ALBERT

Description: Although multiagent combination chemotherapy is curative in a significant fraction of childhood acute lymphoblastic leukemia (ALL) patients, 20% of cases relapse and most die because of chemorefractory disease. Here we used whole-exome and whole-genome sequencing to analyze the mutational landscape at relapse in pediatric ALL cases. These analyses identified numerous relapse-associated mutated genes intertwined in chemotherapy resistance-related protein complexes. In this context, RAS-MAPK pathway-activating mutations in the neuroblastoma RAS viral oncogene homolog (NRAS), kirsten rat sarcoma viral oncogene homolog (KRAS), and protein tyrosine phosphatase, nonreceptor type 11 (PTPN11) genes were present in 24 of 55 (44%) cases in our series. Interestingly, some leukemias showed retention or emergence of RAS mutant clones at relapse, whereas in others RAS mutant clones present at diagnosis were replaced by RAS wild-type populations, supporting a role for both positive and negative selection evolutionary pressures in clonal evolution of RAS-mutant leukemia. Consistently, functional dissection of mouse and human wild-type and mutant RAS isogenic leukemia cells demonstrated induction of methotrexate resistance but also improved the response to vincristine in mutant RAS-expressing lymphoblasts. These results highlight the central role of chemotherapy-driven selection as a central mechanism of leukemia clonal evolution in relapsed ALL, and demonstrate a previously unrecognized dual role of RAS mutations as drivers of both sensitivity and resistance to chemotherapy.

Description: Background: survival of young patients with high IPI DLBCL treated with RCHOP chemotherapy needs to be improved. In this poor risk population the combination of RCHOP with new drugs is an attractive approach, along with performing an early evaluation with PET/CT after 2 to 4 cycles and change induction therapy if a complete response is not achieved. Bortezomib has been combined with RCHOP [1]. We present preliminary data of patients treated in a clinical trial comparing 6 cycles of RCHOP vs 6 cycles of BRCAP, a modified RCHOP regimen changing vincristine by bortezomib at a dose of 1.3 mg/m2 sc days 1, 8, and 15 of every 21 days cycle (NCT01848132). Methods: patients younger than 70 yrs diagnosed of DLBCL with aIPI 2-3 or aIPI 1 with elevated beta2microglobulin were eligible. The main objective was to evaluate the proportion of patients who survives free of event at 2 years. Central pathology review was performed in all cases, and samples were classified as GC vs non-GC subtypes by IHC (Hans algorithm). PET/CTs were performed at diagnosis, after 2, 4 and 6 cycles (PET2, PET4 , and PET6), and were reviewed by at least 3 experts of a central panel at real time. Response was analyzed following the visual method with the Deauville scale, and for PET2 and PET4 the semiquantitative method was used. Patients with persistent disease after 4 cycles were considered a failure of therapy and were dropped out from the trial. Results: data from the first 76 patients were analyzed. Diagnosis of DLBCL was confirmed in all except 3 pts, 36 pts were treated in the experimental arm and 37 in the control arm. Median age was 58.2 yo (range 23-70), 37 (50.7%) were males. Characteristics at diagnosis were: non-GC subtype 18/46 (39.1%), C-myc expression 35/43 (81.4%), bcl2 expression 43/49 (87.7%), double expression cmyc/bcl2 30/42 (71%), stage III-IV 64 (87.6%), ≥2 extranodal locations 27 (42.2%), ECOG 2-3 24 (33%), elevated LDH 43 (62.3%), elevated beta 2 microglobulin 47 (75.8%), aIPI 2: 42 (57.5%), aIPI 3: 21 (28.8%). Among 160 cycles of BRCAP chemotherapy, 5 (3.1%) on day 8, and 22 (13.7%) on day 15, were given without bortezomib due to a neutrophil count below 0.5 /L. The most common toxicities are shown in table 1 without significant differences between both arms. Twenty-one (32.8%) out of 64 patients had a positive PET2. Fifteen (26.8%) out of 56 patients who have finished the 4 cycles had a positive PET4 according to central review and were withdrawn of the trial. Table 1. Episodes of treatment-related adverse events Control arm: RCHOP n=166 Experimental arm: BRCAP n=160 Any grade