Phase 2 study of CHOP-R-14 followed by 90Y-ibritumomab tiuxetan in patients with previously untreated diffuse large B-cell lymphoma.

The aim of this open-label, single-center, phase 2 study was to assess the efficacy and safety of dose-dense CHOP-R-14 followed by 90Y-ibritumomab radioimmunotherapy (RIT) in patients with previously untreated diffuse large B-cell lymphoma (DLBCL). A total of 20 patients, the majority presenting with high-risk characteristics, were enrolled to receive dose-dense cyclophosphamide, doxorubicin, vincristine, prednisone and rituximab every 14 days (CHOP-R-14), followed by 90Y-ibritumomab tiuxetan consolidation. Sixteen patients completed RIT consolidation (rituximab 250 mg/m2 on day 1 and day 7, 8, or 9, followed by a single injection of 90Y-ibritumomab). Complete response (CR) rates of 75 and 95% were observed after treatment with CHOP-R-14 and RIT, respectively; 4 of the 5 patients who achieved a partial response after CHOP-R-14 converted to CR following treatment with RIT. With a median follow-up of 89.7 months, the progression-free and overall survival rates for the cohort were 75 and 85%, respectively. Hematological adverse events were common following CHOP-R-14 and RIT, but they were manageable with treatment interruption. Therefore, this regimen achieved promising survival outcomes in high-risk DLBCL on long term follow-up, with manageable toxicity.

CHOP Chemotherapy Followed by Tositumomab and Iodine-131 Tositumomab for Previously Untreated Diffuse Large B-cell Lymphoma.

The efficacy and safety of tositumomab/iodine-131 tositumomab (TST/I-131 TST) were evaluated in diffuse large B-cell lymphoma patients who responded to first-line cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP). Fifteen patients (median age, 52 years) received dosimetric and therapeutic doses of TST/I-131 TST. The most common Grade 3/4 hematologic adverse events were decreased absolute neutrophil count (47%), white blood cell count (40%), platelet count (27%), and hemoglobin (20%). The complete response (CR) rate increased from 60% post-CHOP to 80% post TST / I-131 TST. With a median follow-up of 120.0 months (range, 14-130 months), median duration of response (95% confidence intervals) was 58.4 months (12.0-not reached [NR]) for patients with confirmed complete response and 58.4 months (20.9-NR) for all confirmed responders. Median progression-free survival and time to treatment failure were 63.0 months (16.1-NR). Median overall survival was not reached; 2 patients died on study. CHOP and TST/I-131 TST demonstrated clinical activity with acceptable toxicity.

Treatment recommendations for patients with Waldenström macroglobulinemia (WM) and related disorders: IWWM-7 consensus.

Waldenström macroglobulinemia (WM) is a distinct B-cell lymphoproliferative disorder for which clearly defined criteria for the diagnosis, initiation of therapy, and treatment strategy have been proposed as part of the consensus panels of International Workshops on WM (IWWM). As part of the IWWM-7 and based on recently published and ongoing clinical trials, the panels updated treatment recommendations. Therapeutic strategy in WM should be based on individual patient and disease characteristics (age, comorbidities, need for rapid disease control, candidacy for autologous transplantation, cytopenias, IgM-related complications, hyperviscosity, and neuropathy). Mature data show that rituximab combinations with cyclophosphamide/dexamethasone, bendamustine, or bortezomib/dexamethasone provided durable responses and are indicated for most patients. New monoclonal antibodies (ofatumumab), second-generation proteasome inhibitors (carfilzomib), mammalian target of rapamycin inhibitors, and Bruton's tyrosine kinase inhibitors are promising and may expand future treatment options. A different regimen is typically recommended for relapsed or refractory disease. In selected patients with relapsed disease after long-lasting remission, reuse of a prior effective regimen may be appropriate. Autologous stem cell transplantation may be considered in young patients with chemosensitive disease and in newly diagnosed patients with very-high-risk features. Active enrollment of patients with WM in clinical trials is encouraged.

Active idiotypic vaccination versus control immunotherapy for follicular lymphoma.

