Follicular B Cells Research Articles

Impact of Conditioning Regimen Intensity On the Outcomes of Allogeneic Hematopoietic Cell Transplantation for Refractory Grade-III Follicular (FL-III) and Diffuse Large B-Cell Lymphomas (DLBCL): A Cibmtr Analysis

AbstractAbstract ▪473▪This icon denotes a clinically relevant abstract Introduction:Patients with chemorefractory aggressive B-cell non-Hodgkin lymphomas (aB-NHL) have a poor prognosis. The role of allogeneic hematopoietic cell transplantation (allo-HCT) and the optimal intensity of conditioning regimen employed for this high-risk group are poorly defined. Methods:We report here the outcomes of allo-HCT in patients with chemorefractory aB-NHL according to the intensity of transplant conditioning regimens, using the CIBMTR database. The study population included all patients with chemorefractory DLBCL and FL-III receiving an allo-HCT reported to the CIBMTR between 1998 and 2010. Patients with evidence of chemosensitive disease (i.e. patients in CR or PR) at the time of allo-HCT were excluded. Primary outcomes were non-relapse mortality (NRM), progression/relapse (P/R), progression-free survival (PFS), and overall survival (OS). The outcomes of patients undergoing myeloablative conditioning (MA) were compared with those of patients receiving reduced intensity/non-myeloablative conditioning (RIC/NST). Conditioning regimen intensity was defined according to CIBMTR guidelines (Bacigalupo A. BBMT). Results:A total of 307 patients received MA, and 226 underwent RIC/NST. Median follow up of survivors for MA and RIC/NST groups was 35mos and 30mos, respectively. Completeness of follow up at 3 years was 80%. The baseline characteristics of both groups are described in Table 1. No significant differences at baseline were observed between the MA and RIC/NST groups in terms of disease stage at diagnosis, B-symptoms, lines of prior therapy, bone marrow or extranodal involvement, disease bulk, central nervous system involvement, prior rituximab use, and donor type. Significantly more patients in the RIC/NST group had a prior autologous-HCT (38% vs. 15%; p<0.001) and received a peripheral blood allograft (88% vs. 79%; p=0.008). Cumulative incidence of grade II-IV acute GVHD at day +100 was 29% and 31% in MA and RIC/NST groups (p=0.68), respectively. Cumulative incidence of chronic GVHD at 1 year post transplantation in similar order was 33% and 38%, respectively (p=0.27). On univariate analysis, at 3 years, MA allo-HCT was associated with a higher NRM compared to RIC/NST (53% vs. 42%; p=0.03), similar PFS (19% vs. 23%; p=0.40), and lower OS (19% vs. 28%; p=0.02), respectively. On multivariate analysis, FL-III histology was associated with lower NRM (relative risk [RR]=0.52; 95% CI 0.35–0.79, p=0.002), reduced risk of R/P (RR=0.42; 95% CI 0.25–0.73, p=0.002) and superior PFS (RR=0.51; 95% CI 0.37–0.7; p<0.001) and OS (RR=0.53; 95% CI 0.39–0.72; p<0.001), while MA conditioning was associated with reduced risk of R/P (RR=0.66; 95% CI 0.47–0.92; p=0.015), but similar OS, NRM, and PFS. Multivariate analysis constructed by excluding patients undergoing a prior autologous-HCT showed similar results. On subgroup analysis, the 3 year PFS of FL-III patients (N=80) in our study for MA and RIC/NST cohorts was 41% and 40% respectively. Conclusions:Despite a refractory disease state, a small subset (∼25%) of DLBCL and FL-III NHL patients can attain durable remissions after allo-HCT. Conditioning regimen intensity was not associated with NRM, PFS and OS despite a higher risk of relapse/progression with RIC/NST allo-HCT.Table 1Baseline Patient CharacteristicsMyeloablative N=307 (%)RIC/NST N=226 (%)P-valueMedian Age (range)46 (19-66)53 (20-70)<0.001Male sex185 (60)126 (44)0.30KPS ≥9090 (29)70 (31)0.60Histology32 (10)48 (21)0.001FL-III275 (90)178 (79)DLBCLNo prior auto-HCT259 (84)140 (62)<0.001Interval from diagnosis to transplant, months15 (1-238)24 (5-340)<0.001Disease status0.005Primary-refractory159 (52)89 (39)Resistant relapse148 (48)137 (61)Graft type0.008Bone marrow65 (21)28 (12)Peripheral blood242 (79)198 (88)HLA-identical sibling162 (53)94 (42)0.090 Disclosures:No relevant conflicts of interest to declare.

Hepatitis B Infection Is Associated with an Increased Risk of Non-Hodgkin Lymphoma: A Meta-Analysis.

