ALBERT

Description: SGN-30 is a monoclonal antibody directed against the CD30 antigen expressed on some hematologic malignancies. Based on encouraging phase I data, a multicenter phase II study was conducted treating patients with refractory or recurrent CD30-positive ALCL with an ECOG performance status of ≤ 2. Thirty-nine patients (24M, 15F) with ALCL were enrolled, with a median age of 57 (range 23–82) and a median of 3 prior therapies (range 2–5). Nine patients had previously received a stem cell transplant. Eighty-five percent of tumors were negative for ALK, a poor prognostic factor. SGN-30 was administred at 6 mg/kg/wk (90 minute infusion, premedications were not required) for 6 consecutive weeks. After 24 patients were enrolled, the dose was escalated to 12 mg/kg/wk in subsequent patients. (Patients with stable disease or objective response were eligible to receive additional cycles of SGN-30. Five patients received ≥ 2 cycles of SGN-30.) Response assessments, as determined by CT scans, were performed 2 weeks after the last infusion. Best response is shown below: CR PR SD PD Pending Eval ORR *Both CRs have ongoing durations of 〉365 days; both patients received additional cycles of SGN-30. **PRs had durations of 27, 53, 139 and 167 days; two additional patients have ongoing durations of 86+ and 25+ days. ***Three SDs have ongoing durations of 96+, 365+, and 365+ days. Two additional patients had SD for 71 and 174 days. 2* 6** 5*** 24 2 21% Three drug-related toxicities ≥ Grade 3 were reported (each was considered possibly related to SGN-30): 1) lymphopenia, 2) catheter related infection and 3) urticaria. No other significant hematologic or biochemical toxicities have been observed. There was one definitely related serious adverse event (Grade 2) in a patient who experienced a transient exacerbation of his cutaneous lesions after 2 doses of SGN-30 but achieved a partial response after continuing on study. This phase II study represents one of the largest prospectively designed trials in relapsed/refractory ALCL and demonstrates good tolerability and clinically meaningful antitumor activity of SGN-30, especially in ALK negative patients who have a particularly poor prognosis.

Description: Abstract 3727 Poster Board III-663 Deacetylases (DACs) are enzymes that remove the acetyl groups from target proteins, leading to regulation of gene transcription and other cellular processes. Entinostat (SNDX-275) is a novel and potent DAC inhibitor that is selective for class I DACs and is currently undergoing pre-clinical and clinical testing in Hodgkin lymphoma (HL). Potent synergistic anti-tumor activity has been observed by combining less potent DAC inhibitors with bortezomib in pre-clinical models. In our efforts to develop more therapeutic options for refractory/resistant B-cell lymphoma, we evaluated the effects of Eentinostat as a single agent and in combination with bortezomib against B-cell non-Hodgkin's lymphoma (NHL) cell lines and primary NHL cells. Studies were conducted in a panel of 12 NHL cell lines representing various subtypes of B-cell lymphoma (i.e. DLBCL/ABC, DLBCL/GCB, Burkitt's, transformed and MCL), which included: rituximab-[chemotherapy]-sensitive cell lines (RSCL, Raji, RL and DHL-4), rituximab-[chemotherapy]-resistant cell lines (RRCL, Raji-4RH, Raji-2R, RL-4RH, and DHL-4 4RH), and primary lymphoma cells isolated from patients with various subtypes of NHL and HL. Patient-derived tumor cells were isolated from fresh specimens by negative selection using magnetic beads. NHL cells and patient-derived primary cells were exposed to entinostat at different doses (0.01 to 100uM) either alone or in combination with CDDP (1 to 100μM), doxorubicin (4 to 16μM), vincristine (1 to 5μM), or bortezomib (1 to 10nM). Anti-tumor activity was measured after a 24 or 48 hr incubation. In cell lines, changes in mitochondrial potential and cell proliferation were determined by alamar blue reduction using a kinetic assay measuring activity at 4 hr intervals for 24 and 48 hrs. For patient-derived primary NHL cells, changes in ATP content (apoptosis) was determined using the cell titer glow assay. Entinostat was highly active in all the cell lines tested including rituximab-[chemotherapy]-resistant cell lines. The IC50 of Entinostat in the majority of the cells tested was 0.5 to 5uM at 48 hrs. Similar findings were observed in primary tumor cells derived from lymphoma patients. In addition, synergistic activity was observed by combining entinostat and bortezomib in both NHL cell lines, as well as in primary NHL/HL tumor specimens. A lesser degree of augmented anti-tumor activity was also observed when entinostat was combined with cisplatin or doxorubicin (but not vincristine). In summary, our data suggests that entinostat is a novel and potent DAC inhibitor with a wide therapeutic spectrum. Entinostat is capable of inducing cell death against various subtypes of B-cell lymphoma cell lines including RSCL, RRCL, as well as patient-derived primary tumor cells and augments the anti-tumor effects of bortezomib and other chemotherapeutic agents. Given the isoform selectivity of entinostat, the results indicate that HDAC1 and 2 may be the key targets of DAC inhibitors in HL and NHL cells. Ongoing studies are evaluating the mechanisms responsible for the synergistic effects of entinostat plus chemotherapy and will be updated at the annual meeting. Current findings strongly suggest that entinostat added to bortezomib and/or other chemo agents may become a novel and potent strategy in the treatment of aggressive and indolent NHL and HL in the future. Disclosures: No relevant conflicts of interest to declare.