PURPOSE: Idiotypes (Ids), the unique portions of tumor immunoglobulins, can serve as targets for passive and active immunotherapies for lymphoma. We performed a multicenter, randomized trial comparing a specific vaccine (MyVax), comprising Id chemically coupled to keyhole limpet hemocyanin (KLH) plus granulocyte macrophage colony-stimulating factor (GM-CSF) to a control immunotherapy with KLH plus GM-CSF. PATIENTS AND METHODS: Patients with previously untreated advanced-stage follicular lymphoma (FL) received eight cycles of chemotherapy with cyclophosphamide, vincristine, and prednisone. Those achieving sustained partial or complete remission (n=287 [44%]) were randomly assigned at a ratio of 2:1 to receive one injection per month for 7 months of MyVax or control immunotherapy. Anti-Id antibody responses (humoral immune responses [IRs]) were measured before each immunization. The primary end point was progression-free survival (PFS). Secondary end points included IR and time to subsequent antilymphoma therapy. RESULTS: At a median follow-up of 58 months, no significant difference was observed in either PFS or time to next therapy between the two arms. In the MyVax group (n=195), anti-Id IRs were observed in 41% of patients, with a median PFS of 40 months, significantly exceeding the median PFS observed in patients without such Id-induced IRs and in those receiving control immunotherapy. CONCLUSION: This trial failed to demonstrate clinical benefit of specific immunotherapy. The subset of vaccinated patients mounting specific anti-Id responses had superior outcomes. Whether this reflects a therapeutic benefit or is a marker for more favorable underlying prognosis requires further study.

Phase III safety study of rituximab administered as a 90-minute infusion in patients with previously untreated diffuse large B-cell and follicular lymphoma.

This phase III, multicenter, single-arm trial investigated the impact of 90 min rituximab infusions on infusion-related reactions (IRRs) in patients with untreated diffuse large B-cell lymphoma (DLBCL) or follicular lymphoma (FL). Patients received six or eight cycles of rituximab plus cyclophosphamide, vincristine, doxorubicin and prednisone for DLBCL or plus cyclophosphamide, vincristine and prednisolone for FL. A total of 425 patients received the first rituximab infusion per standard guidelines; median duration 240 min. Patients who did not experience grade ≥ 3 IRRs received subsequent infusions over 90 min (363 patients). A total of 303 patients received ≥ 6 cycles of rituximab. Fifty-three patients withdrew after cycle 1; 10 for grade 3 or 4 IRRs and one for a grade 3 adverse event. During cycle 2, 139 patients had IRRs, including four grade 3 IRRs. A 90 min rituximab infusion is well tolerated and feasible for patients with DLBCL or FL who tolerate the first standard rate infusion.

Long-term follow-up of R-CHOP with bevacizumab as initial therapy for mantle cell lymphoma: clinical and correlative results.

BACKGROUND: Emerging evidence indicates that MCL has increased angiogenesis within the tumor microenvironment. We initiated a phase II trial to determine if the addition of bevacizumab to the standard R-CHOP regimen could enhance antitumor effects in patients with previously untreated MCL. PATIENTS AND METHODS: Eleven patients with previously untreated MCL received bevacizumab at 15 mg/kg on day 1, and standard CHOP-21 (CHOP given every 21 days per cycle) with rituximab (375 mg/m(2) per cycle) on day 3 of each cycle for a total of 6 cycles. Planned study end points included safety and efficacy assessment, and exploratory analysis of angiogenic profiles. The study was suspended in August of 2010 based on safety findings in DLBCL (diffuse large B-cell lymphoma) of increased cardiovascular events with the regimen. RESULTS: Beyond the standard R-CHOP safety profile, Grade 3 left ventricular dysfunction developed in 2 patients (18%), Grade 1/2 hypertension, proteinuria, and bleeding each developed in 1 patient (9%). The overall response rate was 82% with 36% complete response (CR)/complete response unconfirmed (CRu). The median progression-free survival (n = 11) was 18 months (95% confidence interval, 3-not reached), and 3-year overall survival rate was 82%. Correlative studies showed increased vascular endothelial growth factor receptor 1 expression in tumor cells at baseline, and elevated levels of plasma vascular endothelial growth factor (VEGF) throughout treatment. CONCLUSION: The addition of bevacizumab to the standard R-CHOP regimen did not appear to significantly improve efficacy beyond that observed from previous studies using R-CHOP alone. Therapeutic strategies that provide sustained inhibition on VEGF-related and VEGF-independent targets within the tumor microenvironment might further improve antiangiogenic effects and warrant further exploration in MCL.

Disabling immune tolerance by programmed death-1 blockade with pidilizumab after autologous hematopoietic stem-cell transplantation for diffuse large B-cell lymphoma: results of an international phase II trial.

