ALBERT

Beschreibung: Introduction: For patients with relapsed or refractory DLBCL with chemosensitive disease after 2nd line (salvage treatment), AutoHCT is considered the standard of care. Risk factors for progression following AutoHCT include primary refractory disease and early relapse (

Beschreibung: Key Points TP53 3′UTR variations demonstrate prognostic value in DLBCL.

Beschreibung: Context and objective Approximately 5-10% of diffuse large B-cell lymphoma (DLBCL) patients carry MYC gene translocations (MYC-translocation+) with a poor prognosis after standard chemotherapy. MYC-translocation+ DLBCL patients carrying BCL2 translocations (MYC+/BCL2+ double-hit lymphoma) have a worse survival. The efficacy of adjuvant radiotherapy in this setting is unknown. The purpose of this study is to evaluate the efficacy of radiotherapy as a part of the therapeutic regimen for patients with MYC-translocation+ DLBCL. Patients and methods From the International DLBCL R-CHOP consortium program, we selected 581 patients with de novo DLBCL treated with standard R-CHOP immunochemotherapy (diagnosed and treated from 2000 to 2010). We excluded patients with transformed DLBCL, primary mediastinal, cutaneous, testicular or central nervous system large B-cell lymphomas, patients with HIV infection, and patients not treated with R-CHOP. The median follow-up was 54.9 months. Fluorescence in situ hybridization assessing MYC was performed for all the patients (n=581) and results were correlated with available clinical data to identify clinicopathologic features associated with MYC translocation, and to evaluate the prognostic significance of MYC translocations regarding overall survival (OS, from the time of diagnosis to death from any cause) and progression-free survival (PFS, from the time of diagnosis to relapse or death from any cause). In the MYC-translocation+ DLBCL group, 38 patients received chemotherapy alone and 21 patients received chemotherapy with adjuvant radiation therapy. The clinicopathologic features and survival of MYC-translocation+ DLBCL patients treated with (n=21) and without radiotherapy (n=38) after immunochemotherapy were compared to in order to evaluate the radiotherapy efficacy and other confounding factors. Results MYC translocations were detected in 59 DLBCL patients (10.2%). Patients with MYC-translocation+ DLBCL more often had bulky tumors, involvement of multiple extranodal sites, and poorer OS (hazard ratio [HR]: 2.0, 95% confidence interval [CI]: 1.20 - 3.35, P= .0083) and PFS (HR: 1.96, 95% CI: 1.22 - 3.13, P= .0005) independent of the International Prognostic Index score. Poor survival was primarily attributable to patients with MYC+/BCL2+ double-hit DLBCL who were predominantly of germinal center B-cell subtype. Among MYC-translocation+ DLBCL patients, a better survival was achieved in patients who received radiotherapy (for OS, HR: .32, 95% CI: .15 - .71, P= .0049; for PFS, HR: .35, 95% CI: .17 - .73, P= .0043). Conversely, radiotherapy abolished the adverse impact of MYC translocations. In addition, radiotherapy was associated with better survival in the subset of patients with MYC+/BCL2+ double-hit lymphoma (P = .017 for OS, and P = .05 for PFS). However, owing to the common use of radiotherapy as consolidation therapy, the favorable prognoses in the group of patients who received radiotherapy could also be attributed to limited-stage disease and more frequent complete remission (CR) after first-line treatment and therefore these factors confound interpretation of the data. To address these issues, we evaluated radiotherapy efficacy in separate patient groups: patients who achieved CR, non-CR (PR/SD/PD) patients, and patient with stage I/II, or stage III/IV disease. The efficacy of radiotherapy appeared more apparent in patients with advanced disease who did not achieve CR after first-line chemotherapy. Multivariate analysis after adjustment for stage and IPI score validated that radiotherapy significantly improved OS (HR: .28, 95% CI: .10 - .81, P= .018) and PFS (HR: .32, 95% CI: .13 - .80, P= .015) of MYC-translocation+ DLBCL patients. Conclusions The presence of MYC translocations in DLBCL is an important biomarker that facilitates prognostic prediction and treatment stratification independent of the IPI score. For chemoresistant MYC-translocation+ DLBCL patients, radiotherapy seems to be an effective adjuvant regimen likely due to the higher frequency of extranodal involvement and bulky disease in MYC-translocation+ DLBCL patients. Our results provide a rationale for larger scale studies to assess the potential role of radiotherapy in the management of MYC-translocation+ DLBCL patients, particularly patients with MYC+/BCL2+double-hit DLBCL. Disclosures: Winter: Millenium: Research Funding; Novartis : Research Funding; Pfizer (Wyeth): Research Funding; Seattle Genetics: Research Funding; Spectrum: Research Funding; Janssen (Pharmacyclics): Research Funding; Spectrum (Allos): Consultancy; Sanofi Aventis: Consultancy; Tgen: Consultancy; AMBIT Biosciences (Spouse): Research Funding; Celgene (Spouse): DSMB, DSMB Other, Research Funding; Ariad Pharmaceuticals (Spouse): Research Funding; Novartis (Spouse): Consultancy, Research Funding; Amgen (Spouse): Consultancy, Research Funding; Astellas (Spouse): Research Funding; Caremark/CVS: Consultancy; Pfizer (Spouse): Consultancy; Sanofi Aventis (Spouse): DSMB, DSMB Other; Bristol Myers Squibb (Spouse): DSMB, DSMB Other; UptoDate, Inc.(Spouse): Patents & Royalties.

