Ofatumumab in combination with ICE or DHAP chemotherapy in relapsed or refractory intermediate grade B-cell lymphoma

Modulating Cholesterol Metabolism via ACAT1 Knockdown Enhances Anti-B-Cell Lymphoma Activities of CD19-Specific Chimeric Antigen Receptor T Cells by Improving the Cell Activation and Proliferation

CD19-specific CAR-T immunotherapy has been extensively studied for the treatment of B-cell lymphoma. Recently, cholesterol metabolism has emerged as a modulator of T lymphocyte function and can be exploited in immunotherapy to increase the efficacy of CAR-based systems. Acetyl-CoA acetyltransferase 1 (ACAT1) is the major cholesterol esterification enzyme. ACAT1 inhibitors previously shown to modulate cardiovascular diseases are now being implicated in immunotherapy. In the present study, we achieved knockdown of ACAT1 in T cells via RNA interference technology by inserting ACAT1-shRNA into anti-CD19-CAR-T cells. Knockdown of ACAT1 led to an increased cytotoxic capacity of the anti-CD19-CAR-T cells. In addition, more CD69, IFN-γ, and GzmB were expressed in the anti-CD19-CAR-T cells. Cell proliferation was also enhanced in both antigen-independent and antigen-dependent manners. Degranulation was also improved as evidenced by an increased level of CD107a. Moreover, the knockdown of ACAT1 led to better anti-tumor efficacy of anti-CD19 CAR-T cells in the B-cell lymphoma mice model. Our study demonstrates novel CAR-T cells containing ACAT1 shRNA with improved efficacy compared to conventional anti-CD19-CAR-T cells in vitro and in vivo.

Impact of tumor microenvironment on efficacy of anti-CD19 CAR T cell therapy or chemotherapy and transplant in large B cell lymphoma

The phase 3 ZUMA-7 trial in second-line large B cell lymphoma demonstrated superiority of anti-CD19 CAR T cell therapy (axicabtagene ciloleucel (axi-cel)) over standard of care (SOC; salvage chemotherapy followed by hematopoietic transplantation) ( NCT03391466 ). Here, we present a prespecified exploratory analysis examining the association between pretreatment tumor characteristics and the efficacy of axi-cel versus SOC. B cell gene expression signature (GES) and CD19 expression associated significantly with improved event-free survival for axi-cel (P = 0.0002 for B cell GES; P = 0.0165 for CD19 expression) but not SOC (P = 0.9374 for B cell GES; P = 0.5526 for CD19 expression). Axi-cel showed superior event-free survival over SOC irrespective of B cell GES and CD19 expression (P = 8.56 × 10-9 for B cell GES high; P = 0.0019 for B cell GES low; P = 3.85 × 10-9 for CD19 gene high; P = 0.0017 for CD19 gene low). Low CD19 expression in malignant cells correlated with a tumor GES consisting of immune-suppressive stromal and myeloid genes, highlighting the inter-relation between malignant cell features and immune contexture substantially impacting axi-cel outcomes. Tumor burden, lactate dehydrogenase and cell-of-origin impacted SOC more than axi-cel outcomes. T cell activation and B cell GES, which are associated with improved axi-cel outcome, decreased with increasing lines of therapy. These data highlight differences in resistance mechanisms to axi-cel and SOC and support earlier intervention with axi-cel.

PD-1 blockade combined with ICE regimen in relapsed/refractory diffuse large B-cell lymphoma

The prognosis of relapsed/refractory (R/R) diffuse large B-cell lymphoma (DLBCL) is poor. The efficacy of salvage therapy with ICE (ifosfamide, carboplatin, and etoposide) is limited. DLBCL can evade immune surveillance by upregulating programmed cell death ligand 1 (PD-L1). The purpose of this study was to explore the efficacy and safety of programmed cell death 1 (PD-1) blockade combined with ICE regimen (P-ICE) in the treatment of R/R DLBCL patients. In this study, we retrospectively explored efficacy and toxicity in R/R DLBCL patients treated with P-ICE. Prognostic biomarkers, including clinical features and molecular markers related to efficacy, were explored. From February 2019 to May 2020, a total of 67 patients treated with the P-ICE regimen were analyzed. The median follow-up time was 24.7 months (range: 1.4-39.6 months), with an objective response rate (ORR) of 62.7% and a complete response rate (CRR) of 43.3%. The 2-year progression-free survival (PFS) and overall survival (OS) rates were 41.1% (95% CI: 35.0-47.2%) and 65.6% (95% CI: 59.5-71.7%), respectively. Age, Ann Arbor stage, international prognostic index (IPI) score, and response to first-line chemotherapy were correlated with the ORR. Grade 3 and 4 adverse events (AEs) related to the P-ICE regimen were reported in 21.5% of patients. The most common AE was thrombocytopenia (9.0%). No treatment-related deaths occurred. In patients with R/R DLBCL, the P-ICE regimen has promising efficacy and mild toxicity.

Three-Year Follow-Up of KTE-X19 in Patients With Relapsed/Refractory Mantle Cell Lymphoma, Including High-Risk Subgroups, in the ZUMA-2 Study

PURPOSE

Brexucabtagene autoleucel (KTE-X19) autologous anti-CD19 chimeric antigen receptor (CAR) T-cell therapy is approved for the treatment of relapsed/refractory mantle cell lymphoma (MCL). Outcomes after a 3-year follow-up in the pivotal ZUMA-2 study of KTE-X19 in relapsed/refractory MCL are reported, including for subgroups by prior therapy (bendamustine and type of Bruton tyrosine kinase inhibitor [BTKi]) or high-risk characteristics.

METHODS

Patients with relapsed/refractory MCL (one to five prior therapies, including prior BTKi exposure) received a single infusion of KTE-X19 (2 × 10⁶ CAR T cells/kg).

RESULTS

After a median follow-up of 35.6 months, the objective response rate among all 68 treated patients was 91% (95% CI, 81.8 to 96.7) with 68% complete responses (95% CI, 55.2 to 78.5); medians for duration of response, progression-free survival, and overall survival were 28.2 months (95% CI, 13.5 to 47.1), 25.8 months (95% CI, 9.6 to 47.6), and 46.6 months (95% CI, 24.9 to not estimable), respectively. Post hoc analyses showed that objective response rates and ongoing response rates were consistent among prespecified subgroups by prior BTKi exposure or high-risk characteristics. In an exploratory analysis, patients with prior bendamustine benefited from KTE-X19, but showed a trend toward attenuated T-cell functionality, with more impact of bendamustine given within 6 versus 12 months of leukapheresis. Late-onset toxicities were infrequent; only 3% of treatment-emergent adverse events of interest in ZUMA-2 occurred during this longer follow-up period. Translational assessments revealed associations with long-term benefits of KTE-X19 including high-peak CAR T-cell expansion in responders and the predictive value of minimal residual disease for relapse.

