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Autologous anti-CD19 chimeric antigen receptor (CAR) T-cell therapy is an effective treatment for approximately 40% of relapsed/refractory large B cell lymphomas (LBCL), and early identification of patients at risk for relapse or progression after CAR T-cell therapy represents a clinical need.The authors conducted a single-center prospective study on 47 relapsed/refractory LBCL receiving CAR T-cell therapy to evaluate the prognostic value of baseline and after infusionDeep variation of standardized uptake value (SUV)PET parameters and association of DS and variation of SUVThis is a single-center prospective study on 47 lymphoma patients receiving commercial chimeric antigen receptor T-cell therapy aimed to evaluate the prognostic value of baseline and after infusion

Supplementary Figures S1-6. Figure S1: Histological staging criteria for acute GvHD Figure S2: Ruxolitinib does not impair post-transplant donor myeloid reconstitution and full donor chimerism. Figure S3: GVT effect against myeloid leukemia RMB-1 cell line is maintained in the presence of ruxolitinib Figure S4: Ruxolitinib at the dose of 90 mg/Kg prevents acute GVHD without affecting T cell alloreactivity Figure S5: Ruxolitinib effect at 45 mg/Kg on absolute numbers of alloreactive T cells, Th17 and Treg cells. Figure S6: Representative Images of Ruxolitinb effect on T cells and macrophage infiltration of GVHD organs

Purpose:In clinical trials, the expansion and persistence of chimeric antigen receptor (CAR) T cells correlate with therapeutic efficacy. However, properties of CAR T cells that enable their in vivo proliferation have still to be consistently defined and the role of CAR T bag content has never been investigated in a real-life setting.Experimental Design:Residual cells obtained after washing 61 anti-CD19 CAR T product bags were analyzed to identify tisagenlecleucel/Tisa-cel and axicabtagene ciloleucel/Axi-cel phenotypic features associated with postinfusion CAR T-cell in vivo expansion and with response and survival.Results:While Tisa-cel was characterized by a significant enrichment in CAR+CD4+ T cells with central memory (P < 0.005) and effector (P < 0.005) phenotypes and lower rates of CAR+CD8+ with effector memory (P < 0.005) and naïve-like (P < 0.05) phenotypes as compared with Axi-cel, the two products displayed similar expansion kinetics. In vivo CAR T-cell expansion was influenced by the presence of CAR T with a CD8+ T central memory signature (P < 0.005) in both Tisa-cel and Axi-cel infusion products and was positively associated with response and progression-free survival (P < 0.05).Conclusions:Our data indicate that despite the great heterogeneity of Tisa-cel and Axi-cel products, the differentiation status of the infused cells mediates CAR T-cell in vivo proliferation that is necessary for antitumor response.

Supplementary Data from Phenotypic Composition of Commercial Anti-CD19 CAR T Cells Affects In Vivo Expansion and Disease Response in Patients with Large B-cell Lymphoma

Purpose: Immune-mediated graft-versus-tumor (GVT) effects can occur after allogeneic hematopoietic stem cell transplantation (HSCT), but GVT is tightly linked to its main complication, graft-versus-host disease (GVHD). Strategies aimed at modulating GVHD, while maintaining the GVT effect, are needed to improve the cure rate of transplant. Given the emerging role of Janus-activated kinase (JAK) signaling in lymphoproliferative and myeloproliferative diseases and its established function at dictating T-cell differentiation, we postulated that JAKs might be potential therapeutic targets through a pharmacologic approach.Experimental Design: We examined the effect of JAK1/JAK2 modulation by ruxolitinib in a mouse model of fully MHC mismatched bone marrow transplant comprising in vivo tumor inoculation.Results: JAK1/JAK2 inhibition by ruxolitinib improved both overall survival (P = 0.03) and acute GVHD pathologic score at target organs (P ≤ 0.001) of treated mice. In addition, treatment with ruxolitinib was associated with a preserved GVT effect, as evidenced by reduction of tumor burden (P = 0.001) and increase of survival time (P = 0.01). JAK1/JAK2 inhibition did not impair the in vivo acquisition of donor T-cell alloreactivity; this observation may account, at least in part, to the preserved GVT effect. Rather, JAK1/JAK2 inhibition of GVHD was associated with the modulation of chemokine receptor expression, which may have been one factor in the reduced infiltration of donor T cells in GVHD target organs.Conclusions: These data provide further evidence that JAK inhibition represents a new and potentially clinically relevant approach to GVHD prevention. Clin Cancer Res; 21(16); 3740–9. ©2015 AACR.

The standard treatment for young patients with untreated PTCLs is based on anthracycline containing-regimens followed by high-dose-chemotherapy and stem-cell-transplantation (HDT + SCT), but only 40% of them can be cured. Romidepsin, a histone-deacetylase inhibitor, showed promising activity in relapsed PTCLs; in first line, Romidepsin was added with CHOP. We designed a study combining romidepsin and CHOEP as induction before HDT + auto-SCT in untreated PTCLs (PTCL-NOS, AITL/THF, ALK-ALCL), aged 18–65 years. A phase Ib/II trial was conducted to define the maximum tolerated dose (MTD) of Ro-CHOEP, and to assess efficacy and safety of 6 Ro-CHOEP as induction before HDT. The study hypothesis was to achieve a 18-month PFS of 70%. Twenty-one patients were enrolled into phase Ib; 7 dose-limiting toxicities were observed, that led to define the MTD at 14 mg/ms. Eighty-six patients were included in the phase II. At a median follow-up of 28 months, the 18-month PFS was 46.2% (95%CI:35.0–56.7), and the 18-month overall survival was 73.1% (95%CI:61.6–81.7). The overall response after induction was 71%, with 62% CRs. No unexpected toxicities were reported. The primary endpoint was not met; therefore, the enrollment was stopped at a planned interim analysis. The addition of romidepsin to CHOEP did not improve the PFS of untreated PTCL patients.

Diffuse large B-cell lymphoma (DLBCL) is a heterogeneous disease, including one-third of cases overexpressing MYC and BCL2 proteins (double expressor lymphoma, DEL) and 5-10% of patients with chromosomal rearrangements of MYC, BCL2 and/or BCL-6 (double/triple-hit lymphomas, DH/TH). TP53 mutations are detected in 20- 25% of DEL. We report the efficacy of dose-adjusted EPOCH and rituximab (DA-EPOCH-R) in a series of 122 consecutive patients, including DEL (n=81, 66%), DEL-MYC (n=9, 7%), DEL-BCL2 (n=13, 11%), or high-grade lymphomas (DH/TH) (n=19, 16%). Central nervous system (CNS) prophylaxis included intravenous methotrexate (n=66), intrathecal chemotherapy (IT) (n=40) or no prophylaxis (n=16). Sixty-seven patients (55%) had highintermediate or high International Prognostic Index (IPI) and 30 (25%) had high CNS-IPI. The 2-year progression-free survival (PFS) and overall survival (OS) for the entire study population were 74% and 84%, respectively. There was a trend for inferior OS for DH/TH (2-year OS: 66%, P=0.058) as compared to all the others. The outcome was significantly better for the IPI 0-2 versus IPI 3-5 (OS: 98% vs. 72%, P=0.002). DA-EPOCH-R did not overcome the negative prognostic value of TP53 mutations: 2-year OS of 62% versus 88% (P=0.036) were observed for mutated as compared to wild-type cases, respectively. Systemic CNS prophylaxis conferred a better 2-year OS (94%) as compared to IT or no prophylaxis (76% and 65%, respectively; P=0.008). DA-EPOCH-R treatment resulted in a favorable outcome in patients with DEL and DEL with single rearrangement, whereas those with multiple genetic alterations such as DEL-DH/TH and TP53 mutated cases still have an inferior outcome.

Purpose: In clinical trials, the expansion and persistence of chimeric antigen receptor (CAR) T cells correlate with therapeutic efficacy. However, properties of CAR T cells that enable their in vivo proliferation have still to be consistently defined and the role of CAR T bag content has never been investigated in a real-life setting. Experimental Design: Residual cells obtained after washing 61 anti-CD19 CAR T product bags were analyzed to identify tisagenlecleucel/Tisa-cel and axicabtagene ciloleucel/Axi-cel phenotypic features associated with postinfusion CAR T-cell in vivo expansion and with response and survival. Results: While Tisa-cel was characterized by a significant enrichment in CAR+CD4+ T cells with central memory (P < 0.005) and effector (P < 0.005) phenotypes and lower rates of CAR+CD8+ with effector memory (P < 0.005) and naïve-like (P < 0.05) phenotypes as compared with Axi-cel, the two products displayed similar expansion kinetics. In vivo CAR T-cell expansion was influenced by the presence of CAR T with a CD8+ T central memory signature (P < 0.005) in both Tisa-cel and Axi-cel infusion products and was positively associated with response and progression-free survival (P < 0.05). Conclusions: Our data indicate that despite the great heterogeneity of Tisa-cel and Axi-cel products, the differentiation status of the infused cells mediates CAR T-cell in vivo proliferation that is necessary for antitumor response.

Summary Patients affected by lymphoid malignancies (LM) are frequently immune‐compromised, suffering increased mortality from COVID‐19. This prospective study evaluated serological and T‐cell responses after complete mRNA vaccination in 263 patients affected by chronic lymphocytic leukaemia, B‐ and T‐cell lymphomas and multiple myeloma. Results were compared with those of 167 healthy subjects matched for age and sex. Overall, patient seroconversion rate was 64·6%: serological response was lower in those receiving anti‐cancer treatments in the 12 months before vaccination: 55% vs 81·9% (P

Background Anthracycline-containing regimens, namely cyclophosphamide, doxorubicin, vincristine and prednisone (CHOP) or CHOEP (CHOP + etoposide), represent the current standard of care for patients with newly diagnosed peripheral T-cell lymphomas (PTCLs), although responses are unsatisfactory. In this study, we investigated the pathways able to mitigate the sensitivity to CHOP-based regimens in preclinical models of T-cell lymphoma (TCL) to select agents for the development of CHOP-based drug combinations. Methods We performed gene expression profiling of malignant T-cell lines exposed to CHOEP; flow cytometry was employed to study the effects of drug combinations on cell viability, cell cycle distribution, apoptosis and mitochondrial membrane depolarisation. Western blot analyses were performed to study cell signalling downstream of the T-cell receptor and apoptosis. The in vivo effect of the drug combination was tested in xenograft models. Results We highlighted a modulation of tyrosine kinases belonging to the T-cell receptor pathway upon chemotherapy that provided the rationale for combining the tyrosine kinase inhibitor dasatinib with CHOEP. Dasatinib improves CHOEP activity and reduces viability in vitro. Furthermore, combination treatment results in tumour growth inhibition in in vivo xenograft mouse models. Conclusions Our data provide the rationale for clinical testing of the dasatinib–CHOEP combination in patients with T-cell lymphoma.