Beschreibung: Abstract 949 Introduction: Diffuse large B cell lymphoma (DLBCL) has a highly variable outcome, and individual risk assessment is largely based on clinical features. Gene expression profiling (GEP) stratifies patients into those with germinal center B-cell (GCB) and activated B-cell subtype (ABC) subtype with different prognoses. These groups have been shown to predict prognosis in patients treated with CHOP or R-CHOP. Conversely, the role of other recognized prognostic markers, such as BCL2 gene abnormalities or Bcl2 expression has been questioned in the new therapeutic era. Materials and Methods: In 438 patients treated with R-CHOP for de novo DLBCL, we analyzed the tumors by immunohistochemistry for Bcl2 protein expression and by interphase fluorescence in situ hybridization (FISH) for BCL2 translocation and other abnormalities. All cases were successfully studied by GEP. The cutoff for Bcl2 protein expression, 60%, used as prognostic factor was determined using receiver operating characteristic curves. Progression-free survival (PFS) and overall survival (OS) were assessed. Results: The t(14;18)(q32;q21) was detected in 82 cases (18.7%) and BCL2 gains occurred in 63 cases (14.3%). Both t(14;18) and BCL2 gains strongly correlated with higher levels of Bcl2 protein expression (p

Beschreibung: Abstract 1994 Background: It has been reported that adults with mycosis fungoides have an increased risk of developing second malignancies. Although children and young adults with mycosis fungoides appear to have a higher proportion of early-stage disease and a more favorable outcome than adults, the risk of second malignancies in this population is not known. Patients and Method: A total of 178 patients diagnosed with mycosis fungoides or Sézary syndrome (MF/SS) before 30 years of age were identified from nine Surveillance, Epidemiology, and End Results (SEER) cancer registries in the U.S. from 1973 to 2007. The risk of second malignancies was assessed by calculating the standard incidence ratio (SIR), which compares the observed cancer incidence in the MF/SS cohort with the expected incidence in the age-, sex-, race-matched general population. Overall survival was calculated among 166 patients diagnosed with MF/SS before age 30 years, identified from the California Cancer Registry between 1988 and 2007. Results: In the MF/SS cohort from 1973 to 2007, 8 second cancers at all sites were reported in 7 patients, among which 5 cases were Hodgkin's and Non-Hodgkin's lymphomas. The SIR for a secondary malignancy at any site was 3.60 (95% confidence interval [CI]=1.55-7.10). Significantly increased risks of lymphoma and melanoma were observed, with SIR=24.23 (95% CI=7.87-56.55) and SIR=10.61 (95% CI=1.29-38.33), respectively. The median time to secondary malignancy was 2.9 years (range = 1.4 to 15.8 years). Among MF/SS patients diagnosed in California from 1988 to 2007, the 5- and 10-year overall survival was 96% (95% CI=91.4-98.5) and 92% (95% CI=86.1-96.5), respectively. Conclusion: Patients with MF/SS diagnosed before 30 years of age have favorable overall survival. However, these patients appear to have an increased risk of developing secondary cancers, similar to what we have seen in the adult MF/SS patients. Additional multi-center studies on the long term outcome of this young patient population are warranted. Disclosures: No relevant conflicts of interest to declare.

