ALBERT

Description: Despite significant advances in the treatment of Hodgkin’s lymphoma (HL), a significant proportion of patients will not respond or will subsequently relapse. We identified CD25, the IL-2 receptor alpha subunit, as a favorable target for systemic radioimmunotherapy of HL. The scientific basis for the clinical trial was that, although most normal cells with exception of Treg cells do not express CD25, it is expressed by a minority of Reed–Sternberg cells and by most polyclonal T cells rosetting around Reed–Sternberg cells. Forty-six patients with refractory and relapsed HL were evaluated with up to seven i.v. infusions of the radiolabeled anti-CD25 antibody 90Y-daclizumab. 90Y provides strong β emissions that kill tumor cells at a distance by a crossfire effect. In 46 evaluable HL patients treated with 90Y-daclizumab there were 14 complete responses and nine partial responses; 14 patients had stable disease, and nine progressed. Responses were observed both in patients whose Reed–Sternberg cells expressed CD25 and in those whose neoplastic cells were CD25− provided that associated rosetting T cells expressed CD25. As assessed using phosphorylated H2AX (γ-H2AX) as a bioindicator of the effects of radiation exposure, predominantly nonmalignant cells in the tumor microenvironment manifested DNA damage, as reflected by increased expression of γ-H2AX. Toxicities were transient bone-marrow suppression and myelodysplastic syndrome in six patients who had not been evaluated with bone-marrow karyotype analyses before therapy. In conclusion, repeated 90Y-daclizumab infusions directed predominantly toward nonmalignant T cells rosetting around Reed–Sternberg cells provided meaningful therapy for select HL patients.

Description: Activating Janus kinase (JAK) and signal transducer and activator of transcription (STAT) mutations have been discovered in many T-cell malignancies, including anaplastic lymphoma kinase (ALK)− anaplastic large cell lymphomas (ALCLs). However, such mutations occur in a minority of patients. To investigate the clinical application of targeting JAK for ALK− ALCL, we treated ALK− cell lines of various histological origins with JAK inhibitors. Interestingly, most exogenous cytokine-independent cell lines responded to JAK inhibition regardless of JAK mutation status. JAK inhibitor sensitivity correlated with the STAT3 phosphorylation status of tumor cells. Using retroviral shRNA knockdown, we have demonstrated that these JAK inhibitor-sensitive cells are dependent on both JAK1 and STAT3 for survival. JAK1 and STAT3 gain-of-function mutations were found in some, but not all, JAK inhibitor-sensitive cells. Moreover, the mutations alone cannot explain the JAK1/STAT3 dependency, given that wild-type JAK1 or STAT3 was sufficient to promote cell survival in the cells that had either JAK1or STAT3 mutations. To investigate whether other mechanisms were involved, we knocked down upstream receptors GP130 or IL-2Rγ. Knockdown of GP130 or IL-2Rγ induced cell death in selected JAK inhibitor-sensitive cells. High expression levels of cytokines, including IL-6, were demonstrated in cell lines as well as in primary ALK− ALCL tumors. Finally, ruxolitinib, a JAK1/2 inhibitor, was effective in vivo in a xenograft ALK− ALCL model. Our data suggest that cytokine receptor signaling is required for tumor cell survival in diverse forms of ALK− ALCL, even in the presence of JAK1/STAT3 mutations. Therefore, JAK inhibitor therapy might benefit patients with ALK− ALCL who are phosphorylated STAT3+.

