Upregulation of TET activity with ascorbic acid induces epigenetic modulation of lymphoma cells

The Ten Eleven Translocation (TET) enzymes have been found to be mutated in both diffuse large B-cell (DLBCL) and peripheral T-cell (PTCL) lymphomas resulting in DNA hypermethylation. Recent studies in embryonal stem cells showed that ascorbic acid (AA) is a cofactor for TET with a binding site at the catalytic domain, and enhances TET activity. We hypothesized that AA could potentially enhance TET activity in lymphoma cells to cause DNA demethylation, reactivate expression of tumor suppressor genes and enhance chemosensitivity. We demonstrate in vitro that AA treatment of DLBCL and PTCL cells using AA concentrations achievable intravenously increased TET activity leading to DNA demethylation. This epigenetic effect is independent of hydrogen peroxide. AA treatment increased the expression of SMAD1, a tumor suppressor gene known to be suppressed by methylation, and increased chemosensitivity of lymphoma cells. Twenty-nine percent (10/34) of unselected lymphoma patients had plasma AA levels that were deficient suggesting an additional clinical mechanism of TET hypofunction. These data indicate that AA has the potential to modify TET function in lymphoma and enhance chemosensitivity. In addition, the AA deficiency seen in some patients may further impair TET function and contribute to resistance. Clinical trials testing intravenous AA with chemotherapy are warranted.

International Working Group consensus response evaluation criteria in lymphoma (RECIL 2017)

In recent years, the number of approved and investigational agents that can be safely administered for the treatment of lymphoma patients for a prolonged period of time has substantially increased. Many of these novel agents are evaluated in early-phase clinical trials in patients with a wide range of malignancies, including solid tumors and lymphoma. Furthermore, with the advances in genome sequencing, new "basket" clinical trial designs have emerged that select patients based on the presence of specific genetic alterations across different types of solid tumors and lymphoma. The standard response criteria currently in use for lymphoma are the Lugano Criteria which are based on [18F]2-fluoro-2-deoxy-D-glucose positron emission tomography or bidimensional tumor measurements on computerized tomography scans. These differ from the RECIST criteria used in solid tumors, which use unidimensional measurements. The RECIL group hypothesized that single-dimension measurement could be used to assess response to therapy in lymphoma patients, producing results similar to the standard criteria. We tested this hypothesis by analyzing 47 828 imaging measurements from 2983 individual adult and pediatric lymphoma patients enrolled on 10 multicenter clinical trials and developed new lymphoma response criteria (RECIL 2017). We demonstrate that assessment of tumor burden in lymphoma clinical trials can use the sum of longest diameters of a maximum of three target lesions. Furthermore, we introduced a new provisional category of a minor response. We also clarified response assessment in patients receiving novel immune therapy and targeted agents that generate unique imaging situations.

Anti-CD20 monoclonal antibody-dependent phagocytosis of chronic lymphocytic leukaemia cells by autologous macrophages

Unconjugated monoclonal antibodies (mAbs) are an important component of effective combination therapies for chronic lymphocytic leukaemia (CLL). Antibody-dependent phagocytosis (ADP) is a major mediator of mAb cytotoxicity, but there is limited knowledge of the determinants of ADP efficacy. We used macrophages derived in vitro from autologous circulating monocytes to test the effects of mAb structure and concentration, target : effector cell ratio, duration of co-incubation and CLL cell CD20 expression on ADP. Next-generation anti-CD20 mAbs (ofatumumab, ublituximab, obinutuzumab, ocaratuzumab) were significantly more effective at inducing ADP compared to rituximab, but none were as effective as the anti-CD52 mAb alemtuzumab. Ofatumumab (10 μg/ml) used as a representative next-generation anti-CD20 mAb achieved an ADP plateau at 3 h co-incubation with a target : effector ratio of 10 : 1 (mean = 2.1 CLL cells/macrophage, range = 1.5-3.5). At 0.156 μg/ml (the lowest concentration tested) ofatumumab ADP was significantly higher than alemtuzumab. However, ofatumumab-induced ADP did not increase significantly at higher mAb concentrations. We show that anti-CD20 mAb ADP efficacy is determined by the mAb characteristics, target : effector ratio and incubation time. We suggest that preclinical evaluation of anti-CD20 mAbs to understand the determinants of ADP could be useful in designing future combination therapies for CLL.

Comprehensive serum cytokine analysis identifies IL-1RA and soluble IL-2Rα as predictors of event-free survival in T-cell lymphoma

BACKGROUND

T-cell malignancies are heterogeneous in their clinical presentation and pathology, and have a poor prognosis. New biomarkers are needed to predict prognosis and to provide insights into signal pathways used by these cells. The goal of this study was to evaluate pretreatment serum cytokines in patients with newly diagnosed T-cell neoplasms and correlate with clinical outcome.