© 2019 Wiley Periodicals, Inc. The histological diagnosis of peripheral T-cell lymphoma (PTCL) can represent a challenge, particularly in the case of closely related entities such as angioimmunoblastic T-lymphoma (AITL), PTCL-not otherwise specified (PTCL-NOS), and ALK-negative anaplastic large-cell lymphoma (ALCL). Although gene expression profiling and next generations sequencing have been proven to define specific features recurrently associated with distinct entities, genomic-based stratifications have not yet led to definitive diagnostic criteria and/or entered into the routine clinical practice. Herein, to improve the current molecular classification between AITL and PTCL-NOS, we analyzed the transcriptional profiles from 503 PTCLs stratified according to their molecular configuration and integrated them with genomic data of recurrently mutated genes (RHOA G17V , TET2, IDH2 R172 , and DNMT3A) in 53 cases (39 AITLs and 14 PTCL-NOSs) included in the series. Our analysis unraveled that the mutational status of RHOA G17V , TET2, and DNMT3A poorly correlated, individually, with peculiar transcriptional fingerprints. Conversely, in IDH2 R172 samples a strong transcriptional signature was identified that could act as a surrogate for mutational status. The integrated analysis of clinical, mutational, and molecular data led to a simplified 19-gene signature that retains high accuracy in differentiating the main nodal PTCL entities. The expression levels of those genes were confirmed in an independent cohort profiled by RNA-sequencing.

In multiple myeloma, novel treatments with proteasome inhibitors (PIs) and immunomodulatory agents (IMiDs) have prolonged survival but the disease remains incurable. At relapse, next-generation sequencing has shown occasional mutations of drug targets but has failed to identify unifying features that underlie chemotherapy resistance. We studied 42 patients refractory to both PIs and IMiDs. Whole-exome sequencing was performed in 40 patients, and RNA sequencing (RNA-seq) was performed in 27. We found more mutations than were reported at diagnosis and more subclonal mutations, which implies ongoing evolution of the genome of myeloma cells during treatment. The mutational landscape was different from that described in published studies on samples taken at diagnosis. The TP53 pathway was the most frequently inactivated (in 45% of patients). Conversely, point mutations of genes associated with resistance to IMiDs were rare and were always subclonal. Refractory patients were uniquely characterized by having a mutational signature linked to exposure to alkylating agents, whose role in chemotherapy resistance and disease progression remains to be elucidated. RNA-seq analysis showed that treatment or mutations had no influence on clustering, which was instead influenced by karyotypic events. We describe a cluster with both amp(1q) and del(13) characterized by CCND2 upregulation and also overexpression of MCL1, which represents a novel target for experimental treatments. Overall, high-risk features were found in 65% of patients. However, only amp(1q) predicted survival. Gene mutations of IMiD and PI targets are not a preferred mode of drug resistance in myeloma. Chemotherapy resistance of the bulk tumor population is likely attained through differential, yet converging evolution of subclones that are overall variable from patient to patient and within the same patient.

Novel treatments for multiple myeloma (MM) have increased rates of complete response, raising interest in more accurate methods to evaluate residual disease. Cell-free tumor DNA (cfDNA) analysis may represent a minimally invasive approach complementary to multiparameter flow cytometry (MFC) and molecular methods on bone marrow aspirates. A sequencing approach using the Ion Torrent Personal Genome Machine was applied to identify clonal IGH gene rearrangements in tumor plasma cells (PCs) and in serial plasma samples of 25 patients with MM receiving second-line therapy. The same clonal IGH rearrangement identified in tumor PCs was detected in paired plasma samples, and levels of IGH cfDNA correlated with outcome and mirrored tumor dynamics evaluated using conventional laboratory parameters. In addition, IGH cfDNA levels reflected the number of PCs enumerated by MFC immunophenotyping even in the complete response context. Patients determined by MFC to be free of minimal residual disease were characterized by low frequencies of tumor clonotypes in cfDNA and longer survival. This pilot study supports the clinical applicability of the noninvasive monitoring of tumor levels in plasma samples of patients with MM by IGH sequencing.

Introduction. The outcome of relapsed/refractory large B-cell lymphomas, not eligible or cured by high dose chemotherapy due to persistent disease, is very unsatisfactory. The introduction of anti-CD19 chimeric antigen receptor T cells (CAR-T) in this setting, showed impressive long-term results in registrative trials. Axicabtagene ciloleucel (axi-cel) and tisagenlecleucel (tisa-cel) are registered and reimbursed in Italy by Agenzia Italiana del Farmaco (AIFA) for the treatment of relapsed/refractory (R/R) diffuse large B-cell lymphoma (DLBCL) and primary mediastinal B-cell lymphoma (PMBCL) patients after at least 2 lines, with an ECOG 0-1, and an age lower than 71 years. To evaluate in real-life the patients treated in Italy with CAR-T cells, the Italian Society of Hematology (SIE) designed an observational study. Methods. The CART-SIE is an ongoing prospective and retrospective observational trial with the following aims: 1. consecutively register all DLBCL and PMBCL treated in the Italian authorized centers; 2. evaluate the intention to treat overall response rate (ORR, complete [CR] and partial response [PR]), duration of response (DOR), progression free survival (PFS) and overall survival (OS); 3. evaluate safety in terms of cytokine release syndrome (CRS), immune effector cell-associated neurotoxicity syndrome (ICANS) and long-term cytopenia; 4. compare the two different CAR-T products. Primary endpoint was to evaluate the overall response and survival at one year of the patients receiving CAR-T cells. Results. Since March 2019 to June 2021, 208 patients were enrolled and leukapheresed; 191 patients were infused (92%); 17 were not due to rapidly progressive disease and worsening of clinical conditions (11), severe infection (4), persistent complete remission (1) and manufacturing failure (1). Clinical characteristics of the 191 infused patients were: median age 53 years (range 19-70), stage III/IV 127 (69%); median number of prior lines was 3 (2-12), including 58 (30%) with prior autologous stem cell transplantation. According to local pathology reports, 134 (70%) were DLBCL, 22 (12%) high-grade B-cell lymphoma (HGBCL) and 35 (18%) PMBCL. Bridging therapy was delivered to 177 (93%) patients: 45 (25%) radiotherapy, 115 (65%) systemic therapy (chemotherapy and/or immunotherapy), 17 (10%) combined therapy (radiotherapy + chemotherapy). All patients received Fludarabine-Cyclophosphamide as lymphodepletion regimen. Axi-cel was infused in 92 (48%), and tisa-cel in 99 (52%) patients. Median follow-up time for infused patients was 7.66 months (IQR: 4.14-14.74). All 191 patients were evaluable for response at 30-days after the infusion: 84 (44%) CR, 61 (32%) PR, with an ORR of 76%. Median DOR was not reached for CR and PR patients, but CR patients did better than PRs (p=0.04). In the whole series, 6 and 12-months PFS were 56% (95% CI:49-65) and 47% (95%CI:39-56); 6 and 12-months OS were 80% (95%CI:74-87); 71% (95%CI:63-80), respectively. The 6-months PFS and OS by histotype were: 52% (95% CI: 44-62) and 79% (95% CI: 72-87) for DLBCL, 57% (95% CI: 39-83) and 72% (95% CI: 54-97) for HGBCL, 73% (95% CI: 59-90) and 87% (95% CI: 76-99) for PMBCL. No outcome differences between axi-cel and tisa-cel were reported: 6-months PFS and OS were 58% (95% CI: 48-70) and 81% (95% CI: 73-91) vs. 55% (95% CI: 45-66) and 79% (95% CI: 70-88), respectively. Of note, tisa-cel was not used in PMBCL. Severe (grade 3-4) CRS was observed in only 9 (5%) patients, and severe ICANS in 15 (8%). One-hundred and eight (57%) patients received at least one dose of tocilizumab and 62 (33%) received steroids; 24 (13%) patients were admitted in intensive care unit. Cytopenia beyond 90 days was reported in 59 of 179 (33%) evaluable patients. At the time of the analysis, 43 (23%) patients had died, 39 due to lymphoma progression, 4 due to complications related to subsequent therapies. Conclusions. In CART-SIE study, the outcome of patients treated with CAR-T was similar to those of the registrative trials. No differences across histotypes and commercial CAR-T products (axi-cel and tisa-cel) were observed. CRS and ICANS in real world are manageable with adequate risk management plan. Cytopenias are emerging problems in real-life setting. Disclosures Chiappella: Gilead Sciences: Other: lecture fee, advisory board; Roche: Other: lecture fee, advisory board; Takeda: Other: advisory board; Clinigen: Other: lecture fee, advisory board; Celgene Bristol Myers Squibb: Other: lecture fee, advisory board; Astrazeneca: Other: lecture fee; Janssen: Other: lecture fee, advisory board; Incyte: Other: lecture fee; Novartis: Other: lecture fee; Servier: Other: lecture fee. Santoro: Eli-Lilly: Speakers Bureau; BMS: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Servier: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Takeda: Speakers Bureau; Arqule: Consultancy, Speakers Bureau; AstraZeneca: Speakers Bureau; Roche: Speakers Bureau; AbbVie: Speakers Bureau; Pfizer: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celgene: Speakers Bureau; Sanofi: Consultancy; Gilead: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Amgen: Speakers Bureau; Sandoz: Speakers Bureau; Eisai: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Novartis: Speakers Bureau; Bayer: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; MSD: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Tisi: Incyte: Membership on an entity's Board of Directors or advisory committees; BWS: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees; Gilead: Honoraria, Membership on an entity's Board of Directors or advisory committees. Perriello: Novartis: Other: Advisory Board. Corradini: AbbVie, ADC Theraputics, Amgen, Celgene, Daiichi Sankyo, Gilead/Kite, GSK, Incyte, Janssen, KyowaKirin, Nerviano Medical Science, Novartis, Roche, Sanofi, Takeda: Consultancy; AbbVie, ADC Theraputics, Amgen, Celgene, Daiichi Sankyo, Gilead/Kite, GSK, Incyte, Janssen, KyowaKirin, Nerviano Medical Science, Novartis, Roche, Sanofi, Takeda: Honoraria; KiowaKirin; Incyte; Daiichi Sankyo; Janssen; F. Hoffman-La Roche; Kite; Servier: Consultancy; Amgen; Takeda; AbbVie: Consultancy, Honoraria, Other: Travel and accommodations; Novartis; Gilead; Celgene: Consultancy, Other: Travel and accommodations; BMS: Other: Travel and accommodation; Sanofi: Consultancy, Honoraria; Incyte: Consultancy; Novartis, Janssen, Celgene, BMS, Takeda, Gilead/Kite, Amgen, AbbVie: Other: travel and accomodations.