Description: Abstract 3917 Treatment with the anti-CD20 monoclonal antibody rituximab (RTX) has become the standard-of-care for the treatment of B-cell non-Hodgkin lymphoma (NHL). Despite revolutionizing NHL therapy, many patients demonstrate resistance de novo or develop resistance to RTX following treatment with RTX-containing regimens and/or RTX-based maintenance schedules. Ofatumumab (OFA) is a new 2nd-generation CD20 mAb targeting a novel membrane-proximal epitope on the CD20 antigen. OFA has been FDA-approved for the treatment of fludarabine- and alemtuzumab-refractory CLL and is being evaluated in several clinical trials in NHL. To better define OFA's activity, we conducted pre-clinical studies comparing OFA vs. RTX in a panel of RSCL, RRCL, primary lymphoma cells (n=10), and in a lymphoma xenograft model. Antibody-dependant cellular cytotoxicity (ADCC) and complement dependent cytotoxicity (CDC) assays were performed to evaluate differences in activity between RTX and OFA. Lymphoma cells were labeled with 51Cr prior to incubation with RTX or OFA (1 or 10 mg/ml) plus effector cells or human serum respectively. 51Cr-release was measured and the percentage of lysis was calculated. In addition, we evaluated the effect of OFA in the cytotoxic effects of chemotherapy agents (doxorubicin, cisplatin and vincristine) and correlated OFA anti-tumor activity to biomarkers known to affect RTX activity (i.e. CD20, CD55, and CD59 surface expression) using qualitative and quantitative flow cytometry. Competitive binding assays were performed using fluorescent-labeled RTX or OFA. OFA was more potent than RTX in elucidating effective CDC at the doses tested not only in RSCL, but also in all RRCL and in primary tumor cells derived from patients with B-cell lymphoma. OFA and RTX were equally effective in ADCC assays. In RSCL and RRCL, there was a linear decrease in sensitivity to RTX (as evaluated by CDC) with decreasing CD20 expression; in contrast, OFA maintained activity even at the lowest levels of CD20 expression. Furthermore, OFA was active despite high levels of CD59 and CD55. OFA had a higher affinity for CD20 than RTX in RSCL. Pre-incubation of RSCL and RRCL with OFA enhanced the anti-tumor activity of chemotherapy agents as determined by alamar blue reduction. Severe combined immunodeficiency (SCID) mice were inoculated via tail vein with Raji cells (day 0) and assigned to observation versus 4 doses of either OFA or RTX (1 or 10mg/kg/dose). The end point of the study was overall survival. Statistical analysis was performed with Kaplan-Meier survival curves and P values calculated by log-rank test. OFA was more effective in controlling in vivo lymphoma growth than RTX. The median survival for animals treated with OFA (1 or 10mg/kg/dose) [73 days and 78 days] was longer than those treated with RTX [56 days and 61 days] (P=0.04 and P=0.04 respectively). Our data suggest that OFA is more potent than RTX not only in RTX-sensitive but also in RTX-resistant models and potentiates the anti-tumor activity of chemotherapy agents commonly used in the treatment of B-cell NHL. We are continuing our research into defining the mechanisms by which OFA increases the lymphoma cell sensitivity threshold to chemotherapy agents and to novel target-specific small molecule inhibitors. Disclosures: Barth: Genmab: Research Funding. Hernandez-Ilizaliturri:Genmab: Research Funding. Mavis:Genmab: Research Funding. Gibbs:Genmab: Research Funding. Deeb:Genmab: Research Funding. Czuczman:Genmab: Research Funding.