PURPOSE: The Programmed Death-1 (PD-1) immune checkpoint pathway may be usurped by tumors, including diffuse large B-cell lymphoma (DLBCL), to evade immune surveillance. The reconstituting immune landscape after autologous hematopoietic stem-cell transplantation (AHSCT) may be particularly favorable for breaking immune tolerance through PD-1 blockade. PATIENTS AND METHODS: We conducted an international phase II study of pidilizumab, an anti-PD-1 monoclonal antibody, in patients with DLBCL undergoing AHSCT, with correlative studies of lymphocyte subsets. Patients received three doses of pidilizumab beginning 1 to 3 months after AHSCT. RESULTS: Sixty-six eligible patients were treated. Toxicity was mild. At 16 months after the first treatment, progression-free survival (PFS) was 0.72 (90% CI, 0.60 to 0.82), meeting the primary end point. Among the 24 high-risk patients who remained positive on positron emission tomography after salvage chemotherapy, the 16-month PFS was 0.70 (90% CI, 0.51 to 0.82). Among the 35 patients with measurable disease after AHSCT, the overall response rate after pidilizumab treatment was 51%. Treatment was associated with increases in circulating lymphocyte subsets including PD-L1E-bearing lymphocytes, suggesting an on-target in vivo effect of pidilizumab. CONCLUSION: This is the first demonstration of clinical activity of PD-1 blockade in DLBCL. Given these results, PD-1 blockade after AHSCT using pidilizumab may represent a promising therapeutic strategy in this disease.

Ocular adnexal MALTomas: case series of patients treated with primary radiation.

BACKGROUND: Ocular adnexal mucosal-associated lymphoid tissue lymphomas (MALTomas) are rare, and there are no phase III trials to guide treatment. Primary radiation therapy has been the typical management. This retrospective series reports the experience of a single institution and adds to the current literature. METHODS: Our electronic medical record system and available paper charts were used to identify patients with MALTomas of the lacrimal gland or sac, conjunctiva, and orbital structures, including extraocular muscles. In order to determine pathology, staging, treatment information, local and distant control, salvage treatments, and late toxicity, records were reviewed. RESULTS: Sixteen patients with ocular adnexal MALTomas had local radiation between 1992 and 2011 for primary or recurrent disease. Fifty percent of patients had lymphoma in the conjunctiva, 25% had lymphoma in the lacrimal sac/gland, and 25% of patients had lymphoma in the posterior orbit. Stage IAE disease occurred in 75% of patients, 6% had stage IIAE disease, and 19% of patients had a positive bone marrow biopsy. One patient received chemotherapy as part of initial therapy. The median radiation dose was 30 Gy (25.5-36 Gy) delivered with electrons (31%) or photons (69%). After a mean follow-up of 62.8 months, 2 patients had residual/progressive disease, 2 had contralateral recurrence, and 1 patient had a distant failure, for local control of 87.5% and overall disease control of 68.75%. Recurrence/progression occurred at a median of 35.45 months. Two patients with residual/progressive disease and 1 patient with a contralateral recurrence were followed, successfully salvaged, and have no evidence of disease. Fourteen patients are still alive, and there were no disease-related/toxicity deaths. Seven patients developed cataracts in the treated eye, 2 patients had radiation retinopathy, 2 had permanent dry eye syndrome, and 1 patient had severe keratopathy requiring enucleation. Six patients (3.75%) had worsening visual acuity of unclear etiology. CONCLUSIONS: Primary radiation therapy for ocular adnexal MALTomas with a median dose of 30 Gy led to excellent local control. Patients who did recur were successfully salvaged. Radiation was generally well tolerated, with expected cataractogenesis, given the dose required to achieve local control (with only 1 patient developing severe keratopathy after receiving the highest dose in this series).

Aggressive disease defined by cytogenetics is associated with cytokine dysregulation in CLL/SLL patients.

Early treatment of CLL/SLL does not impact survival-reflecting limitations in detecting progression early and identifying asymptomatic patients likely to benefit from early treatment. Improved understanding of CLL/SLL biology would identify better prognostic/predictive markers. This study attempts to address these issues by determining the relationship between cytokine aberrations and poor clinical outcomes in CLL/SLL in the context of a genetic-based prognostic model. Fifty-nine serum cytokines/chemokines were measured in 28 untreated CLL/SLL patients. Patients were stratified as GR or int/PR using cytogenetics. Comparison of CLL/SLL with 28 HCs revealed increased expression of Th2 cytokines (IL-10, IL-5, sIL-2Rα; P≤0.01) and decreased levels of Th1 cytokines (IL-17, IL-23, IFN-γ; P≤0.003). In a multivariate analysis of GR versus int/PR groups, differential expression of sIL-2Rα maintained significance with increased expression in int/PR CLL/SLL. With median follow-up of 54.3 months after diagnosis, four patients incurred disease progression, with an IL-17/sIL-2Rα model predicting need for treatment in all cases. In summary, specific cytokine signatures are associated with genetically defined aggressive disease and predict need for therapy. This suggests utility in detecting disease progression early, identifying those likely to incur a survival advantage with early treatment, and directing future therapy.