Introduction: Peripheral T-cell lymphomas (PTCL) have a 40-50% cure rate when treated with cyclophosphamide-doxorubicin-etoposide-vincristine-prednisone (CHOEP) and hematopoietic stem cell transplantation (HSCT). Romidepsin, a histone deacetylase inhibitor, showed promising activity in relapsed or refractory PTCLs. Methods: On these premises, we designed a phase I/II trial (PTCL13 NCT02223208) to evaluate whether the addition of romidepsin to CHOEP improves the outcome of newly diagnosed PTCLs. In the phase Ib part of the study, we defined 14 mg/ms as the maximum tolerated dose of romidepsin when administered in combination with CHOEP (Ro-CHOEP). Thus, in the phase II part of the study we evaluated the efficacy of Ro-CHOEP followed by HSCT in young patients. The primary objective of the study was to demonstrate a 15% increase in 18-months progression-free survival (PFS) for the combination Ro-CHOEP plus HSCT (from 55% to 70%, planned sample size=110), compared to the previous Italian trial (Corradini P et al, Leukemia 2014). Patients aged 18-65 years with stage II-IV PTCL-NOS, angioimmunoblastic/T follicular helper (AITL/THF) and ALK negative anaplastic large cell lymphoma, were eligible. Treatment plan consisted of 6 courses of Ro-CHOEP every 21 days (14 mg/ms Ro day 1 and 8), followed by cisplatin-cytarabine-dexamethasone (DHAP) with stem cell harvest and HSCT. Patients in complete response (CR) after induction proceeded to autoHSCT, while those in partial response (PR), with an available HLA-matched donor, proceeded to alloHSCT upfront. Results: From September 2017 to October 2020, 86 patients were enrolled into the phase II part of the study; median age was 55 years (IQR 49;60); 78 (91%) had stage III-IV and 31 (36%) IPI score >2. Pathological materials were collected at the time of diagnosis, and centrally reviewed by expert hemo-pathologists; subgroups were: 33 PTCL-NOS, 21 ALK negative, 31 AITL/THF, and one case not classified due to inadequate material. According to the statistical plan, an interim analysis was performed on the first 75 patients. At a median follow-up of 26 months, the 18-months PFS was 48% (95% CI: 0.36-0.58) and the OS was 75% (95% CI: 0.64-0.83). The 18-months PFS for PTCL-NOS versus ALK negative vs AITL/THF was 37% (95% CI: 0.20-0.54) vs. 51% (95% CI: 0.28-0.70) vs. 58% (95% CI: 0.36-0.74), p 0.118; the 18-months OS for PTCL-NOS vs. ALK negative vs. AITL/THF was 72% (95% CI: 0.51-0.85) vs. 76% (95% CI: 0.51-0.89) vs. 81% (95% CI: 0.60-0.92), p 0.957. All 86 patients completed the induction phase and were evaluable for response after 6 Ro-CHOEP: the overall response rate (ORR) was 71% (61 patients), with 62% (53 patients) CR. Four patients with ongoing treatment are not evaluable for response at the end of therapy, at the time of the analysis. Only 39 of 82 patients (48%) underwent HSCT and 43 did not: 28 due to progressive disease, 8 for poor mobilization, 7 for adverse events (1 sepsis, 2 cardiological events, 4 others). Among the 82 patients evaluable for response at the end of treatment, the final ORR after HSCT was 40% (33 patients), with 39% CR (32 patents). The most frequent toxicities during Ro-CHOEP treatment were hematological, with grade 3-4 neutropenia and thrombocytopenia in 33% and 34% of all the 459 cycles, respectively; severe febrile neutropenia was reported in only 4% of Ro-CHOEP courses. Severe non-hematological toxicities were observed in 35 (41%) of patients: cardiological in 5 patients (6%), gastrointestinal in 9 (10%), infections in 10 (12%), others in 11 (13%). Twenty-four deaths were recorded: 22 due to lymphoma progression, 1 due to transplant related mortality for a septic shock after alloSCT, 1 due to secondary malignancy. Conclusions: In the PTCL13 phase I part of the study we demonstrated the feasibility of the combination Ro 14 mg/ms plus CHOEP followed by high-dose chemotherapy and HSCT; in the phase 2 part of the study, the primary objective was not achieved, with a 18-months PFS of 48%. Based on these results, the enrollment of the trial was stopped due to inefficacy of the experimental combination. The benefit of adding romidepsin to chemotherapy was not observed neither in PTCL-NOS nor in AITL/THF. In conclusion, the addition of romidepsin to CHOEP did not ameliorate prognosis in newly diagnosis PTCLs eligible to HSCT. Disclosures Chiappella: Roche: Other: lecture fee, advisory board; Incyte: Other: lecture fee; Takeda: Other: advisory board; Celgene Bristol Myers Squibb: Other: lecture fee, advisory board; Clinigen: Other: lecture fee, advisory board; Novartis: Other: lecture fee; Janssen: Other: lecture fee, advisory board; Gilead Sciences: Other: lecture fee, advisory board; Astrazeneca: Other: lecture fee; Servier: Other: lecture fee. Flenghi: Roche: Other: Travel, Accomodations, Expenses; Janssen: Other: Travel, Accomodations, Expenses. Zilioli: Gentilli: Consultancy, Speakers Bureau; Takeda: Consultancy, Other, Speakers Bureau; Gilead: Consultancy, Speakers Bureau; Servier: Consultancy, Speakers Bureau; MSD: Membership on an entity's Board of Directors or advisory committees; Janssen: Membership on an entity's Board of Directors or advisory committees; Roche: Consultancy; Italfarmaco: Consultancy. Cavallo: Servier: Speakers Bureau; Gilead: Speakers Bureau; ROCHE: Membership on an entity's Board of Directors or advisory committees. Musuraca: roche: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; incyte: Consultancy, Honoraria, 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. Varettoni: janssen: Membership on an entity's Board of Directors or advisory committees; beigene: Membership on an entity's Board of Directors or advisory committees; AstraZeneca: Membership on an entity's Board of Directors or advisory committees; roche: Membership on an entity's Board of Directors or advisory committees. Corradini: Incyte: Consultancy; Novartis, Janssen, Celgene, BMS, Takeda, Gilead/Kite, Amgen, AbbVie: Other: travel and accomodations; BMS: Other: Travel and accommodation; Sanofi: Consultancy, Honoraria; Novartis; Gilead; Celgene: Consultancy, Other: Travel and accommodations; Amgen; Takeda; AbbVie: Consultancy, Honoraria, Other: Travel and accommodations; KiowaKirin; Incyte; Daiichi Sankyo; Janssen; F. Hoffman-La Roche; Kite; Servier: Consultancy; AbbVie, ADC Theraputics, Amgen, Celgene, Daiichi Sankyo, Gilead/Kite, GSK, Incyte, Janssen, KyowaKirin, Nerviano Medical Science, Novartis, Roche, Sanofi, Takeda: Honoraria; AbbVie, ADC Theraputics, Amgen, Celgene, Daiichi Sankyo, Gilead/Kite, GSK, Incyte, Janssen, KyowaKirin, Nerviano Medical Science, Novartis, Roche, Sanofi, Takeda: Consultancy. OffLabel Disclosure: Romidepsin is not registered in first line treatment. Romidepsin was provided free for the clinical trial.

