Human Anaplastic Large Cell Lymphoma Research Articles

Abstract 3337: Preclinical activity of NVL-655 in ALK-driven cancer models beyond non-small cell lung cancer

Abstract The ALK receptor tyrosine kinase can be aberrantly activated by gene fusions, point mutations, or amplification to promote cancer. ALK fusions are detected in approximately 5% of advanced non-small cell lung cancers (NSCLC), 50% of inflammatory myofibroblastic tumors, 50% of adult and 90% of childhood anaplastic large cell lymphomas, and rare cases of cholangiocarcinomas. Over 90 fusion partners of ALK have been identified, each exerting a different influence on the biochemical properties of the fusion protein and its preclinical sensitivity to ALK inhibitors. Besides fusions, ALK point mutations and amplification account for up to 14% and 2% of sporadic neuroblastomas, respectively, with most activating mutations occurring at residues F1174, F1245, or R1275. Some activating mutations, such as those occurring at F1174 and I1171, also confer resistance to FDA-approved ALK inhibitors. Because ALK plays an oncogenic role in diverse cancer types, it is an important therapeutic target for other indications beyond NSCLC. NVL-655 is a novel, brain-penetrant ALK-selective inhibitor that exhibits preclinical activity against ALK alterations, including resistance mutations, while also sparing inhibition of TRKB. TRKB inhibition in the central nervous system has been implicated in adverse events observed with FDA-approved ALK inhibitor lorlatinib. We previously reported the preclinical activity of NVL-655 in several NSCLC models bearing ALK-fusions, including human cell lines, a human cell-line derived xenograft, and a patient-derived xenograft. Here we report a broader characterization of NVL-655 in ALK-driven cancer models beyond NSCLC, alongside other ALK inhibitors that are either FDA-approved or in development. In biochemical assays, NVL-655 showed potent inhibition (IC50 < 10 nM) of ALK with mutations at residues 1151, 1174, or 1275, all of which have been identified in neuroblastoma. In cell-based assays, NVL-655 was observed to inhibit proliferation of a human anaplastic large cell lymphoma cell line harboring NPM1-ALK fusion and human neuroblastoma cell lines harboring ALK activating mutations or amplification. In conclusion, the preclinical profile of NVL-655 supports its potential to address a medical need for patients with ALK-driven disease in both NSCLC and other cancers such as anaplastic large cell lymphoma and neuroblastoma. Citation Format: Anupong Tangpeerachaikul, Ludovic Bigot, Luc Friboulet, Henry E. Pelish. Preclinical activity of NVL-655 in ALK-driven cancer models beyond non-small cell lung cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3337.

NIPA (Nuclear Interaction Partner of ALK) Is Crucial for Effective NPM-ALK Mediated Lymphomagenesis.

The NPM-ALK fusion kinase is expressed in 60% of systemic anaplastic large-cell lymphomas (ALCL). A Nuclear Interaction Partner of ALK (NIPA) was identified as a binding partner of NPM-ALK. To identify the precise role of NIPA for NPM-ALK-driven lymphomagenesis, we investigated various NPM-ALK+ cell lines and mouse models. Nipa deletion in primary mouse embryonic fibroblasts resulted in reduced transformation ability and colony formation upon NPM-ALK expression. Downregulating NIPA in murine NPM-ALK+ Ba/F3 and human ALCL cells decreased their proliferation ability and demonstrated synergistic effects of ALK inhibition and NIPA knockdown. Comprehensive in vivo analyses using short- and long-latency transplantation mouse models with NPM-ALK+ bone marrow (BM) revealed that Nipa deletion inhibited NPM-ALK-induced tumorigenesis with prolonged survival and reduced spleen colonies. To avoid off-target effects, we combined Nipa deletion and NPM-ALK expression exclusively in T cells using a lineage-restricted murine ALCL-like model resembling human disease: control mice died from neoplastic T-cell infiltration, whereas mice transplanted with Lck-CreTG/wtNipaflox/flox NPM-ALK+ BM showed significantly prolonged survival. Immunophenotypic analyses indicated a characteristic ALCL-like phenotype in all recipients but revealed fewer “stem-cell-like” features of Nipa-deficient lymphomas compared to controls. Our results identify NIPA as a crucial player in effective NPM-ALK-driven ALCL-like disease in clinically relevant murine and cell-based models.

Systemic Anaplastic Large T-Cell Lymphoma with Initial Presentation of Dysuria in a Dog

A 6-year-old spayed female Akita Dog had dysuria, severe urinary retention and miliary masses in the vagina. Computed tomography revealed a mass at the urethrovaginal junction. The dog died 2 months after initial presentation. At necropsy, the urethrovaginal mass was greyish‒white, solid and 9×6×6cm in size with circumferential thickening of the urethral wall. Multiple whitish nodules were seen in the visceral organs and skin. Histopathologically, the urethrovaginal mass comprised a diffuse population of medium-sized to large round neoplastic cells with ovoid to bean-shaped nuclei and eosinophilic cytoplasm. Aberrantly large neoplastic cells with eccentric, horseshoe-shaped or irregularly-shaped nuclei and abundant eosinophilic cytoplasm resembled 'hallmark cells' of human anaplastic large cell lymphoma. Similar neoplastic lesions were present in all the grossly visible masses. Neoplastic cells were diffusely immunopositive for CD3 and occasionally for CD30 and granzyme B. On the basis of the clinical, pathological and immunohistochemical findings, the case was diagnosed as systemic anaplastic large cell lymphoma arising from the lower urinary tract.

The Role of IgM Antibodies in T Cell Lymphoma Protection in a Novel Model Resembling Anaplastic Large Cell Lymphoma.