Grade 3-4 Any grade Grade 3-4 Anemia 6 0 22 9 ( 5.6%) Neutropenia 31 26 (15.6%) 47 37 (23.1%) Thrombocytopenia 9 4 ( 2.4%) 16 5 ( 3.1%) Febrile neutropenia - 6 ( 3.6%) - 10 ( 6.2%) Fever 8 1 ( 0.6%) 8 0 Infection 4 1 ( 0.6%) 7 1 ( 0.6%) Nausea/vomiting 12 0 19 0 Peripheral neuropathy 7 1 ( 0.6%) 7 1 ( 0.6%) Diarrhea 4 0 8 0 Constipation 7 0 4 0 Hepatotoxicity 6 0 6 0 Conclusions: BRCAP regimen with bortezomib sc d1, 8, and 15 is feasible. Its main toxicity is hematological, and some patients cannot receive some doses of bortezomib due to neutropenia. Grade 3-4 non-hematological toxicity is rare, including peripheral neuropathy, and do not differ from RCHOP toxicity. 1.Ruan J et al, JCO 2011;29:690-7 Disclosures Sancho: CELLTRION, Inc.: Research Funding. Lopez-Guillermo:Roche, Celgene, Mundipharma, Gilead, Novartis: Membership on an entity's Board of Directors or advisory committees, Research Funding.

Description: Abstract 2867 Introduction. Survival of Follicular Lymphoma patients has significantly increased with the introduction of immunomodulatory agents, such as Interferon (IFN) and Rituximab (R). Until 2002 our Follicular Lymphoma patients were included in a trial and received induction therapy with CVP + Interferon (LNH-pro, JCO 16; 1538–1546). Since 2006, Rituximab is being added to the same induction regimen (LNH-pro-05, EHA 09). Herein we communicate the comparative results between these two trials in Intermediate-High risk Follicular Lymphoma patients. Aim. To compare toxicity and efficacy in terms of complete remission (CR) and Progression Free Survival (PFS) between both trials in Intermediate-High risk Follicular Lymphoma patients. Methods. Patients in the LNH-pro trial (1990-2006) received CVP (CY 400mg/m2 p.o D1-5, VCR 1.4mg/m2 iv D1, PRD 100mg/m2 po D1-5) + IFN (3MU/m2 sc, 3 times/wk, for 12 wks). When it became available, G-CSF support was permited. In the LNH-pro-05 trial (2006-ongoing), Rituximab (R: 375mg/m2 iv D1) was added to the same induction regimen. All patients received 8 cycles as per protocol, with G-CSF support and Pn. jiroveci prophilaxis. In both studies, complete re-assessment was performed after cycle 4, at the end of induction therapy, every 4 months for the first 2 years and every 6 months thereafter. Results. We analysed data from 74 and 36 FL patients with FLIPI≥2, included in the LNH-pro and LNH-pro-05 trials, respectively. Patients' characteristics are shown in table 1. No significant differences were found between groups, except for a higher incidence of elevated B2-microglobulin in patients treated with CVP+IFN and higher Bulky disease (〉7cm) among patients with R+CVP+IFN. Median number number of cycles were 6 and 8, respectively. Response: Seventy one patients (96%) in the LNH-pro Trial (CVP+IFN) were evaluable for response. Overall Response (OR) rate was 87%, with 68% Complete Remission (CR) and 19% Partial Remission (PR) (9% non-responders). In the LNH-pro-05 Trial (R+CVP+IFN), 36 patients (92%) and 33 patients (83%) were evaluable for response after 4th and 8th cycle. At cycle 4, all assesed patients achieved remission (15% PRs and 85% CR+uCR), while after the 8th cycle 100% of patients are in CR or uCR. Toxicity. Main hematologic grade 3–4 toxicity was neutropenia, 33% for CVP+IFN and 28% for R+CVP+IFN, with 12% and 6% of infections, respectively. Other non-hematologic toxicities were infrequent and mild (5% and 10% in each group). Eight percent of patients in the LNH-pro trial withdrew treatment due to toxicity. At the moment, none of the patients in the LNH-pro-05 trial have experienced an unacceptable toxicity. Survival . Median follow-up was 7.7 years for CVP+IFN and 2 years for R+CVP+IFN. A significant increase of PFS was seen among patients who received R (66% vs. 86%, at 3 years, P 0.05). There is also a trend to a longer overall survival in patients treated with R+CVP+IFN (P 0.07). Conclusion. The addition of Rituximab to CVP+IFN induction regimen in Intermediate-High risk Follicular Lympoma patients, significantly increases complete remission rates (88% to 100%) and progression free survival (86%, at 3 years), with a low toxicity profile. Disclosure: No relevant conflicts of interest to declare.

