relapsed and/or refractory MM patients, and approved in Europe in combination with prednisone for elderly newly diagnosed MM. Since bendamustine may be more efficient than other alkylators, an attractive possibility would be to explore it in combination with bortezomib and prednisone (BVP) in newly diagnosed MM patients both transplant and non transplant candidates. Patients and Methods 60 newly diagnosed MM patients were included in the trial. The first cycle consisted on bendamustine at 90 mg/m2 given IV on days 1 and 4, in combination with bortezomib at 1,3 mg/m2 given IV on days 1, 4, 8, 11, 22, 25, 29 and 32 and prednisone at 60 mg/m2 given PO on days 1 to 4. In the following cycles, bendamustine was given on days 1 and 8, and bortezomib on days 1, 8, 15 and 22 (weekly schedule), and prednisone as it was previously described. Patients younger than 65 years proceeded to peripheral blood stem cell collection (PBSC) using growth factors alone after 4 cycles; HDT-ASCT was performed after 6 cycles. Patients older than 65 years received up to nine 28-day cycles. Results Between May 2011 and July 2012 enrollment was completed (60 pts). Median age was 61 years (range 38-82; 18 pts ≥65), 67% had ISS stage II/III, and 67% had unfavorable cytogenetics: t(4;14), t(14;16), del 17p or 1q gains by FISH. After a median of 6 cycles (2-9), 75% of patients achieved at least PR, including 16% of sCR, 9% CR and 28% of VGPR. Although the differences were not statistically significant, there was a trend to higher CR rate in the group of patients

Description: Background VMP and Rd are two of the most efficient and widely accepted regimens in the treatment of elderly newly diagnosed MM patients. In order to further improve the outcome of elderly patients, one possibility would be to use regimens including all these drugs simultaneously, but this may result into high toxicity. Alternatively, the use of these regimens (VMP and Rd) in a sequential or alternating scheme could improve the treatment of elderly patients. We hypothesized the alternating scheme would minimize the emergence of resistant clones, and would reduce the cumulative toxicity. In order to test this hypothesis we decided to compare VMP and RD in a sequential vs an alternating scheme. Patients and methods 241 patients were randomized to receive a sequential scheme consisting on 9 cycles of VMP followed by 9 cycles of Rd or the same regimens in an alternating approach (one cycle of VMP alternating with one Rd (half of the patients started by VMP and half by Rd) up to 18 cycles). VMP included the iv administration of bortezomib 1.3 mg/m2 twice weekly for 1 six-weeks cycle, followed by once weekly for 8 four-weeks cycles in combination with oral melphalan 9 mg/m2 and prednisone 60 mg/m2 once daily on days 1–4 of each cycle. Rd treatment consisted on lenalidomide 25 mg daily on days 1-21 plus dexamethasone 40 mg weekly. Results 121 patients were allocated to receive the sequential scheme and 120 the alternating regimen. Both arms were well balanced according to the baseline characteristics. 52% patients in the sequential arm and 55% in the alternating and had high risk cytogenetic abnormalities (t(4;14), t(14;16), del17p or 1q gains). After 9 cycles of treatment, in the sequential arm, 35 out of 66 (54%) achieved at least VGPR vs 51 out of 65 patients (78%) in the alternating arm (p=0.002), including sCR/CR rate of 28% vs 38% in the sequential and alternating arms, respectively (p=NS). Seven patients in each arm achieved immunophenotypic CR. Moreover, while four patients progressed in the sequential arm under treatment with VMP, no patients in the alternating scheme developed disease progression during the first 9 cycles, After a median follow up of 12 months, there was a trend for shorter TTP in the sequential as compared with the alternating scheme (18 m-TTP of 83% vs 89% (p=NS)). In terms of OS, 83% of patients in the sequential arm were alive at 18 m versus 93% in the alternating (p=NS). Patients who achieved sCR/CR had a significantly longer 18 m-TTP as compared with patients who didn’t achieve it in both sequential (100% vs 71%; p=0.006) and alternating arms (100% vs 79%; p=0.006) and this translated into a significant benefit in OS. No differences were observed in overall response