Abstract 2658 Introduction:Hepatitis B virus (HBV) infection is a major global public health problem with the World Health Organization reporting about 350 million people with chronic HBV infection with the highest rates seen in Asia and Africa. Multiple studies have attempted to show an association between HBV infection and non-Hodgkin lymphoma (NHL) but have had conflicting results. Objectives:The primary aim of our study was to evaluate the association between HBV infection and the incidence of NHL using a meta-analysis of epidemiological studies. Secondary aims were to evaluate such association in NHL subtypes and by geographical region. Methods:A MEDLINE and Google Scholar search through July 2012 were undertaken using (Hepatitis B or hepatitis) AND (lymphoma OR “risk of lymphoma” OR “hematologic malignancies” OR “lymphoproliferative disorders” OR “non Hodgkin lymphoma”). Only epidemiological studies reporting on HBV infection and NHL were included. Hepatitis B status confirmation method was recorded. Meta-analyses were performed for NHL in general, by NHL subtypes, and according to geographical region. The outcome was calculated as odds ratio (OR). The random effects model (REM) was used to calculate the outcome. Heterogeneity was assessed by the I2 statistic. Publication bias was assessed by the trim-and-fill analysis. Literature search and data gathering were performed independently by at least 2 of the investigators. All graphs and calculations were obtained using Comprehensive Meta-Analysis version 2 (Biostat, Englewood, NJ). Results:Our search yielded 21 studies; 17 case-control studies accounted for 38,630 cases and 1,659,449 controls, and 4 prospective cohort studies accounted for 1,258 cases indentified in a cohort of over 2.4 million individuals. HBV infection was confirmed by seropositivity in 81% of studies (n=17). HBV infection patients had an OR 2.30 (95% CI 1.87–2.84; p=<0.001) of developing NHL. OR was significant in patients from Asian countries (OR 2.31, 95% CI 1.87–2.86, p<0.001) and in patients from American/European/Australian countries (OR 2.58, 95% CI 1.43–4.62, p=0.002). In subgroup analysis, HBV infection patients had an OR 2.10 (95% CI 1.27–3.49, p=0.004) of developing diffuse large B-cell lymphoma (DLBCL). In patients from Asian countries, HBV infection was associated with an increased risk of DLBCL (OR 3.05, 95% CI 1.86–5.00, p<0.001); an association was not found in patients from Europe or Australian studies. Patients with HBV infection had increased risk to develop follicular lymphoma (OR 1.966, 95% CI 1.211–3.193, p<0.001) and B-cell lymphomas (OR 2.67, 95% CI 2.08–3.43, p<0.001). Patients with HBV infection did not have increased risk to develop chronic lymphocytic leukemia/small cell lymphoma (OR 1.58, 95% CI 0.70–3.62, p=0.27) or T-cell lymphomas (OR 1.37, 95% CI 0.95–1.98, p=0.091). Conclusions:The results of this meta-analysis suggest a positive association between HBV infection and NHL, DLBCL, follicular lymphoma, and B-cell lymphoma. There was no association between HBV infection and chronic lymphocytic leukemia/small cell lymphoma or T-cell lymphomas. Future research is needed to better understand molecular mechanisms responsible for lymphomagenesis in patients with chronic HBV infection. Disclosures:No relevant conflicts of interest to declare.

Collection of Hematopoietic Stem Cells After Previous Exposure to Ittrium-90 Ibritumumab Tiuxetan (Zevalin) Is Feasible and Does Not Impair Autologous Stem Cell Transplantation Outcome in Follicular Lymphoma.

Abstract 3019 Background:Radioimmunotherapy (RIT) is an effective and manageable treatment option for those patients (pts) affected by follicular B-cell lymphoma (FL) who experience disease relapse. The results of RIT in the setting of first line consolidation are also very promising in terms of progression free and overall survival. On the other hand autologous stem cell transplantation (ASCT) is a suitable treatment option for relapsed FL patients. Although major concerns about the widespread use of RIT early in the disease course are the long term hematologic toxicity and the theoretical possible irreparable damage to bone marrow function with impairment of peripheral stem cell harvest, very few data are available about mobilization rates after Zevalin exposure. Methods:The aim of this monocentric study was to analyze the impact of prior Zevalin administration on peripheral blood stem cells (PBSC) mobilization and on the outcome of subsequent ASCT. Moreover the impact of different prior treatment regimens [Cyclophosphamide, Doxorubicin, Vincristine, Prednisone plus Rituximab (R-CHOP) or CHOP-like regimens vs Fludarabine, Mitoxantrone plus Rituximab (FM-R) vs Zevalin] and number of previous lines of therapy given earlier in the disease course, was prospectively evaluated in all FL patients (n=100) who underwent stem cell mobilization from January 2005 to March 2012. Results:At the time of mobilization, 68 pts had received R-CHOP or CHOP-like regimens, 20 pts FM-R, 12 pts RIT with Zevalin earlier in the disease course. Characteristics of pts such as age, weight and number of prior therapies, were well balanced in the 3 groups. Sixty one pts had received one prior therapy, 31 pts 2 therapies, 8 pts ≥ 3 lines of therapy. All pts received chemotherapy plus granulocyte colony stimulating factor (G-CSF) 5 μg/kg (n=94) or G-CSF alone (10 μg/kg) (n=6) as mobilization regimen. Mean CD34+ cells yield was 8.9 × 106/kg in the CHOP group, vs 5.8 × 106 CD34 + cells/kg in the FM-R group, vs 2.7 × 106 CD34 + cells/kg in the Zevalin group (p=0.05 CHOP vs FM-R; p<0.001 CHOP vs Zevalin; p<0.01 FM-R vs Zevalin; t test). The collection yield of 2.0 × 106 CD34 + cells/kg was reached in 98% (n=67) of pts in the CHOP group, vs 80% (n=16) in the FM-R group, vs 42% (n=5) in the Zevalin group. The number of previous treatments did not significantly affect PBSC harvest (1 vs 2 lines: p=0.1; 1 vs 3 lines: p=0.1; 2 vs 3 lines: p=0.3). Regarding the engraftment no differences were noted between the 3 groups and the median time to neutrophils (> 1000/μL) and platelets recovery (>20000/μL) was 10 and 11 days in all groups respectively. Only one pt in the CHOP group and one in the FM-R group did not undergo ASCT because of insufficient CD34+ harvest. Considering the Zevalin group (n=12), median age was 51 years (range 36–66). Seven pts received Zevalin as first line consolidation, 5 patients at disease relapse. Median number of prior therapies was 2 (range 1–4). Ten pts received chemotherapy plus G-CSF as initial mobilization regimen, 2 pts received G-CSF alone. Median time from RIT to mobilization was 13 months (4–60 months). Five pts (42%) reached the collection yield of > 2.0 × 106 CD34 + cells/kg with the first mobilization attempt. Considering the remaining 7 pts who failed (CD34+ cells below 10/mL before apheresis, or cell harvest below 2.0 × 106 CD34 + cells/kg), a surgical procedure was attempted in 4 pts, G-CSF + Plerixafor (240 μg/kg) in 3 pts. Remarkably the second harvest allowed 5 additional pts (3 pts after surgery, 2 pts after G-CSF + Plerixafor) to undergo ASCT. Finally ASCT was succesfully performed in 9 pts (75%). Median number of reinfused CD34+ cells was 2.3 × 106 CD34 + cells/kg (0.4–4.2). Three pts did not undergo ASCT, one because of disease progression, 2 pts because of insufficient CD34+ harvest. Conclusions:The type of previous therapy may significantly influence the mobilization rate in FL pts. Although mobilization was significantly impaired in pts previously treated with Zevalin compared to other chemotherapy regimens, stem cell harvest after RIT was feasible and the vast majority of patients retained the possibility to undergo ASCT with a second stem cell harvest, with no significant impact on engraftment. The use of Plerixafor seems to be particularly promising for those patients previously exposed to RIT who failed the first mobilization. Disclosures:No relevant conflicts of interest to declare.