Background: CD19-directed CAR-T cell therapy has shown promising efficacy in relapsed/refractory (R/R) B-cell malignancies in clinical trials resulting in the approval and commercialization of two products (tisagenlecleucel/Tisa-cel and axicabtagene ciloleucel/Axi-cel) for R/R diffuse large B cell lymphoma (DLBCL) and primary mediastinal large B cell lymphoma (PMBCL). However, relapses occur in 60-65% of patients (pts) and thus a better understanding of the early determinants of response is critical to improve long-term survival in the real-world scenario. Aims of the study: To assess whether CAR-T cell expansion after infusion represents a crucial determinant to sustain effective anti-tumor responses to both Tisa-cel and Axi-celTo evaluate differences in CAR-T cell kinetics due to the use of CD28 or 4-1BB costimulatory moleculesTo identify immune phenotypic features of infusion products accounting for CAR-T cell expansion and survival probability Methods: We analyzed samples from 43 pts [29 DLBCL, 8 high grade B-cell lymphoma (HGBCL) and 6 PMBCL] treated with Axi-cel (n=22) and Tisa-cel (n=21) at the Fondazione IRCCS Istituto Nazionale Tumori prospectively collected between November 2019 and April 2021. CAR-T cells were monitored in the peripheral blood (PB) on days 0, 4, 7, 10, 14, 21, 28 and monthly post infusion by flow cytometry (FCM). Cells were stained with CD19 CAR Detection Reagent (Miltenyi), CD3, CD4, CD8, CD45, CD14, CD45RO, CD62L, CD197, CD279, CD223 and CD366. Residual cells obtained from washings of 32 infused commercial CAR-T bags (10 Tisa-cel and 22 Axi-cel) were also analyzed by FCM. Data were acquired on a BD FACSCanto II (BD Biosciences) and a MACSQuant® Analyzer MQ10 (Miltenyi) and analyzed using FlowJo software, version 10. Results: The median time to maximal expansion of CAR-T cells was at day 10 post infusion with no differences between Axi-cel and Tisa-cel [median concentration at day 10 (C 10) 25 for Axi-cel vs 26 CAR-T cells/µl for Tisa-cel; p, ns], nor among the different histologies (median C 10 33 for DLBCL vs 19 for HGBCL vs 18 CAR-T cells/µl for PMBCL; p, ns). On the contrary, CAR-T peak concentration (C max) was higher in responders at 3 months post infusion (RE, n=28) (defined as pts achieving complete or partial response by PET/CT) than in non responders (NR, n=13) (median C max 87 in RE vs 26 in NR CAR-T cells/µl; p Conclusion: To the best of our knowledge, this is the first study assessing the clinical utility of early CAR-T cell monitoring in lymphoma pts receiving both commercial anti-CD19 CAR-T cell therapies. We provide evidence that in pts treated with Axi-cel and Tisa-cel: i) the in vivo kinetics of the CAR-T cell products are similar, consistent with the fact that no differences in the outcome of Axi-cel and Tisa-cel treated pts were detected; ii) CAR-T cell expansion is critical for efficacy and predicts the PFS; iii) circulating CAR-T cells in responders have a naïve phenotype; iv) a memory signature in the CAR-T cell product before infusion is associated with in vivo expansion and survival. Figure 1 Figure 1. Disclosures Chiappella: Celgene Bristol Myers Squibb: Other: lecture fee, advisory board; Incyte: Other: lecture fee; Novartis: Other: lecture fee; Astrazeneca: Other: lecture fee; Servier: Other: lecture fee; Takeda: Other: advisory board; Gilead Sciences: Other: lecture fee, advisory board; Clinigen: Other: lecture fee, advisory board; Roche: Other: lecture fee, advisory board; Janssen: Other: lecture fee, advisory board. Corradini: AbbVie, ADC Theraputics, Amgen, Celgene, Daiichi Sankyo, Gilead/Kite, GSK, Incyte, Janssen, KyowaKirin, Nerviano Medical Science, Novartis, Roche, Sanofi, Takeda: Consultancy; AbbVie, ADC Theraputics, Amgen, Celgene, Daiichi Sankyo, Gilead/Kite, GSK, Incyte, Janssen, KyowaKirin, Nerviano Medical Science, Novartis, Roche, Sanofi, Takeda: Honoraria; KiowaKirin; Incyte; Daiichi Sankyo; Janssen; F. Hoffman-La Roche; Kite; Servier: Consultancy; Novartis; Gilead; Celgene: Consultancy, Other: Travel and accommodations; BMS: Other: Travel and accommodation; Sanofi: Consultancy, Honoraria; Amgen; Takeda; AbbVie: Consultancy, Honoraria, Other: Travel and accommodations; Incyte: Consultancy; Novartis, Janssen, Celgene, BMS, Takeda, Gilead/Kite, Amgen, AbbVie: Other: travel and accomodations.

BACKGROUND The authors describe a family with a high penetrance of plasma cell dyscrasias, suggesting inheritance of an autosomal dominant risk allele. METHODS The authors performed whole-exome sequencing and reported on a combined approach aimed at the identification of causative variants and risk loci, using the wealth of data provided by this approach. RESULTS The authors identified gene mutations and single-nucleotide polymorphisms of potential significance, and pinpointed a known risk locus for myeloma as a potential area of transmissible risk in the family. CONCLUSIONS To the authors' knowledge, the current study is the first to provide a whole-exome sequencing approach to such cases, and a framework analysis that could be applied to further understanding of the inherited risk of developing plasma cell dyscrasias. Cancer 2017. © 2017 American Cancer Society.

Background: Chimeric antigen receptor (CAR) T-cell therapy is an effective treatment in approximately 40% of relapsed/refractory lymphomas. High rates of complete remission (CR) observed in clinical trials, led to fast-track FDA and EMA approval and commercialization of two CD19-directed CAR T-cell products (tisagenlecleucel/Tisa-cel/Kymriah and axicabtagene ciloleucel/Axi-cel/Yescarta) for refractory/relapsed diffuse large B cell lymphoma (DLBCL) and primary mediastinal large B cell lymphoma (PMBCL). In these studies, CAR T-cell engraftment and in vivo expansion have a crucial impact on disease response and toxicity. It is of paramount importance to develop homogeneous standardized approaches for monitoring expansion and persistence of CAR T-cells also in the case of cells not detectable by flow cytometry (FCM) as these data can guide clinical decision making. Aims of this study were: to assess relevant time-points for FCM analysis across the different products to develop a unique quantitative PCR assay to detect both tisa-cel and axi-cel. Methods: We prospectively collected samples from 28 patients (pts) (16 DLBCL, 5 transformed follicular lymphoma and 7 PMBCL) treated with axi-cel (n=15) and tisa-cel (n=13) at the Fondazione IRCCS Istituto Nazionale Tumori between Nov 2019 and July 2020. CAR T-cells were monitored in the peripheral blood (PB) on days 0, 4, 7, 9, 14, 21, 28 and monthly post infusion by FCM. Cells were stained with CD19 CAR Detection Reagent (Miltenyi), Anti-Biotin-PE, CD3-FITC, CD4-VioGreen, CD8-APC-Vio770, CD45-VioBlue, CD14-APC and 7-AAD Staining Solution and analyzed by FCM using the MACSQuant® Analyzer (Miltenyi). To evaluate CAR T-cell persistence, we also generated a unique droplet digital PCR (ddPCR) primer-probe assay to target both tisagen-cel and axi-cel. We obtained a partial cDNA sequence of the two CAR constructs by amplification and direct sequencing of fragments generated with primers designed by educated guess to bind to the anti-CD19 murine single-chain variable fragment (scFV) and to the CD8α or CD28 trans-membrane regions of tisagen-cel and axi-cel vectors respectively. The assay was used to quantify CAR+ cells on genomic DNA extracted from PB cells collected serially after infusion. FCM and molecular data were correlated to outcome. Results: Peak expansion of CAR T-cells by FCM occurred within the first 14 days post-infusion. At the point of maximal expansion, collectively a mean of 17% of circulating CD3+ T cells were CAR+ and CAR+ cells were more abundant among CD3+ cells in pts receiving axi-cel (26% vs 8.5% for tisagen-cel, p62/ul was prognostic with sensitivity of 67% and specificity of 76% (Receiver operating characteristic analysis). At subsequent time points the number of CAR T-cells decreased, but continued to be detectable by FCM up to 6 months post infusion although at very low levels (mean 2 CAR+ cell/ul) irrespective of outcome. To evaluate whether these low counts reliably represent CAR T+ cells or are rather signals due to aspecific binding of the antibodies, a ddPCR assay was set up. The assay displayed an excellent separation between positive and negative droplets on both axi-cel and tisagen-cel products, good reproducibility and specificity with max standard deviation of 0.06 and no CAR positive signal in healthy donors. Additionally, the CAR specific signal was detectable up to the 0,01% dilution. FCM and ddPCR data had a good correlation (r=0.93, p Conclusion: The combined use of FCM and the novel molecular assay facilitates the precise enumeration of commercial anti-CD19 CAR T-cells. Higher frequencies of CAR+ T cells at day 9 distinguish responders irrespectively of the product they received in our small prospective series. Updated results will be presented. Disclosures Chiappella: Servier: Honoraria; Roche: Honoraria; Takeda: Honoraria; Iqone: Honoraria; Janssen: Honoraria; Gilead-Kite: Honoraria; Celgene: Honoraria. Corradini:Kite: Consultancy, Honoraria; Janssen: Consultancy, Honoraria; Incyte: Consultancy; BMS: Other; Takeda: Consultancy, Honoraria, Other; Servier: Consultancy, Honoraria; Sanofi: Consultancy, Honoraria; F. Hoffman-La Roche Ltd: Consultancy, Honoraria; Novartis: Consultancy, Honoraria, Other: Travel and accommodations paid by for; KiowaKirin: Consultancy, Honoraria; Amgen: Consultancy, Honoraria, Other: Travel and accommodations paid by for; AbbVie: Consultancy, Honoraria, Other: Travel and accommodations paid by for; Gilead: Consultancy, Honoraria, Other: Travel and accommodations paid by for; Daiichi Sankyo: Consultancy, Honoraria; Celgene: Consultancy, Honoraria, Other: Travel and accommodations paid by for.

