Steven H. Bernstein

Characterization of a rare IL-10–competent B-cell subset in humans that parallels mouse regulatory B10 cells

Regulatory B cells control inflammation and autoimmunity in mice, including the recently identified IL-10-competent B10 cell subset that represents 1% to 3% of spleen B cells. In this study, a comparable IL-10-competent B10 cell subset was characterized in human blood. B10 cells were functionally identified by their ability to express cytoplasmic IL-10 after 5 hours of ex vivo stimulation, whereas progenitor B10 (B10pro) cells required 48 hours of in vitro stimulation before they acquired the ability to express IL-10. B10 and B10pro cells represented 0.6% and approximately 5% of blood B cells, respectively. Ex vivo B10 and B10pro cells were predominantly found within the CD24(hi)CD27(+) B-cell subpopulation that was able to negatively regulate monocyte cytokine production through IL-10-dependent pathways during in vitro functional assays. Blood B10 cells were present in 91 patients with rheumatoid arthritis, systemic lupus erythematosus, primary Sjögren syndrome, autoimmune vesiculobullous skin disease, or multiple sclerosis, and were expanded in some cases as occurs in mice with autoimmune disease. Mean B10 + B10pro-cell frequencies were also significantly higher in patients with autoimmune disease compared with healthy controls. The characterization of human B10 cells will facilitate their identification and the study of their regulatory activities during human disease.

Multicenter Phase II Study of Bortezomib in Patients With Relapsed or Refractory Mantle Cell Lymphoma

PURPOSE Evaluate response rate, duration of response (DOR), time-to-progression (TTP), overall survival (OS), and safety of bortezomib treatment in patients with relapsed or refractory mantle cell lymphoma (MCL). PATIENTS AND METHODS Bortezomib 1.3 mg/m(2) was administered on days 1, 4, 8, and 11 of a 21-day cycle, for up to 17 cycles. Response and progression were determined using International Workshop Response Criteria, both using data from independent radiology review and by the investigators. Primary efficacy analyses were based on data from independent radiology review. RESULTS In total, 155 patients were treated. Median number of prior therapies was one (range, one to three). Response rate in 141 assessable patients was 33% including 8% complete response (CR)/unconfirmed CR. Median DOR was 9.2 months. Median TTP was 6.2 months. Results by investigator assessments were similar. Median OS has not been reached after a median follow-up of 13.4 months. The safety profile of bortezomib was similar to previous experience in relapsed multiple myeloma. The most common adverse events grade 3 or higher were peripheral neuropathy (13%), fatigue (12%), and thrombocytopenia (11%). Death from causes that were considered to be treatment related was reported for 3% of patients. CONCLUSION These results confirm the activity of bortezomib in relapsed or refractory MCL, with predictable and manageable toxicities. Bortezomib provides significant clinical activity in terms of durable and complete responses, and may therefore represent a new treatment option for this population with usually very poor outcome. Studies of bortezomib-based combinations in MCL are ongoing.

Bortezomib in patients with relapsed or refractory mantle cell lymphoma: updated time-to-event analyses of the multicenter phase 2 PINNACLE study

BACKGROUND We previously reported results of the phase 2, multicenter PINNACLE study, which confirmed the substantial single-agent activity of bortezomib in patients with relapsed or refractory mantle cell lymphoma (MCL). MATERIALS AND METHODS We report updated time-to-event data, in all patients and by response to treatment, after extended follow-up (median 26.4 months). RESULTS Median time to progression (TTP) was 6.7 months. Median time to next therapy (TTNT) was 7.4 months. Median overall survival (OS) was 23.5 months. In responding patients, median TTP was 12.4 months, median duration of response (DOR) was 9.2 months, median TTNT was 14.3 months, and median OS was 35.4 months. Patients achieving complete response had heterogeneous disease characteristics; among these patients, median TTP and DOR were not reached, and median OS was 36.0 months. One-year survival rate was 69% overall and 91% in responding patients. Median OS from diagnosis was 61.1 months, after median follow-up of 63.7 months. Activity was seen in patients with refractory disease and patients relapsing following high-intensity treatment. Toxicity was generally manageable. CONCLUSIONS Single-agent bortezomib is associated with lengthy responses and notable survival in patients with relapsed or refractory MCL, with considerable TTP and TTNT in responding patients, suggesting substantial clinical benefit.