MRL/lpr mice typically succumb to immune complex-mediated nephritis within the first year of life. However, MRL/lpr mice that only secrete IgM Abs because of activation-induced deaminase deficiency (AID-/-MRL/lpr mice) experienced a dramatic increase in survival. Further crossing of these mice to those incapable of making secretory IgM (μS mice) generated mice lacking any secreted Abs but with normal B cell receptors. Both strains revealed no kidney pathology, yet Ab-deficient mice still experienced high mortality. In this article, we report Ab-deficient MRL/lpr mice progressed to high-grade T cell lymphoma that can be reversed with injection of autoreactive IgM Abs or following adoptive transfer of IgM-secreting MRL/lpr B cells. Anti-nuclear Abs, particularly anti-dsDNA IgM Abs, exhibited tumor-killing activities against a murine T cell lymphoma cell line. Passive transfers of autoreactive IgM Abs into p53-deficient mice increased survival by delaying onset of T cell lymphoma. The lymphoma originated from a double-negative aberrant T cell population seen in MRL/lpr mice and most closely resembled human anaplastic large cell lymphoma. Combined, these results strongly implicate autoreactive IgM Abs in protection against T cell lymphoma.

Phase I Study of Yttrium-90 Labeled ANTI-CD25 (aTac) Monoclonal Antibody PLUS BEAM for Autologous Hematopoietic Cell Transplantation (AHCT) in Patients with Mature T-Cell NON-Hodgkin Lymphoma, the “a-TAC-BEAM Regimen”

Background: Peripheral T cell lymphomas (PTCL) have a poor prognosis with current treatment regimens. High-dose chemotherapy followed by autologous stem cell transplant (ASCT) has been used as a consolidation strategy in remission states (CR1 or above) endorsed by the NCCN guidelines in appropriate patients. 5-year DFS is reported at 70% for alk -ve anaplastic large cell lymphoma (ALCL) and 30-40% for most other histologies (D'Amore et al, 2012, JCO). It is also performed in the relapsed settings if no previous ASCT performed and allogeneic transplant is not an option. CD25 is a targetable protein expressed differentially in PTCL and antibody based anti-CD25 therapies are efficacious in PTCL i.e denileukin diftitox (Foss et al Blood 2006, Dang et al, BJH 2006) , monoclonal antibody dacluzimab (Waldman et al 1995 Blood). Yttrium-90 (90Y) labeled chimeric antiCD25 antibody basiliximab emits beta particles and has been shown to inhibit the growth of human ALCL tumors and increase survival in SUDHL-1 xenograft mice (Zhang et al 2009 Cancer Biother Radiopharm). Previous investigations at COH by Raubitschek, Colcher et al established a safe does of Yttrium-90 (90Y) labeled basiliximab at 0.4mCi/kg in combination with BEAM. This is a phase 1 clinical trial of a novel conditioning regimen that includes the use of Yttrium-90 (90Y) labeled basiliximab with BEAM chemotherapy for PTCL patients eligible for ASCT. The trial utilizes a modified version of the rolling 6 design (Skolnik et al) to test 3 dose levels of Yttrium-90 (90Y) Basiliximab i.e 0.4mCi/kg, 0.5miC/kg and 0.6mCi/kg with the primary objective of evaluating the safety and tolerability of this combination and to establish the MTD. Secondary objectives include estimating incidence of relapse, OS, PFS, NRM at day 100, 1 year and 2 years post-transplant. Patients and Methods: Dose limiting toxicity (DLT) is defined according to the Bearman and CTCAE 4.03 scales, the latter for hematologic toxicity. The study/treatment schema is shown in Figure 1. Results: From 07/29/2015 to 06/10/2020, 20 patients underwent ASCT on this trial; n=4 at 0.4mCi/kg n=4 at 0.5mCi/kg and n=12 at 0.6mCi/kg. Median age at ASCT was 51 years (range: 18-76), and histologies included; PTCL-nos (n=10); alk-ve ALCL (n=5); angioimmunoblastic T-cell lymphoma (n=3); and intestinal T-cell lymphoma (n=2). Disease status at ASCT were CR1 in18, CR2 in 2 patients. Median number of prior therapies was 1 (range: 1-4). At a median follow-up of 17.1 months (range: 0.9-26.2), 12 patients remain in remission, 8 have relapsed out of which 5 have died of progressive lymphoma. OS was 100% (95% CI: N/A) at 100-days, and 83% (95% CI: 57-94) at 1 year. Non-relapse Mortality was 0% at both 100-days and 1-year. All patients successfully engrafted with the median days to ANC >= 500/ul was 10 (range: 10 - 21), and days to PLT >= 20,000/ul: 13 (12 - 92). Overall, no dose limiting toxicities were experienced. The most common/highest grade toxicity experienced (per Bearman Scale) was grade 2 stomatitis, which was seen in 3 patients at 0.4mCi/kg; 4 patients at 0.5 mCi/kg, and 7 at0.6mCi/kg. The only other toxicities seen were grade 2 GI in 2 patients at 0.4mCi/kg, and grade 2 bladder in one patient at 0.6mCi/kg dose.. Toxicities >grade 2 were not seen. Conclusion: aTac- BEAM appears to be safe as an ASCT conditioning regimen for PTCL with no increased toxicity as compared to the historical toxicities seen with BEAM alone in this patient population (D'Amore 2012 J of Clin Onc). The dose level 0.6mCi/kg will likely be the recommended phase II dose. An expanded phase is planned to evaluate the efficacy of this regimen followed by a randomized trial of BEAM alone plus a combination of aTac- BEAM. Figure 1 Disclosures Zain: Mundi Pharma: Research Funding; Seattle Genetics: Research Funding; Kyowa Kirin: Research Funding. Herrera:Gilead Sciences: Consultancy, Research Funding; Seattle Genetics: Consultancy, Research Funding; Immune Design: Research Funding; AstraZeneca: Research Funding; Karyopharm: Consultancy; Pharmacyclics: Research Funding; Genentech, Inc./F. Hoffmann-La Roche Ltd: Consultancy, Research Funding; Bristol Myers Squibb: Consultancy, Other: Travel, Accomodations, Expenses, Research Funding; Merck: Consultancy, Research Funding. Salhotra:Kadmon: Membership on an entity's Board of Directors or advisory committees; Celgene: Research Funding. Nakamura:NapaJen Pharma: Consultancy; Celgene: Other: Support on seminar; Magenta Therapeutics: Other: Advisory board meeting; Viracor: Consultancy; Merck: Other: advisory board meeting; Alexion: Other: Support on a meeting presentation; Kyowa-Kirin: Other: Support on a meeting presentation; Kadmon Corporation: Other: Advisory board meeting. OffLabel Disclosure: Yittrium labelled Basiliximab