Description: Background: Survival of DLBCL patients with high IPI treated with RCHOP immunochemotherapy is poor. In this population, the combination of RCHOP with new drugs is an attractive approach, along with performing an evaluation with PET/CT after 2 to 4 cycles to change the therapy if an early complete response is not achieved. Methods : We performed a clinical trial comparing 6 cycles of RCHOP vs 6 cycles of BRCAP, a modified RCHOP regimen changing vincristine by bortezomib 1.3 mg/m2 sc days 1, 8, and 15 of a 21-day cycle. Pre-phase therapy was permitted for patients who could not wait the results of the screening procedures to start therapy due to the aggressiveness of the disease. (ClinicalTrials.gov Identifier: NCT01848132). Patients younger than 71 yrs diagnosed with DLBCL and an age-adjusted IPI (aaIPI) 2-3 or aaIPI 1 with increased beta2microglobulin were eligible. The primary endpoint was the proportion of patients who survives free of event at 2 years. Centralized anatomopathology review was performed in all cases; samples were classified as germinal center B-cell-like (GCB) vs non-GCB subtypes by immunohistochemistry according to the Hans algorithm. PET/CTs were performed baseline, after 2, 4 and 6 cycles (PET2, PET4, and PET6), and were reviewed at real time by at least 3 experts of a central panel. Response at the end of therapy was analyzed following the visual method with the Deauville scale, and response after PET2 and PET4 was evaluated using the semiquantitative method. Persistent disease at PET4 was considered as failure of therapy and these patients were removed from trial treatment. EFS was calculated from diagnosis until event defined as death from any cause, relapse, progression or need of salvage therapy (defined as PET4 or PET6 positive). Overall survival (OS) was calculated from diagnosis until death for any cause. We present here a preliminary analysis of results. Results: One hundred and twenty-one patients were included; data on 113 are presented (diagnosis not confirmed in 6, data missing in 2). Median age was 57.1 yrs (range 23-70), 57 (50.4%) were males. Characteristics at diagnosis were: non-GCB subtype 32/87 (36.8%), immunohistochemical co-expression of myc/bcl2 56/82 (77.8%), stage III-IV 107 (94.7%), ≥2 extranodal locations 55/76 (72.5%), ECOG 2-3 36 (32.1%), increased LDH 88 (77.9%), increased beta 2 microglobulin 73 (64.6%), aaIPI 3: 32 (28.3%). No differences were found between treatment arms. Fifty-five patients were treated in the experimental arm (EA) and 58 in the control arm (CA). Twenty-eight (28.3%) out of 99 patients required of pre-phase treatment. The mean relative dose intensity for bortezomib was 88.3%. Data about the most frequent toxicity are shown in table 1. Twenty-nine (30.2%) out of 96 patients who have finished 4 cycles had a positive PET4 according to central review and were withdrawn to receive salvage therapy. Complete remission (CR) at the end of therapy (PET4-/PET6-) was observed in 44 (45.8%) patients. After a median follow-up of 9 months, estimated 12-mo EFS was 36.6%, and 12-mo OS was 82.9% in the whole series. Data of the subgroup analysis according the immunohistochemistry subtypes by Hans algorithm are show in table 2. Conclusions: In the present preliminary analysis, no significant differences were found between RCHOP and BRCAP in terms of CR and EFS in this very high-risk population of young DLBCL patients. However, in the subgroup analysis of patients with non-GCB disease, we found a significantly better CR rate in patients treated with BRCAP. A longer follow-up is needed to evaluate the real impact of this therapy on survival. Disclosures González-Barca: Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Gilead: Honoraria; Servier: Honoraria, Membership on an entity's Board of Directors or advisory committees; Sanofi: Membership on an entity's Board of Directors or advisory committees; Roche: Honoraria. Martín:Sevier: Honoraria, Membership on an entity's Board of Directors or advisory committees; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen: Honoraria; Gilead: Membership on an entity's Board of Directors or advisory