ALBERT

Description: Pediatric-type nodal follicular lymphoma (PTNFL) is a variant of follicular lymphoma (FL) characterized by localized presentation and excellent behavior despite its often high-grade histologic appearance. We recently identified high proliferation index and the absence of BCL2, BCL6, and IRF4 gene rearrangements as defining features of PTNFL in both children and adults (Louissaint, Blood 2012). In contrast to typical FL, children with PTNFL consistently have persistent remissions after surgical excision alone. Therefore, it is critically important to identify PTNFL in order to avoid unnecessary therapy. Considering the unique clinical behavior of PTNFL, we hypothesized that the mutational landscape of this disease would differ from that of typical FL. Twenty-four cases were collected from several institutions (MGH, Brigham & Women's, Weill Cornell, Chicago Children's, Boston Children's, University of Pittsburgh, SUNY Downstate, and Stanford). PTNFL was defined by the following criteria: 1) nodal involvement, 2) architectural effacement by a clonal follicular proliferation, 3) high proliferation index and 4) absence of both MUM1/IRF4 expression and BCL2/BCL6 rearrangements by FISH. All cases presented with localized nodal involvement and demonstrated no evidence of recurrence or progression after chemotherapy (n=5), radiation (n=3) or surgical excision alone (n=13) (therapeutic approach to be confirmed in 3 cases), with a median follow-up of 33.1 months (range 10-124 months). Subjects ranged in age from 4-60 years, including 14 children (4-18 years; median 15) and 10 adults (20-60 years; median 29.5). Whole exome sequencing performed on 7 PTNFL cases showed a strikingly low mutation burden (7.1 non-silent mutations/exome), more than an order of magnitude lower than the exomic mutation burden of typical FLs (Green, PNAS 2015; Pasqualucci, Cell Rep 2015). Given these findings, we pursued targeted exome capture and next-generation sequencing for 112 genes previously reported to be recurrently mutated in FL across a panel of 20 PTNFLs. Targeted sequencing (mean depth, 250) again demonstrated very low mutation burden in PTNFL, with a median number of non-silent mutations of 1.67/case compared with 4 mutations/case (P

Description: Background: Ten to 15% of diffuse large B cell lymphoma (DLBCL) patients exhibit primary refractory disease (nonresponse or relapse within 3 months of therapy) and an additional 20-25% relapse following initial response. There is an unmet need for effective therapeutic regimens in relapsed/refractory (R/R) DLBCL. Lenalidomide is an immune modulator that reverses T cell dysfunction and also inhibits the NFκB pathway, which is constitutively active in non-germinal center (non-GCB) DLBCL. Lenalidomide and nivolumab, an anti-PD-1 antibody, each have single agent activity in R/R DLBCL. Here, we report the results of the dose-escalation cohort of this investigator-initiated, single-arm open-label study of the combination of nivolumab, lenalidomide and rituximab (NiLeRi) in R/R non-GCB DLBCL. Methods: Adult patients with R/R non-GCB DLBCL, as determined by the Hans algorithm, with adequate organ function and an ECOG performance status of ≤2 were eligible for the study. The primary objective was to evaluate the safety of NiLeRi, and determine the maximum tolerated dose (MTD) of lenalidomide in combination with fixed doses of rituximab and nivolumab, using a 3+3 dose escalation design. The secondary objectives were to determine efficacy in terms of overall response rate (ORR), progression free survival (PFS), and overall survival (OS) of patients treated with NiLeRi. All patients received nivolumab IV 3 mg/kg on days 1 and 15 and rituximab IV 375mg/m2 on day 1 of each 28-day cycle. Lenalidomide was initiated at 5 mg po once daily on days 1-21. Additional planned dose levels were 10 mg, 15 mg and 20 mg. Patients were evaluable for toxicity if they received all doses of nivolumab and rituximab and at least 16 doses of lenalidomide during cycle 1 or if they experienced a dose limiting toxicity (DLT), regardless of the number of doses. NiLeRi was given for 8 cycles and patients with partial response could receive lenalidomide and nivolumab for an additional 4 cycles. Response was assessed by PET-CT after 2, 5 and 8 cycles and defined by Lugano criteria. Results: Six patients with non-GCB subtype of DLBCL were enrolled in this study. The median age was 60.5 years (range 28-79), and 5 patients were male. The median number of prior lines of therapy was 4 (range 2-5), and the median IPI score was 3. None of the patients had bone marrow involvement. One patient each had been treated with autologous stem cell transplant (Auto-SCT) and CAR-T cell therapy. One patient withdrew consent before completing cycle 1 and was not evaluable for safety or efficacy. Safety: Five out of the six enrolled patients were evaluable for safety. All patients received lenalidomide 5 mg dose. Two patients experienced DLTs (grade 3 rash) resulting in lenalidomide discontinuation during cycle 2. The most common grade 3/4 toxicities were fatigue (20%), neutropenia (60%), thrombocytopenia (40%), and rash (40%). A total of 3 patients experienced grade 1/2 diarrhea and elevated liver enzymes. One patient experienced a grade 1 infusion reaction with rituximab. Efficacy: Patients who completed at least 1 cycle of therapy were evaluable for response, and this included 5 out of the 6 enrolled patients. The ORR and complete response (CR) rate were both 40%. Patients who responded did so early, with one patient achieving CR after 2 cycles and another patient achieving CR after 5 cycles. The best response seen in patients with primary refractory disease was PR. At a median follow up of 9.5 months, median PFS was 8.4 months (95% CI; 4.3 to not reached), and median OS was not reached. Discussion: This is the first study reporting the safety results of the combination of lenalidomide, nivolumab and rituximab in non-Hodgkin lymphoma. Rash was the most common DLT, limiting dose escalation of lenalidomide above 5mg in this cohort of patients. Two patients experienced durable CR early in the study after 2 and 5 cycles, respectively. This ORR and CR rate of 40% each in this small cohort of patients who had relapsed after multiple prior lines of therapy is encouraging. Correlative studies, including whole exome sequencing of patient samples, are underway, in an attempt to explore predictive markers for response and toxicity. Figure. Disclosures Mason: Sysmex: Honoraria. Oluwole:Pfizer: Consultancy; Spectrum: Consultancy; Gilead Sciences: Consultancy; Bayer: Consultancy. Morgan:Biogen: Equity Ownership; Eli Lilly: Equity Ownership; Vertex: Equity Ownership; Zoetis: Equity Ownership; Pfizer: Equity Ownership; Novo Nordisk: Equity Ownership; Gilead: Equity Ownership; Johnson and Johnson: Equity Ownership; Merck: Equity Ownership. Reddy:Abbvie: Consultancy; Genentech: Research Funding; Celgene: Consultancy; BMS: Consultancy, Research Funding; KITE Pharma: Consultancy. OffLabel Disclosure: Nivolumab and lenalidomide are not FDA approved for use in diffuse large B cell lymphoma

Description: Key Points PTNFL is a biologically distinct indolent lymphoma characterized by common MEK/ERK pathway mutations. The biology of PTNFL is not defined by age, as the mutational profile is similar in pediatric and adult cases.

Description: Introduction:Most patients with central nervous system lymphoma (CNSL) have an inferior response to therapy compared with systemic diffuse large B-cell lymphoma (DLBCL), in part possibly because 95% of CNSL are of activated B-cell (ABC) phenotype. Recent studies have revealed the genetic basis of pathways active in CNSL. Activated anti-apoptotic NFκB and B-cell receptor pathways are key to sustained cancer cell survival. Myeloid differentiation primary-response protein 88 (MYD88) is an adaptor protein that upon stimulation of TLR, mediates downstream activation of the NFκB pathway. The objective of this study is to examine the association of MYD88 mutation and PD-1/PD-L1 expression with clinical outcome and the overlap between PD-1/ PD-L1 expression and