Description: Key Points A subset of DHL patients may be cured, and some patients may benefit from intensive induction. Further investigations into the roles of SCT and novel agents are needed.

Description: Background: Primary cutaneous B-cell lymphoma (PCBCL) refers to B-lymphocyte derived lymphoma that develops in the skin without any extracutaneous involvement at the time of diagnosis. Primary cutaneous follicle center lymphoma (PCFCL), primary cutaneous marginal zone lymphoma (PCMZL), and primary cutaneous large B-cell lymphoma (PCLBCL) are the three major entities of PCBCL under the World Health Organization/European Organization for Research and Treatment of Cancer (WHO/EORTC) classification of cutaneous lymphomas. Current guidelines recommend obtaining staging Positron emission tomography/computed tomography (PET/CT) scan or CT scan for all PCBCL, and bone marrow biopsy for at least PCLBCL-leg type variant. However, evidence supporting these recommendations, especially radiological imaging, is lacking. Methods: Data including demographics, white blood cell (WBC) count at diagnosis, lactate dehydrogenase (LDH) at diagnosis, and results of staging CT-scan, PET/CT-scan, single-photon emission computed tomography scan (SPECT-scan), and bone marrow biopsy were collected through chart review on all patients seen at Roswell Park Cancer Institute between 2001-2016 who presented with a skin lesion and had a biopsy diagnostic of B-cell lymphoma. Patients without any radiological imaging at diagnosis and those diagnosed of diffuse large B-cell lymphoma (DLBCL), marginal zone lymphoma (MZL), or follicular lymphoma (FL) prior to cutaneous manifestation were excluded. Results: 67 patients met criteria for this study of whom 97% were Caucasian and 60% were male. Cutaneous biopsies noted follicle center cell histology (16 patients; 24%), marginal zone histology (32 patients; 48%), or large B-cell histology (19 patients; 29%). Staging CT-scan, functional imaging (PET/CT-scan or SPECT-scan), and bone marrow biopsy were performed for 59 (88%), 48 (72%), and 36 (54%) patients respectively (distribution across B-cell lymphomas shown in Figure 1). Radiological imaging studies were over-interpreted in 13 patients. Radiological imaging upstaged diagnosis in 13 patients (8 DLBCL, 3 MZL, 2 FL) while bone marrow biopsy alone upstaged diagnosis in only 1 patient (DLBCL). Together, work-up upstaged diagnosis in patients with cutaneous high-grade lymphoma (large B-cell lymphoma) significantly more than it did for cutaneous low-grade lymphoma (follicle center cell and marginal zone lymphoma) histology (47% vs. 10%; p=0.0018). Presence of B-symptoms correlated with systemic disease (0 patients with PCBCL vs. 4 patients with systemic disease; p=0.0013). However, age (p=0.059), gender (p=0.5418), WBC (p=0.6676), and LDH (p=0.1736) had no correlation with systemic disease. Conclusion: Our single center retrospective analysis showed that staging work-up including radiological imaging (CT-scan or functional imaging like PET/CT-scan) and bone marrow biopsy upstaged the diagnosis in a small minority (10%) of low-grade cutaneous B-cell lymphomas. However, nearly half (47%) of those with cutaneous large B-cell lymphoma histology were found to have systemic disease upon staging. Given the aggressive disease course of large B-cell lymphomas, staging through radiological imaging and bone marrow biopsy should be pursued as currently recommended. However, for low-grade B-cell lymphomas, where even observation is a reasonable management option in selected stage IV patients, staging radiological imaging and bone marrow biopsies could be avoided unless dictated by clinical judgment. Figure 1 Staging radiologic imaging and bone marrow biopsies (BM bx) performed in patients with cutaneous B-cell lymphoma Figure 1. Staging radiologic imaging and bone marrow biopsies (BM bx) performed in patients with cutaneous B-cell lymphoma Disclosures No relevant conflicts of interest to declare.