committees. Sancho:Gilead: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Roche: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celltrion, Inc: Research Funding; Sanofi: Membership on an entity's Board of Directors or advisory committees; Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees. López-Jiménez:Abbvie: Membership on an entity's Board of Directors or advisory committees; Velgene: Honoraria, Membership on an entity's Board of Directors or advisory committees; Roche: Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees; MSD: Honoraria, Membership on an entity's Board of Directors or advisory committees; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees; MundiPharma: Honoraria, Membership on an entity's Board of Directors or advisory committees. López-Guillermo:Janssen: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees; MundiPharma: Membership on an entity's Board of Directors or advisory committees; Roche: Membership on an entity's Board of Directors or advisory committees; Gilead: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees. Ramírez:Bristol-Myers-Squibb: Honoraria; Novartis: Honoraria; Roche: Honoraria; Janssen: Membership on an entity's Board of Directors or advisory committees. Conde:Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Roche: Honoraria; Amgen: Membership on an entity's Board of Directors or advisory committees; Servier: Membership on an entity's Board of Directors or advisory committees.

Description: Abstract 4942 INTRODUCTION. Patients with Mantle cell lymphoma (MCL) have an adverse outcome after relapse due to chemorefractory disease with conventional treatments. Bendamustine, a nitrogen mustard compound chemically related to the alkylating agents, has demonstrated high efficacy with a low toxicity profile in reported clinical trials. AIM. To analyze the Spanish experience in patients with relapsed/refractory MCL treated with Bendamustine. METHODS. Retrospective analysis of spanish experience in relapsed/refractory MCL treated with Bendamustine alone or in combination. This study has been approved by local ethical committees. RESULTS. Currently, there are 36 patients registered and 28 are available for this analysis. Patients'characteristics: 69% male, median age 65 years old (range 41–81), 87% ECOG≤ 1, 83% Ann Arbor stage IV, 37% high risk MIPI and 9% blastic variant. Previous regimens were CHOP or CHOP like ± R in 42.5%, HyperCVAD/MtxAraC ± R in 42.5%, R-CVP in 9% and other regimens in 6%. Median number of previous treatments were 2.6 (range 1–6), all patients had received prior Rituximab and 73% had chemosensitive disease to the last treatment. Bendamustine regimen was R-B (R-375mg/m2 D1, B-90 mg/m2 D1-2) in 78% patients, R-B with B-70 mg/m2 in 8%, B alone in 3%, R-B-Bortezomib in 3% and R-B plus consolidation (SCT, Y90Ibritumomab-tiuxetan) in 8%. Median number of cycles was 4.61 (range 1–7). G- CSF support was administered in 43% of cycles. Response: Overall response rate was 73%, with 43% CR & uCR and 30% PR. Survival: Median overall survival from diagnosis is 8,26 years (range: 1.6–11,6 years) without plateau. Median progression free survival (PFS) after Bendamustine treatment was 16 months (95% CI: 11.7–20.4), data that compares favourably with patients' PFS to previous therapy (12 months, 95% CI: 6.5–17.5). Median PFS for patients who achieved CR/uCR is 32.6 months (95% CI: 19.9–45.4) versus 11 months in patients with PR (95% CI: 3.9–18.8). With a median follow-up for surviving patients of 12 months since Bendamustine treatment, the estimated OS at 3 years is 47% (+ SD 14%). Toxicity: No treatment related mortality has been described so far. Over 152 cycles, only 10 hospitalizations due to febrile neutropenia were reported. No one case of lysis tumoral syndrome has been reported. CONCLUSION. Bendamustine plus Rituximab is a good rescue treatment in non selected pretreated patients with mantle cell lymphoma. CR rate and duration of response seem to reproduce in current clinical practice the good data reported in previous clinical trials and compares favourably with other available treatments. Disclosures: No relevant conflicts of interest to declare.