Results of a Phase II Study of Lenalidomide in Combination with Rituximab for the Treatment of Indolent Non Follicular Non Hodgkin Lymphoma (NHL)

AbstractAbstract 1645 Background:Indolent non follicular B-Cell Lymphomas (INFL) are an eterogenous group of lymphomas and include small lymphocityic lymphoma (SLL), lymphoplasmacytic lymphoma (LPL), and marginal zone lymphoma (MZL). Relapsed INFLs in advanced stage have a relatively poor prognosis, with low complete response to conventional chemotherapy and short survival. Lenalidomide (R®) is an immunomodulatory drug with effects on the innate immune system that may enhance antibody-dependent cell mediated cytotoxicity as well as the development of specific anti-tumor immune responses. These immunologic effects may synergize with the action of rituximab (R). To test the efficacy of R® combined with R (R2), we have conducted a multi center, open label phase II clinical trial in patients (pts) with relapsed INFL. Methods:Eligible pts must have indolent non follicular B-cell lymphoma relapsed after at least 2 but less than 4 prior lines of R-containing immuno-chemotherapy with measurable disease. Patients received oral R® 20 mg once daily on days 1–21. R is administered at a dose of 375 mg/m2 at day 14 of every course. Treatment is repeated every 28 days for up to 6 courses. The primary objectives of the study were to evaluate the antitumor activity of oral R® when given in combination with R and to assess the safety of R2 evaluated by standard criteria (CTC-NCI 3.0). The secondary objectives were progression free survival (PFS), event free survival (EFS) and duration of remission (DR). Results:From July 2010 and June 2012, 39 patients were enrolled: 19 had SLL, 11 had LPL, 4 splenic MZL, 3 extranodal MZL and a 2 nodal MZL. Median age was 68 years (51–76) and 58% were male. LDH value was increased in 17% of pts and β-2-microglobulin in 87%; 41% of pts had Hb<12 g/dL and 62% were bone marrow positive. At time of current analysis treatment and response data were available in 27 pts. Overall treatment was completed in 18 pts (67%); in 9 cases treatment was interrupted prematurely primarily due to hematological toxicity (n=5) and due to disease progression (n=4). Of the 27 pts, 5 achieved a complete remission and 9 a partial remission with an ORR of 52%. In general, the regimen R2 was relatively well-tolerated. Grade 3–4 hematological events included neutropenia occurring in 50% of pts, infection in 7% and piastrinopenia in 3%. Growth factors were administered in 60% of pts. The median dose intensity was 0.94 for R and 0.92 for R®. With a median follow-up of 13 months (range 1–36), overall 9 pts had a lymphoma progression and 2 of them died. The 1-year overall survival and the 1-year PFS were 92% (IC95% 57–99%) and 78 months (IC95% 54–91%) respectively. Conclusions:In our trial follicular histology was an exclusion criteria and all pts were relapsed/refractory to immuno-chemotherapy rituximab-containing regimens. Thus the results observed with the chemo-free R2 scheme compare favorably with other previously reported results observed in relapsed indolent lymphoma treated with standard immuno-chenotherapy. Further the R2 combination was relatively well tolerated. In conclusion our results, although obtained in a small series of patient are encouraging and support further evaluation of R2 scheme in a larger cohort of patients. Disclosures:No relevant conflicts of interest to declare.