Background: Eighty-five percent of PMBCL are cured by standard therapy, but the outcome of refractory/relapsed (R/R) PMBCL is very poor. Checkpoint inhibitors (CPIs) have shown promising activity in relapsed PMBCL. Axibactagene ciloleucel (axi-cel) CAR-T cell therapy, can induce durable responses and is currently approved for the treatment of adult patients with R/R PMBCL. Aims of this analysis were: to register all Italian PMBCL patients candidate to CAR-T in the 6 active centers;to evaluate the intention to treat overall response rate (ORR, complete [CR] and partial response [PR]) in patients treated with axi-cel and CPIs for salvage or bridging before CAR-T and for relapse after CAR-T;to evaluate cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS). Methods: In August 2019 the Italian Drug Agency (AIFA) approved axi-cel; before the reimbursement by AIFA, an expanded access program supported by Kite/Gilead started. One patient slot per month per qualified center was available. Patients were included in a large national CAR-T prospective observational study approved by ethics committees. Results: Since April 2019 to March 2020, 20 R/R PMBCL were evaluated and 18 were apheresized in order to receive axi-cel; 2 were excluded because active CNS disease in one, and eligibility to transplant, while in CR, in the second one. Their clinical characteristics were: median age 38 years (range 22-50), male 8 (44%), stage II 6 (33%), advanced stage III/IV 12 (66%), bulky disease 6 (33%); LDH upper than normal 3 (2%). Median number of prior lines was 3 (2-6); 5 patients (28%) had a previous autologous stem cell transplant and 12 (66%) received a prior radiotherapy. The majority of patients, 16 (89%) were refractory to the last treatment when they were evaluated for CAR-T eligibility; 9 of 18 patients had CPI exposure before leukoapheresis: 6 pembrolizumab and 3 nivolumab in combination with brentuximab-vedotin. No manufacturing failures were reported. Bridging therapy was performed in 16 of 18 patients (88%). Seventeen patients (94%) received lymphodepleting Flu-Cy chemotherapy and only 16 pts received CAR-T for central nervous system (CNS) progression during bridging therapy (n=1) and respiratory failure due to pneumonia (n=1); the 2 patient not infused were exposed to CPIs. Median vein to vein time was 40 days (30-79). Median follow-up time for infused patients was 209 days (9-444). CRS was observed in 12 of 16 infused patients: 5 grade 2 and 7 grade 1. ICANS (2 grade 1, 2 grade 2, 1 grade 3) was recorded in 5 patients. No differences regarding CRS and ICANS occurrence were observed in patients exposed or not to CPIs. At 30-days after the infusion, all the 16 infused patients were evaluable for response: 7 (44%) CR, 5 (31%) PR, with ORR 75%, 3 (19%) stable disease (SD) and 1 (6%) progressive disease (PD). Two patients in PR at 30 days converted to CR at 90 days, with continuous CR at 180 days; all the 3 patients in SD and 1 out of 5 in PR at 30 days progressed at 90 days. Considering the 9 patients exposed to CPIs before CAR-T, 7 out of 9 were infused and all the 7 infused were evaluable for response: 2 (29%) CR, 4 (57%) PR, with ORR 86%, and 1 (14%) died because of a rapid CNS progression after infusion. Two patients in PR at 30-days converted to CR at 90-days, one with continuous CR at 180 days after CAR-T. Conclusions: In our series of 16 infused patients, axi-cel was effective with an ORR of 75% (CR 44%) at 30-days after CAR-T infusion and ORR of 54% (CR 46%) in the 13 patients evaluable at the median follow-up time (180-days after CAR-T infusion). It is important to note the 4 patients from the original real life cohort never received axi-cel. It is noteworthy that ORR was 86% in patients receiving CPIs before CAR-T and 75% in those not exposed to CPIs. With the limitation of small number, the exposure of immune-checkpoint inhibitors seems not to affect negatively response rate and adverse events. Disclosures Chiappella: Janssen: Honoraria; Iqone: Honoraria; Servier: Honoraria; Roche: Honoraria; Celgene: Honoraria; Gilead-Kite: Honoraria; Takeda: Honoraria. Zinzani:Bayer: Consultancy. Corradini:BMS: Other; Sanofi: Consultancy, Honoraria; Servier: Consultancy, Honoraria; Takeda: Consultancy, Honoraria, Other; Amgen: Consultancy, Honoraria, Other: Travel and accommodations paid by for; AbbVie: Consultancy, Honoraria, Other: Travel and accommodations paid by for; KiowaKirin: Consultancy, Honoraria; Novartis: Consultancy, Honoraria, Other: Travel and accommodations paid by for; F. Hoffman-La Roche Ltd: Consultancy, Honoraria; Janssen: Consultancy, Honoraria; Incyte: Consultancy; Gilead: Consultancy, Honoraria, Other: Travel and accommodations paid by for; Daiichi Sankyo: Consultancy, Honoraria; Celgene: Consultancy, Honoraria, Other: Travel and accommodations paid by for; Kite: Consultancy, Honoraria.

Novel treatments for multiple myeloma (MM) have increased rates of complete response, raising interest in more accurate methods to evaluate residual disease. Cell-free tumor DNA (cfDNA) analysis may represent a minimally invasive approach complementary to multiparameter flow cytometry (MFC) and molecular methods on bone marrow aspirates. A sequencing approach using the Ion Torrent Personal Genome Machine was applied to identify clonal IGH gene rearrangements in tumor plasma cells (PCs) and in serial plasma samples of 25 patients with MM receiving second-line therapy. The same clonal IGH rearrangement identified in tumor PCs was detected in paired plasma samples, and levels of IGH cfDNA correlated with outcome and mirrored tumor dynamics evaluated using conventional laboratory parameters. In addition, IGH cfDNA levels reflected the number of PCs enumerated by MFC immunophenotyping even in the complete response context. Patients determined by MFC to be free of minimal residual disease were characterized by low frequencies of tumor clonotypes in cfDNA and longer survival. This pilot study supports the clinical applicability of the noninvasive monitoring of tumor levels in plasma samples of patients with MM by IGH sequencing.

International audience; In multiple myeloma, next generation sequencing (NGS) has expanded our knowledge of genomic lesions, and highlighted a dynamic and heterogeneous composition of the tumor. Here, we used NGS to characterize the genomic landscape of 418 multiple myeloma cases at diagnosis and correlate this with prognosis and classification. Translocations and copy number changes (CNAs) had a preponderant contribution over gene mutations in defining the genotype and prognosis of each case. Known and novel independent prognostic markers were identified in our cohort of proteasome inhibitor and IMiD-treated patients with long follow-up, including events with context-specific prognostic value, such as deletions of the PRDM1 gene. Taking advantage of the comprehensive genomic annotation of each case, we used innovative statistical approaches to identify potential novel myeloma subgroups. We observed clusters of patients stratified based on the overall number of mutations and number/type of CNAs, with distinct effects on survival, suggesting that extended genotype of multiple myeloma at diagnosis may lead to improved disease classification and prognostication.

Purpose: Immune-mediated graft-versus-tumor (GVT) effects can occur after allogeneic hematopoietic stem cell transplantation (HSCT), but GVT is tightly linked to its main complication, graft-versus-host disease (GVHD). Strategies aimed at modulating GVHD, while maintaining the GVT effect, are needed to improve the cure rate of transplant. Given the emerging role of Janus-activated kinase (JAK) signaling in lymphoproliferative and myeloproliferative diseases and its established function at dictating T-cell differentiation, we postulated that JAKs might be potential therapeutic targets through a pharmacologic approach. Experimental Design: We examined the effect of JAK1/JAK2 modulation by ruxolitinib in a mouse model of fully MHC mismatched bone marrow transplant comprising in vivo tumor inoculation. Results: JAK1/JAK2 inhibition by ruxolitinib improved both overall survival (P = 0.03) and acute GVHD pathologic score at target organs (P ≤ 0.001) of treated mice. In addition, treatment with ruxolitinib was associated with a preserved GVT effect, as evidenced by reduction of tumor burden (P = 0.001) and increase of survival time (P = 0.01). JAK1/JAK2 inhibition did not impair the in vivo acquisition of donor T-cell alloreactivity; this observation may account, at least in part, to the preserved GVT effect. Rather, JAK1/JAK2 inhibition of GVHD was associated with the modulation of chemokine receptor expression, which may have been one factor in the reduced infiltration of donor T cells in GVHD target organs. Conclusions: These data provide further evidence that JAK inhibition represents a new and potentially clinically relevant approach to GVHD prevention. Clin Cancer Res; 21(16); 3740–9. ©2015 AACR.

Myeloid-derived suppressor cells (MDSCs) are powerful immunomodulatory cells that in mice play a role in infectious and inflammatory disorders, including acute graft-versus-host disease (GVHD) after allogeneic hematopoietic stem cell transplantation. Their relevance in clinical acute GVHD is poorly known. We analyzed whether granulocyte colony-stimulating factor (G-CSF) administration, used to mobilize hematopoietic stem cells, affected the frequency of MDSCs in the peripheral blood stem cell grafts of 60 unrelated donors. In addition, we evaluated whether the MDSC content in the peripheral blood stem cell grafts affected the occurrence of acute GVHD in patients undergoing unrelated donor allogeneic stem cell transplantation. Systemic treatment with G-CSF induces an expansion of myeloid cells displaying the phenotype of monocytic MDSCs (Linlow/negHLA-DR−CD11b+CD33+CD14+) with the ability to suppress alloreactive T cells in vitro, therefore meeting the definition of MDSCs. Monocytic MDSC dose was the only graft parameter to predict acute GVHD. The cumulative incidence of acute GVHD at 180 days after transplantation for recipients receiving monocytic MDSC doses below and above the median was 63% and 22%, respectively (P = .02). The number of monocytic MDSCs infused did not impact the relapse rate or the transplant-related mortality rate (P > .05). Although further prospective studies involving larger sample size are needed to validate the exact monocytic MDSC graft dose that protects from acute GVHD, our results strongly suggest the modulation of G-CSF might be used to affect monocytic MDSCs graft cell doses for prevention of acute GVHD.

The authors describe a family with a high penetrance of plasma cell dyscrasias, suggesting inheritance of an autosomal dominant risk allele.The authors performed whole-exome sequencing and reported on a combined approach aimed at the identification of causative variants and risk loci, using the wealth of data provided by this approach.The authors identified gene mutations and single-nucleotide polymorphisms of potential significance, and pinpointed a known risk locus for myeloma as a potential area of transmissible risk in the family.To the authors' knowledge, the current study is the first to provide a whole-exome sequencing approach to such cases, and a framework analysis that could be applied to further understanding of the inherited risk of developing plasma cell dyscrasias. Cancer 2017;123:3701-3708. © 2017 American Cancer Society.