PATIENTS AND METHODS

We evaluated 30 cytokines in pretreatment serum from 68 untreated patients and 14 normal controls. Significantly elevated cytokines were correlated with patterns of abnormalities, event-free survival (EFS) and overall survival (OS).

RESULTS

Our data demonstrated significantly elevated levels (versus controls) of seven cytokines-epidermal growth factor (EGF), IL-6, IL-12, interferon gamma-induced protein (IP)-10, soluble interleukin (sIL)-2Rα, monokine induced by gamma interferon (MIG), and IL-1RA-in all T-cell neoplasms (P < 0.05). In the angioimmunoblastic subset, all seven cytokines except IP-10 and in the peripheral T-cell lymphoma (TCL)-not otherwise specified subset, only IP-10, sIL-2Rα, MIG, and IL-8 were statistically elevated compared with control. Of these, elevated cytokines all but EGF were predictive of an inferior EFS; IL-1RA, sIL-2Rα, and MIG predicted an inferior OS. In a multivariate analysis, sIL-2Rα [hazard ratio (HR) = 3.95; 95% confidence interval (CI) 1.61-8.38] and IL-1RA (HR = 3.28; 95% CI 1.47-7.29) levels remained independent predictors of inferior EFS. TCL cell lines secreted high levels of sIL-2Rα and expressed the IL-2Rα surface receptor.

CONCLUSIONS

This report describes the cytokines relevant to prognosis in patients with untreated TCL and provides the rationale to include serum IL-1RA and sIL-2Rα as biomarkers in future trials. Inhibition of these cytokines may also be of therapeutic benefit.

Whole-exome analysis reveals novel somatic genomic alterations associated with outcome in immunochemotherapy-treated diffuse large B-cell lymphoma

Lack of remission or early relapse remains a major clinical issue in diffuse large B-cell lymphoma (DLBCL), with 30% of patients failing standard of care. Although clinical factors and molecular signatures can partially predict DLBCL outcome, additional information is needed to identify high-risk patients, particularly biologic factors that might ultimately be amenable to intervention. Using whole-exome sequencing data from 51 newly diagnosed and immunochemotherapy-treated DLBCL patients, we evaluated the association of somatic genomic alterations with patient outcome, defined as failure to achieve event-free survival at 24 months after diagnosis (EFS24). We identified 16 genes with mutations, 374 with copy number gains and 151 with copy number losses that were associated with failure to achieve EFS24 (P<0.05). Except for FOXO1 and CIITA, known driver mutations did not correlate with EFS24. Gene losses were localized to 6q21-6q24.2, and gains to 3q13.12-3q29, 11q23.1-11q23.3 and 19q13.12-19q13.43. Globally, the number of gains was highly associated with poor outcome (P=7.4 × 10⁻¹²) and when combined with FOXO1 mutations identified 77% of cases that failed to achieve EFS24. One gene (SLC22A16) at 6q21, a doxorubicin transporter, was lost in 54% of EFS24 failures and our findings suggest it functions as a doxorubicin transporter in DLBCL cells.

Prognostic factors for diffuse large B-cell lymphoma in the R(X)CHOP era

BACKGROUND

The introduction of rituximab (R) to conventional CHOP chemotherapy for newly diagnosed diffuse large B-cell lymphoma (DLBCL) led to an unequivocal improvement in survival, establishing RCHOP as the standard of care. Still, nearly 40% of DLBCL patients will eventually die of relapsed disease. Efforts to improve outcomes by addition of new biologic agents (X) to the RCHOP backbone are underway. In this era of R(X)CHOP, it is imperative to develop prognostic and predictive markers, not only to identify patients who will suffer a particularly aggressive course, but also to accurately select patients for clinical trials from which they will most benefit.

DESIGN

The following review was undertaken to describe prognostic factors in DLBCL, with emphasis on markers that are accurate, relatively available, and clinically applicable in 2014.

RESULTS

The International Prognostic Index retains its validity in the era of RCHOP, although with limited ability to predict those with <50% chance of long-term survival. Gene expression profiling has provided novel insights into the biology of DLBCL and led to the development of immunohistochemistry (IHC) algorithms that are in routine practice. Identification of a 'double-hit' (DH) lymphoma by fluorescent in situ hybridization with aberrations involving MYC and/or BCL2 and BCL6 genes has important implications due to its extremely dismal prognosis with RCHOP. Other markers such as the absolute lymphocyte count (ALC), serum immunoglobulin free light chains, vitamin D levels, serum cytokines/chemokines, and imaging with positron emission tomography (PET) have all shown promise as future predictive/prognostic tests.

CONCLUSIONS

The future for new treatment options in DLBCL is promising with current clinical trials testing novel targeted agents such as bortezomib, lenalidomide, and ibrutinib as the 'X' in R(X)CHOP. Predictive factors are required to select and randomize patients appropriately for these trials. We envision the day when 'X' will be chosen based on the biological characteristics of the tumor.