Frontline Therapy with Low Risk Chemotherapy (R-CVP/R-CHOP) in Follicular B-Cell Lymphoma Recently Diagnosed. Clinical Experience in Two Centers of Bogotá, Colombia

AbstractAbstract 4893 Background:The follicular lymphoma (FL) it is a subset of non-Hodgkin lymphomas, accounting for between 15% and 30% of new diagnoses of lymphoma. It has raised many combinations of treatments, but the long-term results remain unchanged. At present there is no consensus on the first line therapy for the management of follicular lymphoma. Since the advent of rituximab use, this change, achieving better response rates and survival, the paradigm is the use of R-CHEMO, but there are many active combinations, including the use CVP, CHOP, FCM, and others, which have shown benefit, but with consequences given for severe toxicity, and treatment-related deaths. In Colombia, the situation it is not different, the use of chemotherapy is left for consideration by the treating physician. This study aimed to assess treatment preferences for patients with new diagnosis of follicular lymphoma in Colombia, evaluate the responses of the combination R-CHEMOTHERAPY in our population, considering the specific ethnic characteristics and limitations of a developing country. Patients and Methods:The study included patients diagnosed with follicular lymphoma confirmed by hematopathologist with experience by performing at least 10 immunohistochemical tumor markers. This study is a descriptive study. During the study took into account the principles of autonomy, beneficence and justice written in the Belmont report. Informed consent was obtained from patients for participation in this study. It also welcomes the resolution expressed law Colombian Ministry of Health No. 008 430 1993 (4 October 1993) Article 11 investigation classified as safe. We analyzed cases diagnosed from January 2007 to July 2011 in two private institutions in the city of Bogotá, Colombia, we obtained 20 cases meeting the inclusion criteria. All the patients were scheduled to undergo primary therapy with 6 cycles of full-dose R-CVP or R-CHOP. Results:in this group, there were 5 men and 15 women (75% of all patients), and the median age at diagnosis was 56 years, the initial stage was 10% for stage II, 40% for stage III and the remaining 50% for stage IV, the bone marrow compromise reached by 45% (9 cases). The initial functional status classified by the ECOG scale was 0: 45%, 1: 50% and 3: 5%. the B symptoms were present in 95% of the patients analyzed. In accordance with the International Prognostic Index (FLIPI), we find the following: low risk: 25% (5 cases), intermediate risk: 35% (7 cases) and high risk: 40% (8 patients). the pathological grading was grade 1: 55% (11 patients), grade 2 for 35% (4 patients) and 3 for 10% (2 patients). When we reviewed found that the preferred treatment, for 80% of the population uses the R-CVP and the remaining 20% use of R-CHOP scheme, one patient in the R-CHOP group was complicated with high-risk febrile neutropenia requiring hospitalization. There were no treatment-related deaths. We found that 80% of patients achieved a complete hematologic remission and 20% partial response for an overall response of 100%. If we analyze separately patients treated with R-CVP scheme was 75% complete response and 25% partial response, with an overall response of 100%. Conclusion:This study shows the preference of treatment in 2 institutions in Bogotá, Colombia, which are in accordance with international guidelines, the results show a population with similar general characteristics with the others studies, in which a 100% overall hematologic response was achieved, 75% complete response for the R-CVP and 100% for the R-CHOP, however the latter with 25% of severe infectious complications. We consider a good treatment strategy for the implementation in our population is the R-CVP scheme, which is well tolerated, showing benefit in our patients and remission rates even higher than the studies previously published. Disclosures:No relevant conflicts of interest to declare.

Self-antigen recognition by follicular lymphoma B-cell receptors

AbstractFollicular lymphoma is a monoclonal B-cell malignancy with each patient's tumor expressing a unique cell surface immunoglobulin (Ig), or B-cell receptor (BCR), that can potentially recognize antigens and/or transduce signals into the tumor cell. Here we evaluated the reactivity of tumor derived Igs for human tissue antigens. Self-reactivity was observed in 26% of tumor Igs (25 of 98). For one follicular lymphoma patient, the recognized self-antigen was identified as myoferlin. This patient's tumor cells bound recombinant myoferlin in proportion to their level of BCR expression, and the binding to myoferlin was preserved despite ongoing somatic hypermutation of Ig variable regions. Furthermore, BCR-mediated signaling was induced after culture of tumor cells with myoferlin. These results suggest that antigen stimulation may provide survival signals to tumor cells and that there is a selective pressure to preserve antigen recognition as the tumor evolves.