CD26 protease inhibition improves functional response of unfractionated cord blood, bone marrow, and mobilized peripheral blood cells to CXCL12/SDF-1.

Hematopoietic stem cell transplantation (HSCT) is an important treatment option for patients with malignant and nonmalignant hematologic diseases. Methods to improve transplant efficiency are being explored with the intent to improve engraftment and immune reconstitution post-HSCT. A current approach under investigation involves treatment of donor cells with inhibitors that target the protease CD26, a negative regulator of the chemokine CXCL12/stromal cell-derived factor-1. CD26 inhibitor treatment has been shown to improve the functional response of CD34(+) cord blood (CB) cells, but not CD34(+) granulocyte colony-stimulating factor-mobilized peripheral blood stem cells, to CXCL12/stromal cell-derived factor-1. The effect of CD26 inhibitors on unfractionated CB, bone marrow, or granulocyte colony-stimulating factor-mobilized peripheral blood mononuclear cells has not been evaluated previously. We observed that although CB had greater CD26 expression than bone marrow or mobilized peripheral blood, treatment with a CD26 inhibitor (Diprotin A) resulted in increased responsiveness to stromal cell-derived factor-1 for all three mononuclear cell sources tested. This suggests that clinical therapeutic benefit might be gained by using CD26 inhibitors as a strategy to improve engraftment of unfractionated mobilized peripheral blood cells as well as CB cells.

Granulocyte-macrophage colony stimulating factor-induced immune priming of cyclophosphamide, doxorubicin, vincristine, and prednisone with rituximab chemoimmunotherapy in previously untreated patients with diffuse large B-cell lymphoma and mantle cell lymphoma.

Granulocyte-macrophage colony stimulating factor (GM-CSF) has been shown to enhance CD20 antigen expression, augment antibody-dependent cell-mediated cytotoxicity, and stimulate immune cell proliferation. This may lead to an improved anti-tumor effect of rituximab while reducing the severity of chemotherapy-induced myelosuppression. We evaluated the safety and efficacy of cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) in sequential combination with GM-CSF priming and rituximab in previously untreated patients (n = 39) with diffuse-large B-cell lymphoma (DLBCL) and mantle cell lymphoma (MCL). CHOP was administered every 21 days on day 1, GM-CSF 250 µg/m(2)/day on days 9 through 15, and rituximab 375 mg/m(2) on day 15 of each cycle. The overall response rate was 87%, with complete response in 64%. At a median follow-up of 84.3 months, the overall and progression-free survival rates were 54% and 49%, respectively. The most common toxicity was myelosuppression. Sequential combination of CHOP with GM-CSF priming and rituximab was feasible and effective, warranting further evaluation.

Safety and efficacy of combination therapy with fludarabine, mitoxantrone, and rituximab followed by yttrium-90 ibritumomab tiuxetan and maintenance rituximab as front-line therapy for patients with follicular or marginal zone lymphoma.

BACKGROUND: We conducted a single-institution phase II clinical trial evaluating the safety and efficacy of combination chemoimmunotherapy followed by radioimmunotherapy consolidation and rituximab maintenance as front-line treatment in indolent lymphomas. PATIENTS AND METHODS: We enrolled 20 patients with intermediate- to high-risk follicular lymphoma and 2 patients with marginal zone lymphoma. Treatment consisted of 4-6 cycles of FM (fludarabine 25 mg/m(2) on days 1-3, mitoxantrone 12 mg/m(2) on day 1 of each 28-day cycle). The protocol was amended after enrolling the first 4 patients to include rituximab 375 mg/m(2) on day 1. After 6-8 weeks, responders received (90)Y-ibritumomab tiuxetan (Zevalin) followed by maintenance rituximab (375 mg/m(2) weekly × 4 doses, repeated every 6 months for 2 years). RESULTS: After R-FM, the overall response rate was 95% with a complete response rate (CR) of 45% (n = 10), a partial response (PR) rate of 50% (n = 11), and stable disease in 1 patient. Nineteen patients received (90)Y-ibritumomab tiuxetan with a 60% conversion rate of PR to CR, resulting in an improved CR of 79% (n = 15) and a PR of 21% (n = 4). Fifteen patients proceeded to rituximab maintenance resulting in 3 patients with PR converting to CR. At median follow-up of 49.6 months, median progression-free survival (PFS) was 47.2 months and median overall survival (OS) was not reached in an intent-to-treat analysis. The most common adverse effects were hematologic, with 2 patients experiencing treatment-related myelodysplastic syndrome (MDS), evolving to acute myelogenous leukemia (AML) in 1 patient. CONCLUSION: R-FM with (90)Y-ibritumomab tiuxetan consolidation and rituximab maintenance is well tolerated, improving CR rates and maintaining durable responses in patients with untreated indolent lymphomas.