Phase I trial of rituximab, cladribine, and temsirolimus (RCT) for initial therapy of mantle cell lymphoma

BACKGROUND

We conducted this trial to determine the maximum tolerated dose (MTD) of temsirolimus added to an established regimen comprised of rituximab and cladribine for the initial treatment of mantle cell lymphoma.

PATIENTS AND METHODS

A standard phase I cohort of three study design was utilized. The fixed doses of rituximab and cladribine were 375 mg/m(2) i.v. day 1 and 5 mg/m(2)/day i.v. days 1-5 of a 28-day cycle, respectively. There were five planned temsirolimus i.v. dose levels: 15 mg day 1; 25 mg day 1; 25 mg days 1 and 15; 25 mg days 1, 8 and 15; and 25 mg days 1, 8, 15, and 22.

RESULTS

Seventeen patients were treated: three each at levels 1-4 and five at dose level 5. The median age was 75 years (52-86 years). Mantle Cell International Prognostic Index (MIPI) scores were low in 6% (1), intermediate in 59% (10), and high in 35% (6) of patients. Five patients were treated at level 5 without dose limiting toxicity. Hematologic toxicity was frequent: grade 3 anemia in 12%, grade 3 thrombocytopenia in 41%, grade 4 thrombocytopenia in 24%, grade 3 neutropenia in 6%, and grade 4 neutropenia in 18% of patients. The overall response rate (ORR) was 94% with 53% complete response and 41% partial response. The median progression-free survival was 18.7 months.

CONCLUSIONS

Temsirolimus 25 mg i.v. weekly may be safely added to rituximab and cladribine at 375 mg/m(2) i.v. day 1 and 5 mg/m(2)/day i.v. days 1-5 of a 28-day cycle, respectively. This regimen had promising preliminary activity in an elderly cohort of patients with mantle cell lymphoma.

CLINICALTRIALSGOV IDENTIFIER

NCT00787969.

Immunoglobulin G4-related disease of the orbit: imaging features in 27 patients

BACKGROUND AND PURPOSE

Immunoglobulin G4-related disease is a systemic fibroinflammatory process of unknown etiology, characterized by tissue infiltration by immunoglobulin G4 plasma cells. The purpose of this study was to retrospectively identify the spectrum of imaging features seen in immunoglobulin G4-related disease of the orbit.

MATERIALS AND METHODS

This study included 27 patients with biopsy-proved immunoglobulin G4-related disease of the orbit and either a CT or MR imaging of the orbits. These CT or MR imaging examinations were evaluated for the following: extraocular muscle size, extraocular muscle tendon enlargement, lacrimal gland enlargement, infiltrative process in the orbital fat (increased attenuation on CT or abnormal signal on MR imaging), infraorbital nerve enlargement, mucosal thickening in the paranasal sinuses, and extension of orbital findings intracranially.

RESULTS

Extraocular muscles were enlarged in 24 of 27 (89%) patients, 21 (88%) bilaterally. In 32 of 45 (71%) affected orbits, the lateral rectus was the most enlarged muscle. In 26 (96%) patients, the tendons of the extraocular muscles were spared. Nineteen (70%) patients had lacrimal gland enlargement. Twelve (44%) patients had an infiltrative process within the orbital fat. Infraorbital nerve enlargement was seen in 8 (30%) patients. Twenty-four (89%) patients had sinus disease. Cavernous sinus or Meckel cave extension was seen in 3 (11%) patients.

CONCLUSIONS

In patients with extraocular muscle enlargement, particularly when the tendons are spared and the lateral rectus is the most enlarged, and even more so when other noted findings are present, immunoglobulin G4-related disease should be a leading differential consideration, even over more commonly known etiologies of extraocular muscle enlargement.

Long-term follow-up of lenalidomide in relapsed/refractory mantle cell lymphoma: subset analysis of the NHL-003 study

BACKGROUND

Mantle cell lymphoma (MCL) is an uncommon type of non-Hodgkin lymphoma with poor overall prognosis, requiring the development of new therapies. Lenalidomide is an immunomodulatory agent demonstrating antitumor and antiproliferative effects in MCL. We report results from a long-term subset analysis of 57 patients with relapsed/refractory MCL from the NHL-003 phase II multicenter study of single-agent lenalidomide in patients with aggressive lymphoma

DESIGN

Lenalidomide was administered orally 25 mg daily on days 1-21 every 28 days until progressive disease (PD) or intolerability. The primary end point was overall response rate (ORR).

RESULTS

Fifty-seven patients with relapsed/refractory, advanced-stage MCL had a median of three prior therapies. The ORR was 35% [complete response (CR)/CR unconfirmed (CRu) 12%], with a median duration of response (DOR) of 16.3 months (not yet reached in patients with CR/CRu) by blinded independent central review. The median time to first response was 1.9 months. Median progression-free survival was 8.8 months, and overall survival had not yet been reached. The most common grade 3/4 adverse events (AEs) were neutropenia (46%), thrombocytopenia (30%), and anemia (13%).