Rituximab in Combination With Fludarabine Chemotherapy in Low-Grade or Follicular Lymphoma

PURPOSE To evaluate the safety and efficacy of fludarabine plus rituximab in treatment-naive or relapsed patients with low-grade and/or follicular non-Hodgkins lymphoma. PATIENTS AND METHODS This was an open-label, single-arm, single-center phase II study enrolling 40 patients. During the first week of the study, patients received two infusions of rituximab 375 mg/m2 administered 4 days apart. Seventy-two hours after the second infusion of rituximab, patients received the first of six cycles of fludarabine chemotherapy (25 mg/m2/d for 5 days on a 28-day cycle). Single infusions of rituximab were administered 72 hours before the second, fourth, and sixth cycles of fludarabine, and two infusions of rituximab were given 4 weeks after the last cycle of fludarabine. Treatment duration was 26 weeks. RESULTS An overall response rate of 90% (80% complete response rate) was achieved in the intent-to-treat population. Similar response rates were seen in treatment-naive and previously treated patients. The median duration of response has not been reached at 40+ months. The median follow-up time in this study is 44 months (range, 15 to 66 months). In patients positive for the 14;18 translocation in blood and/or marrow at enrollment, molecular remission was achieved in 88% of cases, with patients remaining negative for up to 4 years to date. Hematologic toxicity was manageable, and except for a 15% incidence of herpes simplex/zoster infections, infectious complications were rare. Nonhematologic toxicities were minimal. CONCLUSION Rituximab plus fludarabine was well tolerated and associated with an excellent complete response rate, including molecular remissions, in patients with low-grade or follicular lymphoma.

The combination of bendamustine, bortezomib, and rituximab for patients with relapsed/refractory indolent and mantle cell non-Hodgkin lymphoma

Given the significant activity and tolerability of bendamustine, rituximab, and bortezomib in patients with relapsed indolent and mantle cell non-Hodgkin lymphoma, and laboratory studies suggesting synergistic activity, we conducted a multicenter phase 2 study of the bendamustine/bortezomib/rituximab combination. Patients with relapsed or refractory indolent and mantle cell lymphoma with adequate organ function were treated with bendamustine 90 mg/m² days 1 and 4; rituximab 375 mg/m² day 1, and bortezomib 1.3 mg/m² days 1, 4, 8, 11. Six 28-day cycles were planned. Thirty patients (7 with mantle cell lymphoma) were enrolled and treated. Eight patients experienced serious adverse events, including one event of grade 5 sepsis. Common nonhematologic adverse events were generally grade 1 or grade 2 and included nausea (50%), neuropathy (47%), fatigue (47%), constipation (40%), and fever (40%). Of 29 patients evaluable for efficacy, 24 (83%) achieved an objective response (including 15 with complete response). With median follow-up of 24 months, 2-year progression-free survival is 47% (95% confidence interval, 25%-69%). On the basis of these promising results, the US cooperative groups have initiated randomized trials to evaluate this regimen in follicular and mantle cell lymphoma. This trial was registered at www.clinicaltrials.gov as #NCT00547534.

Phase II Study of Alisertib, a Selective Aurora A Kinase Inhibitor, in Relapsed and Refractory Aggressive B- and T-Cell Non-Hodgkin Lymphomas

PURPOSE Aurora A kinase (AAK) is overexpressed in aggressive lymphomas and can correlate with more histologically aggressive forms of disease. We therefore designed a phase II study of alisertib, a selective AAK inhibitor, in patients with relapsed and refractory aggressive non-Hodgkin lymphomas. PATIENTS AND METHODS Patients age ≥ 18 years were eligible if they had relapsed or refractory diffuse large B-cell lymphoma (DLBCL), mantle-cell lymphoma (MCL), transformed follicular lymphoma, Burkitts lymphoma, or noncutaneous T-cell lymphoma. Alisertib was administered orally at 50 mg twice daily for 7 days in 21-day cycles. RESULTS We enrolled 48 patients. Histologies included DLBCL (n = 21), MCL (n = 13), peripheral T-cell lymphoma (n = 8), transformed follicular lymphoma (n = 5), and Burkitts (n = 1). Most common grade 3 to 4 adverse events were neutropenia (63%), leukopenia (54%), anemia (35%), thrombocytopenia (33%), stomatitis (15%), febrile neutropenia (13%), and fatigue (6%). Four deaths during the study were attributed to progressive non-Hodgkin lymphoma (n = 2), treatment-related sepsis (n = 1), and unknown cause (n = 1). The overall response rate was 27%, including responses in three of 21 patients with DLBCL, three of 13 with MCL, one of one with Burkitts lymphoma, two of five with transformed follicular lymphoma, and four of eight with noncutaneous T-cell lymphoma. The alisertib steady-state trough concentration (n = 25) revealed the expected pharmacokinetic variability, with a trend for higher incidence of adverse event-related dose reductions at higher trough concentrations. Analysis for AAK gene amplification and total AAK protein revealed no differences between histologies or correlation with clinical response. CONCLUSION The novel AAK inhibitor alisertib seems clinically active in both B- and T-cell aggressive lymphomas. On the basis of these results, confirmatory single-agent and combination studies have been initiated.