Recombinant expression, characterization, and quantification in human cancer cell lines of the Anaplastic Large-Cell Lymphoma-characteristic NPM-ALK fusion protein

Systemic anaplastic large cell lymphoma (ALCL) is an aggressive T-cell lymphoma most commonly seen in children and young adults. The majority of pediatric ALCLs are associated with the t(2;5)(p23;q35) translocation which fuses the Anaplastic Lymphoma Kinase (ALK) gene with the Nucleophosmin (NPM) gene. The NPM-ALK fusion protein is a constitutively-active tyrosine kinase, and plays a major role in tumor pathogenesis. In an effort to advance novel diagnostic approaches and the understanding of the function of this fusion protein in cancer cells, we expressed in E. coli, purified and characterized human NPM-ALK fusion protein to be used as a standard for estimating expression levels in cultured human ALCL cells, a key tool in ALCL pathobiology research. We estimated that NPM-ALK fusion protein is expressed at substantial levels in both Karpas 299 and SU-DHL-1 cells (ca. 4–6 million molecules or 0.5–0.7 pg protein per cell; based on our in-house developed NPM-ALK ELISA; LOD of 40 pM) as compared to the ubiquitous β-actin protein (ca. 64 million molecules or 4.5 pg per lymphocyte). We also compared NPM-ALK/ β-actin ratios determined by ELISA to those independently determined by two-dimensional electrophoresis and showed that the two methods are in good agreement.

Examining the Role of CD30 in an Anaplastic Large Cell Lymphoma Mouse Model

Anaplastic large cell lymphoma (ALCL) represents a heterogeneous group of T-cell non-Hodgkin lymphoma (NHL) mainly affecting children and young adults. About 70% of systemic ALCLs are associated with a characteristic chromosomal translocation, t(2;5)(p23;35) which fuses the anaplastic lymphoma kinase (ALK) gene on chromosome 2 with the nucleophosmin (NPM) gene on chromosome 5, resulting in the NPM-ALK fusion gene, its over-expression and constitutive kinase activity. Immunophenotypic characterization of human ALCL revealed highly CD30-positive cells of T- or Null-Cell-origin and resulted in promising clinical trials with CD30-coupled antibodies. However, the impact of CD30 on disease development remains unclear and the relationship between NPM-ALK and CD30 has been investigated mostly using cell line models. Syngeneic mouse models of cancer can serve as useful models since the tumors develop in situ where the contribution made by the immune system and the extracellular matrix can be investigated. Here, we focus on the involvement of CD30 in a retroviral murine bone marrow transplantation model of ALCL. In this model, the BM of Lck-Cre-transgenic mice is infected with a MSCV-Stop-NPM-ALK-IRES-EGFP vector leading to expression of NPM-ALK in early T-cells. With a latency of 3-4 months, mice develop lymphomas and die from neoplastic T-cell-infiltration of BM and lymphatic organs. To investigate the impact of abrogation of CD30 signals on the development of NPM-ALK+ ALCL in our model, CD30 knockout mice were crossed with Lck-Cre mice. Both Lck-Cre NPM-ALK CD30 wt and Lck-Cre NPM-ALK CD30 ko recipients develop a human ALCL-like lymphoma with a pure T-cell phenotype characterized by Thy1.2+ cells infiltrating the thymus, lymph nodes, spleen and BM. First results from Lck-Cre NPM-ALK CD30 ko transplanted mice showed impaired disease induction and prolonged survival compared to CD30 wt animals. Moreover, secondary transplantation of NPM-ALK thymic lymphomas led to distinct deceleration of disease development upon CD30 deletion. Microarray analyses have shed some light on the mechanisms underlying the delayed lymphoma progression of CD30 deleted tumors with an upregulation of inflammatory pathways and proteins that are master players in inflammation and immune responses. Further characterization of the role of CD30-mediated immune response in disease progression using this mouse model and immunocompromised mice is ongoing. An improved understanding of how the immune system affects tumor progression will extend the rationale in translational strategies to use immunotherapies for patients with T-NHLs. Disclosures No relevant conflicts of interest to declare.

Preclinical Evaluation of Gilteritinib on NPM1-ALK Driven Anaplastic Large Cell Lymphoma Cells