CONCLUSIONS

These results show the activity of lenalidomide in heavily pretreated, relapsed/refractory MCL. Responders had a durable response with manageable side-effects. Clinical trial number posted on www.clinicaltrials.gov NCT00413036.

Epigenetic mechanisms of protein tyrosine phosphatase 6 suppression in diffuse large B-cell lymphoma: implications for epigenetic therapy

Protein tyrosine phosphatases such as PTPN6 can be downregulated in various neoplasms. PTPN6 expression by immunohistochemistry in 40 diffuse large B-cell lymphoma (DLBCL) tumors was lost or suppressed in 53% (21/40). To elucidate the molecular mechanisms of PTPN6 suppression, we performed a comprehensive epigenetic analysis of PTPN6 promoter 2 (P2). None of the DLBCL primary tumors (0/37) had PTPN6 hypermethylation on the CpG1 island using methylation-specific PCR, pyrosequencing, and high-resolution melting assays. However, hypermethylation in 57% (21/37) of cases was found in a novel CpG island (CpG2) in P2. PTPN6 gene suppression was reversed by 5-aza-deoxycytidine (5-Aza), a DNA methyltransferase inhibitor, and the histone deacetylase inhibitor (HDACi) LBH589. LBH589 and 5-Aza in combination inhibited DLBCL survival and PTPN6 hypermethylation at CpG2. The role of histone modifications was investigated with a chromatin-immunoprecipitation assay demonstrating that PTPN6 P2 is associated with silencing histone marks H3K27me3 and H3K9me3 in DLBCL cells but not normal B cells. 3-Deazaneplanocin A, a histone methyltransferase inhibitor, decreased the H3K27me3 mark, whereas HDACi LBH589 increased the H3K9Ac mark within P2 resulting in re-expression of PTPN6. These studies have uncovered novel epigenetic mechanisms of PTPN6 suppression and suggest that PTPN6 may be a potential target of epigenetic therapy in DLBCL.

Bowel perforation in intestinal lymphoma: incidence and clinical features

BACKGROUND

Perforation is a serious life-threatening complication of lymphomas involving the gastrointestinal (GI) tract. Although some perforations occur as the initial presentation of GI lymphoma, others occur after initiation of chemotherapy. To define the location and timing of perforation, a single-center study was carried out of all patients with GI lymphoma.

PATIENTS AND METHODS

Between 1975 and 2012, 1062 patients were identified with biopsy-proven GI involvement with lymphoma. A retrospective chart review was undertaken to identify patients with gut perforation and to determine their clinicopathologic features.

RESULTS

Nine percent (92 of 1062) of patients developed a perforation, of which 55% (51 of 92) occurred after chemotherapy. The median day of perforation after initiation of chemotherapy was 46 days (mean, 83 days; range, 2-298) and 44% of perforations occurred within the first 4 weeks of treatment. Diffuse large B-cell lymphoma (DLBCL) was the most common lymphoma associated with perforation (59%, 55 of 92). Compared with indolent B-cell lymphomas, the risk of perforation was higher with aggressive B-cell lymphomas (hazard ratio, HR = 6.31, P < 0.0001) or T-cell/other types (HR = 12.40, P < 0.0001). The small intestine was the most common site of perforation (59%).

CONCLUSION

Perforation remains a significant complication of GI lymphomas and is more frequently associated with aggressive than indolent lymphomas. Supported in part by University of Iowa/Mayo Clinic SPORE CA97274 and the Predolin Foundation.

High levels of peripheral blood circulating plasma cells as a specific risk factor for progression of smoldering multiple myeloma

Smoldering multiple myeloma (SMM) carries a 50% risk of progression to multiple myeloma (MM) or related malignancy within the first 5 years following diagnosis. The goal of this study was to determine if high levels of circulating plasma cells (PCs) are predictive of SMM transformation within the first 2–3 years from diagnosis. Ninety-one patients diagnosed with SMM at Mayo Clinic from January 1994 through January 2007 who had testing for circulating PCs using an immunofluorescent assay and adequate follow up to ascertain disease progression, were studied. High level of circulating PCs was defined as absolute peripheral blood PCs >5000 ×10⁶/L and/or > 5% cytoplasmic immunoglobulin (Ig) positive PCs per 100 peripheral blood mononuclear cells. Patients with high circulating PCs (14 of 91 patients, 15%) were significantly more likely to progress to active disease within 2 years compared with patients without high circulating PCs, 71% versus 25%, respectively, P=0.001. Corresponding rates for progression within 3 years were 86% versus 35%, respectively, P<0.001. Overall survival (OS) after both SMM diagnosis and MM diagnosis was also significantly different. High levels of circulating PCs identify SMM patients with an elevated risk of progression within the first 2 to 3 years following diagnosis.