Beschreibung: Introduction and Objectives: Mycosis fungoides and Sezary syndrome (MF/SS) represent a group of heterogeneous diseases. Recent studies demonstrated dysregulation of several signaling pathways in MF/SS, including PI3K/AKT, JAK/STAT, RAS and NFkB pathways. We performed a high throughput drug screen to determine the potential of novel agents targeting these pathways for the treatment of MF/SS. Materials and Methods: We compiled a libraryof 94 compounds targeting pathways known to be relevant in cancer biology. These included kinases involved in growth factor receptor signaling, HDACs, proteasome, DNA repair and regulators of apoptosis. The compounds were screened for anti-proliferative activity against four MF/SS cell lines in high throughput proliferation assays. Selected hits were further studied in xenograft models of MF/SS and in primary T cell lymphomas. Promising candidates from different classes were also tested in combination therapy assays using a matrix block method across dose gradients of each compound designed to detect synergistic activities. Results: From the high throughput screen, we identified 14 compounds with anti-proliferative activity in MF/SS, including multiple inhibitors of the PI3K pathway. PI3K inhibitors emerged as preliminary hits in this screen and secondary validation assays confirmed the class effect of PI3K inhibitors. From this class, the PI3K inhibitor BKM120 was selected for in vivo studies. In a xenograft model of MF, BKM120 exhibited striking anti-tumor activity measured by a marked suppression of tumor growth and prolonged survival of tumor-bearing mice compared with vehicle control. In a search for even more effective combination therapies, we identified that BKM120 and the HDAC inhibitor class of compounds exhibit synergistic anti-proliferative effects in MF/SS tumor cells. Each of three HDAC inhibitors including LBH, Romidepsin and Vorinosat showed synergistic activity with BKM120, most evident at the GI50 concentrations of each drug, and apparent in both growth inhibition and apoptotic assays. Conclusion: BKM120 is highly active in preclinical models of MF/SS. Furthermore, it synergistically potentiates the effect of HDAC inhibitors against MF/SS tumor cells. These are highly promising approaches for the treatment of MF/SS and warrant clinical investigation. Disclosures No relevant conflicts of interest to declare.

Beschreibung: Background Bu-based conditioning regimens are commonly used prior to autologous hematopoietic stem cell transplantation (ASCT) for lymphoma, but clinical results of an intravenous (IV) Bu-based regimen have been limited to single center studies. This multi-center, single-arm, Phase 2 study prospectively evaluated the safety and efficacy of the IV BuCyE regimen in lymphoma patients undergoing ASCT. Methods The primary endpoint was progression-free survival (PFS). Secondary endpoints included overall survival (OS), transplant-related mortality (TRM) and overall response rate. TRM was defined as a death after transplant due to any cause other than disease progression. Subjects underwent first ASCT for Hodgkin lymphoma (HL) and B-cell non-Hodgkin lymphoma (NHL) that relapsed after initial therapy, was initially refractory to an anthracycline-based chemotherapy, or for high-risk NHL histology in first complete remission (CR) [International Prognostic Index (IPI) score of 4-5, or mantle cell lymphoma (MCL)]. Eligible subjects achieved CR or partial remission (PR) following salvage chemotherapy. The study initially enrolled subjects of 18-80 years, but the protocol was amended to reduce the upper age limit to 65 years due to a high TRM rate at post-transplant 100 days for the subjects 〉65 years. Therefore, we report safety for all the subjects undergoing ASCT (n=203) and efficacy from those 65 years old or younger (n=186). IV Bu doses were individually adjusted based on pre-conditioning test PK results; the area under the concentration-time curve of Bu was targeted to 20,000 mM*min. Bu was given as a 3-hour infusion once daily from Days -8 through Day -5. E (1.4 g/m2) was administered on Day -4, followed by 2.5 