MYD88 L265P mutation in CNSL. Methods:Twenty-two patients with CNSL on whom complete treatment records and tissue were available were included in our study following IRB approval. On a corresponding archived formalin-fixed, paraffin-embedded tissue block from each case, 10 5-um unstained slides for immunohistochemistry and a 10-50 um tissue curl for MYD88 DNA analysis by PCR were prepared. PAX5, CD3, CD68, PD-1 and PD-L1 immunostains were performed and evaluated by light microscopy by two of the authors blinded to the clinical data, including one hematopathologist. Extracted DNA was analyzed using allele-specific PCR designed to detect the common MYD88 gene mutation c.794T〉C (p.L265P). DLBCL immunophenotype data, based on Hans algorithm was extracted from the pathology reports. Comparisons between two groups were analyzed using Chi-square and Student t tests. Kaplan Meier method was used to calculate progression-free survival (PFS) and overall survival (OS). Log-rank test was used to determine the differences in survival. Pearson and Spearman's rho coefficients were calculated for correlation analysis. Statistical analysis was performed using SPSS.22 software. Results:The median age at diagnosis was 67 years (range 28-81). Thirteen patients were male (59%). Twelve patients had ECOG performance status of 〉 1. Median LDH at diagnosis was 190 U/L. Two patients with CNSL had HIV. Two patients had received prior solid-organ transplant. Seventeen patients received high-dose methotrexate-based therapy, and 9 received radiation. In terms of histopathology, 19 (86%) were of ABC subtype, all were CD20 positive, and 4 were EBV-positive, including both post-transplant cases. The median PFS of all patients was 6.52 months, and the OS was 12 months. Tumor content of the tissue sections was estimated from H&E and PAX-5 stains and showed 30-100% tumor areas, barring 3 cases with

Description: Background: Diffuse large B cell lymphoma (DLBCL) is the most common lymphoma, but comprises a heterogenous group. Recent studies have identified aggressive subsets of DLBCL including double-hit lymphomas (DHL, with rearrangements of both MYC and BCL2 oncogenes and often classified in a separate DLBCL/Burkitt overlap category) and double-expressing lymphomas (DEL, which overexpress both MYC and BCL2). These subsets respond poorly to standard R-CHOP chemotherapy and account for most of the mortality associated with DLBCL. While recent studies have associated TP53 protein overexpression with worse prognosis in DLBCL, the effect of TP53 aberrations on these more aggressive DLBCL subsets is still uncertain. Design: We performed a retrospective single institution analysis of a cohort of 26 DHL and a cohort of 65 R-CHOP-treated DLBCL, including 10 DEL. We recorded clinical information, treatment, and patient outcome. The DHL cases were treated with either R-CHOP or a more intensive regimen. A tissue microarray or recuts from original blocks were used for immunostains for TP53, BCL2, MYC, and cell-of-origin determination by Hans algorithm, which were scored blindly. Results: TP53 expression (〉10% of tumor cells) was significantly associated with higher expression of BCL2 (p=0.02), MYC (p=0.0009), and DEL status (p=0.005) in the DLBCL group. With respect to the association of DEL with TP53 expression, 7/10 (70%) cases of DEL were TP53+ compared to 10/55 (18%) of non-DEL DLBCL. There was no association with TP53 expression and cell-of-origin. No statistically significant difference in overall or relapse free survival between TP53+ and TP53- cases was identified in either cohort. Conclusion: The findings in this small sample suggest that the relationship between TP53 staining and DLBCL outcome is more complex than previously reported, and may reflect an association of TP53 expression with DEL. The use of intensified treatment regimens (such as R-EPOCH) in the DHL cohort may abrogate any negative effects of TP53 overexpression in the TP53+ subset. Disclosures Abramson: Seattle Genetics: Consultancy; Gilead: Consultancy; Abbvie: Consultancy; Kite Pharma: Consultancy.