Anaplastic large cell lymphoma (ALCL) is an aggressive type of non-Hodgkin's lymphoma (NHL) comprising 2-8% of adult and 10-20% of pediatric and adolescent NHL. More than three-fourths of anaplastic lymphoma kinase (ALK)-positive ALCL express (nucleophosmin1) NPM1-ALK fusion gene as a result of t(2;5) chromosomal translocation. The self-dimerization of fusion kinase NPM1-ALK mediates constitutive activation of the chimeric tyrosine kinase activity leading to downstream signaling pathways responsible for lymphoma cell proliferation and survival. The current standard treatment regimen for ALK+ ALCL is CHOP (cyclophosphamide, hydroxy doxorubicin, vincristine, prednisone) chemotherapy. Oftentimes, resistance and failure of remission occur with CHOP therapy, making it a suboptimal treatment regimen for many patients. Therefore, an alternative therapeutic approach is warranted to better address the needs of the ALK+ ALCL population. Gilteritinib is a recently FDA approved tyrosine kinase inhibitor for the treatment of FMS-like tyrosine kinase (FLT3) mutation-positive acute myeloid leukemia. Along with inhibition of FLT3, gilteritinib also inhibits other tyrosine kinases such as AXL and ALK. In this study, for the first time, we demonstrated gilteritinib mediated growth inhibitory effects on NPM1-ALK driven ALCL cells. We have used a total of five cell lines in our study: NPM1-ALK endogenously expressing human ALCL cell lines (SUDHL-1, SUP-M2, SR-786, and DEL), and our laboratory generated ectopically overexpressing Ba/F3-FG-NPM1-ALK, a murine cell line. Gilteritinib treatment (5-20 nM) inhibited NPM1-ALK fusion kinase phosphorylation, which resulted in downregulation of downstream survival signaling pathways including AKT, ERK1/2, and STAT3 leading to induced apoptosis and decreased clonogenic survival. Gilteritinib mediated apoptosis was associated with caspase 3/9 and poly (ADP-ribose) polymerase cleavage with increased pro-apoptotic protein BAD and decreased anti-apoptotic protein MCL-1. Increased expression of c-Myc is associated with ALK-positive ALCL and gilteritinib treatment decreased c-Myc levels in a dose dependent manner. Cell cycle analysis demonstrated gilteritinib treatment induced cell cycle arrest at the G0/G1 phase with a concomitant decrease in G2/M and S phases. In summary, our preclinical results suggest gilteritinib has therapeutic potential for the treatment of ALCL cells expressing NPM1-ALK and other ALK /ALK-fusion driven hematologic or solid malignancies. Disclosures Lin: Jazz Pharmaceuticals: Honoraria; Pfizer: Membership on an entity's Board of Directors or advisory committees. Ganguly:Daiichi Sankyo: Research Funding; Seattle Genetics: Speakers Bureau; Janssen: Honoraria, Other: Advisory Board; Kite Pharma: Honoraria, Other: Advisory Board. McGuirk:ArticulateScience LLC: Other: Assistance with manuscript preparation; Juno Therapeutics: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Bellicum Pharmaceuticals: Research Funding; Astellas: Research Funding; Novartis: Research Funding; Fresenius Biotech: Research Funding; Pluristem Ltd: Research Funding; Gamida Cell: Research Funding; Kite Pharmaceuticals: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau.

A novel ALK inhibitor ZYY inhibits Karpas299 cell growth in vitro and in a mouse xenograft model and induces protective autophagy

In recent years, anaplastic lymphoma kinase (ALK) rearrangement-positive anaplastic large cell lymphoma (ALCL) has rising morbidity and mortality. Unfortunately, no ALK inhibitor has been approved by the FDA for single treatment of ALK rearrangement-positive ALCL. In this study, we investigated the antitumor effect of ZYY, a novel ALK inhibitor, showing a strong growth inhibitory effect on Karpas299 cells in vitro and in vivo. Specifically, ZYY significantly reduced the mRNA and protein expression of ALK and its downstream signaling proteins in Karpas299 cells. Furthermore, ZYY induced G1 phase arrest and promoted apoptosis in Karpas299 cells. Furthermore, we demonstrated that ZYY-induced apoptosis was mainly related to the mitochondria-dependent endogenous pathway. In vitro studies further showed that ZYY induced autophagy in Karpas299 cells, along with increased levels of the autophagy-related proteins, including LC3II and Beclin-1. Moreover, knockdown Beclin-1 and application of autophagy inhibitor chloroquine potentiated ZYY-induced cytotoxicity and apoptosis in vitro, indicating that cytoprotective autophagy might be triggered by ZYY in Karpas299 cells. Taken together, the novel ALK inhibitor ZYY has tremendous potential for treating human ALCL, and a combination of autophagy and ALK inhibition could effectively elicit potent antitumor effects.

Phase I Study of Yttrium-90 Labeled ANTI-CD25 (aTac) Monoclonal Antibody PLUS BEAM for Autologous Hematopoietic CELL Transplantation (AHCT) in Patients with Mature T-CELL NON-Hodgkin Lymphoma, the “a-TAC-BEAM Regimen”

Background: Peripheral T cell lymphomas (PTCL) have a poor prognosis with current treatment regimens. High-dose chemotherapy followed by autologous stem cell transplant (ASCT) has been used as a consolidation strategy in remission states (CR1 or above) endorsed by the NCCN guidelines in appropriate patients. 5 year DFS is reported at 70% for alk -ve anaplastic large cell lymphoma (ALCL) and 30-40% for most other histologies (D'Amore et al, 2012, JCO). It is also performed in the relapsed settings if no previous ASCT performed and allogeneic transplant is not an option. CD25 is a targetable protein expressed differentially in PTCL and antibody based anti-CD25 therapies are efficacious in PTCL i.e denileukin diftitox (Foss et al Blood 2006, Dang et al , BJH 2006) , monoclonal antibody dacluzimab (Waldman et al 1995 Blood). Yttrium-90 (90Y) labeled chimeric antiCD25 antibody basiliximab emits beta particles and has been shown to inhibit the growth of human ALCL tumors and increase survival in SUDHL-1 xenograft mice (Zhang et al 2009 Cancer Biother Radiopharm). Previous investigations at COH by Raubitschek, Colcher et al established a safe does of Yttrium-90 (90Y) labeled basiliximab at 0.4mCi/kg in combination with BEAM. This is a phase 1 clinical trial of a novel conditioning regimen that includes the use of Yttrium-90 (90Y) labeled basiliximab with BEAM chemotherapy for PTCL patients eligible for ASCT. The trial utilizes a modified version of the rolling 6 design (Skolnik et al) to test 3 dose levels of Yttrium-90 (90Y) Basiliximab i.e 0.4mCi/kg, 0.5miC/kg and 0.6mCi/kg with the primary objective of evaluating the safety and tolerability of this combination and to establish the MTD. Secondary objectives include incidence of relapse, OS, PFS, NRM at day 100, 1 year and 2 years post-transplant.Patients and Methods: Dose limiting toxicity (DLT) is defined according to the Bearman and CTCAE 4.03 scales, the latter for hematologic toxicity. The study/treatment schema is shown in Figure 1.Results: From 07/29/2015 to 05/29/2018, 14 patients underwent ASCT on this trial; n=4 at 0.4mCi/kg n=4 at 0.5mCi/kg and n=6 at 0.6mCi/kg. Median age at ASCT was 51 years (range: 18-76), and histologies included; PTCL-nos (n=7); alk-ve ALCL (n=3); angioimmunoblastic T-cell lymphoma (n=2); and intestinal T-cell lymphoma (n=2). Disease status at ASCT were CR1 in12, CR2 in 2 patients. Median number of prior therapies was 1 (range: 1-2). At a median follow-up of 14.4 months (range: 0.9-26.2), 8 patients remain in remission, 4 have relapsed out of which 2 have died of progressive lymphoma. OS was 100% (95% CI: N/A) at 100-days, and89% (95% CI: 43-98) at 1 year. Non-relapse Mortality was 0% at both100-days and 1-year (95%CI: N/A) (95%CI: N/A). All patients successfully engrafted with the median days to ANC >= 500/ul was 11 (range: 10 - 12), and days to PLT >= 20,000/ul: 13 (12 - 92). No dose limiting toxicities were experienced. The most common/highest grade toxicity experienced (per Bearman Scale) was grade 2 stomatitis, which was seen in 3 patients at 0.4mCi/kg; 4 patients at 0.5 mCi/kg, and 3 at0.6mCi/kg. The only other toxicities seen were grade 2 GI in 2 patients at 0.4mCi/kg,and grade 2 bladder in one patient at 0.6mCi/kg dose.. Toxicities >grade 2 were not seen. Conclusion: aTac- BEAM appears to be safe as an ASCT conditioning regimen for PTCL with no increased toxicity as compared to the historical toxicities seen with BEAM alone in this patient population (D'Amore 2012 J of Clin Onc). The dose level 0.6mCi/kg will likely be the recommended phase II dose. An expanded phase is planned to evaluate the efficacy of this regimen followed by a randomized trial of BEAM alone plus a combination of aTac- BEAM. DisclosuresHerrera:Seattle Genetics: Research Funding; Bristol-Myers Squibb: Consultancy, Research Funding; Genentech: Consultancy, Research Funding; Immune Design: Research Funding; KiTE Pharma: Consultancy, Research Funding; Merck, Inc.: Consultancy, Research Funding; Pharmacyclics: Consultancy, Research Funding; AstraZeneca: Research Funding; Gilead Sciences: Research Funding. Salhotra:Kadmon Corporation, LLC: Consultancy.