rates and CR rates in standard and high risk patients. The 18 m-TTP was similar in standard and high risk groups in both sequential (86% vs 81%) and alternating arms (84% vs 94%), noting that 94% of patients receiving the alternating scheme were progression-free at 18 months. Regarding hematologic toxicity, the frequency of G3-4 neutropenia was slightly lower in the sequential than in the alternating arm (16% and 23%) and the same trend was observed for G3-4 thrombocytopenia (16% vs 20%). Concerning non-hematologic toxicity, 5% and 4% of the patients in the sequential and alternating arms developed G3-4 infections, respectively; the rate of G3-4 skin rash was 4% in the sequential and 3% in the alternating arm; 4% of patients in the sequential arm developed G3-4 peripheral neuropathy and 3% in the sequential arm. The rate of grade 3-4 thrombotic events was 2% in both arms. Nevertheless, the detailed evaluation of the toxicity will be done at the completion of the trial when all patients will have received the same amount of drugs in either a sequential or an alternating scheme (at the present time, 42 patients in the sequential arm were not yet at risk for the development of lenalidomide-related side effects). Conclusions The administration of melphalan, bortezomib, lenalidomide and steroids in elderly MM patients in a sequential or alternating scheme is feasible. Although longer follow-up is necessary, the alternating scheme may be superior in terms of response rate and outcome, as result of the early exposure of the plasma cell to different agents. Toxicity profile is acceptable. Aparently both schemes of therapy seems to overcome the poor prognosis of high risk cytogenetic. Disclosures: Mateos: Janssen, Celgene: Honoraria. Off Label Use: Lenalidomide plus dexamethasone is not approved for newly diagnosed MM patients. Ocio:Onyx: Consultancy, Research Funding; Novartis: Consultancy; Array Biopharma: Consultancy, Research Funding; Bristol Myers Squibb: Consultancy; Celgene: Consultancy, Research Funding. San Miguel:Janssen, Celgene: Membership on an entity’s Board of Directors or advisory committees.

Description: Abstract 4155 Beyond the conventional criteria of lymphoma classification (integrated clinical, morphological, immunophenotypic, and molecular features) additional markers are still required for a more precise differential diagnosis and a better understanding of lymphoma pathogenesis. MicroRNAs (miRNA) are non-coding small RNAs that play an important role in gene expression regulation, contributing to cell differentiation and tumorigenesis. Specifically, miRNAs have been already described to play a relevant role in B cell differentiation, and in some cases proposed to constitute lymphoma-type specific markers and possible therapeutic targets. We explore the potential diagnostic application of miRNA expression in a large series of 147 cases including all B-cell non-Hodgkin lymphomas (NHL) major types and appropriate controls. As an example of a practical application, data were also used to identify miRNAs differentially expressed when comparing Burkitt Lymphoma (BL) and Diffuse Large B-Cell Lymphoma (DLBCL) in paraffin-embedded samples. Each lymphoma type (BL, CLL, DLBCL, FL, MCL, MZL/MALT, NMZL and SMZL) was compared to the whole series of NHL by Significant Analysis of Microarray (SAM) method. The analysis identified a set of 128 characteristic miRNAs (FDR1.5 log2). All lymphoma types were characterized by specific miRNA signatures, reflecting cell of origin and/or discrete oncogene alterations. Of interest is also the comparison with reactive lymphoid tissues, since it revealed a specific B-cell lymphoma miRNA profile, which includes a cluster of downregulated miRNAs, such as let7 family, miR-1 and miR-200 family. Burkitt Lymphoma was also directly compared to DLBCL, and 43 miRNA selected by SAM analysis were studied in a new series of 28 BL and 43 DLBCL samples using quantitative RT-PCRIn this second step, the differential expression of a set of 19 miRNAs was confirmed between BL and DLBCL. (FDR 〈 0.05 after t-test (limma)). These findings expand the potential diagnostic markers in lymphoma diagnosis and provide useful information on lymphoma pathogenesis. Disclosures: No relevant conflicts of interest to declare.