g/m2/day of Cy on Days -3 and -2. Results A total of 207 subjects with HL (n=66) or NHL (n=141) were enrolled from 32 centers in the US and Canada between February 2010 and April 2012. Four subjects did not proceed with ASCT due to insurance or eligibility issues; the remaining 203 underwent ASCT. The final TRM rates at Day 100 for all subjects (n=203), for those older than 65 year old (n=17), and for those 65 years old or younger (n=186) were 4.5% (95% confidence intervals (CI) 2.1-8.3%), 23.5% (95% CI; 6.8-49.9%) and 2.7% (95% CI: 0.9-6.2%), respectively. The most common grade (Gr) 3 or 4 adverse events (CTCAE v3.0) observed from Day -8 through Day 100 were febrile neutropenia (Gr 3: 58.1%; Gr 4: 3.0%), stomatitis (Gr 3: 40.9%; no Gr 4), nausea (Gr 3: 8.9%; no Gr 4), and hypophosphatemia (Gr 3:6.9%; Gr 4: 1.0%). There was no instance of seizure or hepatic veno-occlusive disease (VOD) meeting the Baltimore criteria. Efficacy was analyzed for 186 subjects ≤65 years old with HL (n=65) or NHL (n=121), which included diffuse large B-cell lymphoma (DLBCL; n=63), MCL (n=29) and follicular lymphoma (FL; n=23). The median age was 49 year old (range: 19-65); 36 % were female, 87% were white, 76% had a Karnofsky Score ≥90. Majority of the patients had CR2 or higher, or PR at transplant except that 19 MCL patients and three DLBCL patients with IPI score 4 had CR1. In addition, five patients (3 for NHL; 2 for HL) who had refractory disease to initial chemotherapy and required salvage therapy to achieve CR1 also enrolled this study. With median 20 months follow-up, the estimated 2-year PFS was 33% for HL and 58%, 77%, and 43% for DLBCL, MCL, and FL respectively [Fig. 1]. The estimated 2-year OS was 76% for HL and 65%, 89%, and 89% for DLBCL, MCL, and FL respectively [Fig. 2 ]. Conclusions IV BuCyE regimen provided good early disease control with acceptable safety profiles in B-cell NHL lymphoma patients 65 year old or younger, but there were early declines in PFS in HL patients. Additional comparisons of PFS and OS from the BuCyE regimen with a pre-specified, matched-control group of approximately 800 matched cases (1:4 ratio) obtained from the Center for International Blood and Marrow Transplant Research registry data who received carmustine, E, cytarabine, and melphalan (BEAM) conditioning regimen are underway, and updated results will be presented. Disclosures: Off Label Use: Busulfan, Cyclophosphamide and VP-16 for Autologous Hematopoietic Stem Cell Transplantation. Costa:Otsuka: Research Funding. Freytes:Otsuka America Pharmaceutical: Research Funding, Travel funds for scientific presentation Other. Armstrong:Otsuka: Employment. Smith:Otsuka Pharmacetical Development & Commercialization: Employment. Elekes:Otsuka Pharmaceutical: Employment. Kato:Otsuka Pharmaceutical Development & Commercialization, Inc: Employment.

Beschreibung: Introduction: Tumor-infiltrating immune cells are thought to be important in the biology and clinical course of follicular lymphoma. Recently a gene expression signature associated with monocyte/macrophages was identified in follicular lymphoma patients with poor overall survival. One hypothesis is that macrophages may act to suppress the immune response to the lymphoma and thus decrease survival. A number of groups have assessed the prognostic value of enumerating tumor-associated macrophages (TAM) using immunohistochemistry for the macrophage marker CD68, with mixed results: some have shown poorer survival with increased CD68+ TAM, others have shown no effect, and others have shown poorer survival only in patients not treated with rituximab. CD68 is a sensitive marker of tissue macrophages which also shows reactivity with other cell types. CD163, by contrast, shows high specificity for the monocyte/macrophage lineage and is thought to be a marker for immunosuppressive M2-polarized macrophages. Methods: 187 follicular lymphoma patients underwent excisional lymph node biopsy prior to treatment. We enumerated extrafollicular and follicular CD163+ and CD68+ TAM in two high power fields (hpf) each of duplicate tissue microarray cores. The median age at diagnosis was 45 yrs, with