A phase III randomized trial of thalidomide plus zoledronic acid versus zoledronic acid alone in patients with asymptomatic multiple myeloma

Patients with asymptomatic (smoldering) multiple myeloma (AMM) have a high risk of transformation to active multiple myeloma (MM). Bisphosphonates such as zoledronic acid (ZLD) reduce skeletal events in MM and the immunomodulatory agent thalidomide (Thal) has proven effectiveness in active MM. We hypothesized that treatment with Thal and ZLD would prolong the time to progression (TTP) to MM over ZLD alone. Eligible patients had asymptomatic MM and all patients received ZLD 4 mg intravenous monthly; the treatment arm also received Thal 200 mg per day. The TTP was superior for Thal/ZLD (n=35) patients compared with ZLD alone (n=33); median TTP of 2.4 years (95% confidence interval (CI): 1.4-3.6) versus 1.2 years (95% CI: 0.7-2.5) (hazard ratio (HR), 2.05; 95% CI: 1.1-3.8; P-value: 0.02). At 1 year, 86% of Thal/ZLD patients were progression free compared with 55% on ZLD alone (P=0.0048). The overall response rate after year 1 was 37% for Thal/ZLD with a median duration of response of 3.3 years (95% CI: 1.1-NA); there were no confirmed responses to ZLD alone (P=0.0004). The addition of Thal to standard ZLD produces anti-tumor responses whereas ZLD alone does not. Thal/ZLD also prolongs TTP from AMM to MM. This study provides the rationale for further studies in patients with AMM to delay chemotherapy.

Regulation of STAT3 by histone deacetylase-3 in diffuse large B-cell lymphoma: implications for therapy

Diffuse large B-cell lymphoma (DLBCL) with an activated B-cell (ABC) gene-expression profile has been shown to have a poorer prognosis compared with tumors with a germinal center B-cell type. ABC cell lines have constitutive activation of STAT3; however, the mechanisms regulating STAT3 signaling in lymphoma are unknown. In studies of class-I histone deacetylase (HDAC) expression, we found overexpression of HDAC3 in phospho STAT3-positive DLBCL and the HDAC3 was found to be complexed with STAT3. Inhibition of HDAC activity by panobinostat (LBH589) increased p300-mediated STAT3(Lys685) acetylation with increased nuclear export of STAT3 to the cytoplasm. HDAC inhibition abolished STAT3(Tyr705) phosphorylation with minimal effect on STAT3(Ser727) and JAK2 tyrosine activity. pSTAT3(Tyr705)-positive DLBCLs were more sensitive to HDAC inhibition with LBH589 compared with pSTAT3(Tyr705)-negative DLBCLs. This cytotoxicity was associated with downregulation of the direct STAT3 target Mcl-1. HDAC3 knockdown upregulated STAT3(Lys685) acetylation but prevented STAT3(Tyr705) phosphorylation and inhibited survival of pSTAT3-positive DLBCL cells. These studies provide the rationale for targeting STAT3-positive DLBCL tumors with HDAC inhibitors.

Denileukin diftitox in combination with rituximab for previously untreated follicular B-cell non-Hodgkin's lymphoma

Follicular lymphoma exhibits intratumoral infiltration by non-malignant T lymphocytes inluding CD4+CD25+ regulatory T (T_reg) cells. We combined denileukin diftitox with rituximab in previously untreated, advanced-stage follicular lymphoma patients anticipating that denileukin diftitox would deplete CD25+ T_reg cells while rituximab would deplete malignant B-cells. Patients received rituximab 375 mg/m2 weekly for 4 weeks and denileukin diftitox 18 mcg/kg/day for 5 days every 3 weeks for 4 cycles; neither agent was given as maintenance therapy. Between August 2008 and March 2010, 24 patients were enrolled. One patient died before treatment was given and was not included in the analysis. Eleven of 23 patients (48%; 95% CI: 27–69%) responded; 2 (9%) had complete responses and 9 (39%) had partial responses. The progression-free rate at 2 years was 55% (95%CI: 37–82%). Thirteen patients (57%) experienced grade ≥3 adverse events and 1 patient (4%) died. In correlative studies, soluble CD25 and the number of CD25+ T-cells decreased after treatment, however there was a compensatory increase in IL-15 and IP-10. We conclude that while the addition of denileukin diftitox to rituximab decreased the number of CD25+ T-cells, denileukin diftitox contributed to the toxicity of the combination without an improvement in response rate or time to progression.