Description: The activated B-cell–like (ABC) subtype of diffuse large B-cell lymphoma (DLBCL) relies on chronic active B-cell receptor (BCR) signaling. BCR pathway inhibitors induce remissions in a subset of ABC DLBCL patients. BCR microclusters on the surface of ABC cells resemble those generated following antigen engagement of normal B cells. We speculated that binding of lymphoma BCRs to self-antigens initiates and maintains chronic active BCR signaling in ABC DLBCL. To assess whether antigenic engagement of the BCR is required for the ongoing survival of ABC cells, we developed isogenic ABC cells that differed solely with respect to the IgH V region of their BCRs. In competitive assays with wild-type cells, substitution of a heterologous V region impaired the survival of three ABC lines. The viability of one VH4-34+ ABC line and the ability of its BCR to bind to its own cell surface depended on V region residues that mediate the intrinsic autoreactivity of VH4-34 to self-glycoproteins. The BCR of another ABC line reacted with self-antigens in apoptotic debris, and the survival of a third ABC line was sustained by reactivity of its BCR to an idiotypic epitope in its own V region. Hence, a diverse set of self-antigens is responsible for maintaining the malignant survival of ABC DLBCL cells. IgH V regions used by the BCRs of ABC DLBCL biopsy samples varied in their ability to sustain survival of these ABC lines, suggesting a screening procedure to identify patients who might benefit from BCR pathway inhibition.

Description: BACKGROUND: HIV-associated primary central nervous system lymphoma (HIV-PCNSL) is an AIDS-defining cancer. Tumors occur in patients with very low CD4+ counts, and tumors are almost always Epstein-Barr virus (EBV) infected. Overall survival (OS) has improved over time with antiretroviral therapy (ART)-associated immune reconstitution but is still generally less than 1 year. Treatment has traditionally included whole brain radiation, which can lead to devastating long-term neurotoxicity, including cognitive decline. ART has made it possible to treat patients with curative-intent, but radiation-sparing approaches have not been studied prospectively in HIV-PCNSL. METHODS: In a prospective phase II pilot study conducted in the HIV & AIDS Malignancy Branch at the National Cancer Institute, we evaluated curative-intent radiation-sparing immunochemotherapy in patients with untreated HIV-PCNSL (NCT00267865). Patients with HIV-PCNSL received ART, rituximab (375 mg/m2) and HD-MTX (6 g/m2) with leucovorin rescue (R-HD-MTX). Responses were evaluated by modified International Working Group Response Criteria for PCNSL after 6 cycles of induction R-HD-MTX and patients with a complete response (CR) received 2 consolidation cycles of R-HD-MTX. Patients with poor renal or cardiac function who were not eligible to receive HD-MTX at enrollment, received ART, rituximab and best-available radiation-sparing care. The primary objective of the study was to estimate the percentage of patients receiving ART and R-HD-MTX alive without recurrent lymphoma at two years. Response to treatment, immune reconstitution, and OS were evaluated using descriptive statistics and Kaplan-Meier methodology. RESULTS: Twelve patients were enrolled between September 2006 and June 2016. One enrolled patient was initially ineligible to receive HD-MTX due to renal dysfunction and received rituximab with temozolomide (TMZ) 150 mg/m2 for 5 days for one cycle followed by 6 cycles of R-HD-MTX + TMZ and 2 consolidation cycles of R-HD-MTX. Patient characteristics: 9 men, 3 women; median (med) age 33 years (range: 21-55); 8 African-American, 3 Hispanic, 1 white non-Hispanic; med Eastern Cooperative Oncology Group performance status 2 (1-3); med baseline Mini Mental State Examination (MMSE, maximum score = 30) was 22 (range: 5-29). Only 4 patients were on ART prior to diagnosis, and all but 1 had been on ART less than 4 months. Med time from HIV infection to PCNSL diagnosis was 30 weeks (range: 0-23 years). Med CD4+ T-cell count at PCNSL diagnosis was 16 cells/µL (0-409). Diagnosis of PCNSL was biopsy-confirmed (11) or made by 18fludeoxyglucose positron emission tomography/cerebral spinal fluid (CSF) EBV viral load criteria (1). 11/12 tumors were EBV positive. Flow cytometry showed leptomeningeal disease in 4 patients. Three had concurrent CNS infections, including Cryptococcus, histoplasmosis, and CMV retinitis. Ten were evaluable for response to R-HD-MTX induction. Two patients received only 1 cycle of therapy and were not evaluable due to treatment failure (TF). Responses after R-HD-MTX induction: CR (5), partial response (PR) (4) and progressive disease (PD) (1). Two patients with a PR received second-line TMZ at end of R-HD-MTX and obtained a subsequent CR. The patient with PD received second-line therapy with the Cancer and Leukemia Group B 50202 induction regimen and obtained a subsequent CR. There were 4 deaths on study: 1 pulmonary embolism, 1 CNS fungal infection in setting of PD, 2 TF. Eight patients (67%), including 3 patients who received second line therapy, obtained a durable CR. Med CD4+ T-cell increase following R-HD-MTX induction was +35 cells/uL (range: -54 - +369). In surviving patients, med MMSE after R-HD-MTX was 28 (27-30). For all patients, estimated 60-month OS was 66% (95% CI: 32-86%) with med potential follow-up of 82 months. Med OS was not reached. CONCLUSIONS:Treatment with ART and R-HD-MTX is associated with a high response rate, CD4+ immune reconstitution, preserved cognition, and improved OS, even in a high-risk patient population. Disclosures Uldrick: Celgene: Patents & Royalties: 10,001,483 B2; Celgene: Research Funding; Merck: Research Funding. Yarchoan:NIH: Patents & Royalties: Patents on IL-12 for KS and cereblon-binding drugs for KSHV diseases. Spouse has patent on KSHV IL-6. Patents assigned to DHHS/NIH.; Celgene Corp.: Research Funding.