Description: Introduction: Indolent B cell non-Hodgkin lymphomas are entities without curative treatment nowadays. However, survival has significantly improved since the incorporation of immunomodulatory agents and now immunochemotherapy has become the gold standard. Most treatment strategies use progression free survival (PFS) as a surrogate marker for overall survival (OS), although updated long term results are frequently lacking. Since 1990 our group introduced IFNα-2b to Bagley’s CVP induction regimen, for naïve indolent NHL (LNH-pro study). Herein we report our long term results. Aim: To evaluate long term outcome and late toxicities of patients who received immunochemotherapy with IFN α-2b plus CVP. Patients and Methods: From February 1990 to November 2001, patients from 7 Spanish institutions were included. Induction therapy consisted of Cyclophosphamide (400 mgs/m2 po) and Prednisone (100 mg/m2 po) daily for 5 days, Vincristine (1.4mg/m2 iv) on day 1, and subcutaneous IFN α-2b (3 MU/m2, three times a week, for a total of 36 doses). Patients received the number of cycles necessary to achieve maximum response. Updated clinical data were retrieved from participating centres up to March 2012. Results. A hundred and seventy patients with low-grade NHL were analyzed. Included entities were: 65% grade 1-2 follicular lymphoma (FL), 21% lymphocytic lymphoma and 14% marginal zone lymphoma. Median age was 56 yo (range 22-78 yo), elevated LDH and β2-microglobuline were 13.6% and 26% respectively, 57.6% had bone marrow involvement and 7.6% bulky disease (〉7cm). According to FLIPI, 33% were high risk, 40% intermediate and 27% low risk FL. Median number of cycles was 6, and overall response rate achieved was 90%, with 68% complete remissions. Median follow up of surviving patients was 12.5 years (range 3-21 ys), with only 14.7% of patients lost to follow-up. Median PFS for all patients was 12.5 years (95% CI 10.5 – 14.5 years) and not reached for FL patients (20-year PFS of 63%; 95%CI: 54-72%). Median OS has not been reached, with a 20-year OS of 59.7% (CI 95%, 50.5-69%) for all low-grade NHL patients and 62% (IC 95%, 50-74%) for FL patients. Long-term toxicity is detailed in table 1. Incidence of secondary malignancies is 13.5%. At time of analysis, 57 out of 170 patients have died (33.5%), mainly due to lymphoma (58% of patients) and other non-lymphoma events (42%). Table Secondary malignancies 23 cases (13.5%) - MDS / AML 3 cases - Solid tumors 18 cases - Dermatologic neoplasia 2 cases Causes of death Number of patients (%) Induction toxicity events 4 (7%) Lymphoma progression / relapse 29 (51%) Secondary malignancies 9 (16%) Other non-lymphoma events 15 (26%) - Miocardiopathy 4 - Chronic Pulmonary disease 3 - Hepatic failure 2 - Brain traumatic injury 1 - Unknown cause 5 Figure 1 Figure 1. Conclusions: Our results confirm that immunochemotherapy with IFN α-2b plus CVP regimen induces a median PFS of 12.5 years and a 20-year OS of 59.7% (median not reached). With a median follow-up of 12.5 years, 58 % died due to lymphoma, 16% from secondary malignancies and 26% for non-lymphoma events. These results highlight the importance of performing long term follow-up in order to assess the real survival benefit of any treatment. Disclosures No relevant conflicts of interest to declare.