Dependency on the TYK2/STAT1/MCL1 axis in anaplastic large cell lymphoma

TYK2 is a member of the JAK family of tyrosine kinases that is involved in chromosomal translocation-induced fusion proteins found in anaplastic large cell lymphomas (ALCL) that lack rearrangements activating the anaplastic lymphoma kinase (ALK). Here we demonstrate that TYK2 is highly expressed in all cases of human ALCL, and that in a mouse model of NPM-ALK-induced lymphoma, genetic disruption of Tyk2 delays the onset of tumors and prolongs survival of the mice. Lymphomas in this model lacking Tyk2 have reduced STAT1 and STAT3 phosphorylation and reduced expression of Mcl1, a pro-survival member of the BCL2 family. These findings in mice are mirrored in human ALCL cell lines, in which TYK2 is activated by autocrine production of IL-10 and IL-22 and by interaction with specific receptors expressed by the cells. Activated TYK2 leads to STAT1 and STAT3 phosphorylation, activated expression of MCL1 and aberrant ALCL cell survival. Moreover, TYK2 inhibitors are able to induce apoptosis in ALCL cells, regardless of the presence or absence of an ALK-fusion. Thus, TYK2 is a dependency that is required for ALCL cell survival through activation of MCL1 expression. TYK2 represents an attractive drug target due to its essential enzymatic domain, and TYK2-specific inhibitors show promise as novel targeted inhibitors for ALCL.

PO-182 Examining the function of PDGFRB in anaplastic large cell lymphoma

Introduction Anaplastic large-cell lymphoma (ALCL) is an aggressive non-Hodgkin T-cell lymphoma (NHL) most commonly diagnosed in children and young adults. A majority of ALCL tumours harbour the translocation t( 2;5 (p23;q35), resulting in the fusion of Nucleophosmin ( NPM ) to the Anaplastic lymphoma kinase ( ALK ) gene. The oncogenic fusion protein (NPM-ALK) is constitutively expressed and consequently contributes to the pathogenesis and progression of about 70% of ALCL cases. Recent studies from our lab identified AP-1 transcription factors JUNB and cJUN as downstream effectors of NPM-ALK, which directly up-regulate platelet derived growth factor receptor beta (PDGFRB) expression in lymphoma cells. We demonstrated that besides increased receptor expression its ligand, PDGFB levels are also elevated in both mouse ALCL tumours and human ALCL patient plasma. Furthermore, therapeutic inhibition of PDGFRB with the kinase inhibitor imatinib resulted in rapid and sustained remission in late-stage therapy-resistant ALCL patients. Material and methods Despite these discoveries, the underlying mechanisms and the nature of PDGFRB signalling in lymphoma formation and progression still remain to be resolved. To elucidate the mechanisms of PDGFRB signalling in ALCL, we have crossed a murine ALCL model, which expresses NPM-ALK under the CD4 promoter, to PDGFRB floxed mice and a CD4 promoter driven Cre recombinase, to yield a specific deletion of PDGFRB in T cells ( CD4 -NPM-ALK-CD4 ΔPDGFRB ). Results and discussions Intriguingly, CD4 -NPM-ALK-CD4 ΔPDGFRB mice have significantly prolonged survival rates and reduced tumour growth, due to increased apoptosis. CD4 -NPM-ALK-CD4 ΔPDGFRB tumours exhibit a decrease in lymphatic vessels, which is accompanied by a decrease in tumour dissemination. Moreover, in vivo deletion of PDGFRB results in a decrease in the signal transducer and activator of transcription (STAT) and NPM-ALK signalling pathways dampening tumour aggressiveness. Manipulation of PDGFRB levels in vitro, via CRISPR/Cas9 mediated knockout or overexpression, in primary tumour cell lines isolated from CD4 -NPM-ALK-CD4 and CD4 -NPM-ALK-CD4 ΔPDGFRB mirrors the changes in signalling pathway observed in the tumours in vivo . Conclusion In summary, loss of PDGFRB leads to decreased tumour development and dissemination in a CD4- NPM-ALK mouse model via modulation of the STAT-signalling pathway. Our data therefore supports the oncogenic role of PDGFRB and opens new avenues for therapeutic intervention in ALCL treatment.