a median follow-up of 8.8 yrs and 51 deaths. All but 6 patients had stage III/IV disease, 3 had stage I/II, and 3 were unknown. The histological grades are as follows: 112 grade 1, 65 grade 2, and 10 grade 3. FLIPI (follicular-lymphoma specific international prognostic index) scores are as follows: 33 low, 95 intermediate, 19 high, 40 unavailable. For their initial treatment regimen 120 patients received CVP +/− fludarabine; 42 received a variety of other chemotherapeutic regimens; and 9 patients received rituximab. Results: CD163 marks a subset of TAMs that is preferentially enriched in the extrafollicular compartment and that does not covary with numbers of CD68+ TAMs overall. CD163+ TAMs are significantly less frequent than CD68+ TAMs: 32 vs 88 TAM/hpf in the extrafollicular compartment (p = 5.89E-62) and 2.5 vs 29 TAM/hpf in the follicular compartment (p = 2.05E-62). Both CD163+ and CD68+ TAMs are enriched in the extrafollicular compartment (p = 5.39E-46 for CD163, p = 2.17E-81 for CD68); however this gradient is more marked for CD163+ than for CD68+ TAMs (7.6% of CD163+ TAM vs 24% of CD68+ TAM are follicular, p = 6.53E-43). There is no correlation between numbers of CD68+ and CD163+ TAM in the follicular (r2 = 0.05) or extrafollicular (r2 = 0.12) compartments. Furthermore, while CD68+ TAM content within follicles increases with grade (26/hpf in grade 1 vs 33/hpf in grade 2 follicular lymphoma, p = 0.01) there is no corresponding increase in CD163+ TAM within follicles (2.8/hpf in grade 1 vs 2.0 per hpf in grade 2 FL, p = 0.15). There was no association between TAM content and FLIPI. We found no statistical difference in overall survival with respect to either CD163+ or CD68+ TAM within follicles or in the extrafollicular compartment. Higher numbers of extrafollicular CD68+ macrophages are associated with longer initial treatment-free interval (time from diagnosis to initial treatment; z = −2.23, p = 0.026). This association is independent of FLIPI and grade (z = −2.94, p =0.0033). Higher numbers of extrafollicular CD163+ macrophages are associated with a longer second treatment-free interval (interval from first treatment to second treatment; z = −2.151, p = 0.031); this association is independent of FLIPI and grade (z = −2.151, p = 0.031). Conclusions: It has been suggested that CD68+ TAM are associated with poorer prognosis in follicular lymphoma; however we found no association with overall survival, and indeed a longer initial treatment-free interval, with increased CD68+ extrafollicular macrophages. CD163 is highly expressed in immunosuppressive M2-polarized macrophages, which are thought to provide an environment permissive to cancer progression. We found that CD163+ macrophages are a small subset of the total CD68+ macrophage count, are distributed differentially, and vary independently of CD68+ macrophage content, suggesting that CD163 highlights a functionally distinct macrophage subpopulation. However CD163+ macrophages, like CD68+ macrophages, were not associated with poorer overall survival and indeed were associated with a longer second treatment-free interval (time from first to second treatment).

Beschreibung: Context and objective Approximately 5-10% of diffuse large B-cell lymphoma (DLBCL) patients carry MYC gene translocations (MYC-translocation+) with a poor prognosis after standard chemotherapy. MYC-translocation+ DLBCL patients carrying BCL2 translocations (MYC+/BCL2+ double-hit lymphoma) have a worse survival. The efficacy of adjuvant radiotherapy in this setting is unknown. The purpose of this study is to evaluate the efficacy of radiotherapy as a part of the therapeutic regimen for patients with MYC-translocation+ DLBCL. Patients and methods From the International DLBCL R-CHOP consortium program, we selected 581 patients with de novo DLBCL treated with standard R-CHOP immunochemotherapy (diagnosed and treated from 2000 to 2010). We excluded patients with transformed DLBCL, primary mediastinal, cutaneous, testicular or central nervous system large B-cell lymphomas, patients with HIV infection, and patients not treated with R-CHOP. The median follow-up was 