CONCLUSION

These data, representing the longest follow-up of CAR T-cell therapy in patients with MCL to date, suggest that KTE-X19 induced durable long-term responses with manageable safety in patients with relapsed/refractory MCL and may also benefit those with high-risk characteristics.

Chicken-derived CD20 antibodies with potent B-cell depletion activity

We report four novel anti-human CD20 (hCD20) monoclonal antibodies (mAbs) discovered from a phylogenetically distant species-chickens. The chicken-human chimaeric antibodies exhibit at least 10-fold enhanced antibody-dependent cellular cytotoxicity (ADCC) and 4-8-fold stronger complement-dependent cytotoxicity (CDC) relative to the clinically used mouse-human chimaeric anti-hCD20 antibody rituximab (RTX). Thus, to our knowledge these mAbs are the first to significantly outperform RTX in both Fc-mediated mechanisms of action. The antibodies show 20-100-fold superior depletion of B cells in whole blood from healthy humans relative to RTX and retain efficacy in vivo. One of the mAbs, AC1, can bind mouse CD20, indicating specificity for a novel hCD20 epitope inaccessible to current (mouse-derived) anti-hCD20 mAbs. A humanized version of one antibody, hAC11-10, was created by complementarity-determining region (CDR) grafting into a human variable region framework and this molecule retained the ADCC, in vitro human whole-blood B-cell depletion, and in vivo lymphoma cell depletion activities of the parent. These mAbs represent promising monotherapy candidates for improving upon current less-than-ideal clinical outcomes in lymphoid malignancies and provide an arsenal of biologically relevant molecules for the development of next-generation CD20-mediated immunotherapies including bispecific T-cell engagers (BiTE), antibody-drug conjugates (ADC) and chimaeric antigen receptor-engineered T (CAR-T) cells.

OBINUTUZUMAB DOES NOT IMPROVE COMPLETE METHABOLIC RESPONSE BUT DOES NOT COMPROMISE MOBILIZATION OR ENGRAFTMENT OF AUTOLOGOUS PERIPHERAL BLOOD STEM CELLS IN DIFFUSE LARGE B CELL LYMPHOMA: RESULTS FROM A FIL PROSPECTIVE PHASE II STUDY (THE GIOTTO STUDY)

Salvage immunochemotherapy and transplant consolidation is the standard treatment for relapsed or refractory (R/R) diffuse large B-cell lymphoma (DLBCL). We tested a combination of Obinutuzumab and DHAP for treating R/R DLBCL. The primary end point was the rate of complete metabolic response (CMR). Secondary end points were stem cell mobilization, stem cell engraftment, overall survival, and feasibility. In this prospective, phase-2, single-arm trial (EudraCT 2014-004014-17) patients received the standard three doses of Obinutuzumab for the first cycle, and then one dose. Patients with CMR were consolidated with an autologous stem cell transplantation (ASCT). An interim analysis was provided after the first 29 patients to confirm the initial null hypothesis that at least 10/29 patients would achieve CMR. Among the 29 patients evaluated for the first stage only 6 patients (6/29, 21%) achieved CMR, thus, study enrollment was stopped. Nine patients exhibited extra-hematologic toxicities ≥grade 3. Among the 19 patients that started stem cell mobilization, one failed (5%) and 18 achieved mobilization (95%). Of these 18 patients, 9 were reinfused. Mobilization was observed in 16 patients (89%) after 1 or 2 apheresis rounds. The mean number of CD34+ cells mobilized was 5.8 x 10⁶ /Kg (median: 5.5, IQR: 5 - 6.75). The mean number of reinfused CD34+ cells in the 9 patients was 4.1 x 10⁶ /Kg (median: 4.1, IQR: 3.5 - 5). Obinutuzumab combined with DHAP did not compromise stem cell mobilization or engraftment after ASCT in patients with DLBCL. However, Obinutuzumab+DHAP provided a lower CMR rate than expected. This article is protected by copyright. All rights reserved.

A phase II trial to evaluate the combination of pixantrone and obinutuzumab for patients with relapsed aggressive lymphoma: Final results of the prospective, multicentre GOAL trial

The prognosis of patients with relapsed diffuse large B-cell lymphoma (DLBCL) remains poor with current options. Here we prospectively evaluated the combination of pixantrone with obinutuzumab for up to six cycles for patients with relapsed or refractory DLBCL. Overall response rate (ORR) was the primary end-point. Sixty-eight patients were evaluated, median age was 75 years, median number of prior lines was three (range 1-10), 52 patients (76.5%) were diagnosed with DLBCL and 16 (23.5%) patients had transformed indolent lymphoma or follicular lymphoma (FL) IIIB. ORR was 35.3% for all and 40% for evaluable patients (16.6% complete response), median progression-free survival (PFS) and overall survival (OS) were 2.8 months and 8 months, respectively. Analysis of the cell of origin revealed a superior course for patients with non-GCB (germinal centre B-cell-like) phenotype [median OS not reached (n.r.) vs 5.2 months]. Patients with one prior line had an improved outcome over patients treated in later lines (PFS n.r. vs 2.5 months). Disease progression was the main reason for premature termination. Adverse events were mainly haematologic. The combination treatment revealed no unexpected adverse events. Most relevant non-haematologic toxicity was infection in 28% of patients. In summary, pixantrone-obinutuzumab showed clinical activity with sometimes long-term remission; however, the trial failed to meet its primary end-point.

Phase I/II study of bendamustine in combination with ofatumumab, carboplatin, etoposide (BOCE) for relapsed or refractory aggressive B-cell non-Hodgkin lymphoma

We developed an outpatient salvage chemotherapy regimen using bendamustine, ofatumumab, carboplatin and etoposide (BOCE) to treat relapsed/refractory non-Hodgkin lymphoma (RR NHL) in a single-center phase I/II study. Primary objectives were safety, tolerability and overall response rate (ORR). Thirty-five RR NHL patients (57% de novo large cell [DLBCL] or grade 3B follicular [FL], 26% transformed DLBCL, 9% grade 3A FL, 3% mantle cell; median age = 62, median prior therapies = 1) were treated. Median follow-up was 24.1 months. ORR was 69% (CR = 49%, PR = 20% [ORR = 70%, CR = 50%, PR = 20% in the de novo DLBCL/grade 3B FL subgroup]). Median progression-free survival was 5.1 months and overall-survival 26.2 months. Twelve patients subsequently underwent stem cell transplantation. The most common non-hematologic grade 3-4 toxicities were neutropenic fever and hypophosphatemia. There were no treatment-related deaths. In conclusion, BOCE is a safe and effective outpatient salvage regimen for patients with RR NHL and serves as an effective bridge to stem cell transplantation.