Lenalidomide can be safely combined with R-CHOP (R2CHOP) in the initial chemotherapy for aggressive B-cell lymphomas: phase I study

Lenalidomide was shown to have significant single-agent activity in relapsed aggressive non-Hodgkin's lymphoma (NHL). We conducted a phase I trial to establish the maximum tolerated dose of lenalidomide that could be combined with R-CHOP (rituximab-cyclophosphamide, doxorubicin, vincristine, and prednisone). Eligible patients were adults with newly diagnosed, untreated CD20 positive diffuse large cell or follicular grade III NHL. Patients received oral lenalidomide on days 1-10 with standard dose R-CHOP every 21 days. All patients received pegfilgrastim on day 2 of the cycle and aspirin prophylaxis. The lenalidomide dose levels tested were 15, 20 and 25 mg. A total of 24 patients were enrolled. The median age was 65 (35-82) years and 54% were over 60 years. Three patients received 15 mg, 3 received 20 mg and 18 received 25 mg of lenalidomide. No dose limiting toxicity was found, and 25 mg on days 1-10 is the recommended dose for phase II. The incidence of grade IV neutropenia and thrombocytopenia was 67% and 21%, respectively. Febrile neutropenia was rare (4%) and there were no toxic deaths. The overall response rate was 100% with a complete response rate of 77%. Lenalidomide at the dose of 25 mg/day administered on days 1 to 10 of 21-day cycle can be safely combined with R-CHOP in the initial chemotherapy of aggressive B-cell lymphoma.

MicroRNA expression in tumor cells from Waldenstrom's macroglobulinemia reflects both their normal and malignant cell counterparts

MicroRNAs (miRNAs) are involved in the regulation of many cellular processes including hematopoiesis, with the aberrant expression of differentiation-stage specific miRNA associated with lymphomagenesis. miRNA profiling has been essential for understanding the underlying biology of many hematological malignancies; however the miRNA signature of the diverse tumor clone associated with Waldenstrom's macroglobulinemia (WM), consisting of B lymphocytes, plasmacytes and lymphoplasmacytic cells, has not been characterized. We have investigated the expression of over 13 000 known and candidate miRNAs in both CD19(+) and CD138(+) WM tumor cells, as well as in their malignant and non-malignant counterparts. Although neither CD19(+) nor CD138(+) WM cells were defined by a distinct miRNA profile, the combination of all WM cells revealed a unique miRNA transcriptome characterized by the dysregulation of many miRNAs previously identified as crucial for normal B-cell lineage differentiation. Specifically, miRNA-9(*)/152/182 were underexpressed in WM, whereas the expression of miRNA-21/125b/181a/193b/223/363 were notably increased (analysis of variance; P<0.0001). Future studies focusing on the effects of these dysregulated miRNAs will provide further insight into the mechanisms responsible for the pathogenesis of WM.

The absolute monocyte and lymphocyte prognostic score predicts survival and identifies high-risk patients in diffuse large-B-cell lymphoma

Despite the use of modern immunochemotherapy regimens, almost 50% of patients with diffuse large-B-cell lymphoma will relapse. Current prognostic models, including the International Prognostic Index, incorporate patient and tumor characteristics. In contrast, recent observations show that variables related to host adaptive immunity and the tumor microenvironment are significant prognostic variables in non-Hodgkin lymphoma. Therefore, we retrospectively examined the absolute monocyte and lymphocyte counts as prognostic variables in a cohort of 366 diffuse large-B-cell lymphoma patients who were treated between 1993 and 2007 and followed at a single institution. The absolute monocyte and lymphocyte counts in univariate analysis predicted progression-free and overall survival when analyzed as continuous and dichotomized variables. On multivariate analysis performed with factors included in the IPI, the absolute monocyte and lymphocyte counts remained independent predictors of progression-free and overall survival. Therefore, the absolute monocyte and lymphocyte counts were combined to generate a prognostic score that identified patients with an especially poor overall survival. This prognostic score was independent of the IPI and added to its ability to identify high-risk patients.

An international phase II trial of single-agent lenalidomide for relapsed or refractory aggressive B-cell non-Hodgkin's lymphoma

BACKGROUND

Lenalidomide is an immunomodulatory agent with antitumor activity in B-cell malignancies. This phase II trial aimed to demonstrate the safety and efficacy of lenalidomide in patients with relapsed or refractory diffuse large B-cell lymphoma (DLBCL), mantle cell lymphoma (MCL), follicular grade 3 lymphoma (FL-III), or transformed lymphoma (TL).

METHODS

Patients received oral lenalidomide 25 mg on days 1-21 every 28 days as tolerated or until progression. The primary end point was overall response rate (ORR).

RESULTS

Two hundred and seventeen patients enrolled and received lenalidomide. The ORR was 35% (77/217), with 13% (29/217) complete remission (CR), 22% (48/217) partial remission, and 21% (45/217) with stable disease. The ORR for DLBCL was 28% (30/108), 42% (24/57) for MCL, 42% (8/19) for FL-III, and 45% (15/33) for TL. Median progression-free survival for all 217 patients was 3.7 months [95% confidence interval (CI) 2.7-5.1]. For 77 responders, the median response duration lasted 10.6 months (95% CI 7.0-NR). Median response duration was not reached in 29 patients who achieved a CR and in responding patients with FL-III or MCL. The most common adverse event was myelosuppression with grade 4 neutropenia and thrombocytopenia in 17% and 6%, respectively.

CONCLUSION

Lenalidomide is well tolerated and produces durable responses in patients with relapsed or refractory aggressive non-Hodgkin's lymphoma.