Abstract 671: Assessing the origins of anaplastic large cell lymphoma in murine models via forced lineage specificity of NPM-ALK expression in T cells

Abstract Background: Anaplastic large cell lymphoma (ALCL) is a T cell lymphoma representing 10-15% of all childhood non Hodgkin lymphomas, whereby those positive for aberrant expression of Anaplastic Lymphoma kinase (ALK) account for 50-80% of cases. The oncogene Nucleophosmin 1 (NPM)-ALK is considered the main driver of pediatric ALCL identified in 83% of ALK+ cases. ALCL cells rarely express a T cell receptor (TCR), CD4 nor CD8 despite displaying an activated cytotoxic T cell phenotype (production of perforin and Granzyme B). Expression of NPM-ALK in mice from the T-cell specific CD4 promoter (which gives rise to expression throughout thymic development) gives rise to thymic lymphomas not mimicking human ALCL suggesting other events are required for peripheral T cell lymphoma development and/or expression of NPM-ALK at different stages of T cell progression: some theories have revolved around the possibility of an infectious aetiology, or subversion of the development of T cells within the thymus in the pathogenesis of ALCL. Objective: To assess the potential cell of origin of ALCL through lineage restriction of NPM-ALK to defined T cell lineages (CD4 or CD8) using TCR transgenic mice. Experimental procedure: Disease presentation following backcrossing of the CD4/NPM-ALK mouse to a clonal transgenic TCR OT1 (CD4/NPM-ALK/OTI) or OTII (CD4/NPM-ALK/OTII) genetic background in the presence and absence of RAG was monitored. The OTI and OTII transgenic mice express a transgenic TCR which is MHC class I restricted, with a CD8 or MHC class II with a CD4 developmental skew respectively. The TCR in these mice has been engineered to recognise ovalbumin peptides (ova). Results: CD4/NPM-ALK/OTI mice develop peripheral disease histopathologically mimicking human ALCL. Conversely, CD4/NPM-ALK/OTII mice develop cortical thymic lymphomas similar to the parental CD4/NPM-ALK strain and mostly of a CD4 single positive T cell phenotype (64%). Intriguingly, the peripheral T cell tumours that develop in the CD4/NPM-ALK/OTI mice do not express the transgenic OTI TCR (or endogenously rearranged TCR). Additionally, haemopoietic tumors only occur on a RAG competent genetic background or in the absence of ova stimulation even though TCR transgene expressing T cells are detected in the periphery of these mice (CD4/NPM-ALK/OTI + MHV-ova administration or CD4/NPM-ALK/OTI/RAG-/-). Conclusions: These data represent the first murine model resembling human ALCL and suggest that restriction of NPM-ALK to the CD8 T cell lineage results in a disease more closely resembling human ALCL. Furthermore, our data suggest that in the periphery, signaling though the TCR may be pejorative towards peripheral lymphoma development. Citation Format: Tim Malcolm, Camilla J. Fairbairn, Katherine Hughes, Lukas Kenner, Amos Burke, Suzanne Turner. Assessing the origins of anaplastic large cell lymphoma in murine models via forced lineage specificity of NPM-ALK expression in T cells. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 671.

Anaplastic large cell lymphoma arises in thymocytes and requires transient TCR expression for thymic egress.

Anaplastic large cell lymphoma (ALCL) is a peripheral T-cell lymphoma presenting mostly in children and young adults. The natural progression of this disease is largely unknown as is the identity of its true cell of origin. Here we present a model of peripheral ALCL pathogenesis where the malignancy is initiated in early thymocytes, before T-cell receptor (TCR) β-rearrangement, which is bypassed in CD4/NPM–ALK transgenic mice following Notch1 expression. However, we find that a TCR is required for thymic egress and development of peripheral murine tumours, yet this TCR must be downregulated for T-cell lymphomagenesis. In keeping with this, clonal TCR rearrangements in human ALCL are predominantly in-frame, but often aberrant, with clonal TCRα but no comparable clonal TCRβ rearrangement, yielding events that would not normally be permissive for survival during thymic development. Children affected by ALCL may thus harbour thymic lymphoma-initiating cells capable of seeding relapse after chemotherapy.

Sialylation and glycosylation modulate cell adhesion and invasion to extracellular matrix in human malignant lymphoma: Dependency on integrin and the Rho GTPase family.

To determine the biological roles of cell surface glycosylation, we modified the surface glycosylation of human malignant lymphoma cell lines using glycosylation inhibitors. The O-glycosylation inhibitor, benzyl-α-GalNAc (BZ) enhanced the fibronectin adhesion of HBL-8 cells, a human Burkitt's lymphoma cell line, and of H-ALCL cells, a human anaplastic large cell lymphoma cell line, both of which were established in our laboratory. The N-glycosylation inhibitor, tunicamycin (TM) inhibited the surface expression of Phaseolus vulgaris leukoagglutinating (L-PHA) lectin- and Canavalia ensiformis (ConA) lectin-reactive oligosaccharides in the HBL-8 cell line. Assay of the adhesion of HBL-8 cells to fibronectin showed that fibronectin adhesion is mediated by the integrin very late antigen (VLA)-4 and that not only BZ but also TM treatment enhanced HBL-8 cell adhesion to fibronectin. Furthermore, although BZ treatment also enhanced H-ALCL cell adhesion to fibronectin, this effect was not mediated by VLA-5 or the RGD sequence of fibronectin. We also showed that H-ALCL cell adhesion to galectin-3 was enhanced by pre-treatment with neuraminidase, which cleaves cell surface sialic acid. Additionally, H-ALCL cell adhesion to galectin-3 was inhibited by pre-treatment with the RGD peptide suggesting that cell adhesion to galectin-3 is mediated by integrin (VLA-5). Furthermore, H-ALCL cell invasion of galectin-1 and galectin-3 was inhibited by pre-treatment with the RGD peptide. Therefore, cell adhesion to and invasion of galectin-1 and galectin-3 are integrin-dependent. In addition to these findings, cell adhesion to galectin-3 was markedly inhibited by treatment with β-lactose compared to treatment with sucrose. Therefore, interactions between integrins and galectin-3 may be mediated through β-galactose that is linked to glycans of integrins. AZA1, an inhibitor of Ras homolog oncoprotein (Rho) GTPase family proteins, RAS-related C3 botulinus toxin substrate 1 (Rac 1) and Cell division control protein 42 homolog (Cdc42) markedly inhibited cell invasion of galectin-1 and galectin-3 suggesting that Rac 1 and Cdc42 may be involved in the regulation of H-ALCL cell invasion of galectins. In conclusion, artificial modification of cell surface glycosylation revealed the biological roles of glycosylation in the adhesion to and invasion of the extracellular matrix (ECM) by human malignant lymphoma cell lines. These findings will provide new insight into the glycobiology of human malignant lymphoma.