Description: The new recently described provisional lymphoma category Burkitt-like lymphoma with 11q aberration comprises cases similar to Burkitt lymphoma (BL) on morphological, immunophenotypic and gene-expression levels but lacking the IG-MYC translocation. They are characterized by a peculiar imbalance pattern on chromosome 11, but the landscape of mutations is not yet described. Thus, we investigated 15 MYC-negative Burkitt-like lymphoma with 11q aberration (mnBLL,11q,) cases by copy-number analysis and whole-exome sequencing. We refined the regions of 11q imbalance and identified the INO80 complex-associated gene NFRKB as a positional candidate in 11q24.3. Next to recurrent gains in 12q13.11-q24.32 and 7q34-qter as well as losses in 13q32.3-q34, we identified 47 genes recurrently affected by protein-changing mutations (each ≥3 of 15 cases). Strikingly, we did not detect recurrent mutations in genes of the ID3-TCF3 axis or the SWI/SNF complex that are frequently altered in BL, or in genes frequently mutated in germinal center–derived B-cell lymphomas like KMT2D or CREBBP. An exception is GNA13, which was mutated in 7 of 15 cases. We conclude that the genomic landscape of mnBLL,11q, differs from that of BL both at the chromosomal and mutational levels. Our findings implicate that mnBLL,11q, is a lymphoma category distinct from BL at the molecular level.

Description: Background: Primary CNS lymphoma (PCNSL) is an aggressive B-cell lymphoma that relies on chronic active B-cell receptor (BCR) signaling. Patients with chemo-refractory PCNSL or relapsed 〈 1y have a median OS of only 2-4 mos. Ibrutinib targets BCR signaling through inhibition of BTK. In a phase 1 study, we showed tumor reductions after a 14-day ibrutinib window in 94%, including complete remissions (CR) (Lionakis et al. Cancer Cell 2017). Further, ibrutinib added to anthracycline-based chemotherapy (DA-TEDDi-R) achieved CR in 86% of evaluable patients. Routine use of DA-TEDDi-R, however, is limited by our observation of 7 presumed or proven cases of Aspergillus when no fungal prophylaxis was given and in conjunction with high dose steroids. Herein, we report the durability of CR and PFS in relapsed/refractory patients with extended follow-up. Methods: Patients with untreated or relapsed/refractory PCNSL, age 〉18, and adequate organ function were enrolled. Previous BTK inhibitor, EBV+, and active pregnancy were excluded. Patients had baseline MRI brain, PET/CT brain and body, Ommaya placed, CSF analysis with flow cytometry, and ophthamologic evaluation. A window of ibrutinib x 14d was given in 3 cohorts at escalating doses (560mg, 700mg, 840mg) then repeat MRI to assess activity. After ibrutinib window, patients received up to 6 cycles of ibrutinib + TEDD-R (temozolamide, etoposide, doxil, dexamethasone, rituximab) with ICV or IT cytarabine. No pt received maintenance or consolidation. All remissions by MRI were confirmed with PET/CT brain and repeat CSF analysis. Surveillance brain MRI after treatment q3mos for 1y, q4mos x 1y, q6mos x 1y, then annually. Results:18 PCNSL patients with a median age 66 (range 49-87) were enrolled between August 2014 and March 2016. 5 patients were untreated, 2 relapsed, and 11 chemo-refractory. After a median potential f/u of 38.9m, the median PFS for all patients who received DA-TEDDi-R is 15.2m (95% CI:3.8-undefined) and the 2-yr PFS is 43.8% (95% CI: 19.8-65.6). Of 13 relapsed/refractory patients, 2 died from Aspergillus infection during the ibrutinib window; neither had fungal prophylaxis and both had high-dose steroids. 