Description: Introduction: Immunotherapy with rituximab alone or in combination with sequential chemotherapy such as CHOP, in addition to a reduction in immunosuppression (IST), has been shown to be effective in achieving long-term, disease-free survival in patients with B-cell PTLD. We have recently observed an increased incidence of HGBL in patients receiving IST following solid-organ transplant. Intensive induction regimens (ex: DA-R-EPOCH) in non-transplant HGBL has been associated with improved complete responses. Intensive regimens have not been previously evaluated in patients with PTLD. The aim of this study is to compare the tolerability of DA-R-EPOCH to R-CHOP in post-transplant patients with HGBL. Methods: Patients treated with either DA-R-EPOCH or R-CHOP were included in this study following IRB approval. Eligible patients were ≥18 years, had biopsy-confirmed B-cell PTLD, and were treated with at least one cycle of DA-R-EPOCH or R-CHOP. The primary outcome was progression-free survival (PFS); secondary outcomes were overall survival (OS), toxicities, and hospitalizations due to treatment-related toxicities. Statistical analysis was performed using SPSS.22 software Results: Sixty-three patients had biopsy-confirmed PTLD. Of these, 26 met inclusion criteria. Among these 26 patients, 19 (73.1%) were men; median age was 57 years (18-75 years); and transplants included 3 (11.5%) lung, 4 (15.4%) heart, 9 (34.6%) kidney, 8 (30.8%) liver, 2 (7.7%) pancreas, and 1 (3.8%) stem cell. All patients were receiving IST at the time of diagnosis of PTLD. Pathology reports found that 24 (92.3%) had diffuse large B-cell lymphoma (DLBCL)-like PTLD, and 11 (57.9%) had EBV-positive disease. HGBL was observed in 10 (38.5%) patients. Seven patients received DA-R-EPOCH, and 19 received R-CHOP. Baseline characteristics were similar between treatment groups. There was a significantly higher number of patients with HGBL in the DA-R-EPOCH arm compared with the R-CHOP arm (100% [7/7] vs. 15.8% [3/19]; 95% CI, -0.01-1.00; p=0.001). The median number of cycles administered was not significantly different between the groups (4.6 cycles vs. 5 cycles; 95% CI, 4.33-6.07; p=0.645). Dose intensification occurred in 8 of 32 cycles for patients who received DA-R-EPOCH. The median follow-up time for patients treated with DA-R-EPOCH was shorter (10 months) than for patients treated with R-CHOP (29 months). PFS was not found to be significantly different between the DA-R-EPOCH and R-CHOP arms (10.4 months vs. 61.4 months; 95% CI, 1.80-18.99; p=0.31). Patients with EBV-positive disease had inferior PFS compared with EBV-negative disease (7.37 months vs. NR; 95% CI, 1.02-10.2; p=0.046). In addition, OS, neutropenia, thrombocytopenia, hospitalizations, and hospitalizations due to febrile neutropenia were not significantly different between groups, though trends toward higher rates of grade 3 or 4 neutropenia, thrombocytopenia, and hospitalizations was observed in the DA-R-EPOCH group. Conclusion: To our knowledge, this is the first study evaluating the role of intensive induction therapy in patients with HGBL with MYC and BCL2 rearrangements observed in solid organ transplant recipients. In patients with PTLD, DA-R-EPOCH is a well-tolerated regimen with concurrent taper in IST. However, this strategy may not overcome the poor prognosis of HGBL. Dose adjustments beyond level 2 were limited by cytopenias. Figure Figure. Disclosures Reddy: KITE: Membership on an entity's Board of Directors or advisory committees; celgene: Membership on an entity's Board of Directors or advisory committees; GILEAD: Membership on an entity's Board of Directors or advisory committees; INFINITY: Membership on an entity's Board of Directors or advisory committees.

Description: Follicular Lymphoma (FL) is the most common indolent lymphoma derived from light zone germinal center B cells and characterized by a t(14;18) translocation resulting in upregulation of BCL2 in over 80% of cases. This translocation alone is not sufficient for tumorogenesis, and must be combined with additional genetic mutations to transform B cells. FL is incurable and the disease course can be highly varied, with survival ranging from a few months to decades following diagnosis and treatment with standard chemoimmunotherapy. The heterogeneity of FL poses major challenges to identifying the association of genetic alterations and clinical outcome. Current WHO guidelines recommend establishing grade for each FL case with grade 3 thought to be more aggressive than 1 and 2. The genetic basis and clinical implications of grade in FL are unclear. Recent sequencing studies have identified many genes found to be recurrently mutated in FL including KMT2D and CREBBP. However, the degree to which genetic alterations cooperate with each other or contribute to clinical outcome is unclear. Based on the observed mutational rates in follicular lymphoma, we estimated 900 cases were needed to comprehensively delineate the genetic alterations that underlie histologic grade and clinical outcome. Accordingly, we enrolled a cohort of 1042 patients