Description: PTLD are heterogeneous monoclonal or polyclonal neoplasm usually of B-cell origin with a variable incidence in allogenic bone marrow and solid organ transplant recipients. Due to immunosuppresion in transplant patients, PTLD follows an aggressive course with enhanced treatment-associated toxicity, leading to a overall poor clinical outcome and mortality. Rituximab is a chimeric monoclonal anti-CD20 antibody with known activity in B-cell PTLD and minimal toxicity. A few anecdotal uncontrolled studies and case reports have evaluated the use of rituximab-based therapy for PTLD. In order to define the efficacy and safety of rituximab single agent in the treatment of patients with PTLD we conducted a review of the current available literature and performed a pooled-analysis. We conducted a MEDLINE literature search using Pub med, Ovid software for the key words rituximab, anti-CD20 antibody, PTLD, hematopoetic stem cell transplant (HSCT), solid organ transplant (SOT) and lymphoproliferative disorders on all available published literature analyzed to date (January 1998 to June 30, 2007). Studies involving children (1 year) in most patients (∼70%). Rituximab was used as first line therapy after failure of immunosuppression withdrawal, and patients were initially treated with four weekly doses of rituximab at 375mg/m2. Rituximab was continued as maintenance therapy in responding patients in few studies. The complete response rate (International Workshop Criteria) was 58% (29%–78%), among SOT patients and 70% (66%–83%) among HSCT patients. Side effects were minimal and no treatment related deaths were attributed to rituximab. Long term follow up from 2 prospective studies demonstrate a durable remission in 30%–37% SOT patients at 5 years. Limited evidence exists for optimal treatment approach in PTLD. Clinical heterogeneity among small number of patients diagnosed makes it difficult to conduct randomized prospective studies in this disorder. Our study is the first pooled analysis evaluating the role of rituximab in PTLD. Minimal toxicity with good efficacy favors rituximab’s use among patients with less aggressive PTLD who fail or unable to tolerate withdrawal of immunosuppression.

Description: We conducted an international phase 2 trial to evaluate 2 dose levels of ofatumumab, a human CD20 mAb, combined with fludarabine and cyclophosphamide (O-FC) as frontline therapy for chronic lymphocytic leukemia (CLL). Patients with active CLL were randomized to ofatumumab 500 mg (n = 31) or 1000 mg (n = 30) day 1, with fludarabine 25 mg/m2 and cyclophosphamide 250 mg/m2 days 2-4, course 1; days 1-3, courses 2-6; every 4 weeks for 6 courses. The first ofatumumab dose was 300 mg for both cohorts. The median age was 56 years; 13% of patients had a 17p deletion; 64% had β2-microglobulin 〉 3.5 mg/L. Based on the 1996 National Cancer Institute Working Group (NCI-WG) guidelines, the complete response (CR) rate as assessed by an independent review committee was 32% for the 500-mg and 50% for the 1000-mg cohort; the overall response (OR) rate was 77% and 73%, respectively. Based on univariable regression analyses, β2-microglobulin and the number of O-FC courses were significantly correlated (P 〈 .05) with CR and OR rates and progression-free survival (PFS). The most frequent Common Terminology Criteria (CTC) grade 3-4 investigator-reported adverse events were neutropenia (48%), thrombocytopenia (15%), anemia (13%), and infection (8%). O-FC is active and safe in treatment-naive patients with CLL, including high-risk patients. This trial was registered at www.clinicaltrials.gov as NCT00410163.