Cytomegalovirus (CMV) replication after allogeneic hematopoietic stem cell transplantation (HSCT) was historically associated with increased nonrelapse mortality (NRM). More recently, different groups have reported an association between CMV replication and reduced risk of acute myeloid leukemia (AML) relapse. Given the conflicting results, we evaluated the impact of CMV replication and other covariates on the outcome of a retrospective cohort of 265 adults with B cell lymphoma receiving allogeneic HSCT from HLA-identical siblings or alternative donors. In time-dependent multivariate analysis, CMV replication, evaluated by pp65 antigenemia, had no independent effect on the risk of relapse (hazard ratio [HR], 1.0; 95% confidence interval [CI], .6 to 1.6; P = .9), although it was associated with a reduced overall survival (HR, 2.0; 95% CI, 1.3 to 3.2; P = .001) and an increased NRM (HR, 2.5; 95% CI, 1.1 to 5.3; P = .01). Consistently, donor and/or recipient CMV seropositivity were not associated with a different outcome relative to CMV double-negative serostatus. In multivariate models, a diagnosis of follicular lymphoma (P

Introduction: Diffuse Large B-Cell Lymphoma (DLBCL) is an heterogeneous disease: 30-40% of cases have high expression of MYC and BCL2 proteins (Dual Expressor, DE) and 5-10% have chromosomal rearrangements involving MYC, BCL2 and/or BCL6 (Double-/ Triple-Hit, DH/TH). Although the optimal treatment for those high-risk lymphomas remains undefined, DA-EPOCH-R produces durable remission with acceptable toxicity (Dunleauvy K, Lancet 2018). TP53 mutation is an independent marker of poor prognosis in patients (pts) with DLBCL treated with R-CHOP therapy. However, its prognostic value in poor prognosis lymphomas, receiving intensive therapy, has not been investigated yet. Methods: A series of consecutive pts (n=87) with biopsy proven diagnosis of DE DLBCL (MYC expression ≥40% and BCL2 expression ≥ 50% of tumor cells) or DE-Single Hit (DE-SH, i.e., DE-DLBCL with a single rearrangement of either MYC, BCL2 or BCL6 oncogenes) or DE-DH/TH (MYC, BCL2 and/or BCL6 rearrangements obtained by FISH) were treated with 6 cycles of DA-EPOCH-R and central nervous system (CNS) prophylaxis consisting of two courses of high-dose intravenous Methotrexate. Additional eligibility criteria included age ≥18 years and adequate organ functions. Cell of origin (COO) was defined according to Hans algorithm [germinal center B cell like (GCB) and non GCB)]. TP3 mutations were evaluated by next generation sequencing (NGS) based on AmpliseqTM technology or Sanger sequencing and considered positive when a variant allelic frequency ≥10% was detected. Results: Eighty-seven pts were included [n=36 DE only, n=32 DE-SH (n=8 MYC, n=10 BCL2, n=14 BCL6), n=19 DE-DH/TH] with 40 patients (46%) showing a non GCB COO. Pts had a median age of 59 years (range, 24-79 years). Seventy-three pts (84%) had advanced disease and 44 (50%) an high-intermediate/high-risk score as defined by International Prognostic Index (IPI). Only 8 of 87 pts (9%) were consolidated in first clinical remission with autologous stem cell transplantation following DA-EPOCH-R. After a median follow-up of 24 months, 73 are alive (84%) and 14 died [n=12 disease (n=2 CNS disease); n=1 pneumonia; n=1 suicide]. The 2-year PFS and OS were 71% (95%CI, 60-80%) and 76% (95%CI, 61%-85%) for the entire population. For those with IPI 3-5 the PFS and OS were not significant different for DE and DE-SH pts versus DE-DH/TH pts [64% vs 57% p=0.77); 78% vs 57% p=0.12)]. The COO did not influence the outcome for DE only and DE-SH [PFS: 78% vs 71% (p=0.71); 92% vs 86% (p=0.16) for GCB vs non -GCB, respectively]. Fourty-six pts (53%;n=18 DE only, n=18 DE-SH, n=10 DE-DH/TH ) were evaluated for TP53 mutations with 11 pts (24%) carrying a clonal mutation (n=6 in DE, n=3 in DE-SH, n=2 in DE-DH/TH). The 2-year PFS and OS did not significantly change for pts DE and DE-SH TP53 wild type as compared to DE and DE-SH mutated [PFS: 84 % vs 77%, (p=0.45); OS: 87% vs 88%, (p=0.92)]. The two pts DE-DH/TH with TP53 mutation are alive and in complete remission.Conclusions: High risk DLBCL pts treated with DA-EPOCH-R have a favourable outcome independently from high IPI score, DE-SH and DE-DH/TH. Also the presence of TP53 mutations does not negatively affect the outcome of pts treated with this intensive regimen. The efficacy of DA-EPOCH-R in overcoming poor prognostic genetic features in DLBCL should be confirmed in a larger prospective clinical trial. Disclosures Rossi: Daiichi-Sankyo: Consultancy; Roche: Membership on an entity's Board of Directors or advisory committees; Janssen: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees; Amgen: Membership on an entity's Board of Directors or advisory committees; Gilead: Membership on an entity's Board of Directors or advisory committees; Sanofi: Membership on an entity's Board of Directors or advisory committees; Abbvie: Membership on an entity's Board of Directors or advisory committees; Pfizer: Membership on an entity's Board of Directors or advisory committees; Jazz: Membership on an entity's Board of Directors or advisory committees; Astellas: Membership on an entity's Board of Directors or advisory committees; Novartis: Honoraria; Mundipharma: Honoraria; BMS: Honoraria; Sandoz: Honoraria. Carlo-Stella:Takeda: Other: Travel, accommodations; F. Hoffmann-La Roche Ltd: Honoraria, Other: Travel, accommodations, Research Funding; Rhizen Pharmaceuticals: Research Funding; Celgene: Research Funding; Amgen: Honoraria; AstraZeneca: Honoraria; Janssen Oncology: Honoraria; MSD: Honoraria; BMS: Honoraria; Genenta Science srl: Consultancy; Janssen: Other: Travel, accommodations; Servier: Consultancy, Honoraria, Other: Travel, accommodations; Sanofi: Consultancy, Research Funding; ADC Therapeutics: Consultancy, Other: Travel, accommodations, Research Funding; Novartis: Consultancy, Research Funding; Boehringer Ingelheim: Consultancy. Corradini:AbbVie: Consultancy, Honoraria, Other: Travel Costs; KiowaKirin: Honoraria; Gilead: Honoraria, Other: Travel Costs; Amgen: Honoraria; Celgene: Honoraria, Other: Travel Costs; Daiichi Sankyo: Honoraria; Janssen: Honoraria, Other: Travel Costs; Jazz Pharmaceutics: Honoraria; Kite: Honoraria; Novartis: Honoraria, Other: Travel Costs; Roche: Honoraria; Sanofi: Honoraria; Takeda: Honoraria, Other: Travel Costs; Servier: Honoraria; BMS: Other: Travel Costs.

In Multiple myeloma (MM) no treatment has a curative potential and even complete response to novel agents such as proteasome inhibitors (PIs) and immunomodulatory agents (IMiDs) are followed by relapse over time. Next generation sequencing (NGS) has showed how MM at diagnosis is defined by several somatic mutations, but only few drivers, even fewer "druggable" mutations, and many found at a subclonal level. At relapse, targeted studies have shown occasional mutations in drug target genes but the genomic and transcriptomic determinants of chemoresistance in MM remains elusive. We selected 42 MM patients refractory to both lenalidomide and PIs. Whole exome sequencing was performed in 40 of them, and RNAseq in 27. Clinical annotation was available for all patients. Standard analysis pipelines where applied to analyze mutations, copy number alterations (CNAs), mutational signatures, gene expression and expressed mutations. Patients received a median of 3 lines of treatment, with median overall survival of 14.6 months from sampling. We found a median of 77.5 mutations per patient, which is more than what reported at diagnosis (Bolli et al, Nature Communications 2014;5:2997). 100% of samples showed evidence of subclonality, and 37% of them exhibited a higher number of subclonal than clonal variants. Therefore, even at this advanced stage the MM genome is evolving and is composed of different subclones that may display different chemosensitivity. The mutational landscape was also different. TP53 mutations were the second most common after KRAS (20% and 17.5%, respectively). Interestingly TP53 mutations all clustered in patients receiving bortezomib as the last line of treatment. Only 2 patients showed a CRBN mutation, both subclonal. Combining mutations and CNA analysis, the TP53 pathway was the most frequently inactivated (45% of patients). Altogether, mutations or deletions of genes in the CRBN E3 ubiquitin ligase complex were found in 32.5% of patients, while proteasomal subunit genes were infrequently hit. Refractory cases were also uniquely characterized by a novel signature linked to exposure to alkylating agents, whose activity was more pronounced after high-dose melphalan suggesting a mutagenic effect of the drug on residual cells at the time of transplant. Whether this has any pathogenetic role on the disease course remains to be elucidated. RNAseq analysis did not show any influence of treatment or mutational data on the clustering of samples, which was mainly influenced by karyotypic events. The main cluster was composed by non-hyperdiploid patients with both amp(1q) and del(13): these showed CCND2 and MCL1 upregulation, the latter representing a marker of venetoclax resistance and novel target of experimental treatments. Only 26.3% of mutations were expressed, and this correlated with the clonality level of the mutation. However, most mutations in driver genes were expressed, with the notable exception of those causing nonsense mediated decay. Overall, classical high-risk features or CRBN pathway mutations were found in 65% of the cohort. However, only amp(1q) predicted survival in our cohort. The lack of prognostic value of high-risk lesions is likely explained by a higher prevalence of such features in double-refractory stages. Our data suggest that gene mutation is not a preferred mode of evolution of drug resistance in MM. Chemoresistance of the bulk tumor population is likely attained though differential, yet converging evolution of different subclones that are overall highly variable from patient to patient and within the same patient. Disclosures Kastritis: Prothena: Honoraria; Genesis: Honoraria; Amgen: Honoraria, Research Funding; Janssen: Honoraria, Research Funding; Takeda: Honoraria; Pfizer: Honoraria. Dimopoulos:Sanofi Oncology: Research Funding. Cavo:bms: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: travel accommodations, Speakers Bureau; sanofi: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; novartis: Honoraria; takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: travel accommodations, Speakers Bureau; AbbVie: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Corradini:Janssen: Honoraria, Other: Travel Costs; Takeda: Honoraria, Other: Travel Costs; Jazz Pharmaceutics: Honoraria; Gilead: Honoraria, Other: Travel Costs; Daiichi Sankyo: Honoraria; Celgene: Honoraria, Other: Travel Costs; Amgen: Honoraria; AbbVie: Consultancy, Honoraria, Other: Travel Costs; KiowaKirin: Honoraria; Kite: Honoraria; BMS: Other: Travel Costs; Sanofi: Honoraria; Servier: Honoraria; Roche: Honoraria; Novartis: Honoraria, Other: Travel Costs. Bolli:Celgene: Honoraria; Novartis: Honoraria; Gilead: Other: travel expenses.