Description: Key Points Melphalan, in combination with bortezomib, should be maintained as one of the standards of care for the treatment of elderly MM patients. Complete response and particularly flow complete response should be an important goal in the treatment of elderly myeloma patients.

Description: p53 overexpression has been found to be a fairly common feature in high grade lymphomas in the majority of tumoral cells. The results vary from series to series, from 25% to 33% of cases. To assess whether immunohistochemical positivity for p53 correlated with the presence of structural gene abnormalities, DNA from 16 non-Hodgkin's lymphomas with high and low p53 values was amplified and sequenced to determine the existence of point mutations in the highly conserved regions of the p53 gene. In the group of 8 cases containing high levels of protein, 3 cases showed missense point mutations at the codons mapping between exons 5 through 8. Of the 8 cases of tumors containing undetectable or low levels of p53 protein, 1 case presented a nonsense point mutation giving a stop codon. No missense mutations were detected in this group. The finding of p53 mutations in 4 of 16 cases confirms the presence of p53 gene mutations in high grade lymphomas distributed over different histologic groups. These include Burkitt's lymphoma, together with centroblastic, immunoblastic, and large cell lymphoma of mucosa origin. Nevertheless, the absence of mutations in 5 of the 8 cases that overexpressed p53 suggests that the nuclear or cytoplasmic stabilization of p53 protein could also depend on other factors. The absence of detectable levels of p53 protein cannot discount the existence of p53 mutations, as is shown by a case of Burkitt's lymphoma in which a nonsense mutation was detected. The impact of this range of p53 alterations on clinical course and treatment response of the patients deserves to be explored, in an attempt to differentiate the specific consequences of each one.

Description: Background and objectives Protocols for acute myeloid leukemia (AML) 1st line patients are centered on the combination of Cytarabine and an anthracycline; Idarubicin (IDA), Daunorubicin (DNR), or Mitoxantrone (MIT). Patients may be treated with IDA, DNR, or MIT depending on the country of residence, because multiple clinical trials have not found significant differences among them. A new Personalized Medicine (PM) test developed by Vivia Biotech based on pharmacological responses in patient samples (ex vivo) is uncovering individual responses to these treatments. Our objective is to explore whether a significant % of individual patients may respond differently to IDA vs DNR vs MIT treatments, in spite that of their “on average” similar response shown by clinical trials. Patients and Methods Multicenter, prospective, non-interventional study of the PETHEMA group for treatment of AML. Bone Marrow (BM) samples were collected at diagnosis for 160 AML patients. Samples were incubated for 48 hours in 96-well plates, each well containing different drugs or drug combinations, each at 8 different concentrations, enabling calculation of dose response curves for each single drug (CYT, IDA, DNR, MIT) and combination used in treatments (CYT-IDA, CYT-DNR, CYT-MIT). Drug response was evaluated as depletion of AML malignant cells in each well after 48 hours incubations. Annexin V-FITC was used to quantify the ability of the drugs to induce apoptosis. Malignant cells were identified with monoclonal antibodies and light scatter properties. 1) We use the whole bone marrow sample, retaining the erythrocyte population and serum proteins, during the entire incubation period; and after 48 h leukocytes are isolated prior to evaluation by flow cytometry. 2) We have pioneered development of a proprietary automated flow cytometry platform called ExviTech. 3) Pharmacological responses are calculated using pharmacokinetic population models. Results Figure left panel shows dose responses for both IDA (red) and DNR (blue) in 125 AML patient samples. Although their average curves (thick red & blue) are similar, the interpatient variability of either drug is quite large. We hypothesized that some patients could show very differential sensitivities to both drugs, as illustrated by the green arrow where a patient sample is resistant to DNR (right shifted dose response curve) but sensitive to IDA (left shifted dose response curve). To identify these cases Figure right panel shows a comparison of the potency IDA vs DNR. Potency is represented by their EC50 (concentration that kills 50% of the cells). Most dots tend to line up, but red dots represent patient samples with a difference in potency between these drugs 〉30%. Repeating this exercise for IDA-MIT and DNR-MIT to cover all alternatives among the 3 anthracyclines identifies 40% of patients samples with 〉30% different potency among IDA-DNR-MIT. Repeating this exercise with the combination treatments CYT-IDA, CYT-DNR, CYT-MIT increases to 58% the population of patients whose samples have a differential sensitivity to these anthracyclines. A fraction of this 57% of patients may benefit in if treatment selection among these 3 treatments were to be aided by this