Bendamustine's emerging role in the management of lymphoid malignancies.

The potent alkylating agent bendamustine has demonstrated substantial efficacy in patients with non-Hodgkin lymphomas (NHLs), including chronic lymphocytic leukemia (CLL), follicular lymphoma, and mantle cell lymphoma. Due to incomplete cross-reactivity between bendamustine and other chemotherapeutic agents, bendamustine has been extensively tested in the relapsed/refractory setting. Bendamustine is highly effective in rituximab-refractory NHL and in patients whose disease is refractory to chemotherapy, including other alkylating agents. It has also demonstrated considerable efficacy in previously untreated NHLs, both alone and in combination with rituximab or other chemotherapeutic agents. Studies suggest complete responses and durability of remission achieved with bendamustine are superior to those achieved with standard regimens. However, longer follow-up is needed to fully establish long-term response duration. Additionally, bendamustine is associated with hematologic toxicity and risk of infection, which must be carefully monitored and managed. This is particularly important in elderly patients with advanced disease. Increased understanding of the mechanisms of action of bendamustine and the efficacy of bendamustine in combination with rituximab in newly diagnosed or relapsed/refractory CLL and indolent lymphomas led to investigation of other combinations. Ongoing studies are examining bendamustine with bortezomib, lenalidomide, temsirolimus, ofatumumab, alemtuzumab, and other novel agents. Bendamustine is also undergoing clinical investigation in patients with relapsed/refractory diffuse large B-cell lymphomas, a patient population with limited therapeutic options currently. This review will summarize current clinical data regarding the efficacy and safety of bendamustine in patients with lymphoma and highlight ongoing clinical trials expanding the role of this alkylating agent in the treatment of hematologic malignancies.

Treatment recommendations for radioimmunotherapy in follicular lymphoma: a consensus conference report.

Radioimmunotherapy (RIT) with (90)Y-ibritumomab tiuxetan or (131)I-tositumomab combines a radiation-emitting radionuclide with an antibody targeting CD20 to treat B-cell non-Hodgkin lymphoma. Multiple studies demonstrate favorable RIT efficacy and safety profiles in follicular lymphoma (FL). The primary toxicity is reversible myelosuppression. Various FL treatment options include single-agent immunotherapy, radiation, chemoimmunotherapy, and RIT. Examining RIT clinical effects and position within treatment algorithms is important to optimal patient benefit. Clinical studies support using single-agent RIT in relapsed/refractory FL, in selected patients with new, untreated FL, and as consolidation after induction chemotherapy or chemoimmunotherapy. RIT as consolidation enhances response rates (with conversion of partial to complete responses following induction therapy) and prolongs disease control versus observation. The overall response rate is 60-80% in the relapsed setting. Time to progression is longer with low-bulk disease, fewer prior therapies, and retained rituximab sensitivity. RIT apparently does not preclude subsequent therapies or increase risk of secondary malignancies compared with chemotherapy's known risk. This article summarizes consensus recommendations for RIT and presents RIT treatment algorithms developed by hematologists/oncologists who regularly treat patients with FL. Maximizing RIT benefit requires healthcare providers to utilize algorithms assisting with treatment decisions.

In vivo expansion of the megakaryocyte progenitor cell population in adult CD26-deficient mice.