Mechanisms of Resistance to Monoclonal Antibodies (mAbs) in Lymphoid Malignancies

PURPOSE OF REVIEW

Passive immunotherapy with therapeutic monoclonal antibodies (mAbs) has revolutionized the treatment of cancer, especially hematological malignancies over the last 20 years. While use of mAbs has improved outcomes, development of resistance is inevitable in most cases, hindering the long-term survival of cancer patients. This review focuses on the available data on mechanisms of resistance to rituximab and includes some additional information for other mAbs currently in use in hematological malignancies.

RECENT FINDINGS

Mechanisms of resistance have been identified that target all described mechanisms of mAb activity including altered antigen expression or binding, impaired complement-mediated cytotoxicity (CMC) or antibody-dependent cellular cytotoxicity (ADCC), altered intracellular signaling effects, and inhibition of direct induction of cell death. Numerous approaches to circumvent identified mechanisms of resistance continue to be investigated, but a thorough understanding of which resistance mechanisms are most clinically relevant is still elusive. In recent years, a deeper understanding of the tumor microenvironment and targeting the apoptotic pathway has led to promising breakthroughs. Resistance may be driven by unique patient-, disease-, and antibody-related factors. Understanding the mechanisms of resistance to mAbs will guide the development of strategies to overcome resistance and re-sensitize cancer cells to these biological agents.

Phase II trial of co-administration of CD19- and CD20-targeted chimeric antigen receptor T cells for relapsed and refractory diffuse large B cell lymphoma

PURPOSE

Anti-CD19 chimeric antigen receptor T (CAR-T) cell therapy has demonstrated remarkable efficacy for refractory and relapsed diffuse large B cell lymphoma (R/R DLBCL). However, this therapy failed in nearly 25% patients mainly due to antigen loss. The authors performed a phase Ⅱ trial by coadministration of anti-CD19 and anti-CD20 CAR-T cells treatment for R/R DLBCL and evaluated its efficacy and toxicity.

METHODS

Totally 21 patients with DLBCL were enrolled in this study. The patients were conditioned with fludarabine and cyclophosphamide before the infusion of anti-CD19 and anti-CD20 CAR-T cells. Treatment response, toxicity, and persistence were monitored continuously.

RESULTS

Of the 21 patients received the treatment, the objective response rate (ORR) is 81.0% (95% confidence interval [CI], 58.1%-94.6%) with four cases of bulk (4/5) and one case of testis involvement; 52.4% (95% CI, 29.8%-74.3%) had a complete response (CR). Peak levels of anti-CD19 and anti-CD20 CAR cells were associated with response (P = .007 and .002). Grade 3-4 cytokine release syndrome (CRS) and neurologic events occurred in 28.5% and 9.5% patients, respectively. Median overall survival (OS) and progression-free survival (PFS) were 8.1 and 5.0 months, respectively. The maximum standard uptake value (SUVmax) of CD4/CD8 ratio before and after infusion were associated with responses, and the total lesion glycolysis (TLG) before infusion correlates with cytokines level.

CONCLUSIONS

Coadministration of anti-CD19 and CD20 CAR-T cells therapy for DLBCL is feasible with manageable toxicity. Cytokine markers are related to toxicity and SUVmax could predict efficacy. This trial was registered at www.clinicaltrials.gov as NCT03207178.

Placing CD20-targeted B cell depletion in multiple sclerosis therapeutic scenario: Present and future perspectives

Multiple sclerosis (MS) is an acquired demyelinating disease of the central nervous system (CNS) that traditionally has been considered to be mediated primarily by T cells. Increasing evidence, however, suggests the fundamental role of B cells in the pathogenesis and development of the disease. Recently, anti-CD20 B cell-based therapies have demonstrated impressive and somewhat surprising results in MS, showing profound anti-inflammatory effects with a favorable risk-benefit ratio. Moreover, for the first time in the MS therapeutic scenario, the anti-CD20 monoclonal antibody ocrelizumab has been granted for the treatment of the primary progressive form of the disease. In this review, we provide a brief overview about anti-CD20 B cell-based therapies in MS, in the perspective of their influence on the future management of the disease, and of their possible positioning in a new wider therapeutic scenario.

Anti-CD20 monoclonal antibodies: reviewing a revolution

Since the inception of rituximab in the 1990s, anti-CD20 monoclonal antibodies have revolutionised the treatment of B cell hematological malignancies and have become a cornerstone of modern gold-standard practice. Additionally, the potent efficacy of these agents in depleting the B cell compartment has been used in the management of a broad array of autoimmune diseases. Multiple iterations of these agents have been investigated and are routinely used in clinical practice. In this review, we will discuss the physiology of CD20 and its attractiveness as a therapeutic target, as well as the pharmacology, pre-clinical and clinical data for the major anti-CD20 monoclonal antibodies: rituximab, obinutuzumab and ofatumumab.

The promise of CAR T-cell therapy in aggressive B-cell lymphoma

Relapsed or refractory aggressive B-cell lymphoma has an extremely poor prognosis and efforts to develop novel therapies for these patients have failed for almost four decades until the advent of chimeric antigen receptor (CAR) T-cell therapy. Within the last one year, two anti-CD19 CAR T-cell therapy products, axicabtagene ciloleucel and tisagenlecleucel, were approved by the United States Food and Drug Administration for the treatment of relapsed or refractory large B-cell lymphoma after at least two lines of systemic therapy based on multicenter single-arm phase two clinical trials. Here, we will discuss the different components of the CAR construct and their mechanisms of action, the role of conditioning chemotherapy, the efficacy and toxicity observed with anti-CD19 CAR T-cell therapies in aggressive B-cell lymphomas, and emerging strategies to further improve the safety and efficacy of these highly promising approaches.

B-chronic lymphocytic leukemia showed triple transformation, to diffuse large B cell, CD20-negative, and T-cell neoplasm during ofatumumab treatment: a case report

Background

Chronic lymphocytic leukemia (CLL) is a mature lymphoid neoplasm currently categorized as an indolent type of malignant lymphoma. CLL progresses slowly over years, but it eventually transforms to a more aggressive lymphoma such as the diffuse large B-cell (DLBCL) type, also known as Richter's syndrome.