Pretreatment circulating serum cytokines associated with follicular and diffuse large B-cell lymphoma: A clinic-based case-control study

BackgroundAbnormal immune function is a key factor in predisposition to non-Hodgkin lymphoma (NHL). We evaluated the association of 30 cytokines individually and as a profile with diffuse large B-cell (DLBCL) and follicular (FL) lymphomas. MethodsWe used a multiplexed assay to measure 30 cytokine concentrations in pre-treatment serum in a case-control study of 234 FL, 188 DLBCL, and 400 control participants. Unconditional logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) adjusted for age and sex, and polytomous regression was used to evaluate heterogeneity between FL and DLBCL. Principal components analysis (PCA) was used to assess cytokine profiles associated with FL and DLBCL. ResultsIn single cytokine modeling, we found that 12 of the 30 circulating serum cytokines were significantly (P<0.05) associated with FL and/or DLBCL after accounting for multiple testing (q<0.05). Soluble IL-2R (sIL-2R) had the strongest association with both FL (OR=6.0 for highest versus lowest tertile, 95% CI 3.8–9.5; p-trend=1.8×10−21) and DLBCL (OR=7.6, 95% CI 4.5–13.1; p-trend=7.2×10−20). IL1RA and IL-12p40 also showed similar associations for DLBCL and FL. In contrast, HGF, MIG, and MIP-1α had a stronger association with DLBCL compared to FL, and IL-6, IL-8, IL-10, IFN-γ, IP-10, and VEGF were only statistically significantly associated with DLBCL after accounting for multiple testing. However, in PCA modeling, a cytokine profile based on sIL-2R, IL-1RA, MIG, IP-10, IL-8, and IL-12p40 explained most of the variability between controls and both FL and DLBCL. ConclusionsWe identified some cytokines unique to DLBCL, but overall cytokine associations were more similar than distinct for DLBCL and FL. While these data are limited by concerns of reverse causality, they do suggest cytokines and cytokine profiles that can be prioritized in future studies.

Postmenopausal unopposed estrogen and estrogen plus progestin use and risk of non-Hodgkin lymphoma in the American Cancer Society Cancer Prevention Study-II Cohort

Results of epidemiologic studies on postmenopausal hormone (PMH) use and non-Hodgkin lymphoma (NHL) are inconsistent. To help clarify this issue, PMH and NHL incidence was examined in the Cancer Prevention Study-II Nutrition Cohort. Between 1992 and 2007, 616 cases of NHL were identified among 67 980 postmenopausal women who were cancer-free at baseline. PMH use was updated during follow-up. Using extended Cox regression, we observed a statistically significant 29% higher risk of NHL for ever unopposed estrogen use compared to never use, which was restricted to follicular lymphoma (current estrogen compared to never use, hazard ratio [HR] = 2.25, 95% confidence interval [CI]: 1.17–4.33) and diffuse large B-cell lymphoma (DLBCL, HR = 1.95, 95% CI: 1.13–3.35). There was no association between current estrogen plus progestin (E + P) use and NHL incidence overall, but a suggested positive association between current E + P use and DLBCL, as well as former E + P use and follicular lymphoma. These results suggest that postmenopausal hormones might play a role in NHL etiology, particularly for follicular lymphoma and DLBCL.

65IN - MTOR Inhibitors and Beyond: Targeting a Critical Pathway

ABSTRACT Upregulation of the PI3K/AKT/mTOR signal pathway has been detected in numerous lymphoma subtypes including mantle cell lymphoma (MCL). Accordingly, the mTOR inhibitor Temsirolimus has been registered in EU based on a prospective randomized trial in 162 patients with relapsed MCL. In comparison to monochemotherapy, Temsirolimus achieved significantly higher response rates (22% vs 2%) and longer progression-free survival (4.8 vs. 1.9 months). Moreover, the efficacy of the mTOR inhibitor was confirmed not only in MCL, but also follicular and diffuse large B-cell lymphoma in numerous phase II studies. Based on in vitro studies current trials investigate the combination with chemotherapy. Thus, all 12 initial patients with relapsed MCL responded to a Bendamustin-Rituximab-Temsirolimus combination (BeRT). Recent research has confirmed the critical role of the B-cell receptor pathway upstream of mTOR in the molecular pathogenesis of malignant lymphoma. This pathway represents the physiological survival signal for maturating lymphocytes in the germinal center. Accordingly, small molecules attacking this pathway displayed high efficacy in various lymphoma subtypes even in monotherapy. Thus, a SYK inhibitor has been shown to be effective in patients with relapsed diffuse large cell lymphoma. Especially both, an inhibitor of the PI3K delta isoform (GS-1101, formally Cal-101) only expressed in lymphoid cells and the BTK inhibitor ibrutinib showed high efficacy in relapsed mantle cell lymphoma (response rate about 70%) as well as CLL (response rate between 70–90% in relapsed or previously untreated disease). In contrast, response rates were lower in follicular lymphoma presumely indicating the different survival signal of the constitutive BCL-2 overexpression in this lymphoma subtype. These data also confirm the crucial role of the micromilieu in lymphoid diseases which are hampered by the inhibition of the B-cell receptor pathway. Finally, recent in vitro data suggest some synergism of different members of the B-cell receptor pathway in combination with mTOR inhibition. Such molecular targeted strategies have therefore the potential to become part of the new treatment strategies in a broad spectrum of lymphoid neoplasias. Disclosure M.H. Dreyling: Pfizer (Temsirolimus): scientific advisory board, speaker\\\'s honoraria Janssen (Ibrutinib): scientific advisory board, support of IITs, speaker\\\'s honoraria