54.9 months. Fluorescence in situ hybridization assessing MYC was performed for all the patients (n=581) and results were correlated with available clinical data to identify clinicopathologic features associated with MYC translocation, and to evaluate the prognostic significance of MYC translocations regarding overall survival (OS, from the time of diagnosis to death from any cause) and progression-free survival (PFS, from the time of diagnosis to relapse or death from any cause). In the MYC-translocation+ DLBCL group, 38 patients received chemotherapy alone and 21 patients received chemotherapy with adjuvant radiation therapy. The clinicopathologic features and survival of MYC-translocation+ DLBCL patients treated with (n=21) and without radiotherapy (n=38) after immunochemotherapy were compared to in order to evaluate the radiotherapy efficacy and other confounding factors. Results MYC translocations were detected in 59 DLBCL patients (10.2%). Patients with MYC-translocation+ DLBCL more often had bulky tumors, involvement of multiple extranodal sites, and poorer OS (hazard ratio [HR]: 2.0, 95% confidence interval [CI]: 1.20 - 3.35, P= .0083) and PFS (HR: 1.96, 95% CI: 1.22 - 3.13, P= .0005) independent of the International Prognostic Index score. Poor survival was primarily attributable to patients with MYC+/BCL2+ double-hit DLBCL who were predominantly of germinal center B-cell subtype. Among MYC-translocation+ DLBCL patients, a better survival was achieved in patients who received radiotherapy (for OS, HR: .32, 95% CI: .15 - .71, P= .0049; for PFS, HR: .35, 95% CI: .17 - .73, P= .0043). Conversely, radiotherapy abolished the adverse impact of MYC translocations. In addition, radiotherapy was associated with better survival in the subset of patients with MYC+/BCL2+ double-hit lymphoma (P = .017 for OS, and P = .05 for PFS). However, owing to the common use of radiotherapy as consolidation therapy, the favorable prognoses in the group of patients who received radiotherapy could also be attributed to limited-stage disease and more frequent complete remission (CR) after first-line treatment and therefore these factors confound interpretation of the data. To address these issues, we evaluated radiotherapy efficacy in separate patient groups: patients who achieved CR, non-CR (PR/SD/PD) patients, and patient with stage I/II, or stage III/IV disease. The efficacy of radiotherapy appeared more apparent in patients with advanced disease who did not achieve CR after first-line chemotherapy. Multivariate analysis after adjustment for stage and IPI score validated that radiotherapy significantly improved OS (HR: .28, 95% CI: .10 - .81, P= .018) and PFS (HR: .32, 95% CI: .13 - .80, P= .015) of MYC-translocation+ DLBCL patients. Conclusions The presence of MYC translocations in DLBCL is an important biomarker that facilitates prognostic prediction and treatment stratification independent of the IPI score. For chemoresistant MYC-translocation+ DLBCL patients, radiotherapy seems to be an effective adjuvant regimen likely due to the higher frequency of extranodal involvement and bulky disease in MYC-translocation+ DLBCL patients. Our results provide a rationale for larger scale studies to assess the potential role of radiotherapy in the management of MYC-translocation+ DLBCL patients, particularly patients with MYC+/BCL2+double-hit DLBCL. Disclosures: Winter: Millenium: Research Funding; Novartis : Research Funding; Pfizer (Wyeth): Research Funding; Seattle Genetics: Research Funding; Spectrum: Research Funding; Janssen (Pharmacyclics): Research Funding; Spectrum (Allos): Consultancy; Sanofi Aventis: Consultancy; Tgen: Consultancy; AMBIT Biosciences (Spouse): Research Funding; Celgene (Spouse): DSMB, DSMB Other, Research Funding; Ariad Pharmaceuticals (Spouse): Research Funding; Novartis (Spouse): Consultancy, Research Funding; Amgen (Spouse): Consultancy, Research Funding; Astellas (Spouse): Research Funding; Caremark/CVS: Consultancy; Pfizer (Spouse): Consultancy; Sanofi Aventis (Spouse): DSMB, DSMB Other; Bristol Myers Squibb (Spouse): DSMB, DSMB Other; UptoDate, Inc.(Spouse): Patents & Royalties.