Description: Abstract 3691 Background. There is currently no established treatment for the management of MALT lymphoma requiring systemic treatment. For patients failing to antibiotics or those with local advanced, refractory or disseminated disease several chemotherapy treatments have been studied. Considering the activity of Bendamustine in relapsed/refractory indolent lymphomas, with or without anti-CD20 antibodies, immunochemotherapy with Bendamustine plus Rituximab (BR) seems very attractive as first-line treatment for MALT lymphoma. Patients and methods. A nation-wide prospective phase II trial (EUDRACT 2008–007725–39) has been carried out in Spain by the GELTAMO group in untreated patients with CD20-positive MALT lymphoma. Patients with lymphoma arisen at any extranodal site and of any stage (Ann Arbor I-IV) could be enrolled. In addition, localized gastric MALT lymphoma previously refractory to H. pylori eradication or those with skin lymphoma not suitable for local therapy or previously treated with selective radiotherapy/surgery were also eligible. Treatment consisted of Bendamustine (90 mg/m2 d1–2) and Rituximab (375 mg/m2 d1), every 28 d. Pts were evaluated after completing 3 cycles: if complete remission (CR), pts received a further cycle (total of 4) and if partial response (PR), pts received 3 more cycles (total of 6). The aims were: feasibility and security of the combination and rate and quality of the responses, and event free survival. From May 2009 to May 2010, 60 patients were enrolled. Clinical characteristics: median age 62 years (range, 26–84); 34 (57%) female; Ann Arbor stage: I in 49%, II in 17% and III-IV in 34%; B-symptoms 5%. 20 patients (33%) had the lymphoma in the stomach, 35 (58%) in extra-gastric sites and the remaining 5 cases (8%) lymphoma was multifocal. The most common extra-gastric sites were lung and ocular adnexa in 11 and 7 patients, respectively. Results. A total of 264 cycles of BR were delivered in the whole population. Only 2 patients received less than 4 cycles. Rituximab dose was no modified at any cycle and only 5 patients required dose reduction of Bendamustine (median dose intensity: 0.98). Only 2 patients have not completed treatment due to toxicity: 1 case after 2 cycles due to severe rituximab-associated toxicity and another one after grade 4 febrile neutropenia in the 5th cycle. Grade 3–4 neutropenia was seen in 18% of patients. A total of 25 grade 3–4 non-haematologic toxicities were documented in 12 patients. Of note, 11 of these episodes were infectious (2 febrile neutropenia, 2 cytomegalovirus enteritis and 7 other).Response after 3 cycles of R was evaluable in 58 patients: 44 achieved CR or uCR and 14 patients PR, for an overall response rate (ORR) of 100% with a CR rate of 76%. CR rate after 3 cycles was higher in patients with gastric origin in comparison with non-gastric (90% vs 64%) (multifocal cases 100%). At the end of treatment, ORR was 100% with CR/uCR of 98%. A remarkable finding was that only 14 pts (23%) required more than 4 cycles of BR. With a median follow-up of 16 months (range, 3–40), one death has been recorded due to a neurologic syndrome and none patient has relapsed. Conclusions. The combination of Bendamustine and Rituximab in first line treatment of MALT lymphoma achieved an ORR of 100% after only 3 cycles. CR rate after completing treatment plan was 98%. Interestingly, a large majority of patients (85%) required only 4 cycles of treatment. This regimen was safe and well accepted by patients, making this response-adapted schedule a foremost therapeutic strategy for this type of lymphoma. Disclosures: Off Label Use: Bendamustine and rituximab are not currently approved for MALT lymphoma in first line, although both are commonly used in the relapse setting.