Cutaneous B-Cell Neoplasms Mimicking Granulomatous Rosacea or Rhinophyma

Unlike T-cell neoplasms, B-cell lymphoproliferative disorders have a limited clinical spectrum of skin involvement. Cutaneous B-cell neoplasms mimicking rosacea or rhinophyma are rare. We described 12 patients with B-cell lymphoproliferative neoplasms presenting with a facial eruption clinically mimicking rosacea or rhinophyma. Eleven patients were women; ages ranged from 36 to 81 years. The clinical presentation included small papules on the nose and cheeks and around the eyes mimicking granulomatous rosacea; nodules on the nose, cheeks, chin, or forehead mimicking phymatous rosacea; or a combination of both. Three patients had preexisting erythematotelangiectatic rosacea and 1 had rhinophyma. Based on a clinicopathologic correlation and B-cell clonality analysis, the diagnosis was primary cutaneous follicular center B-cell lymphoma in 4 cases, primary cutaneous marginal zone lymphoma in 6, and skin involvement of chronic lymphocytic leukemia in 2. All patients had an indolent course as expected for their disease. Cutaneous involvement of B-cell neoplasms may mimic granulomatous rosacea or rhinophyma. This unusual clinical presentation is more common in women and appears in the setting of preexisting rosacea or as a new eruption. Proliferative B-cell disorders should be added to the differential diagnosis of symmetric papular or papulonodular eruptions of the face.

CD23+CD21highCD1dhigh B Cells in Inflamed Lymph Nodes Are a Locally Differentiated Population with Increased Antigen Capture and Activation Potential

CD23(+)CD21(high)CD1d(high) B cells in inflamed nodes (Bin cells) accumulate in the lymph nodes (LNs) draining inflamed joints of the TNF-α-transgenic mouse model of rheumatoid arthritis and are primarily involved in the significant histological and functional LN alterations that accompany disease exacerbation in this strain. In this study, we investigate the origin and function of Bin cells. We show that adoptively transferred GFP(+) sorted mature follicular B (FoB) cells home preferentially to inflamed LNs of TNF-α-transgenic mice where they rapidly differentiate into Bin cells, with a close correlation with the endogenous Bin fraction. Bin cells are also induced in wild-type LNs after immunization with T-dependent Ags and display a germinal center phenotype at higher rates compared with FoB cells. Furthermore, we show that Bin cells can capture and process Ag-immune complexes in a CD21-dependent manner more efficiently than can FoB cells, and they express greater levels of MHC class II and costimulatory Ags CD80 and CD86. We propose that Bin cells are a previously unrecognized inflammation-induced B cell population with increased Ag capture and activation potential, which may facilitate normal immune responses but may contribute to autoimmunity when chronic inflammation causes their accumulation and persistence in affected LNs.

CALGB 50401: A randomized trial of lenalidomide alone versus lenalidomide plus rituximab in patients with recurrent follicular lymphoma.

8000 Background: Lenalidomide (L) and rituximab (R) are active as single agents in follicular (FL) and other B-cell lymphomas, although combination strategies have not been previously assessed in a randomized fashion. Methods: CALGB 50401 is a randomized phase II study, initially designed to evaluate 3 regimens: R alone (375 mg/m2 weekly x 4), L alone (15 mg cycle 1, then escalated to 20 mg cycles 2-12, administered days 1-21 q 28 days x 12 cycles) or the combination of L+ R (other 2 arms combined). The R alone arm was discontinued due to slow accrual with 3 enrolled subjects. Eligibility included recurrent FL, prior therapy with rituximab alone or in combination, and TTP of ≥ 6 months from last rituximab dose. Prophylactic ASA or LMW heparin was recommended for patients at high risk for thrombosis. Results: Of 94 pts registered to L or LR, 89 (45 L and 44 LR) received at least one dose and had adequate data for analysis. Baseline characteristics include median age 63 (range 34-85) and 60% with intermediate- or high-risk FLIPI. Grade 3-4 adverse events (AE) were most commonly neutropenia (16% L,19% LR), fatigue (9% L, 14% LR) and thrombosis (16% - 7 pts L, 4% - 2 pts LR, p=0.158), and overall were seen in 49% (L) and 52% (LR) with 9% grade 4 in each arm. The full regimen was completed in 33% (L) and 59% (LR) of patients, with the difference due to more progressions or non-responders in the L group. In both arms about 19% of subjects discontinued therapy early due to AEs and dose intensity was over 80%. Objective response rates are L - 49% (13% CR) and LR - 75% (32% CR). With a median follow-up of 1.5 years (range 0.1- 3.6 years), median EFS is 1.2 years (L) and 2.0 years (LR), p=0.0063, log-rank test. Conclusions: Lenalidomide + rituximab is more active than lenalidomide alone in patients with recurrent FL with similar toxicity. A trend toward lower thrombosis risk with LR may relate to greater anti-tumor efficacy. The LR regimen warrants further study in FL including as a backbone for addition of novel agents in relapsed and frontline settings.

Abstract 3767: Use of pharmacokinetic-pharmacodynamic modeling to characterize platelet response following inotuzumab ozogamicin treatment in patients with follicular or diffuse large B-cell non-Hodgkin's lymphoma