Evidence Suggesting That Discontinuous Dosing of ALK Kinase Inhibitors May Prolong Control of ALK+ Tumors.

The anaplastic lymphoma kinase (ALK) is chromosomally rearranged in a subset of certain cancers, including 2% to 7% of non-small cell lung cancers (NSCLC) and ∼70% of anaplastic large cell lymphomas (ALCL). The ALK kinase inhibitors crizotinib and ceritinib are approved for relapsed ALK(+) NSCLC, but acquired resistance to these drugs limits median progression-free survival on average to ∼10 months. Kinase domain mutations are detectable in 25% to 37% of resistant NSCLC samples, with activation of bypass signaling pathways detected frequently with or without concurrent ALK mutations. Here we report that, in contrast to NSCLC cells, drug-resistant ALCL cells show no evidence of bypassing ALK by activating alternate signaling pathways. Instead, drug resistance selected in this setting reflects upregulation of ALK itself. Notably, in the absence of crizotinib or ceritinib, we found that increased ALK signaling rapidly arrested or killed cells, allowing a prolonged control of drug-resistant tumors in vivo with the administration of discontinuous rather than continuous regimens of drug dosing. Furthermore, even when drug resistance mutations were detected in the kinase domain, overexpression of the mutant ALK was toxic to tumor cells. We confirmed these findings derived from human ALCL cells in murine pro-B cells that were transformed to cytokine independence by ectopic expression of an activated NPM-ALK fusion oncoprotein. In summary, our results show how ALK activation functions as a double-edged sword for tumor cell viability, with potential therapeutic implications.

Sialylation by β-galactoside α-2,6-sialyltransferase and N-glycans regulate cell adhesion and invasion in human anaplastic large cell lymphoma.

The interaction between cell surface glycans and extracellular matrix (ECM) including galectins is known to be closely associated with tumor cell adhesion, invasion and metastasis. We analyzed the roles of cell surface sialylation or glycosylation in galectin or ECM-mediated cell adhesion and invasion of human malignant lymphoma cells. Neuraminidase from Arthrobacter ureafaciens (AU) treatment resulted in reduction of cell adhesion to galectin-8 in human anaplastic large cell lymphoma (H-ALCL) which was established in our laboratory. The knockdown of β-galactoside α-2,6-sialyltransferase (ST6Gal1) by siRNA showed inhibition of ST6Gal1 expression in the cytoplasm of H-ALCL cells on immunohistochemical findings, and showed dramatic enhancement of cell adhesion to galectin-8. On the other hand, α-2,3-specific neuraminidase treatment resulted in moderate enhancement of cell adhesion to galectin-8. We performed chemically artificial modification of cell surface O-glycans by treatment of benzyl 2-acetamido-2-deoxy-α-D-galactopyranoside (Bz-α-GalNAc) in H-ALCL. Cell adhesion to galectin-8 was enhanced by treatment of Bz-α-GalNAc suggesting that inhibition of elongation of O-glycans may enhance cell adhesion to galectin-8 in H-ALCL cells. On the other hand inhibition of elongation of N-glycosylation by tunicamycin (TM) resulted in inhibition of Phaseolus vulgaris-L (L-PHA) lectin-binding activity and inhibited cell adhesion to galectin-8,laminin and fibronectin. Neuraminidase treatment enhanced cell adhesion to laminin, and knockdown of ST6Gal1 resulted in enhancement of cell adhesion to laminin, but not to fibronectin, collagen type 1 and 4. Galectin-8 pre-treatment dramatically enhanced cell adhesion to laminin and neuraminidase treatment also enhanced cell adhesion to laminin in combination with galectin-8. Rho inhibitor, C3-transferase pre-treatment resulted in inhibition of cell invasion to galectin-8. Phosphatidylinositol 3-phosphate kinase (PI3K) inhibitor, wortmannin inhibits the cell invasive capacity to galectin-8. Neuraminidase treatment induces growth inhibition of lymphoma cells by galectin-8.

Identification of the Lymphoma-Initiating Cell Population in a T Cell Lymphoma Mouse Model Resembling Human Anaplastic Large Cell Lymphoma