Case presentation

We treated a 69-year-old Japanese male who was histologically diagnosed with Richter's syndrome after 6 years of CLL. His lymphadenopathy had systemically progressed for years, with lymphocyte counts of less than 10,000 cells/μL and a disease status of Rai classification stage I and Binet classification B. He had high fever and hepatosplenomegaly upon Richter's transformation. The patient was treated with ofatumumab for refractory CLL, which relieved his febrile lymphadenopathy. He received a total of 11 ofatumumab courses and achieved partial remission. On the day of the 12th course of ofatumumab, his disease relapsed with febrile lymphadenopathy. Computed tomography revealed multiple liver masses and systemic lymphadenopathy, while a liver biopsy confirmed T-cell lymphoma. Concomitantly, CD20-lacking CLL cells were detected in his peripheral blood and bone marrow, and pathological examination of his left cervical lymph node biopsy showed CD20-positive DLBCL. The final diagnosis was three different types of lymphoma pathologies: (1) CD20-positive DLBCL of the lymph nodes, (2) CD20-lacking CLL of the peripheral blood and bone marrow, and (3) peripheral T-cell lymphoma (PTCL) of the liver. He received intravenous and oral dexamethasone therapy as palliative care. He died because of the rapid progression of abdominal masses 2 months after the diagnosis of triple transformation CLL. An autopsy revealed aggressive PTCL with aggressive systemic involvement of the liver, spleen, gall bladder, pericardium, bone marrow, and mediastinal-paraaortic-intraceliac lymph nodes. T-cell receptor study of an autopsy specimen supported the diagnosis of PTCL that spread to the intraceliac organs and lymph nodes. We concluded that his pathogenicity progressed to a mixture of triple lymphoma as a result of double malignant transformations, which included PTCL from CLL, CD20-negative CLL, and CD20-positive DLBCL by Richter's transformation.

Conclusions

Our case provides information on the biology of CLL, to transform from a low-grade chemosensitive status to a malignant chemoresistant status.

Combination of ofatumumab and reduced-dose CHOP for diffuse large B-cell lymphomas in patients aged 80 years or older: an open-label, multicentre, single-arm, phase 2 trial from the LYSA group

BACKGROUND

In 2011 we reported a rituximab plus miniCHOP (reduced-dose cyclophosphamide, doxorubicin, vincristine, and prednisone) combination for patients older than 80 years with diffuse large B-cell lymphoma (DLBCL). The 2-year overall survival was 59% (95% CI 49-67) with an excess of early toxicity. To improve those results we tested the same chemotherapy protocol in combination with ofatumumab and a pre-phase treatment.

METHODS

For this open-label, multicentre, single-group, phase 2 trial, we recruited patients older than 80 years with untreated histologically-proven CD20-positive DLBCL, Ann Arbor stage I to IV, from 41 academic and hospital centres in France and Belgium. Patients received a pre-phase with oral vincristine (1 mg total dose 1 week before cycle 1 [day -7]) and oral prednisone (60 mg total dose starting 1 week before cycle 1, for 4 days [day -7 to day -4]) before the first cycle of the ofatumumab plus miniCHOP regimen. The regimen consisted of 1000 mg total dose of intravenous ofatumumab, 25 mg/m² of intravenous doxorubicin, 400 mg/m² of intravenous cyclophosphamide, and 1 mg of intravenous vincristine, on day 1 of each cycle; and 40 mg/m² of oral prednisone on days 1-5. Ofatumumab was administered with 1000 mg of paracetamol and 50 mg of diphenhydramine. The primary endpoint was overall survival in the intention-to-treat population. The statistical analysis has been done on an intention-to-treat principle. This study was registered with ClinicalTrials.gov, number NCT01195714.

FINDINGS

Between June 2, 2010, and Nov 4, 2011, we enrolled 120 patients. Age-adjusted International Prognostic Index was 2-3 in 68 (57%) of them. The median follow-up time was 26·8 months (IQR 24·5-30·1). The 2-year overall survival was 64·7% (95% CI 55·3-72·7) and median overall survival was not reached (95% CI 30·2-not reached). 45 patients died during the treatment, of whom 28 (62%) died due to lymphoma. The most common side-effect was haematological toxicity. Among the 120 patients, grade 3-4 neutropenia was reported in 24 (21%) patients and thrombocytopenia in two (2%), during the treatment period. Grade 3-4 anaemia was reported in six (5%) patients; seven (6%) patients had one episode of febrile neutropenia. 17 (15%) of 115 patients in the modified intention-to-treat population had red blood cell transfusions and three (3%) had platelet transfusions.

INTERPRETATION

Our result suggest that, in patients older than 80 years with DLBCL, ofatumumab and pre-phase treatment seem to improve overall survival compared with the previously reported data. The combination of pre-phase treatment, a monoclonal antibody against CD20, and miniCHOP can be considered a new treatment platform for use in randomised clinical trial design for DLBCL treatment in patients older than 80 years.

FUNDING

The Lymphoma Study Association, GlaxoSmithKline.

Axicabtagene Ciloleucel CAR T-Cell Therapy in Refractory Large B-Cell Lymphoma

BACKGROUND

In a phase 1 trial, axicabtagene ciloleucel (axi-cel), an autologous anti-CD19 chimeric antigen receptor (CAR) T-cell therapy, showed efficacy in patients with refractory large B-cell lymphoma after the failure of conventional therapy.

METHODS

In this multicenter, phase 2 trial, we enrolled 111 patients with diffuse large B-cell lymphoma, primary mediastinal B-cell lymphoma, or transformed follicular lymphoma who had refractory disease despite undergoing recommended prior therapy. Patients received a target dose of 2×106 anti-CD19 CAR T cells per kilogram of body weight after receiving a conditioning regimen of low-dose cyclophosphamide and fludarabine. The primary end point was the rate of objective response (calculated as the combined rates of complete response and partial response). Secondary end points included overall survival, safety, and biomarker assessments.

RESULTS

Among the 111 patients who were enrolled, axi-cel was successfully manufactured for 110 (99%) and administered to 101 (91%). The objective response rate was 82%, and the complete response rate was 54%.With a median follow-up of 15.4 months, 42% of the patients continued to have a response, with 40% continuing to have a complete response. The overall rate of survival at 18 months was 52%. The most common adverse events of grade 3 or higher during treatment were neutropenia (in 78% of the patients), anemia (in 43%), and thrombocytopenia (in 38%). Grade 3 or higher cytokine release syndrome and neurologic events occurred in 13% and 28% of the patients, respectively. Three of the patients died during treatment. Higher CAR T-cell levels in blood were associated with response.

CONCLUSIONS

In this multicenter study, patients with refractory large B-cell lymphoma who received CAR T-cell therapy with axi-cel had high levels of durable response, with a safety profile that included myelosuppression, the cytokine release syndrome, and neurologic events. (Funded by Kite Pharma and the Leukemia and Lymphoma Society Therapy Acceleration Program; ZUMA-1 ClinicalTrials.gov number, NCT02348216 .).

The use of ofatumumab in the treatment of B-cell malignancies

Ofatumumab has been extensively studied in the treatment of B-cell malignancies. Currently, it has been approved for the treatment of chronic lymphocytic leukemia in a number of different situations. However, there is still no compelling evidence confirming the superiority of ofatumumab over rituximab in vivo. In this article, we summarize the currently available clinical data supporting the use of ofatumumab in the treatment of B-cell malignancies. The clinical studies were searched from clinicaltrials.gov with the key words ofatumumab, HuMax-CD20. Out of 115 trials available, studies for B-cell malignancies were selected, followed by selection of completed studies with results and active ongoing studies. The results from completed studies were thoroughly analyzed and active ongoing studies were listed in tables.