BACKGROUND. Axicabtagene ciloleucel and tisagenlecleucel have been approved by FDA and EMA for the treatment of relapsed/refractory diffuse large B-cell and mediastinal Lymphoma (NHL) patients (pts). Selection of pts who can benefit the most from these novel treatments with a low risk of life-threatening toxicities is currently a matter of discussion and outside clinical trials the selection of pts is up to clinicians of the CAR T-cell team in several countries. However, based on the results and follow up of clinical trials and the US reports about real life treatment with CAR T-cells, it is emerging that an expert clinical assessment and application of some inclusion criteria could optimize the success of therapy and minimize the severity of adverse events. AIMS.We are conducting a single center prospective observational trial to evaluate the accessibility and feasibility of CAR T-cells treatment among the population of NHL pts potentially eligible to this therapy. METHODS. Since September 2018 we have prospectively registered all pts referred at our center for CART-cells eligibility evaluation either for the enrollment in clinical trials or in the contest of the expanded access program (EAP) open for enrollment since February 2019 at our Institution. We have recorded clinical data including disease characteristics, comorbidities, history and present disease status at imaging. Patients were evaluated and screened for inclusion/exclusion criteria of the CAR T-cells program available at that moment and planned for treatment. RESULTS. Fifty-four pts with relapsed or refractory NHL potentially eligible to treatment according to EMA were recorded in 10 months. Median age was 48 yrs (range, 20 - 70). Thirty-nine pts were affected by DLBCL and 15 by PMBCL, all pts were refractory or relapsed to at least two chemotherapy regimens, median number of previous therapy was 3. Overall, among the 54 pts referred to our center only 7 pts (13%) have been enrolled in CAR T-cells programs (4 pts treated, 2 pts are waiting for infusion, one is in screening for a protocol) whereas other 11 (20%) have been considered eligible for CART-cells treatment but are still waiting for availability of treatment-slots. On the contrary 36 pts were considered not eligible. Seventeen pts (31%) were excluded after the first CAR T cell team visit because of rapidly progressive disease, or ECOG >1 or lymphoma mass larger than 20 cm and 7 pts (13%) were excluded for comorbidities. Nine pts requiring a treatment in a short time period were shifted to other strategies (conventional or experimental) and 3 pts were lost at follow-up. Overall 18 pts in 10 months (33%) have been considered eligible but only 7 out of 18 have been treated, remaining pts are waiting for the treatment. One third of pts have been excluded and cardiopathy, uncontrolled progressive disease and poor performance status represent the major causes for not being eligible to treatment. More criteria such as high ferritin levels, total tumor volume and active infections will delineate even better the patient population really receiving the infusion. CONCLUSIONS. Among all pts with relapsed and refractory NHL referred at our Center only 33% presented clinical and disease characteristics suitable for CAR T-cells treatment. Moreover, the majority of eligible pts are at the risk of becoming ineligible because of poor disease control. The time needed to plan the apheresis and the 4-5 weeks period to obtain CAR T-cells is a major obstacle to a larger applicability of this strategy, therefore exclusion of pts with large tumor mass and with rapid progressive disease is indicated. Probably, CAR T-cells treatment needs to be planned earlier in the disease course to optimize the outcome. In Italy the feasibility over the last 10 months of CAR T-cells treatment has been largely unsatisfactory and primarily limited by the lack of commercial products. Our observational study is ongoing. Disclosures Corradini: Novartis: Honoraria, Other: Travel Costs; Janssen: Honoraria, Other: Travel Costs; KiowaKirin: Honoraria; Celgene: Honoraria, Other: Travel Costs; Amgen: Honoraria; AbbVie: Consultancy, Honoraria, Other: Travel Costs; Sanofi: Honoraria; Servier: Honoraria; Takeda: Honoraria, Other: Travel Costs; Gilead: Honoraria, Other: Travel Costs; Daiichi Sankyo: Honoraria; Jazz Pharmaceutics: Honoraria; Kite: Honoraria; Roche: Honoraria; BMS: Other: Travel Costs.

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) has a large number of biological effects, including skin, cardiovascular, neurologic diseases, diabetes, infertility, cancers and immunotoxicity. We analysed the in vitro TCDD effects on human CD34+ cells and tested the gene expression modulation by means of microarray analyses before and after TCDD exposure. We identified 257 differentially modulated probe sets, identifying 221 well characterized genes. A large part of these resulted associated to cell adhesion and/or angiogenesis and to transcription regulation. Synaptic transmission and visual perception functions, with the particular involvement of the GABAergic pathway were also significantly modulated. Numerous transcripts involved in cell cycle or cell proliferation, immune response, signal transduction, ion channel activity or calcium ion binding, tissue development and differentiation, female or male fertility or in several metabolic pathways were also affected after dioxin exposure. The transcriptional profile induced by TCDD treatment on human CD34+ cells strikingly reproduces the clinical and biological effects observed in individuals exposed to dioxin and in biological experimental systems. Our data support a role of dioxin in the neoplastic transformation of hemopoietic stem cells and in immune modulation processes after in vivo exposure, as indicated by the epidemiologic data in dioxin accidentally exposed populations, providing a molecular basis for it. In addition, TCDD alters genes associated to glucidic and lipidic metabolisms, to GABAergic transmission or involved in male and female fertility, thus providing a possible explanation of the diabetogenic, dyslipidemic, neurologic and fertility effects induced by TCDD in vivo exposure.

Introduction.The recommended treatment for newly diagnosed nodal Peripheral T-cell lymphomas (PTCLs) patients eligible to high-dose therapy is cyclophosphamide-doxorubicin-vincristine plus etoposide (CHOEP) followed by autologous stem cell transplantation (auto-SCT) in chemo-sensitive disease. However, 25-30% of patients experienced primary refractoriness or early progression. Romidepsin (Ro), a histone deacetylase inhibitor, showed antitumor activity and a manageable toxicity profile in PTCLs. On these bases, we designed the FIL-PTCL13 phase Ib/II study (NCT02223208), aimed to define the maximum tolerated dose (MTD) of Ro in addition to CHOEP followed by consolidation with auto or allogeneic-SCT according to clinical response, and to evaluate the safety and the efficacy of this combination as first line in PTCLs. Patients and methods. Inclusion criteria were: untreated PTCL not otherwise specified, angioimmunoblastic, ALK negative anaplastic lymphoma at stage II-IV, aged 18-65. Treatment scheme was: an induction with 6 courses of CHOEP every 21 days combined with Ro at the allocated dose, at day 1 and 8 of each cycle (Ro-CHOEP). Patient in complete (CR) or partial response (PR) without an available donor, received one course of cisplatin, citarabine, desamethasone (DHAP) followed by stem cell harvest and proceeded to auto-SCT; patients in PR and with an available donor, were sent to upfront allogeneic-SCT. Romidepsin dose allocation for sequential cohorts of 3 patients at each dose was defined according to the Continual Reassessment Method (O'Quigley and Zohar, 2006). Dose-limiting toxicity (DLT) of Ro-CHOEP were: any grade ≥ 3 non-hematologic toxicity (according to the NCI Common Terminology Criteria for Adverse Events, version 4.0) or a delay >15 days of planned cycle date, observed during the first 2 cycles. The MTD of Ro was defined as the dose that achieved a DLT in 33% of patients. Four dose levels of Ro were tested, namely 8, 10, 12 and 14 mg/ms. Results. From September 2014 to July 2017, 21 patients were enrolled into the phase Ib part of the study. Clinical characteristics were: median age 57 years (IQR 53;61); bone marrow involvement in 6 (29%) patients; stage III-IV in 18 (86%); International Prognostic Index (IPI) risk ≥3 in 8 (38%). The first cohort of 3 patients was treated with Ro at 12 mg/ms, and no DLTs were observed; the subsequent 6 cohorts were treated with Ro at 14 mg/ms. Nine DLTs were reported in 7 patients: 3 events of grade (g)3 mucositis and one event of g3 maculopapular rash, g3 fatigue, g3 fever, g3 respiratory failure, g3 typhlitis and g4 neutropenic fever. The observed toxicity was 35.2% (95%CI: 17.1%-56.5%) and prompted to define 14 mg/ms the recommended dose of Ro in addition to CHOEP. No unexpected toxicities and no toxic deaths were reported. The most frequent toxicities reported during Ro-CHOEP were g3-4 neutropenia in 38% and thrombocytopenia in 45% of all the performed 117 courses. Severe extra-hematological toxicities by patients were: g3 arrhythmia in one (5%), g3 gastrointestinal in 3 (14%) and g3-4 infections in 5 (24%). The addition of Ro during induction did not impact the harvest, with a median of 4.3 × 10⁶ (IQR 3.4-5.71) peripheral blood CD34-positive cells/Kilogram collected. At least 90% of the planned dose of doxorubicine, cyclophosphamide, etoposide and vincristine were administered in: 87%, 86%, 83% and 89% of Ro-CHOEP, respectively. Median interval time between Ro-CHOEP was 21 days (range 19-36). At the end of induction 12/21 (57%) patients obtained CR and underwent auto-SCT, one patient (5%) in PR received auto-SCT due to lack of identical donor; 8 (38%) did not perform SCT due to lymphoma progression in 7 and to toxicity in one. At a median follow-up of 26 months, 12-months Progression Free Survival was 52% (95%CI: 29-71) and 12-months Overall Survival was 76% (95%CI: 52-89). Biomarkers and biological analysis are ongoing. The enrollment of the phase II part of the study is still open. Conclusions.The phase Ib FIL-PTCL13 part of the study defined Romidepsin 14 mg/ms on day 1 and day 8 as the MTD, when administered in combination to CHOEP as induction prior consolidation with up-front SCT, in untreated young PTCLs patients. The addition of Ro to chemotherapy did not impact the feasibility of CHOEP, without unexpected toxicities. The efficacy of this scheme is under investigation in the phase II part of the study. Disclosures Chiappella: Nanostring: Other: lecture fees; Teva: Other: lecture fees; Celgene: Membership on an entity's Board of Directors or advisory committees, Other: lecture fees; Amgen: Other: lecture fees; Roche: Other: lecture fees; Janssen: Membership on an entity's Board of Directors or advisory committees, Other: lecture fees.