In 60% of anaplastic large cell lymphoma (ALCL) patients a translocation t(2;5) (p23;q35) is found, which results in NPM-ALK fusion gene expression and constitutive activation of the ALK tyrosine kinase. Immunophenotypic characterization of human ALCLs revealed highly CD30-positive cells of T- or Null-cell-origin. However, the origin of the lymphoma initiating cell population as well as NPM-ALK signal transduction in course of the disease remains unclear.In this regard, we established a retroviral murine bone marrow transplantation model resembling human ALCL. Therefore we use an inducible Cre/loxP system where NPM-ALK expression is restricted to early T cells. We infected bone marrow of Lck-Cre transgenic mice with our MSCV-Stop-NPM-ALK-IRES-EGFP vector and transplanted it into lethally irradiated recipient mice. With a latency of 4-5 months, these mice developed Thy1.2-positive lymphomas and died from neoplastic T cell infiltration of bone marrow and lymphatic organs. Immunophenotypic analysis confirmed T cell origin of the lymphomas with the characteristic high CD30 expression. Staining of the T cell subpopulations demonstrated high NPM-ALK expression in immature CD4-/CD8- double negative T cells and undifferentiated CD4+/CD8+ double positive T cells. Interestingly, FACS-staining for the proliferation marker Ki-67 as well as the activation marker CD30 revealed highest expression in the CD4-/CD8- double negative T cells. Therefore we hypothesized that the lymphoma-initiating cell must be within this early T cell population.To substantiate our hypothesis we performed secondary transplantations with sorted T cell subpopulations and indeed, only the CD4-/CD8- double negative population was able to initiate T cell lymphoma in the recipient mice. Immunophenotypic characterization of the lymphoma population of these secondary transplanted mice revealed undifferentiated T cells of all CD4/CD8 subtypes, which argues for the existence of a lymphoma initiating cell population, which can still partly differentiate. Interestingly the CD4-/CD8- double negative lymphoma population aberrantly expressed the T cell receptor alpha/beta chain, which may allow these early T cells to establish a systemic lymphoma. Further analysis of the lymphoma population showed lymphatic precursors (CLP) as well as multipotent progenitors (MMP) and haematopoetic stem cells (LSK), which suggests early bone marrow or thymic progenitor cells as the pool of the lymphoma-initiating cell population.We therefore were able to prove the existence of lymphoma initiating stem cells in a highly relevant NPM-ALK positive CD30 expressing mouse model of ALCL. Further analysis will give insides into eradication of the identified lymphoma stem cell population by clinical relevant NPM-ALK inhibitors and CD30 immunotoxins. DisclosuresNo relevant conflicts of interest to declare.

Galectin-1-mediated cell adhesion, invasion and cell death in human anaplastic large cell lymphoma: Regulatory roles of cell surface glycans

Galectin-1 is known to be one of the extracellular matrix proteins. To elucidate the biological roles of galectin-1 in cell adhesion and invasion of human anaplastic large cell lymphoma, we performed cell adhesion and invasion assays using the anaplastic large cell lymphoma cell line H-ALCL, which was previously established in our laboratory. From the cell surface lectin array, treatment with neuraminidase from Arthrobacter ureafaciens which cleaves all linkage types of cell surface sialic acid enhanced Arachis hypogaea (PNA), Helix pomatia (HPA) and Phaseolus vulgaris-L (L-PHA) lectin binding reactivity to cell surface of lymphoma cells suggesting that neuraminidase removes cell surface sialic acid. In cell adhesion and invasion assays treatment with neuraminidase markedly enhanced cell adhesion to galectin-1 and decreased cell invasive capacity through galectin-1. α2,6-linked sialic acid may be involved in masking the effect of the interaction between galectin-1 and cell surface glycans. H-ALCL cells expressed the β-galactoside-α2,6-sialyltransferase ST6Gal1. On resialylation assay by recombinant ST6Gal1 with CMP-Neu5Ac, α2,6-resialylation of L-PHA reactive oligosaccharide by ST6Gal1 resulted in inhibition of H-ALCL cell adhesion to galectin-1 compared to the desialylated H-ALCL cells. On knockdown experiments, knockdown of ST6Gal1 dramatically enhanced cell adhesion to galectin-1. N-glycosylation inhibitor swainsonine treatment resulted in enhancement of cell adhesion to galectin-1. In glycomic analysis using the lectin blocking assay treatment with PNA, Artocarpus integrifolia (Jacalin), Glycine max (SBA), Helix pomatia (HPA), Vicia villosa (VVA), Ulex europaeus (UEA-1), Triticum vulgaris (WGA), Canavalia ensiformis (ConA), Phaseolus vulgaris-L (L-PHA), Phaseolus vulgaris-E4 (E-PHA), Datura stramonium (DSA) lectins resulted in modulation of lymphoma cell to galectin-1 suggesting that several types of glycans may regulate cell adhesion to galectin-1 by steric hindrance. The adhesive capacity of H-ALCL cells is regulated by phosphatidylinositol 3 phosphate kinase (PI3K) and actin cytoskeleton, and the invasive capacity of H-ALCL cells is regulated by PI3K, mitogen-activated protein kinase (MAPK), Rho and actin cytoskeleton. Furthermore, galectin-1-induced cell death in H-ALCL cells was accompanied by inhibition of CD45 protein tyrosine phosphatase (PTP) activity. In conclusion, cell adhesion and invasion to galectin-1 appeared to be regulated by cell surface sialylation and N-glycosylation, and galectin-1 regulates cell death through inhibition of CD45 PTP activity of H-ALCL.

A cancer cell-activatable aptamer-reporter system for one-step assay of circulating tumor cells.

The current antibody-mediated numeration assays of circulating tumor cells (CTCs) require multiple steps and are time-consuming. To overcome these technical limitations, a cancer cell-activatable aptamer-reporter was formulated by conjugating a biomarker-specific aptamer sequence with paired fluorochrome-quencher molecules. In contrast to the antibody probes, the intact aptamer-reporter was optically silent in the absence of cells of interest. However, when used in an assay, the aptamer selectively targeted cancer cells through interaction with a specific surface biomarker, which triggered internalization of the aptamer-reporter and, subsequently, into cell lysosomes. Rapid lysosomal degradation of the aptamer-reporter resulted in separation of the paired fluorochrome-quencher molecules. The released fluorochrome emitted bright fluorescent signals exclusively within the targeted cancer cells, with no background noise in the assay. Thus, the assays could be completed in a single step within minutes. By using this one-step assay, CTCs in whole blood and marrow aspirate samples of patients with lymphoma tumors were selectively highlighted and rapidly detected with no off-target signals from background blood cells. The development of the cancer cell-activatable aptamer-reporter system allows for the possibility of a simple and robust point-of-care test for CTC detection, which is currently unavailable.