Outcomes in refractory diffuse large B-cell lymphoma: results from the international SCHOLAR-1 study

Diffuse large B-cell lymphoma (DLBCL) is the most common subtype of non-Hodgkin lymphoma. Although 5-year survival rates in the first-line setting range from 60% to 70%, up to 50% of patients become refractory to or relapse after treatment. Published analyses of large-scale outcome data from patients with refractory DLBCL are limited. SCHOLAR-1, an international, multicohort retrospective non-Hodgkin lymphoma research study, retrospectively evaluated outcomes in patients with refractory DLBCL which, for this study, was defined as progressive disease or stable disease as best response at any point during chemotherapy (>4 cycles of first-line or 2 cycles of later-line therapy) or relapsed at ≤12 months from autologous stem cell transplantation. SCHOLAR-1 pooled data from 2 phase 3 clinical trials (Lymphoma Academic Research Organization-CORAL and Canadian Cancer Trials Group LY.12) and 2 observational cohorts (MD Anderson Cancer Center and University of Iowa/Mayo Clinic Lymphoma Specialized Program of Research Excellence). Response rates and overall survival were estimated from the time of initiation of salvage therapy for refractory disease. Among 861 patients, 636 were included on the basis of refractory disease inclusion criteria. For patients with refractory DLBCL, the objective response rate was 26% (complete response rate, 7%) to the next line of therapy, and the median overall survival was 6.3 months. Twenty percent of patients were alive at 2 years. Outcomes were consistently poor across patient subgroups and study cohorts. SCHOLAR-1 is the largest patient-level pooled retrospective analysis to characterize response rates and survival for a population of patients with refractory DLBCL.

Outcomes of primary refractory diffuse large B-cell lymphoma (DLBCL) treated with salvage chemotherapy and intention to transplant in the rituximab era

Rituximab-containing salvage chemotherapy followed by high-dose therapy and autologous stem cell transplant (ASCT) in chemosensitive patients remains the standard of care for patients with relapsed and refractory diffuse large B-cell lymphoma (DLBCL). However, its role in those patients achieving less than a complete response to first-line therapy (primary refractory disease) in the rituximab era is not well defined. We reviewed the outcomes of 82 transplant-eligible patients with primary refractory DLBCL who underwent salvage therapy with the intent of administering high-dose therapy and ASCT to patients achieving chemosensitive remission. The estimated 3-year overall and progression-free survival for all patients was 38% and 29%, respectively, and 65% and 60% respectively for patients proceeding to stem cell transplant. Long-term remission was achieved in 45% of patients achieving a partial response (PR) to initial induction therapy and <20% of patients with stable or progression of disease following initial therapy. These results suggest that salvage chemotherapy with the intent of subsequent high-dose therapy and ASCT remains a feasible strategy in certain patients with primary refractory DLBCL, particularly for those achieving a PR to frontline therapy. The primary barrier to curative therapy in patients with primary refractory disease is resistance to salvage therapy, and future studies should be aimed towards increasing the response rate in this population.

Phase 1 Results of ZUMA-1: A Multicenter Study of KTE-C19 Anti-CD19 CAR T Cell Therapy in Refractory Aggressive Lymphoma

Outcomes for patients with refractory diffuse large B cell lymphoma (DLBCL) are poor. In the multicenter ZUMA-1 phase 1 study, we evaluated KTE-C19, an autologous CD3ζ/CD28-based chimeric antigen receptor (CAR) T cell therapy, in patients with refractory DLBCL. Patients received low-dose conditioning chemotherapy with concurrent cyclophosphamide (500 mg/m2) and fludarabine (30 mg/m2) for 3 days followed by KTE-C19 at a target dose of 2 × 106 CAR T cells/kg. The incidence of dose-limiting toxicity (DLT) was the primary endpoint. Seven patients were treated with KTE-C19 and one patient experienced a DLT of grade 4 cytokine release syndrome (CRS) and neurotoxicity. Grade ≥3 CRS and neurotoxicity were observed in 14% (n = 1/7) and 57% (n = 4/7) of patients, respectively. All other KTE-C19-related grade ≥3 events resolved within 1 month. The overall response rate was 71% (n = 5/7) and complete response (CR) rate was 57% (n = 4/7). Three patients have ongoing CR (all at 12+ months). CAR T cells demonstrated peak expansion within 2 weeks and continued to be detectable at 12+ months in patients with ongoing CR. This regimen of KTE-C19 was safe for further study in phase 2 and induced durable remissions in patients with refractory DLBCL.

Ofatumumab Versus Rituximab Salvage Chemoimmunotherapy in Relapsed or Refractory Diffuse Large B-Cell Lymphoma: The ORCHARRD Study

Purpose We compared the efficacy of ofatumumab (O) versus rituximab (R) in combination with cisplatin, cytarabine, and dexamethasone (DHAP) salvage treatment, followed by autologous stem-cell transplantation (ASCT) in patients with relapsed or refractory diffuse large B-cell lymphoma (DLBCL). Patients and Methods Patients with CD20⁺ DLBCL age ≥ 18 years who had experienced their first relapse or who were refractory to first-line R-CHOP (cyclophosphamide, doxorubicin, vincristine, prednisone)-like treatment were randomly assigned between three cycles of R-DHAP or O-DHAP. Either O 1,000 mg or R 375 mg/m² was administered for a total of four infusions (days 1 and 8 of cycle 1; day 1 of cycles 2 and 3 of DHAP). Patients who experienced a response after two cycles of treatment received the third cycle, followed by high-dose therapy and ASCT. Primary end point was progression-free survival (PFS), with failure to achieve a response after cycle 2 included as an event. Results Between March 2010 and December 2013, 447 patients were randomly assigned. Median age was 57 years (range, 18 to 83 years); 17% were age ≥ 65 years; 63% had stage III and IV disease; 71% did not achieve complete response (CR) or experience response for < 1 year on first-line R-CHOP. Response rate for O-DHAP was 38% (CR, 15%) versus 42% (CR, 22%) for R-DHAP. ASCT on protocol was completed by 74 patients (33%) in the O arm and 83 patients (37%) in the R arm. PFS, event-free survival, and overall survival were not significantly different between O-DHAP versus R-DHAP: PFS at 2 years was 24% versus 26% (hazard ratio [HR], 1.12; 95% CI, 0.89 to 1.42; P = .33); event-free survival at 2 years was 16% versus 18% (HR, 1.10; P = .35); and overall survival at 2 years was 41% versus 38% (HR, 0.90; P = .38). Positron emission tomography negativity before ASCT was highly predictive for superior outcome. Conclusion No difference in efficacy was found between O-DHAP and R-DHAP as salvage treatment of relapsed or refractory DLBCL.

Diffuse large B-cell lymphoma: R-CHOP failure-what to do?