11 patients received a median of 5 cycles (range 1-6) of DA-TEDDi-R. Nine (82%) of these patients achieved CR/CRu. Notably, none of the 6 patients with relapsed/refractory PCNSL (1 relapsed, 5 refractory) in CR at the time of publication have relapsed or died. The median duration of CR in relapsed/refractory PCNSL has not yet been reached (range 2-43m) and the 2-year durable CR rate is 66.7% (95% CI: 28.2-87.8) (Figure 1). Of the 11 relapsed/refractory patients who received DA-TEDDi-R, the median PFS has not yet been reached and the 2-yr PFS is 54.5% (95% CI: 22.9-78.0) (Figure 2). Conclusions: Ibrutinib + anthracycline-based chemotherapy (TEDDi-R) induces durable complete remissions in PCNSL without maintenance or consolidation, including patients with disease refractory to chemotherapy. Risk of Aspergillus infections mandates use of fungal prophylaxis and judicious use of steroids. Phase 1 study of escalating ibrutinib doses with concurrent isavuconazole is currently enrolling patients with relapsed and refractory PCNSL (NCT02203526). This work was supported by the Intramural Research Program of NCI at NIH Disclosures No relevant conflicts of interest to declare.

Description: Burkitt lymphoma (BL) is the most common non-Hodgkin lymphoma (NHL) in children. Although it accounts for only 1-5% of NHL in adults, approximately 60% of the BL cases diagnosed each year in western countries occur in patients 〉40 years of age. Although adult and pediatric BL cases are indistinguishable by molecular classification, pediatric patients have a significantly better outcome than adults. While translocation of MYC to the immunoglobulin heavy or light chain genes is characteristic of pediatric and adult BL, genetic differences may contribute to the superior clinical outcome of childhood cases. Therefore, we aimed to identify the spectrum of additional genetic abnormalities that occur in adult and pediatric BL. Copy number analysis, gene expression profiling (GEP), and targeted sequencing of ~400 genes known to be mutated in NHLs were performed on a cohort of molecularly defined BL samples. Copy number abnormalities (CNAs) were identified by the Affymetrix 250k NspI SNP array in 73 BL tumors (28 adult, 45 pediatric), and sequencing was performed on 52 BLs (21 adult, 31 pediatric). Pediatric cases had fewer CNAs than adults. The most common focal abnormality identified was a gain on 13q31.3 encompassing MIR17HG. It was more frequent in adult compared to pediatric cases (35% vs 16%, p=0.085) and was associated with increased expression of miR-17~92 cluster members; and among adults, patients with this gain trended towards worse overall survival, though the number of cases with available information was small. Gain of 8q was found in ~20% of adult cases, but in no pediatric cases. Surprisingly, cases with 8q gain had significantly lower MYC mRNA expression (p〈 0.001) and lower protein expression. In cases with MYC gain 0/4 cases were positive for MYC protein expression by immunohistochemistry; in contrast,6/10 cases with no MYC gain were positive for MYC expression. This suggests that gain of 8q is driven by another gene in the region. Additional genetic alterations included gains of genomic loci encompassing MCL1 and MDM4 (1q21-24) and losses encompassing RB1, p53 and CDKN2A/CDKN2B. Pathway analysis of genes differentially expressed by CN status showed an enrichment of genes involved in cell cycle regulation, the p53 signaling pathway, and the ubiquitin proteasome pathway. The frequencies of mutations in commonly mutated genes including MYC, ID3, TP53, CCND3, DDX3X, ARID1A, and TCF3 were not significantly different in adult and pediatric BL. However, BCL2, (43%, p