More Than Structural Cells, Fibroblasts Create and Orchestrate the Tumor Microenvironment

The tumor microenvironment comprises many cell types including infiltrating immune cells such as lymphocytes, endothelial cells and a complex stroma consisting mainly of fibroblasts. Fibroblasts are heterogeneous and consist of Thy-1+ and Thy-1− subsets that define different biosynthetic and differentiation potential. They produce mediators linked to carcinogenesis and metastasis, including Cox-2 and PGE2, both of which are also increased in most cancers. This review will highlight the emerging role of the complex fibroblastic stroma in establishing a microenvironment supporting malignant transformation, tumor growth and attenuation of host anti-tumor immune responses.

Activated human B lymphocytes express cyclooxygenase-2 and cyclooxygenase inhibitors attenuate antibody production.

Nonsteroidal anti-inflammatory drugs (NSAIDs) are widely used for the treatment of inflammatory diseases and target cyclooxygenases 1 and 2 (Cox-1, Cox-2) that are responsible for PG production. Newer Cox-2-selective drugs have been heavily prescribed to quench inflammation. Little is known about whether or not these drugs influence human B lymphocytes and their ability to produce Ab. We report herein that activated human B cells not only highly express Cox-2 and produce PGs, but that the NSAID indomethacin and Cox-2-selective drugs profoundly inhibit the ability of human B cells to produce IgG and IgM in vitro. Human blood B cells highly express Cox-2 mRNA and protein and produce PGs after activation with CD40L, pansorbin, or CD40L plus BCR engagement. Cox-2 is also highly expressed by human tonsil B cells, as shown by immunohistochemistry. Cox-inhibiting drugs modestly affect purified B cell proliferation but profoundly reduce Ab production. The ability of whole blood to produce IgM and IgG following stimulation is also strongly inhibited. In support that Cox-2 plays a seminal role in B lymphocyte Ab production, Cox-2 knockout mice have 64% less IgM and 35% less IgG than normal littermate controls. These findings support that NSAIDs and the new Cox-2-selective drugs have an unsuspected target, the B cell, and attenuate Ab production in humans. Use of NSAIDs may therefore influence autoantibody production in autoimmune diseases and may dampen humoral immunity in response to antigenic challenge/vaccination.

Expression of the early growth response 1 and 2 zinc finger genes during induction of monocytic differentiation.

Members of the early growth response (EGR) gene family are rapidly induced after mitogenic stimulation of diverse cell types. The present work has examined EGR gene expression during differentiation of myeloid leukemia cells along the monocytic lineage and in activated monocytes. Low levels of EGR-1 transcripts were detectable in untreated U-937 and HL-60 leukemia cells. In contrast, treatment of these cells with 12-O-tetradecanoylphorbol-13-acetate (TPA) was associated with increases (within 1 h) in EGR-1 mRNA levels. The induction of monocytic differentiation by TPA and other agents was further associated with increases in EGR-2, but not EGR-3 or EGR-4, mRNA levels in these cells. Treatment of resting peripheral blood monocytes with the macrophage colony-stimulating factor (M-CSF) was also associated with rapid (within 15 min) increases in expression of the EGR-1 and EGR-2 genes. The results of nuclear run-on assays demonstrate that EGR-1 mRNA levels are increased in part by transcriptional activation of this gene in M-CSF-stimulated monocytes. The results also demonstrate that both EGR-1 and EGR-2 mRNA levels are regulated at the posttranscriptional level by a labile protein that destabilizes these transcripts. Finally, we demonstrate that dexamethasone, an inhibitor of monocytic differentiation, blocks the associated increases in EGR-1 and EGR-2 expression. Taken together, the results indicate that the EGR-1 and EGR-2 early response genes are involved in the induction of myeloid leukemia cell differentiation along the monocytic lineage and in the activation of human monocytes.

A phase II multicenter trial of hyperCVAD MTX/Ara-C and rituximab in patients with previously untreated mantle cell lymphoma; SWOG 0213

BACKGROUND Rituximab-hyper-CVAD alternating with rituximab-high-dose methotrexate and cytarabine is a commonly utilized regimen in the United States for mantle cell lymphoma (MCL) based on phase II single institutional data. To confirm the clinical efficacy of this regimen and determine its feasibility in a multicenter study that includes both academic and community-based practices, a phase II study of this regimen was conducted by SWOG. PATIENTS AND METHODS Forty-nine patients with advanced stage, previously untreated MCL were eligible. The median age was 57.4 years (35-69.8 years). RESULTS Nineteen patients (39%) did not complete the full scheduled course of treatment due to toxicity. There was one treatment-related death and two cases of secondary myelodysplastic syndrome (MDS). There were 10 episodes of grade 3 febrile neutropenia, 19 episodes of grade 3 and 1 episode of grade 4 infection. With a median follow-up of 4.8 years, the median progression-free survival was 4.8 years (5.5 years for those ≤ 65 years) and the median overall survival (OS) was 6.8 years. CONCLUSIONS Although this regimen is toxic, it is active for patients ≤ 65 years of age and can be given both at academic centers and in experienced community centers.