Although rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) is the standard treatment for patients with diffuse large B-cell lymphoma (DLBCL), ∼30% to 50% of patients are not cured by this treatment, depending on disease stage or prognostic index. Among patients for whom R-CHOP therapy fails, 20% suffer from primary refractory disease (progress during or right after treatment) whereas 30% relapse after achieving complete remission (CR). Currently, there is no good definition enabling us to identify these 2 groups upon diagnosis. Most of the refractory patients exhibit double-hit lymphoma (MYC-BCL2 rearrangement) or double-protein-expression lymphoma (MYC-BCL2 hyperexpression) which have a more aggressive clinical picture. New strategies are currently being explored to obtain better CR rates and fewer relapses. Although young relapsing patients are treated with high-dose therapy followed by autologous transplant, there is an unmet need for better salvage regimens in this setting. To prevent relapse, maintenance therapy with immunomodulatory agents such as lenalidomide is currently undergoing investigation. New drugs will most likely be introduced over the next few years and will probably be different for relapsing and refractory patients.

Effect of the addition of rituximab to salvage chemotherapy prior to autologous stem cell transplant in aggressive CD20+ lymphoma: a cohort comparison from the NCIC Clinical Trials Group Study LY.12<sup/>

The impact of the addition of rituximab to salvage chemotherapy prior to autologous stem cell transplant (ASCT) was evaluated in a retrospective subgroup analysis of NCIC CTG LY.12. Among 414 patients who relapsed following R-CHOP, 96 received salvage chemotherapy alone [R - cohort]; and 318 received rituximab with chemotherapy [R + cohort] following a protocol amendment. The R-cohort had a higher proportion of patients with PS ≥2 and relapse <1 year after R-CHOP. The response rate (45.6% vs. 25.0%, p = 0.0003), CR/CRu (15.7% vs. 4.2%, p = 0.003) and transplantation rate (51.9% vs. 31.3%, p = 0.0004) was higher in the R + cohort. Event-free (27% vs. 22%, p = 0.0954) and overall survival at four years (43% vs. 31%; p = 0.045) were greater in the R + cohort when the patients with best response SD/PD to R-CHOP were excluded. Addition of rituximab to salvage therapy before ASCT appears to improve the response rate, transplantation rate, and overall survival in patients with CD20+ lymphoma who responded to R-CHOP.

Ofatumumab for B cell depletion therapy in ANCA-associated vasculitis: a single-centre case series

Objectives. B cell depletion is an effective treatment strategy in ANCA-associated vasculitis (AAV). Ofatumumab is a fully humanized anti-CD20 mAb that has shown efficacy in the treatment of haematological malignancy and RA. The use of ofatumumab in the treatment of AAV has not previously been reported.

Methods. This study was based on a case series of eight patients who received ofatumumab, in conjunction with low-dose CYC and oral steroids, in the treatment of AAV.

Results. Eight patients received ofatumumab: seven for remission induction in active disease (three relapsing; four with new disease) and one for remission maintenance. B cell depletion was achieved in all patients by 1 month, and was sustained for at least 6 months. All patients with active disease achieved clinical remission (BVAS of zero, or BVAS ⩽5 if all scores due to persistent urinary abnormalities in the presence of stable or improving renal function) by 3 months. This was associated with a rapid fall in ANCA titres, reduced inflammatory responses and improvements in renal function. At 12 months, three patients had repopulated B cells associated with the recurrence of circulating ANCAs, although no patients experienced major clinical relapse in the first 24 months. No unexpected side effects were observed.

Conclusion. Treatment with ofatumumab resulted in similar serological and clinical responses to those seen in previous cohorts treated at our centre with a comparable CS, CYC and rituximab-based regimen. Ofatumumab should be considered an alternative B cell depleting agent in patients who are intolerant of, or unresponsive to, rituximab.

Ifosfamide, Cisplatin or Carboplatin, and Etoposide (ICE)-based Chemotherapy for Mobilization of Autologous Peripheral Blood Stem Cells in Patients with Lymphomas

Background:

High-dose chemotherapy followed by autologous stem cell transplantation (ASCT) is a promising approach for lymphomas. This study aimed to evaluate the effect of ifosfamide, cisplatin or carboplatin, and etoposide (ICE)-based regimen as a mobilization regimen on relapsed, refractory, or high-risk aggressive lymphoma.

Methods:

From June 2001 to May 2013, patients with lymphomas who mobilized by ICE-based regimen for ASCT were analyzed in this retrospective study. The results of the autologous peripheral blood stem cells collection, toxicity, engraftment after ICE-based mobilization regimen were analyzed in this study. Furthermore, risk factors for overall survival (OS) and progression free survival (PFS) were evaluated by univariate analysis.

Results:

The stem cells were mobilized using ICE-based regimen plus rituximab or ICE-based regimen alone in 12 patients and 54 patients, respectively. The results of stem cell mobilization were excellent. Ninety-seven percentages of the patients had the stem cell collection of at least 2.0 × 10⁶ CD34⁺ cells/kg and 68% had at least 5 × 10⁶ CD34⁺ cells/kg. Fifty-eight percentage of the patients experienced Grade 4 neutropenia, 20% developed febrile neutropenia, and only 12% had Grade 4 thrombocytopenia. At a median follow-up of 63.8 months, the 5-year PFS and OS were 64.4% and 75.3%, respectively.

Conclusion:

ICE is a powerful regimen for stem cell mobilization in patients with lymphomas.

Gemcitabine enhances rituximab-mediated complement-dependent cytotoxicity to B cell lymphoma by CD20 upregulation

Although rituximab, a chimeric monoclonal antibody that specifically binds to CD20, has significantly improved the prognosis for diffuse large B cell lymphoma (DLBCL), one-third of DLBCL patients demonstrate resistance to rituximab or relapse after rituximab treatment. Thus, a novel approach to rituximab-based treatment is likely to be required to improve the efficacy of DLBCL treatment. As complement dependent cytotoxicity (CDC) is a key mechanism mediating rituximab's tumoricidal activity, rituximab binding to CD20 on tumor cells is a critical factor for effective rituximab-based treatments against DLBCL. We found that gemcitabine (GEM), but not lenalidomide (LEN) or azacitidine (AZA), can upregulate CD20 expression in TK and KML-1 cells, two human DLBCL cell lines. Treatment of TK and KML-1 cells with GEM enhanced CD20 expression at both the mRNA and protein levels. CD20 upregulation by GEM treatment was accompanied by increased rituximab binding to CD20. In TK cells, GEM treatment synergistically increased rituximab-mediated CDC activity in a dose-dependent manner. In KML cells, GEM treatment also induced upregulation of complement regulatory proteins, possibly leading to resistance to CDC. Treatment with LEN, a drug that did not upregulate CD20, did not enhance rituximab-mediated CDC activity. GEM treatment activated nuclear factor-kappa B (NF-kB) signaling in these cells. Furthermore, a specific inhibitor to NF-kB suppressed GEM-induced CD20 upregulation, indicating that GEM-induced NF-kB activation is closely associated with CD20 upregulation. These results suggest that when used in combination, GEM might enhance the antitumor efficacy of rituximab against DLBCL due to its unique ability to upregulate CD20.