Description: Despite the improved outcome in patients with DLBCL treated with rituximab (R) in combination with systemic chemotherapy (R + chemotherapy), a significant number of patients either relapse or fail to respond as a consequence of resistant disease. HDC and ASCT is the best therapeutic strategy to rescue relapsed/refractory DLBCL. It has been postulated that R+chemotherapy may lead to the selection of highly resistant lymphoma cells diminishing the clinical benefit of HDC and ASCT. Preliminary data from the CORAL study (Gisselbrecht et al Blood2007; 11:517a) suggest that overall response rates (ORR) and 2-year event free survival (EFS) are lower in R+chemotherapy relapsed/ refractory DLBCL when compared to DLBCL treated with chemotherapy alone. However the second randomization of this study to observation versus R-maintenance may affect the interpretation of the data. We retrospectively studied the difference in the outcomes of relapsed/refractory DLBCL patients following HDC and ASCT according to the front line therapy utilized (R+chemotherapy versus chemotherapy). Using the Roswell Park Cancer Institute (RPCI) Tumor Registry and the RPCI Blood and Marrow Transplant (BMT) Database we identified 130 patients with relapsed/refractory NHL who underwent for HDC + ASCT from 1991 to 2008. After excluding patients with a diagnosis other than B-cell DLBCL (patients with transformed NHL were excluded) and those patients receiving allo-BMT after progression from ASCT, the analysis included 63 refractory/ relapsed DLBCL. Demographic characteristics, clinical data, treatment history in the front line and salvage setting were collected. In addition response to salvage therapy and disease status at day +100 from ASCT was recorded for each subject. Progression free and overall survival were calculated from ASCT. Differences in clinical outcomes between patients receiving R as part of first line or salvage treatment and those treated with chemotherapy alone were evaluated by multivariate analysis, adjusting for significant univariate predictors of survival. The patient cohort included 34 males and 29 females with median age of 46 yrs (14.4 to 69.4). Two-thirds of the patients had advance disease and the majority had a Karnofsky performance status (KPS) of 80–100% at diagnosis. R+chemotherapy was given in the front line setting to 25 pts and while 38 received chemotherapy alone. In the salvage setting, 35 pts (55%) received R+chemotherapy. Most relapses (44 pts) occurred within 6 months of completion of front line therapy (17 pts with vs. 27 pts without R). The use of R in the front line setting was associated with significantly higher response rates (PR + CR) to salvage chemotherapy (P = 0.036) and better disease control on day +100 post-ASCT (P = 0.016) when compared to chemotherapy alone. In our cohort, there have been 32 deaths, 23 in chemotherapy treated DLBCL in contrast to 9 deaths in R+chemotherapy treated patients There was a significantly higher response rate post-ASCT for R+chemotherapy treated (as front-line or salvage) DLBCL versus chemotherapy alone (P = 0.007). A multivariate analysis demonstrated that achieving a CR pre-ASCT was the most important predictor of post-ASCT progression free and overall survival . In summary, our data suggest that the use of R + chemotherapy during frontline therapy and in the salvage setting yields better disease control and less incidence of chemo-resistant disease at the time of BMT. Applying the natural selection theory, the use of R+chemotherapy is expected to result in the development of resistant lymphomas. The length of time and the amount of R therapy that will render lymphoma cells resistant to chemo-immunotherapy remain to be determined. Standard doses of R (6 to 8 doses) do not appear to affect response to salvage therapy or autologous BMT outcomes. In our single institution analysis over the last 18 years, it appears that HDC + ASCT is an effective and viable option for patients with R +/− chemotherapy relapsed/refractory DLBCL.

Description: Resistance to currently available therapies is a major impediment to the successful treatment of hematological malignancies. Here, we used a model of therapy-resistant B-cell nonHodgkin lymphoma (B-NHL) developed in our laboratory along with primary B-NHL cells to study basic mechanisms of bortezomib activity. In resistant cells and a subset of primary B-NHLs, bortezomib treatment led to stabilization of Bak and subsequent Bak-dependent activation of apoptosis. In contrast to sensitive cells that die strictly by apoptosis, bortezomib was capable of killing resistant cells through activation of apoptosis or caspase-independent mechanism(s) when caspases were pharmacologically inhibited. Our data demonstrate that bortezomib is capable of killing B-NHL cells via multiple mechanisms, regardless of their basal apoptotic potential, and contributes to growing evidence that proteasome inhibitors can act via modulation of B-cell lymphoma 2 (Bcl-2) family proteins. The capacity of bortezomib to act independently of the intrinsic apoptotic threshold of a given B-NHL cell suggests that bortezomib-based therapies could potentially overcome resistance and result in relevant clinical activity in a relapsed/refractory setting.