ex vivo testing sensitivities. To identify which fraction would benefit we would need a trial specifically designed. Conclusions This preliminary results show that Vivia's PM test seems able to identify a subset of AML patients who's ex vivo pharmacological response to anthracycline drugs is significantly different. Because this ex vivo test accurately predicts the clinical response to CYT-IDA, if these selective anthracycline ex vivo responses translate to clinical responses, a fraction of this 57% subpopulation could benefit significantly from receiving 1st or 2nd line treatments based on either IDA, DNR, MIT, and their combinations. Hence this approach stands for European integration of treatment protocols, based on ex vivo individual responses data rather than nationality. Disclosures: Primo: Vivia Biotech: Employment. Hernandez-Campo:Vivia Biotech: Employment. Rojas:Vivia Biotech: Employment. Bennett:Vivia Biotech: Employment. Liebana:Vivia Biotech: Employment. Lopez:Vivia Biotech: Employment. Ballesteros:Vivia Biotech: Equity Ownership.

Description: Background and objectives Complete remission (CR) after induction therapy is the first treatment goal in acute myeloid leukemia (AML) patients. The aim of this study is to determine the ability of the Vivia’s novel ex vivo drug sensitivity platform Exvitech analyzing leukemic cell death to predict the CR rates after induction chemotherapy with cytarabine (Ara-C) and idarubicin (Ida) in 1st line AML. Patients and Methods This non-interventional and prospective study included samples from adult patients over 18 years of age diagnosed with de novo AML in Spanish centers from the PETHEMA group. Marrow samples were collected at diagnosis, sent to the Vivia laboratories, and incubated for 48 hours in whole samples in well plates containing Ara-C, Ida, or the combination Ara-C+Ida, each at 8 different concentrations to calculate dose responses. Annexin V-FITC was used to quantify the drug-induced apoptosis. Pharmacological responses are calculated using pharmacokinetic population models. Induction response was assessed according to the Cheson criteria (2003). Patients attaining a CR/CRi were classified as responders. The remaining patients were considered as resistant. Patients dying during induction response assessment were non-evaluable. The correlation was modeled using a generalized additive model with a logit link and a binomial distribution for residuals. Kernel density estimates were then used to plot empirical probability density functions for both groups. Their separation was quantified as the area under the ROC curve and a cut point was selected using the Youden’s criteria to optimize the classification probabilities (sensitivity, specificity). 95% confidence intervals for sampling errors were calculated for all these quantifiers. Results 125 patient samples were used to calculate the dose response curves for Ara-C alone, Ida alone, and the synergism of the Ara-C plus Ida combination. For clinical correlation we used 64 patients with a median age of 55 years (range 31 to 72). Dose responses for Ara-C alone are shown in Figure 1.A; note that for many samples there is a significant number (〉20%) of resistant cells to Ara-C (bracket). This is a strong clinical predictor of resistance because in the patient the drug will never be present at these high doses for 48 h. The second variable that is a good predictor of response is the synergism between these 2 drugs. The generalized additive model identified an algebraic combination of these 2 variables that yielded the best marker to separate both groups of patients. The probability density functions had minimal overlap. The area under the corresponding ROC curve was 0.965 (0.928, 1.000), and the classification probabilities for the optimal cut point (set at 0.414 for the marker), expressed as percentages, were 85% (62.1% to 96.8%) and 86.4% (72.6% to 94.8%) for sensitivity and specificity, respectively. Results are shown in Figure 1.B; Forty-four patients (68.8%) achieved CR after Ida+Ara-C, and the remaining 20 (31.3%) were resistant. Correlations of the PM test are shown in Figure 1.B. Seventeen of the 20 (85%) patients who fail to achieve CR were predicted as resistance in the ex vivo test. Thirty-eight of the 44 patients (86.4%) who achieved CR showed good ex vivo sensitivity to Ida+Ara-C predicting for CR. When the ex vivo test predicted a patient as sensitive it was correct in 38/39 cases (93%), and when it predicted resistant it was correct 17/23 cases (74%). Overall, 45 patients (86%) had an accurate prediction of their response to treatment. Conclusions This study shows that this novel ex vivo pharmacological profile test is able to predict the clinical response to Ida+Ara-C induction. We are increasing the number of patients in this ongoing study, and we are planning a PM Test-adapted Clinical Trial. Disclosures: Martínez: Vivia Biotech: Employment. Ortega:Vivia Biotech: Employment. Primo:Vivia Biotech: Employment. Hernandez-Campo:Vivia Biotech: Employment. Rojas:Vivia Biotech: Employment. Bennett:Vivia Biotech: Employment. Liebana:Vivia Biotech: Employment. Lopez:Vivia Biotech: Employment. Ballesteros:Vivia Biotech: Equity Ownership.