OBJECTIVE: Megakaryopoiesis involves commitment of hematopoietic stem cells (HSC) toward the myeloid lineage in combination with the proliferation, maturation, and terminal differentiation of progenitors into megakaryocytes. The exact mechanism of megakaryocyte development from HSC is unknown, but growth factors such as thrombopoietin have been identified as critical. Additionally, it has been suggested that the chemokine CXCL12/stromal-cell derived factor-1α has a role in regulating megakaryopoiesis and thrombopoiesis. We recently reported the importance of the extracellular protease CD26 (dipeptidylpeptidase IV) in regulating HSC responses to CXCL12, as well as modulating HSC trafficking into and out of the bone marrow. However, the importance of CD26 for megakaryopoiesis has not been reported. We therefore compared megakaryocyte development between CD26-deficient (CD26(-/-)) mice and C57BL/6 control mice. MATERIALS AND METHODS: Adult CD26(-/-) mice and C57BL/6 control mice were evaluated using blood differentials, histological analysis, flow cytometric analysis, and progenitor colony assays. RESULTS: Bone marrow from CD26(-/-) mice has a significantly expanded megakaryocyte and megakaryocyte progenitor population compared to control C57BL/6 mice bone marrow. CONCLUSIONS: Our results indicate that endogenous CD26 normally suppresses megakaryopoiesis and that loss of CD26 activity results in expansion of the megakaryocyte progenitor population in vivo. This suggests the potential use of CD26 inhibitors to improve megakaryocyte progenitor function and/or reconstitution of the megakaryocyte cell population.

Clinical and laboratory features of myelofibrosis and limitations of current therapies.

Myelofibrosis (MF) is a life-threatening clonal stem cell malignancy characterized by progressive bone marrow fibrosis and ineffective hematopoiesis. The term "MF" encompasses primary myelofibrosis (PMF) as well as 2 other phenotypically similar malignancies: post-polycythemia vera (PV) MF (PPV-MF) and post-essential thrombocythemia (ET) MF (PET-MF). The World Health Organization classification system for myeloid malignancies recognizes PMF, PV, ET, and chronic myeloid leukemia (CML) as the "classic" myeloproliferative neoplasms (MPNs). Patients with low- or intermediate-1-risk disease have a median survival of 6-15 years, in contrast to those with intermediate-2- or high-risk disease, which is associated with a considerably worse prognosis. Following transformation into (secondary) acute myeloid leukemia (AML), the prognosis of MF is even worse, with a median survival of 3 months or less. Due to the heterogeneous nature of MF, the diagnosis and treatment of this malignancy can be challenging. At present, the only treatment that can be applied with curative intent is allogeneic stem cell transplantation (SCT), whereas no other specific therapies exist that are approved by the US Food and Drug Administration (FDA) for MF. Since most patients with MF appear not to be eligible for allogeneic SCT, patients are often treated by conventional "older" drugs such as androgens and hydroxyurea (HU; hydroxycarbamide), with the principal objective being palliation. Following the establishment of a causal role of a specific mutation in the Janus kinase type 2 (JAK2) gene, namely JAK2V617F, in the molecular pathogenesis of MPNs in 2005, many efforts have been directed towards the development of novel JAK2 (including JAK1/JAK2) inhibitors. Other investigative approaches include immunomodulatory agents, histone deacetylase inhibitors, hedgehog inhibitors, and others. Recently, the positive results of the first in class of the JAK1/JAK2 inhibitors, ruxolitinib (formerly INCB18242), from 2 large phase III studies were presented and are discussed herein.

The future of CD20 monoclonal antibody therapy in B-cell malignancies.

Limitations of therapeutic options for chronic lymphocytic leukemia (CLL) and non-Hodgkin lymphoma (NHL) have necessitated the development of novel treatments/strategies. Rituximab (chimeric anti-CD20 monoclonal antibody [mAb]) considerably improved therapeutic outcomes for patients with B-cell malignancies, particularly when combined with chemotherapy; outcomes, however, are limited by rituximab resistance or reduced response upon re-treatment. Novel anti-CD20 mAbs are in development that may enhance mAb therapy. Ofatumumab (human anti-CD20 mAb) induces highly potent cell lysis, including in cells with low CD20 expression, and is the most clinically advanced new anti-CD20 mAb. Positive phase III interim data for ofatumumab in fludarabine-refractory CLL that is also refractory to alemtuzumab or less suitable for alemtuzumab due to bulky (>5 cm) lymphadenopathy has led to FDA approval of this agent in this population. Preclinical and early clinical assessment of other novel anti-CD20 mAbs include: ocrelizumab, veltuzumab, GA101, AME-133v, and PRO131921; data suggest potential for improved efficacy over rituximab that will require substantiation in large-scale clinical trials. New treatment strategies and novel anti-CD20 mAbs have the potential to enhance long-term outcomes for CLL and NHL.