A phase II trial of the oral mTOR inhibitor everolimus in relapsed aggressive lymphoma

The phosphatidylinositol 3-kinase signal transduction pathway members are often activated in tumor samples from patients with non-Hodgkin's lymphoma (NHL). Everolimus is an oral agent that targets the raptor mammalian target of rapamycin (mTORC1). The goal of this trial was to learn the antitumor activity and toxicity of single-agent everolimus in patients with relapsed/refractory aggressive NHL. Patients received everolimus 10 mg PO daily. Response was assessed after two and six cycles, and then every three cycles until progression. A total of 77 patients with a median age of 70 years were enrolled. Patients had received a median of three previous therapies and 32% had undergone previous transplant. The overall response rate (ORR) was 30% (95% confidence interval: 20-41%), with 20 patients achieving a partial remission and 3 a complete remission unconfirmed. The ORR in diffuse large B cell was 30% (14/47), 32% (6/19) in mantle cell and 38% (3/8) in follicular grade 3. The median duration of response was 5.7 months. Grade 3 or 4 anemia, neutropenia and thrombocytopenia occurred in 14, 18 and 38% of patients, respectively. Everolimus has single-agent activity in relapsed/refractory aggressive NHL and provides proof-of-concept that targeting the mTOR pathway is clinically relevant.

The de-ubiquitinase UCH-L1 is an oncogene that drives the development of lymphoma in vivo by deregulating PHLPP1 and Akt signaling

De-ubiquitinating enzymes (DUBs) can reverse the modifications catalyzed by ubiquitin ligases and as such are believed to be important regulators of a variety of cellular processes. Several members of this protein family have been associated with human cancers; however, there is little evidence for a direct link between deregulated de-ubiquitination and neoplastic transformation. Ubiquitin C-terminal hydrolase (UCH)-L1 is a DUB of unknown function that is overexpressed in several human cancers, but whether it has oncogenic properties has not been established. To address this issue, we generated mice that overexpress UCH-L1 under the control of a ubiquitous promoter. Here, we show that UCH-L1 transgenic mice are prone to malignancy, primarily lymphomas and lung tumors. Furthermore, UCH-L1 overexpression strongly accelerated lymphomagenesis in Emu-myc transgenic mice. Aberrantly expressed UCH-L1 boosts signaling through the Akt pathway by downregulating the antagonistic phosphatase PHLPP1, an event that requires its de-ubiquitinase activity. These data provide the first in vivo evidence for DUB-driven oncogenesis and suggest that UCH-L1 hyperactivity deregulates normal Akt signaling.

Sorafenib, a dual Raf kinase/vascular endothelial growth factor receptor inhibitor has significant anti-myeloma activity and synergizes with common anti-myeloma drugs

Multiple myeloma is characterized by increased bone marrow neovascularization driven in part by vascular endothelial growth factor (VEGF). In addition, the Ras/Raf/MEK/ERK pathway is critical for the proliferation of myeloma cells and is often upregulated. Sorafenib (Nexavar) is a novel multi-kinase inhibitor that acts predominantly through inhibition of Raf-kinase and VEGF receptor 2, offering the potential for targeting two important aspects of disease biology. In in vitro studies, sorafenib-induced cytotoxicity in MM cell lines as well as freshly isolated patient myeloma cells. It retained its activity against MM cells in co-culture with stromal cells or with interleukin-6, VEGF or IGF; conditions mimicking tumor microenvironment. Examination of cellular signaling pathways showed downregulation of Mcl1 as well as decreased phosphorylation of the STAT3 and MEK/ERK, as potential mechanisms of its anti-tumor effect. Sorafenib induces reciprocal upregulation of Akt phosphorylation; and simultaneous inhibition of downstream mTOR with rapamycin leads to synergistic effects. Sorafenib also synergizes with drugs such as proteasome inhibitors and steroids. In a human in vitro angiogenesis assay, sorafenib showed potent anti-angiogenic activity. Sorafenib, through multiple mechanisms exerts potent anti-myeloma activity and these results favor further clinical evaluation and development of novel sorafenib combinations.

Final results of NCCTG N0489: Epratuzumab and rituximab in combination with cyclophosphamide, doxorubicin, vincristine, and prednisone chemotherapy (ER-CHOP) in patients with previously untreated diffuse large B-cell lymphoma