Role of Rituximab and Rituximab Biosimilars in Diffuse Large B-Cell Lymphoma

Diffuse large B-cell lymphoma (DLBCL), an aggressive non-Hodgkin lymphoma (NHL), is the most-common subtype of NHL. DLBCL can be classified into at least 3 major immunologically distinct types, which contributes to considerable variation in disease prognosis and response to treatment. DLBCL potentially is curable, even when diagnosed at advanced stages. The current standard of care for most patients with untreated or relapsed/refractory DLBCL is chemoimmunotherapy containing rituximab, an anti-CD20 monoclonal antibody. With advanced understanding of the molecular mechanisms involved in the pathogenesis of DLBCL and specific signaling pathways that are activated in different subtypes, potential new therapeutic targets have been identified, some of which are at the late stages of clinical development. This review summarizes the critical role of rituximab in the current standard of care treatment for DLBCL and discusses why rituximab is likely to remain an important component of treatment options for DLBCL in the foreseeable future. In addition, current and emerging therapeutic agents, including potential benefits of rituximab biosimilars, for patients with DLBCL are discussed. The advent of rituximab biosimilars may facilitate accessibility of rituximab-based chemotherapies to patients with DLBCL and has potential cost-saving benefits for healthcare systems globally.

Breakthrough therapies in B-cell non-Hodgkin lymphoma

The last 5 years have seen significant advances in our understanding of the molecular pathogenesis of B-cell lymphomas. This has led to the emergence of a large number of new therapeutic agents exploiting precise aspects of the tumor cell's signaling pathways, surface antigens or microenvironment. The purpose of this comprehensive review is to provide a detailed analysis of the breakthrough agents in the field, with a focus on recent clinical data. We describe agents targeting the B-cell receptor pathway, Bcl-2 inhibitors, emerging epigenetic therapies, new monoclonal antibodies and antibody drug conjugates, selective inhibitors of nuclear export, agents targeting the programmed cell death axis and chimeric antigen receptor T cells.

Outcome of patients with relapsed diffuse large B-cell lymphoma who fail second-line salvage regimens in the International CORAL study

Salvage chemotherapy followed by autologous stem cell transplantation (ASCT) is the standard second-line treatment for relapsed and refractory diffuse large B-cell lymphoma (DLBCL). However, the strategy is less clear in patients who require third-line treatment. Updated outcomes of 203 patients who could not proceed to scheduled ASCT in the Collaborative Trial in Relapsed Aggressive Lymphoma (CORAL) are herein reviewed. In the intent-to-treat analysis, overall response rate to third-line chemotherapy was 39%, with 27% CR or CR unconfirmed, and 12% PR. Among the 203 patients, 64 (31.5%) were eventually transplanted (ASCT 56, allogeneic SCT 8). Median overall survival (OS) of the entire population was 4.4 months. OS was significantly improved in patients with lower tertiary International Prognostic Index (IPI), patients responding to third-line treatment and patients transplanted with a 1-year OS of 41.6% compared with 16.3% for the not transplanted (P<0.0001). In multivariate analysis, IPI at relapse (hazard ratio (HR) 2.409) and transplantation (HR 0.375) independently predicted OS. Third-line salvage chemotherapy can lead to response followed by transplantation and long-term survival in DLBCL patients. However, improvement of salvage efficacy is an urgent need with new drugs.

Emerging immunotherapy and strategies directly targeting B cells for the treatment of diffuse large B-cell lymphoma

During the last decade, significant prolonged survival in diffusive large B-cell lymphoma (DLBCL) has been observed. The efficacy of initial treatment improved mostly due to addition of a chimeric anti-CD20 monoclonal antibody (rituximab) to standard chemotherapeutic regimens. Moreover, accurate understanding of DLBCL pathogenesis and remarkable progress in gene expression profiling have led to the development of a variety of tumor-specific regimens. Novel agents target directly the pathways involved in signal transduction, lead to apoptosis and cancer cells differentiation. In this article, we mainly focus on new treatment options, such as monoclonal antibodies, tyrosine kinase inhibitors and immunomodulatory drugs, currently investigated in aggressive B-cell lymphoma with particular attention to DLBCL type.

A review of monoclonal antibody therapies in lymphoma

Monoclonal antibodies (moAb) represent a novel way of delivering therapy through specific target antigens expressed on lymphoma cells and minimizes the collateral damage that is common with conventional chemotherapy. The paradigm of this approach is the targeting of CD20 by rituximab. Since its FDA approval in 1997, rituximab has become the standard of care in almost every line of therapy in most B-cell lymphomas. This review will briefly highlight some of the key rituximab trials while looking more closely at the evidence that is bringing other antibodies, including next generation anti-CD20 moAbs, and anti-CD30 moAbs, among others to the forefront of lymphoma therapy.

Ofatumumab in the treatment of non-Hodgkin's lymphomas

INTRODUCTION

Ofatumumab is a second-generation humanized monoclonal antibody targeting CD20 registered for the treatment of patients with relapsing/refractory chronic lymphocytic leukemia. This review will describe the activity of ofatumumab in patients with CD20 B-cell lymphomas.

AREAS COVERED

A review of all manuscript published on ofatumumab activity in B-cell lymphomas is presented with conclusions on the future use of this antibody in these patients.

EXPERT OPINION

Ofatumumab activity is low in indolent or aggressive B-cell lymphomas. The future of this drug is challenged by new monoclonal antibodies and new targeted drugs.

Investigational therapies targeting lymphocyte antigens for the treatment of non-Hodgkin's lymphoma

INTRODUCTION

The advent of the anti-CD20 mAb rituximab has opened a new era in the treatment of non-Hodgkin's lymphomas (NHL), markedly altering standard treatment strategies. Moreover, the proof-of-concept that targeting a specific lymphocyte surface antigen may induce a highly effective and safe targeted killing of malignant cells has opened the door to the development of a plethora of novel mAbs directed towards different B- and T-cell-specific antigens.

AREAS COVERED

This review discusses the recent available clinical data about new-generation anti-CD20 mAbs characterized by increased antibody- (obinutuzumab) or complement-dependent cyotoxicity (ofatumumab) as well as novel investigational agents targeting other lymphocyte antigens (e.g., CD19, CD22, CD30, CD40, CD52, CCR4), which are currently under investigation for B- and T-cell NHL treatment. In addition, antibody-drug conjugates (inotuzumab ozogamicin, brentuximab vedotin, polatuzumab vedotin), bispecific T-cell engagers (blinatumomab) and a new class of antibodies targeting cytotoxic T-lymphocyte-associated antigen 4, programmed death 1 or programmed death ligand 1 (immune checkpoint inhibitors) are specifically considered.