Beschreibung: Background Despite advances in therapy, relapsed or refractory (RR) non-Hodgkin lymphoma (NHL) remains a major treatment challenge. Preclinical data support the activity of proteasome inhibitors against lymphoma through multiple mechanisms including activation of the endoplasmic reticulum (ER) stress response and reduction in the threshold for apoptosis in response to chemotherapy. Clinically, proteasome inhibiton with bortezomib added to bendamustine yielded promising results in patients (pts) with indolent NHL with limited additional toxicity. Compared to bortezomib, carfilzomib is a more target specific and potent proteasome inhibitor with less neurotoxicity. We embarked on a multicenter, phase 1b dose escalation trial to assess the combination of carfilzomib with bendamustine and rituximab in pts with RR aggressive or indolent NHL. Methods The primary objective of the study is to determine the maximum tolerated dose (MTD) and recommended phase II dose of carfilzomib when combined with bendamustine and rituximab. The secondary objective is to evaluate the preliminary antitumor activity of the combination in select NHL histologies. Correlative studies examine markers of ER stress and apoptosis in response to treatment. Here we report the preliminary results of the dose escalation phase expected to be completed in Fall 2019. We followed a standard 3+3 design with escalation of the carfilzomib dose in 4 dose level cohorts combined with bendamustine dosed at 90 mg/m2 IV on Days 1 and 2 and Rituximab dosed at 375 mg/m2 IV on Day 9 of cycle 1 and Day 1 of subsequent cycles. Initially, carfilzomib was dosed twice a week with dose level 1 at 15 mg/m2 IV on days 1,2,8,9, 15, and 16. Subsequently, we explored weekly dosing schedules with carfilzomib at 36 mg/m2 (dose level 2), 56 mg/m2 (dose level 3), and 70 mg/m2 (dose level 4) on days 9 and 16 with a 20 mg/m2 starting dose on day 2. Dose limiting toxicity (DLT) was defined as Gr4 or specific Gr3 events attributable to the combination. Pts are treated for up to 6 cycles with an interim PET/CT after cycle 3. Results To date, 10 pts have been treated on the dose escalation phase with one patient currently on study treatment. Overall, 5 pts had diffuse large B-cell lymphoma (DLBCL), 3 mantle cell lymphoma (MCL), 1 follicular lymphoma (FL), and 1 marginal zone lymphoma (MZL). Pts received a median of 3 prior lines of therapy. Four pts were treated on dose level 1, 3 on dose level 2, and 3 on dose level 3. Treatment-emergent Grade 2-4 adverse events included thrombocytopenia in 1 pt (Gr 4), neutropenia in 1 pt (Gr 4), febrile neutropenia in 1 pt (Gr 3), culture negative fevers in 1 pt (Gr 3), nausea/vomiting in 2 pts (Gr 2 and 3), other GI toxicities in 1 pt (Gr 2), lower back pain in 1 pt (Gr 2), arthralgias in 1 pt (Gr 2), and cerebrevoascular ischemia in 1 pt (Gr 2). Two pts had treatment related-SAEs (Gr3 culture negative fevers; Gr 3 febrile neutropenia and Gr 3 vomiting) at dose level 2 and 3 respectively. One patient experienced DLT (Gr 3 febrile neutropenia) at dose level 3. There were no treatment related deaths. Of 10 evaluable pts to date, the overall response rate (ORR) is 40% with 3 pts achieving complete remission (one with FL, one with DLBCL and one with MCL) and one pt with MCL achieving a partial remission. The responder with FL had relapsed disease after achieving prior complete remission with rituximab and bendamustine alone. For the 9 pts who completed study treatment, median duration of treatment was 2.4 months, median progression free survival was 1.9 months and median overall survival was 11.6 months. The median duration of response for the 3 responders who completed therapy was 21.8 months. Conclusion Carfilzomib in combination with bendamustine and rituximab is a safe and well-tolerated treatment for pts with RR NHL. The MTD has not been reached and enrollmemt continues, with dose escalation phase anticipated to complete in Fall 2019. Preliminary data indicate that this combination may have efficacy with an acceptable side effect profile in this heavily pre-treated patient population with limited treatment options. Disclosure: This study was approved and funded by the National Comprehensive Cancer Network (NCCN) Oncology Research Program with general research support provided by Amgen. Disclosures Tuscano: Spectrum: Research Funding; Celgene: Honoraria, Research Funding; Novartis: Research Funding; Pharmacyclics: Research Funding; Seattle Genetics: Honoraria; Amgen: Honoraria; Takada: Research Funding; Abbvie: Research Funding; Genentech: Research Funding. Wieduwilt:Celgene: Membership on an entity's Board of Directors or advisory committees; Amgen, Leadiant, Merck, Servier: Research Funding; Daiichi Sankyo: Membership on an entity's Board of Directors or advisory committees; Reata Pharmaceuticals: Equity Ownership. Andreadis:Genentech: Equity Ownership, Other: Spouse is Employee; Novartis: Honoraria, Research Funding; Amgen: Consultancy, Research Funding; Celgene: Consultancy, Research Funding; Gilead: Consultancy; Jazz Pharmaceuticals: Consultancy; Bayer: Consultancy.