Abstract Background: Inotuzumab ozogamicin (CMC-544) is an immunoconjugate chemotherapy agent composed of a CD22-directed IgG4 antibody linked to calicheamicin, a potent cytotoxic anti-tumor antibiotic. Thrombocytopenia was the most frequent adverse event observed in phase 1/2 studies. This integrated population pharmacokinetic-pharmacodynamic (PK/PD) analysis was undertaken to a) elucidate the relationship between exposure of inotuzumab or total calicheamicin (tCali) and the decrease in platelet count; b) identify the covariates that influence the PK of inotuzumab and platelet response; and c) optimize the dosing schedule. Methods: Serum concentrations of inotuzumab, tCali (sum of conjugated and unconjugated forms), and platelet count were available from 5 phase 1/2 studies with follicular or diffuse large B-cell non-Hodgkin's lymphoma (NHL) who received inotuzumab alone or in combination with rituximab. Most patients received 1.8 mg/m2 of inotuzumab infused over 1 hour every 3 to 4 weeks (dose range, 0.4-2.4 mg/m2). The sequential PK/PD analysis was performed by nonlinear regression using NONMEM, version 7, level 1.2 (Icon Development Solutions, Hanover, MD). Covariates (factors for demography, hematology measures, renal and hepatic function, and baseline tumor size) were evaluated using graphical analysis, a general additive model (GAM), and a stepwise covariate model by forward addition and backward elimination process (SCM). Results and Conclusion: A 2-compartment model with linear elimination adequately described the PK of inotuzumab and tCali. The time course of platelet response was modeled using a semi-mechanistic transit compartment model model with drug effect as a sigmoidal Emax function. Significant covariate effects identified for PK estimates of inotuzumab included baseline body surface area (BSA) on clearance (CL) and central volume (V1), and baseline creatinine clearance on inter-compartment clearance (Q). For tCali, significant covariate effects included baseline BSA on CL and V1, treatment occasion (cycle) on CL and V1, and gender on peripheral volume (V2). The CL of tCali decreased from 0.73 L/h in Cycle 1 to 0.3 L/h in Cycles 2 and 3, suggesting a nonlinear disposition process. For the platelet model, the EC50 estimates for effect of inotuzumab and tCali on production of platelets were 219 and 50.2 ng/mL, respectively. Baseline platelet count was identified as a significant covariate. Integrated modeling of drug concentration and platelet count provides a means to quantify the magnitude of platelet suppression and to identify dosing schedules that mitigate the incidence of thrombocytopenia. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 3767. doi:1538-7445.AM2012-3767

Abstract 1034: Upregulation of Ezh2 expression correlates with higher tumor proliferation and grade in non-Hodgkin's B- and T-cell lymphoma

Abstract Polycomb group (PcG) proteins are involved in regulation of hematopoiesis, which include two main members Ezh2 and Bmi-1. Reports on their expression levels in different subtypes of malignant lymphoma and role in lymphomagensis and tumor progression are rather limited. To address this issue, we analyzed a total of 197 patient samples including 10 samples of Hodgkin lymphoma (HL), 109 of B-cell lymphoma (BCL) and 78 of T-cell lymphoma (TCL) by immunohistochemistry. The results showed overall expression in HL, BCL and TCL to be 90%, 56.9% and 84.6% for Ezh2 and 90%, 82.5% and 84.6% for Bmi-1 respectively. Among BCL, highest Ezh2 positivity was seen in Burkitt's lymphoma (BL) followed by high-grade follicular lymphoma (FL) and diffuse large B-cell lymphoma (DLBCL). In TCL, Ezh2 expression was observed in all subtypes and seemed more homogenous. Difference in its expression between aggressive and indolent subtypes of BCL was statistically significant (p= 0.000∼0.010). On the other hand, Bmi-1 was rather more consistently expressed in both BCL and TCL up to 100% in 7 subtypes. Difference in its expression between aggressive and indolent subtypes was statistically insignificant. Ki67 showed strong positive correlation with Ezh2 in BCL (Correlation coefficient (Co) =0.983, p= 0.000) and moderate correlation in TCL (Co=0 .629, p= 0.000). This correlation could not be detected in case of Bmi1. These data suggest that out of the two Polycomb group (PcG) proteins, only Ezh2 correlates with tumor proliferation and signals a more aggressive nature. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 1034. doi:1538-7445.AM2012-1034

Germinal centers

Germinal centers

Primary cutaneous follicular B-cell lymphoma on the scalp

Primary cutaneous follicular B-cell lymphoma on the scalp

A functional role for the histone demethylase UTX in normal and malignant hematopoietic cells

Ubiquitously transcribed tetratricopeptide repeat, X chromosome (UTX), an H3K27Me2/3 demethylase, has been implicated in development, self-renewal, and differentiation of various organs and embryonic stem cells through chromatin modifications and transcriptional regulation of important developmentally related genes, such as Hox genes. However, the function of UTX in hematopoiesis is not well understood. To study the role of UTX in the mammalian hematopoietic system, we used lentiviral short hairpin RNA constructs to knockdown UTX in the murine hematopoietic progenitor cell line EML, in primary murine bone marrow cells and in leukemic cell lines. We report that Utx is highly expressed in the hematopoietic compartment and that it plays an important role in cell proliferation and homeostasis of hematopoietic cells in vitro. Knockdown of UTX in EML and primary murine bone marrow cells impairs their colony-forming ability. Moreover, knockdown of UTX affects expression of key genes that regulate hematopoietic differentiation such as Mll1, Runx1, and Scl in primary murine bone marrow cells. And we further demonstrate that UTX directly associates with the promoters of the Mll1, Runx1, and Scl genes and modulate their transcription by controlling H3K27me3 marks on respective promoter regions. In addition, UTX depletion severely impaired proliferation of several human leukemia cell lines. Together, these data demonstrate a functional role for UTX in normal and malignant hematopoiesis.

Is radioimmunotherapy a 'magic bullet'?