Description: INTRODUCTION Cell free tumor DNA (cftDNA) based targeted next generation sequencing (NGS) is a novel tool that enables accurate and minimally invasive tumor genotyping. MATERIAL AND METHODS Here we have performed cftDNA targeted NGS for the molecular diagnosis of a series of 92 peripheral blood samples obtained at diagnosis in patients included in a phase II randomized clinical trial comparing standard RCHOP versus BRCAP as first line treatment in patients with poor IPI (aaIPI2-3 or aaIPI1 with high b2m, age 18-71, NCT01848132). Centralized histopathological review of diagnostic tissue samples confirmed the diagnosis: 83 DLBCL (68%, 55/81 GCB, 32%, 26/81 non-GCB, according to Hans immunohistochemical algorithm), 4 TCHRBCL, 3 PMBCL, 1 concurrent DLBCL and FL3A, 1 FL 3B. 7 out of 83 cases had DLBCL morphology and DH by FISH (6 MYC/BCL2 and 1 MYC/BCL6, all GCB-type by IHC). A targeted NGS approach using amplicon-based chemistry (Truseq, Illumina) that interrogates exonic regions of 35 relevant genes in DLBCL (1458 amplicons analyzed) was used for library generation from plasma derived DNA. Germline DNA from peripheral blood granulocytes from 89 out of 92 patients was sequenced in parallel and used as control DNA for variant calling. Only somatic variants with a read depth above 100 and Variant Allele Frequency 〉 5% were considered. RESULTS cftDNA concentration (hGE/mL) was associated with LDH levels (U/mL) at diagnosis. Mean cftDNA concentration was lower in patients with low LDH (U Mann whitney p= 0.005). Somatic mutations were identified in 74% (68 out of 92) patient plasma samples. 242 somatic mutations were considered after filtering. Mean of 3.6 mutations per patient. 10 genes were mutated in 〉10% of the patients, including: FAT2 (19.6%), ARID1A (18%), NOTCH1 (17.4%), NOTCH2 (15.2%), KMT2D (14.13%), SMARCA4 (14%), ATM (13%), EP300 (13%), EZH2 (13%), PLCG2 (13%). Recurrent mutations were found in EZH2 (2 patients). Mutations in BCR/TLR pathway genes were found in less than 10% of the cases (CARD11, 7.6%; MYD88, 4.4%; CD79A, 5.4%; CD79B, 1%; BTK, 4.4%). NOTCH1 mutations were found preferentially in GCB type DLBCL (12/55 GCB vs 1/26 nonGCB, Chi square p value

Description: INTRODUCTION. Treatment with IFN and chemotherapy induces a significant improvement of PFS in patients with low-grade NHL, specially in patients with responsive disease. However, the best IFN schedule is still pending as benefits are observed when IFN is administered associated to the induction therapy or, as maintenance treatment or, in both treatment phases. OBJETIVE. To evaluate the additional benefit or not of one year maintenance treatment with IFN in patients who achieve response after an induction treatment with CVP and IFN for 3 months. PATIENTS & METHODS. From February 1990- October 2002, 165 patients with low-grade NHL were recruited. Patients received treatment with CVP (median number 6 cycles) and IFN, 3MU/m2 three times a week during 3 months. Patients with complete or partial responses were then randomized to receive treatment with 12 months of IFN, 3MU/m2 three times a week vs observation. With a median of 4,7 years (range 0.3 to 11.7 years) for surviving patients, we analysed response, PFS and overall survival. RESULTS. Patients median age was 63 years (range 28–89 years), with 65.5% having follicular (FL), 20% small lymphocyte and 14% marginal zone lymphoma. Most patients (83%) were in advance stage and 75% had extranodal involvement. Thirty-three percent of FL patients had a FLIPI index score 〉 3. Dose-intensity for cyclophosphamide and IFN in the induction treatment was 71% and 69%, respectively. Ten patients withdraw the study due to grade 3–4 toxicity events (6.5%). Response : 86% of patients achieved a response, 80% complete. One hundred and twelve out of the 143 responding patients were randomised to receive IFN for 12 months (56 patients) vs observation (56 patients). Patients and disease characteristics for each group were similar. Median dose of maintenance IFN treatment was 67% (range 8%–113%). Fourteen patients (25%) withdraw the study, 7 due to IFN toxicity. PFS : Median PFS of the whole series was 6.76 years, 6.6 years for patients in the maintenance IFN group vs 7.8 years for the observation group, p=0.7. Overall survival at 12 years is 81% for both groups. Interestingly, 31 patients who achieved a good response but were not randomised showed a significantly shorter OS, p=0.001. CONCLUSION. No additional increase on PFS has been observed when maintenance IFN is administered to patients responding to CVP and short term IFN induction therapy. With our data, very good response rates and long lasting remission are achieved with only 3 months IFN treatment. Treatment tolerance is therefore significantly better.