Historically, the differential diagnosis between different nodal peripheral T-cell lymphoma (PTCL) subtypes based on morphological and phenotypic grounds has posed great challenges. In the last few years, our knowledge of the molecular bases of different PTCLs has significantly expanded. However, peripheral T-cell lymphomas not otherwise specified (PTCL-NOSs) are still regarded to as a heterogeneous category encompassing PTCL cases not fitting other, more homogeneous, subtypes. In fact, PTCL-NOS is one of the few lymphoma subtypes where no recurrent driver mutations have been reported so far. In order to better characterized the PTCL-NOS genomic landscape, we decided to investigate 11 PTCL-NOS patients by a whole genome sequencing (WGS) approach (median coverage 27X). Ten out of eleven samples were collected from FFPE blocks and 2 were removed from analysis: one due to low cancer cell fraction (CCF) and the other based on cluster generation issues during sequencing likely caused by a hyper-fragmented DNA. Among the remaining 9 cases, we extracted 59,617 somatic base substitutions (range 2,471-10,756, median 6,358 per patient) and 20,531 small insertion-deletions (indels) (range 84-6,397, median 1,580). We were able to characterize the spectrum of FFPE-induced artefacts, mostly composed of point mutations and indels within LINE-1 (L1) elements, predominantly of the L1PA family. This is a crucial quality control step that could be applied to similar future studies from archive samples. Four samples were heavily involved by FFPE-related artefacts and were excluded for this reason. Using a non-negative matrix factorization (NNMF) algorithm we investigated for the first time the PTCL-NOS mutational signature landscape. We did not find novel processes in this entity, but rather known processes operative in other lymphoid malignancies. Among those: signatures 1 and 5, deriving from the age-related process of spontaneous deamination of methylated cytosines; signatures 2 and 13 deriving from aberrant activity of the APOBEC family of DNA deaminases; signatures 17 and 8, pertaining to two yet poorly characterized processes. The contribution of different processes to the mutational spectrum of each case was profoundly heterogeneous. Combining our data set with 64 previously published whole exome sequencing cases (23 ALCL, 15 AITLs, 9 PTCL-NOSs and 16 EATL-II), we confirmed the lack of recurrent driver mutations among PTCL-NOS. Taking advantage of WGS data, we therefore focused on structural variants (SVs: inversions, translocations, internal tandem duplications and deletions) and copy number alterations (CNAs). We found 372 SVs, with a stunning median of 73 per sample (range 56-86). Even more interesting, at least one complex event was observed in all but one patients, including one whole genome duplication (WGD) and five chromothripsis events in three patients, suggesting a critical role of SVs in shaping the PTCL-NOS genome. We found that known onco-drivers were recurrently disrupted by such events: the most frequent target was CDKN2A, deleted in 4 out of 5 patients, 2 of which carried homozygous deletions. Interestingly, PTEN loss was observed in 2 out of 4 CDKN2A-deleted patients. Given the high prevalence of these deletions, we extended our observation to an independent validation set of ALCLs (n=56), AITL (n=22) and PTCL-NOS (n=59) investigated by FISH (n=36), next generation sequencing (n=25) or SNP6 array series (n=76). Overall, CDKN2A was deleted in 22/59 (37%) PTCL-NOSs cases, and in 17/22 (77%) both alleles were lost. PTEN was deleted in 12/59 (20%) PTCL-NOS cases, all of which also carried a CDKN2A loss. Strikingly, the co-occurrence of CDKN2A and PTEN was found only among PTCL-NOS, and in none of the other entities. With the limitations of the small sample size, the presence of CDKN2A bi-allelic deletions was associated with inferior survival (25% [95% CI: 9-66%] 5-y OS for deleted cases vs 52% [95% CI: 28-96%] for wt/hemizygous cases, p=0.042) among patients treated with an autologous bone marrow transplant front line program for advance stage and high-risk disease (n=19). Our observations point at SVs as a main driver of PTCL-NOS, often involving known cancer genes and their downstream pathways. Furthermore, our data highlighted recurrent gene deletions that may be relevant for differential diagnosis within this category of lymphomas. Disclosures Bolli: Celgene: Honoraria. Chiappella:Roche: Other: lecture fees; Amgen: Other: lecture fees; Janssen: Membership on an entity's Board of Directors or advisory committees, Other: lecture fees; Nanostring: Other: lecture fees; Celgene: Membership on an entity's Board of Directors or advisory committees, Other: lecture fees; Teva: Other: lecture fees. Corradini:Celgene: Honoraria, Other: Advisory Board & Lecturer; Novartis: Honoraria, Other: Advisory Board & Lecturer; Roche: Honoraria, Other: Advisory Board & Lecturer; Sanofi: Honoraria, Other: Advisory Board & Lecturer; Gilead: Honoraria, Other: Advisory Board & Lecturer; Sandoz: Other: Advisory Board; Abbvie: Honoraria, Other: Advisory Board & Lecturer; Takeda: Honoraria, Other: Advisory Board & Lecturer; Amgen: Honoraria, Other: Advisory Board & Lecturer; Janssen: Honoraria, Other: Lecturer.

Peripheral T-cell lymphomas (PTCLs) represent a rare and heterogeneous group of aggressive non-Hodgkin's lymphomas comprising different entities. Anthracycline-based regimens (usually CHOP, cyclophosphamide/doxorubicin/vincristine/prednisone) followed by stem cell transplantation are considered the standard of care in the front-line setting. However, long-term disease control can be achieved only in 30-40% of young patients. Increasing evidences highlight the role of tumor microenvironment in sustaining tumor progression and aggressiveness. Among microenvironment components, a central role is played by cancer associated fibroblast (CAFs). Recent studies demonstrated that this is applicable not only to solid tumors but also to haematological malignancies. Here, we report for the first time the isolation and characterization of PTCL-CAFs and their role in promoting cell proliferation. We kept in culture a skin biopsy of a cutaneous localization of a peripheral T cell lymphoma. Fibroblast-like cells grown out from the biopsy were isolated, cultivated for few passages and then characterized. Flow cytometric analyses revealed that the cell population entirely expressed cell-surface antigens specific for fibroblasts, such as CD140b and CD90, while they did not express CD45 and CD31, thus excluding hematopoietic or endothelial origin. Biochemical analyses confirmed that all cells were positive for vimentin, while αSMA expression highlighted the activated status of the cells isolated. We then assessed the in vitro effect of CAFs on PTCL cell growth by co-colture experiments. For this purpose, we coltured for 8 days the PTCL cell line OCI-Ly12 in fresh medium or in medium previously conditioned by CAFs or normal skin fibroblasts (NFs). PTCL cell growth was not affected by co-colture either with CAFs or with NFs. Moreover, the presence of conditioned medium did not alter the response of OCI-Ly12 cells to CHOP treatments. We then assessed the in vivo effect of PTCL-CAFs. We subcutaneously injected CAFs alone, OCI-Ly12 cells alone and OCI-Ly12 together with CAFs (ratio 1:1) in NOD/SCID mice and monitored tumor growth for 20 days. In contrast to the effect observed in vitro, co-injection of CAFs with cancer cells substantially promoted tumor growth (tumor volume OCI-Ly12 0,87±0,47 cm3; OCI-Ly12+CAFs 2,30±0,26 cm3). As expected, CAFs alone did not develop a measurable mass. Subsequent immunohistochemical staining with CD31 revealed the presence of more vascular structures in tumors originated by OCI-Ly12+CAFs co-injection than by OCI-Ly12 alone, suggesting that CAFs presence sustains tumor growth by promoting angiogenesis. In summary, we show that PTCL-derived CAFs promote cancer cell growth in vivo, while leaving unaffected cell growth in vitro and the response to chemotherapy. This is the first evidence of the role played by the microenvironment in promoting malignant cell proliferation in PTCLs. Citation Format: Martina Magni, Sara Rizzitano, Alessio Pellegrinelli, Paolo Corradini, Cristiana Carniti. Peripheral T cell lymphoma-associated fibroblasts promote tumor growth in an in vivo model [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3123.

This study describes a patient with a relapsed, diffuse, large B cell lymphoma (DLBCL) treated with radioimmunotherapy (RIT) with yttrium-90 ((90)Y)-ibritumomab tiuxetan (Zevalin) who 5 months later developed acute myeloid leukemia (AML) with inversion of chromosome 16. Our data indicate that molecular biological techniques should be used in selected cases to integrate data obtained with standard cytogenetics: using RT-PCR we showed that inversion of chromosome 16 was already present before RIT, in striking contrast to the normal karyotype found with conventional cytogenetics. This approach will allow investigators to avoid misleading data and provide support for conclusions regarding the side effects of treatment.