Radioimmunotherapy (RIT) uses monoclonal antibodies directed against specific tumor antigens that are labeled with a particle-emitting radioisotope to deliver radiation directly to tumors (Fig. 1). Lymphoma is a good model for elucidating the effect of RIT because more than 90% of lymphoma B-cells express the cell-surface antigen CD-20. The 2 therapeutic agents for the management of lymphoma currently approved by the United States Food and Drug Administration (FDA) are 90Y ibritumomab tiuxetan and 131I tositumomab. FDA-labeled indications for RIT are the treatment of relapsed or refractory CD20+ follicular B-cell non-Hodgkin's lymphoma (NHL) and consolidation therapy in patients with follicular NHL who have shown a partial or complete response to first-line chemotherapy [1]. Fig. 1 Radioimmunotherapy (RIT) using monoclonal antibodies labeled with a radioisotope emitting gamma- or beta- rays. High-dose chemotherapy (HDC) conditioning administered in association with autologous stem cell transplantation (ASCT) or reduced-intensity conditioning with allogeneic stem cell transplantation are established treatment approaches for patients with chemotherapy-sensitive, relapsed, aggressive, or low-grade NHL. These approaches have been shown to be the only curative options for patients with relapsed NHL. Despite significant advances in ASCT, relapses occur in many patients receiving HDC in conjunction with ASCT because of contaminated grafts or cancer cells remaining in the patient after ablative chemotherapy. The role of RIT in conditioning therapy with stem cell transplantation for NHL is not yet established [2]. The current issue of the Korean Journal of Hematology includes a comparative study of this controversial issue. Jo et al. report that the use of ibritumomab tiuxetan in combination with busulfan, cyclophosphamide, and etoposide (BuCyE) as a conditioning regimen elicited similar hematologic side effects and was associated with a potential benefit in efficacy when compared to treatment with BuCyE alone [3]. Although this study was not designed to evaluate the effect of the conditioning regimen on patient survival, the findings of this study indicate shorter event-free survival and overall survival than those reported by previous studies conducted in Western countries. As the authors point out, most patients in this study had heavily pretreated aggressive lymphomas, and poorer risk factors, which may have contributed to these results. Han et al. previously reported that tandem consolidation therapy using 90Y ibritumomab tiuxetan followed by HDC with ASCT was not feasible for the treatment of high-risk patients with diffuse large B-cell lymphoma in remission after treatment with rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP), because of poor efficacy [4]. Further studies are needed to determine whether ethnic differences in tumor biology affect survival. Well-designed randomized controlled trials for evaluating RIT as a conditioning regimen are also warranted. This study could have important implications for Korean medicine and may suggest that RIT can be safely adopted as a conditioning regimen for malignant lymphomas.

Complementary IL-23 and IL-27 anti-tumor activities cause strong inhibition of human follicular and diffuse large B-cell lymphoma growth in vivo

Interleukin (IL)-23 and IL-27 are pro-inflammatory cytokines that share functional and structural similarities and may exert anti-tumor activities against solid and hematological malignancies. Here, we asked whether IL-23 and IL-27, alone or in combination, may act directly against human follicular lymphoma (FL) and diffuse large B-cell lymphoma (DLBCL) cells. In this study, we demonstrated for the first time that human primary FL and DLBCL cells expressed complete and functional IL-23 and IL-27 receptors (R) and that IL-23 and IL-27 exerted anti-tumor activities in vitro and in vivo through different and complementary mechanisms. In vivo studies using severe combined immunodeficiency /non-obese diabetic mice-injected subcutaneously with human SU-DHL-4 cell line revealed that IL-23 inhibited directly tumor-cell proliferation, whereas IL-27 impaired the angiogenic program of lymphoma cells resulting in strong reduction of cell growth. In addition, combined treatment of IL-23 and IL-27 amplified the anti-tumor effects in vivo as compared with administration of each cytokine alone. These anti-tumor mechanisms were confirmed by in vitro experiments performed with primary lymphoma cells and cell lines. Our results strongly encourage the development of future clinical trials to evaluate the toxicity and efficacy of the IL-23 and IL-27 in lymphoma patients.

Lyn deficiency affects B‐cell maturation as well as survival

Lyn, an Src-family protein tyrosine kinase expressed in B lymphocytes, contributes to initiation of BCR signaling and is also responsible for feedback inhibition of BCR signaling. Lyn-deficient mice have a decreased number of follicular B cells and also spontaneously develop a lupus-like autoimmunity. We used flow cytometric analysis, BrdU labeling and our mathematical models of B-cell population dynamics, to analyze how Lyn deficiency impacts B-cell maturation and survival. We found that Lyn-deficient transitional 1 (T1) cells develop normally, but T2 cells develop primarily from the T1 subset in the spleen and fail to also develop directly from BM immature B cells. Lyn-deficient T2 cells either mature to the follicular B-cell type at a close to normal rate, or die in this compartment rather than access the T3 anergic subset. The ≈ 40% of WT follicular cells that were short-lived exited primarily by joining the T3 anergic subset, whereas the ≈ 15% Lyn(-/-) follicular cells that were not long lived had a high death rate and died in this compartment rather than entering the T3 subset. We hypothesize that exaggerated BCR signaling resulting from weak interactions with self-antigens is largely responsible for these alterations in Lyn-deficient B cells.