Description: Introduction: Burkitt Lymphoma (BL) is an aggressive B-cell lymphoma with a translocation involving MYC and immunoglobulin(Ig) loci. It is most common in children, but also affects adults, and occurs in sporadic, endemic and HIV-associated forms. The Epstein-Barr virus (EBV)-associated endemic subtype is the most common pediatric cancer in equatorial Africa, but also occurs in other parts of the world, for example in the rain forest of Brazil. Intensive chemotherapy is effective, but the associated toxicity requires supportive care that is not readily available in resource-poor regions. Previously published molecular characterization of small numbers of tumors indicated that the mutation profiles of endemic and sporadic cases are similar, but not identical. One goal of the BLGSP is to conduct comprehensive molecular characterization of BL by sequencing DNA and RNA from a large BL cohort - including endemic, sporadic, pediatric and adult cases - in order to define the genetic and phenotypic features that drive these cancers. These data will be analyzed with an intent toward developing new therapeutic strategies that can be deployed worldwide. Methods: The goal is to collect 160 BL cases, of which 50% will be endemic, 38% sporadic (pediatric and adult) and 12% from HIV+ patients. For the discovery phase, each tumor requires case-matching normal DNA as well as treatment, outcome and other clinical information. The optimal source of tumor DNA and RNA is from frozen tissue with at least 50% tumor nuclei, but FFPE immobilization is also accepted. Accrual locations include Africa, Brazil, Europe and the US. The BLGSP has developed extensive standard operating procedures for tissue collection, pathology review and tissue processing to reduce the variation associated with these parameters in the interpretation of the results (see https://ocg.cancer.gov/programs/cgci/projects/burkitt-lymphoma). The project also established procedures that allow sharing of all clinical and sample information through the National Cancer Institute Genomic Data Commons (https://gdc.cancer.gov). Molecular characterization includes whole genome sequencing of tumor and normal DNA (80X and 40X coverage, respectively), RNA-sequencing (RNA-seq) and micro-RNA sequencing. These data will enable the BLGSP to identify chromosomal rearrangements, chromosomal copy number alternations, somatic mutations (single nucleotide, insertions, deletions), viral insertions, expression signatures, viral expressions and miRNA regulation of transcripts. Results: To date we have accrued 80 cases of BL of which 75% passed diagnostic pathology review. There was an additional 25% attrition at the tissue processing stage, either due to low quality nucleic acids or low percent tumor nuclei. We have completed sequencing for 45 cases, all but one of which have a MYC translocation involving one of the 3 Ig loci; one case has a MYC rearrangement by FISH analysis that is being characterized further. We have identified recurrent mutations in ID3, DDX3X, ARID1A, FOXO1, TP53, SMARCA4 and other genes. Most mutations are supported by the RNA-seq data, which is also useful in defining the pattern of EBV genome transcription. Preliminary unsupervised hierarchical clustering and principal component analysis of gene expression data defined sample clusters that do not correspond to mutation status or EBV infection, warranting further investigation. Some genes accumulated somatic mutations in a BL subtype-specific fashion. Discussion: BLGSP is an ongoing international collaborative project that will provide a comprehensive molecular portrait of BL subtypes when completed, with the potential to suggest new molecular targets for therapy that can eventually lead to effective treatments that are less toxic than the current regimens. Disclosures Casper: Janssen: Consultancy, Research Funding; Roche: Consultancy, Other: Travel, Accommodation, Expenses; TempTime: Consultancy, Other: Travel, Accommodation, Expenses; Up to Date: Patents & Royalties; GSK: Other: Travel, Accommodation, Expenses. Abramson:Kite Pharma: Consultancy; Abbvie: Consultancy; Seattle Genetics: Consultancy; Gilead: Consultancy. Noy:Pharmacyclics, LLC, an AbbVie Company: Other: travel, accommodations, expenses, Research Funding.