with newly diagnosed FL. All treated patients received rituximab-containing standard regimens. To go beyond the identification of gene-coding events, we developed a very large panel of 110 Mbp covering exonic (~40Mbp) and non-exonic regions (~70Mbp) of interest to enable a wide range of genomic analysis including mutation calling in both coding and non-coding regions, rearrangement detection, viral identification, and copy number analysis. In addition to the whole exome, we extended coverage to include introns, promoters, and untranslated regions of all known driver genes in cancer. We included the entirety of the immunoglobulin loci, T-cell receptor loci and CD3 loci to detect clonotypes and rearrangements. We also included lymphoma-relevant long non-coding RNAs, microRNAs, enhancers, and breakpoint-prone regions. For viral detection, we targeted the genomes of eight cancer-related viruses: Epstein-Barr virus, human papillomavirus, human immunodeficiency virus, hepatitis B, hepatitis C, Kaposi's sarcoma-associated herpesvirus, human T-lymphotropic virus, and Merkel cell polyomavirus. In addition, to enable high resolution identification of copy number variation (CNV) calls, the entire genome was tiled with probes spaced 10kb apart. DNA and RNA were extracted from all tumors and their paired normal samples, prepared into DNA and RNA sequencing libraries and subjected to sequencing on the Illumina platform to a targeted coverage of 150X. Somatic events were identified and further filtered to identify driver events in both coding and non-coding regions. FLs demonstrated a significant degree of genetic heterogeneity with over 100 genes mutated with a frequency of at least 2%. Nearly 100% of FL cases had a mutation in at least one chromatin-modifying gene. The most frequently mutated genes in follicular lymphoma were KMT2D, BCL2, IGLL5 and CREBBP. In addition, we identified frequent mutations in SPEN, BIRC6 and SETD2. To our knowledge, this is the first description of alterations in these genes in FL. Transcriptome analysis indicated a strong correlation between BIRC6 mutations and the previously described immune response 2 signature that is associated with a poor prognosis. We further performed unbiased clustering of genetic alterations in these FL cases. We identified a cluster that was specifically enriched in BCL6 and TP53 alterations and was strongly associated with grade 3 FLs which are predicted to have poorer outcomes with low intensity therapies. We further examined the genetic profiles of 1001 DLBCLs in comparison to this cohort of FLs. Our data indicate a continuum of highly overlapping genetic alterations with DLBCL displaying more complex patterns that included alterations in MYC, TP53 and CDKN2A (mainly copy number losses), indicating shared pathogenetic mechanisms underlying FL and DLBCL, particularly those germinal center B cell origin. Disclosures Koff: Burroughs Wellcome Fund: Research Funding; V Foundation: Research Funding; Lymphoma Research Foundation: Research Funding; American Association for Cancer Research: Research Funding. Leppä:Roche: Honoraria, Research Funding; Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Bayer: Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen-Cilag: Research Funding; Novartis: Membership on an entity's Board of Directors or advisory committees. Gang:ROCHE: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees. Hsi:Abbvie: Research Funding; Eli Lilly: Research Funding; Cleveland Clinic&Abbvie Biotherapeutics Inc: Patents & Royalties: US8,603,477 B2; Jazz: Consultancy. Flowers:AbbVie: Consultancy, Research Funding; Denovo Biopharma: Consultancy; BeiGene: Consultancy, Research Funding; Burroughs Wellcome Fund: Research Funding; Eastern Cooperative Oncology Group: Research Funding; National Cancer Institute: Research Funding; V Foundation: Research Funding; Optimum Rx: Consultancy; Millenium/Takeda: Research Funding; TG Therapeutics: Research Funding; Gilead: Consultancy, Research Funding; Celgene: Consultancy, Research Funding; Karyopharm: Consultancy; AstraZeneca: Consultancy; Pharmacyclics/Janssen: Consultancy, Research Funding; Spectrum: Consultancy; Bayer: Consultancy; Acerta: Research Funding; Genentech, Inc./F. Hoffmann-La Roche Ltd: Consultancy, Research Funding. Neff:Enzyvant: Consultancy; EUSA Pharma: Honoraria, Membership on an entity's Board of Directors or advisory committees. Fedoriw:Alexion Pharmaceuticals: Other: Consultant and Speaker. Reddy:Genentech: Research Funding; BMS: Consultancy, Research Funding; Celgene: Consultancy; KITE Pharma: Consultancy; Abbvie: Consultancy. Mason:Sysmex: Honoraria. Behdad:Loxo-Bayer: Membership on an entity's Board of Directors or advisory committees; Thermo Fisher: Membership on an entity's Board of Directors or advisory committees; Pfizer: Other: Speaker. Burton:Bristol-Myers Squibb: 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, Other: Travel; Celgene: Membership on an entity's Board of Directors or advisory committees; Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees. Dave:Data Driven Bioscience: Equity Ownership.