8508

Background: A prior pilot study of epratuzumab (Immunomedics) and rituximab in combination with CHOP chemotherapy (ER-CHOP) in untreated patients with diffuse large B-cell lymphoma demonstrated feasibility and safety. This multicenter NCCTG phase II study was carried out to assess efficacy. Methods: Patients received immunochemotherapy on the following schedule: epratuzumab 360 mg/m2, rituximab 375 mg/m2, and standard dose CHOP every 3 weeks for 6 cycles. Weekly blood counts were obtained to monitor hematological toxicity. Primary endpoint was 12 month event free survival (EFS12). Secondary endpoints were response rate, progression free survival, functional CR (PET negative) and toxicity. Results: 107 patients were accrued from Feb 2006 to Aug 2007. 29 patients were ineligible resulting in 78 eligible patients. Baseline patient characteristics for the eligible patients included median age 61 (range 21–82); 59% were male. 81% had advanced stage; IPI was 0–1 in 17 pts (22%), 2 in 22 pts (28%), 3 in 29 pts (37%) and 4–5 in 10 pts (13%). Based on the revised IPI (R-IPI) 50% were poor/high risk (IPI 3–5). 71% had an elevated LDH. Performance score was 0–1 in 69 pts and 2–3 in 9 pts. The ORR was 95% (CR/CRu: 73%). For the low risk IPI (0–2), ORR was 95% (CR/CRu: 74%) and for the high risk IPI (3–5), ORR was 95% (CR/CRu: 72%). The EFS at 12 months was 80%. The 12 month progression free survival (PFS12) and overall survival (OS12) is 82% and 88% respectively. EFS12, PFS12 and OS12 by IPI risk category is shown ( Table ). Conclusions: ER-CHOP every 21 days is feasible and safe. The ORR, EFS and PFS compare favorably to studies using R-CHOP especially in the high-intermediate and high risk IPI subgroups. A randomized phase III trial of R-CHOP vs ER-CHOP is needed to prove that dual antibody targeting in combination with CHOP is better.

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No significant financial relationships to disclose.

Efficacy and safety of lenalidomide oral monotherapy in patients with relapsed or refractory mantle-cell lymphoma: Results from an international study (NHL-003)

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Introduction: Relapsed or refractory MCL patients demonstrated a promising overall response rate (ORR) of 53% with a median duration of response (DR) of 13.7 months to single-agent lenalidomide when analyzed as a subset in a recent a phase II study (NHL-002). A supporting international phase II trial (NHL-003) of single-agent lenalidomide was initiated for patients with relapsed or refractory aggressive NHL. In this report, we analyze the current results from the MCL patients enrolled in this trial. Methods: Patients with relapsed or refractory MCL and measurable disease 2 cm after at least 1 prior treatment regimen were eligible. Patients received 25 mg of lenalidomide orally once daily on days 1–21 of every 28-day cycle. Patients continued therapy until disease progression or toxicity. The 1999 IWLRC methodology was used to assess response and progression. Results: Fifty-four MCL patients were enrolled and were evaluable for response assessment. Median age was 69 years (33–82) and 40 patients (74%) were male. Median time from diagnosis was 3.2 years (0.4–10.4), patients had received a median of 3 prior treatments (1–8), 17 of the patients (32%) had received prior bortezomib therapy (MCL-bortezomib), and 14 (26%) had received a prior stem cell transplant (MCL-stem cell). Response rates are shown in the Table. The most common grade 3 or 4 adverse events were neutropenia (43%), thrombocytopenia (22%) and anemia (11%). Conclusions: This is the second study to demonstrate that lenalidomide oral monotherapy is effective in the treatment of patients with relapsed or refractory MCL, with manageable side effects.

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Efficacy of lenalidomide oral monotherapy in relapsed or refractory indolent non-Hodgkin's lymphoma: Final results of NHL-001

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Background: Lenalidomide has shown activity in a wide range of hematological malignancies. We conducted a phase II trial of single-agent lenalidomide in indolent non-Hodgkin's lymphoma (NHL). Methods: Patients with relapsed or refractory indolent NHL were eligible, with no limit on the number of previous therapies. Oral lenalidomide 25 mg was self-administered once-daily on days 1–21 of every 28-day cycle for up to 52 weeks as tolerated, or until disease progression. The primary endpoint was overall response rate (ORR), with secondary endpoints of response duration, progression-free survival (PFS), and safety. Results: Forty-three patients were enrolled and were evaluable for response and safety. Patients had received a median of 3 prior systemic therapies (1–17) and half of all patients were refractory to their last therapy. The ORR was 23% (10/43), including a complete response (CR) or unconfirmed CR (CRu) rate of 7%. The median time to first response was 3.6 months (1.7–4.2) and the median time to CR or CRu was 4.2 months (1.9–11.1). Twenty-seven percent (6/22) of patients with follicular lymphoma grade 1 or 2, and 22% (4/18) of patients with small lymphocytic lymphoma responded to therapy. The median duration of response has not reached, but is longer than 16.5 months with 7 of 10 responses ongoing at 15–28 months. Median PFS was 4.4 months (2.5–10.4). Adverse events were consistent with the known safety profile of lenalidomide and manageable; the most common grade 3 or 4 adverse events were neutropenia (30% and 16%, respectively) and thrombocytopenia (14% and 5%, respectively). Conclusions: Oral lenalidomide monotherapy produces durable responses with manageable side effects in relapsed or refractory indolent NHL and warrants further investigation in the treatment of indolent NHL.

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