Description: Introduction P210 BCR-ABL translocation resulting from rearrangements within the major breakpoint cluster region (M-BCR), either e13a2 or e14a2, is the molecular hallmark of chronic myeloid leukemia (CML). However, some CML patients may harbor atypical BCR-ABL rearrangements such e1a2 P190 BCR-ABL which involves the minor breakpoint cluster region (m-BCR). Response to therapy with tyrosine kinase inhibitors (TKI) and outcome of such atypical patients is not well defined. Objective To evaluate response to TKI therapy of CML patients with the atypical e1a2 P190 BCR-ABL translocation. Patients and Methods Since 2009, 4 patients with CML in chronic phase and with atypical e1a2 P190 BCR-ABL rearrangement have been recruited in various institutions belonging to the Hematological Molecular Biology Group (GBMH) of the Spanish Society of Hematology (SEHH). Patient characteristics, treatments administered and response to therapy for the 4 patients is shown in Table 1. BCR-ABL transcripts were revealed at diagnosis by quantitative PCR followed by conventional agarose electrophoresis of PCR products. Molecular follow-up of BCR-ABL transcripts throughout treatment was performed by quantitative PCR following the guidelines of the European Leukemia Net. Results One patient received treatment (HU and INF+araC) prior to TKI (Pat. 1; Table 1). All 4 patients received Imatinib as initial TKI treatment. Two of the patients treated with Imatinib (Pat. 1,2) obtained a complete molecular response (CMR) and the other 2 (Pat. 3,4) only achieved a complete hematological response (CHR) as best response (Table 1). All patients had to switch to a second generation TKI (3 Nilotinib and 1 Dasatinib) due to intolerance to Imatinib (n=1; Pat. 1) or resistance (n=3; Pat. 2-4). The patient who received Dasatinib as second line TKI (Pat. 3) only achieved a partial hematologic response (PHR) and was changed to Nilotinib as third line TKI, achieving CHR after which the patient entered in blast crisis and died 36 months after diagnosis (Table 1). Overall, only 1 (Pat. 1) out of the 4 patients included in the present study achieved a sustained molecular response with Imatinib. At last follow-up, among the 4 patients included in the study, all 4 had needed a change of TKI, 1 had died due to disease progression (Pat. 3) and only 2 of them retained a molecular response (Pat. 1,2). Conclusion CML patients harboring atypical e1a2 P190 BCR-ABL transcripts show a poor response and short-lived responses to TKI therapy and therefore should be identified as high-risk patients at diagnosis. These patients must be closely monitored during therapy with TKI and should be treated upfront with a second generation TKI or even be considered for allogeneic SCT in the early phase of the disease. Paper presented on behalf of the Hematological Molecular Biology Group (GBMH) of the Spanish Society of Hematology (SEHH). AJ-V and IB contributed equally to this work. Disclosures: No relevant conflicts of interest to declare.