EXPERT OPINION

Among the novel mAbs challenging rituximab, obinutuzumab seems to be in the most advanced phase, with the results of randomized trials awaited shortly. Brentuximab vedotin is increasing its role in T-cell NHL. Furthermore, immune checkpoint inhibitors have the potential to acquire a great relevance in NHL therapy.

Ofatumumab in combination with glucocorticoids for primary therapy of chronic graft-versus-host disease: phase I trial results

Standard primary therapy for chronic graft-versus-host disease (GVHD) is incompletely effective. Based on biologic insights implicating pathogenic B cells, we conducted a phase I trial examining the combination of standard (1 mg/kg/day prednisone) glucocorticoid therapy with ofatumumab, a humanized anti-CD20 monoclonal antibody, for primary chronic GVHD therapy. Patients ages ≥ 18 with National Institutes of Health Consensus moderate-to-severe chronic GVHD newly requiring 1 mg/kg/day prednisone were treated at 3 escalating dose levels (300 mg, 700 mg, and 1000 mg) of i.v. ofatumumab on days 1 and 14 of initial glucocorticoid therapy. Dose-limiting toxicity (DLT) was defined by grade 4 infusion reactions, related grade 4 constitutional symptoms, related grade ≥ 3 organ toxicities, or grade 4 neutropenia lasting > 14 days. A total of 12 patients (median age 54; range, 25 to 72) were treated (dose level 1: n = 3; level 2: n = 3; level 3: n = 6). At enrollment, overall chronic GVHD was moderate (n = 7) or severe (n = 5), with diverse organ involvement (skin: n = 8; mouth: n = 8; eye: n = 8; lung: n = 4; gastrointestinal: n = 3; liver: n = 5; genital: n = 2; joint/fascia: n = 5). Infusion of ofatumumab was well tolerated, and no DLT was observed. From the total number of adverse events (n = 29), possibly related adverse events (n = 4) included grade 1 fatigue, grade 1 transaminitis, and 2 infusion reactions (grades 2 and 3). Infectious complications were expected, and there were no cases of hepatitis B reactivation or progressive multifocal leukoencephalopathy. Ofatumumab in combination with prednisone is safe and a phase II examination of efficacy is ongoing.

Rituximab, Gemcitabine, Cisplatin and Methylprednisolone (R-GEM-P) is an effective regimen in relapsed diffuse large B-cell lymphoma

BACKGROUND

Patients with relapsed diffuse large B-cell lymphoma (DLBCL) have a poor prognosis. Gemcitabine, methylprednisolone, cisplatin +/- rituximab (GEM-P+/-R) is a salvage regimen with limited overlap in toxicity with first-line therapy and short duration of inpatient delivery.

METHODS

We assessed the efficacy and safety of GEM-P+/-R in a retrospective single-centre analysis including patients meeting criteria of ≥ 18 yr of age, histologically proven DLBCL, treated between 2001 and 2011 in second-line with gemcitabine 1000 mg/m(2) day 1, 8 and 15, methylprednisolone 1000 mg day 1-5, cisplatin 100 mg/m(2) day 15 (replaced with carboplatin AUC5 if contraindication/toxicity) +/- rituximab 375 mg/m(2) day 1 and 15, every 28 d.

RESULTS

Forty-five patients aged 25-74 received a median of three cycles of GEM-P+/-R; 64% received rituximab. In 44 evaluable patients receiving GEM-P+/-R, overall response rate (ORR) was 48%; in 28 evaluable patients treated with rituximab + GEM-P (R-GEM-P), ORR was 61%. With median follow-up of 50.5 months (95% CI: 28.3-72.7), 3-yr overall survival (OS) from start of GEM-P+/-R was 31.4% (95% CI: 16.5-46.3); in patients treated with R-GEM-P, 3-yr OS was 49.1% (95% CI: 28.7-69.5). Predominant grade ≥ 3 toxicities were haematological; thrombocytopenia 69%, neutropenia 60% and febrile neutropenia 7%.

CONCLUSION

R-GEM-P is a deliverable regimen with useful activity in second-line treatment of DLBCL. Our data suggest that rituximab should be given concurrently.

Emerging drugs for diffuse large B-cell lymphoma

Diffuse large B-cell lymphoma (DLBCL) is the most frequent non-Hodgkin lymphoma in western countries. Despite the addition of rituximab to chemotherapy, the prognosis is still poor and almost one-third of patients fail or relapse after first-line treatment. Gene expression profiling has identified three main signatures related to subgroups with different biological characteristics and responses to treatment. Novel agents targeting the oncogenic drivers of these subsets are currently under investigation with the aim of providing a tailored approach and avoiding unnecessary toxicity. Herein, we review the emerging therapies for DLBCL with a focus on preclinical and early clinical trials as well as future directions.

Early failure of frontline rituximab-containing chemo-immunotherapy in diffuse large B cell lymphoma does not predict futility of autologous hematopoietic cell transplantation

The poor prognosis for patients with diffuse large B cell lymphoma (DLBCL) who relapse within 1 year of initial diagnosis after first-line rituximab-based chemo-immunotherapy has created controversy about the role of autologous transplantation (HCT) in this setting. We compared autologous HCT outcomes for chemosensitive DLBCL patients between 2000 and 2011 in 2 cohorts based on time to relapse from diagnosis. The early rituximab failure (ERF) cohort consisted of patients with primary refractory disease or those with first relapse within 1 year of initial diagnosis. The ERF cohort was compared with those relapsing >1 year after initial diagnosis (late rituximab failure [LRF] cohort). ERF and LRF cohorts included 300 and 216 patients, respectively. Nonrelapse mortality (NRM), progression/relapse, progression-free survival (PFS), and overall survival (OS) of ERF versus LRF cohorts at 3 years were 9% (95% confidence interval [CI], 6% to 13%) versus 9% (95% CI, 5% to 13%), 47% (95% CI, 41% to 52%) versus 39% (95% CI, 33% to 46%), 44% (95% CI, 38% to 50%) versus 52% (95% CI, 45% to 59%), and 50% (95% CI, 44% to 56%) versus 67% (95% CI, 60% to 74%), respectively. On multivariate analysis, ERF was not associated with higher NRM (relative risk [RR], 1.31; P = .34). The ERF cohort had a higher risk of treatment failure (progression/relapse or death) (RR, 2.08; P < .001) and overall mortality (RR, 3.75; P <.001) within the first 9 months after autologous HCT. Beyond this period, PFS and OS were not significantly different between the ERF and LRF cohorts. Autologous HCT provides durable disease control to a sizeable subset of DLBCL despite ERF (3-year PFS, 44%) and remains the standard-of-care in chemosensitive DLBCL regardless of the timing of disease relapse.

New antibody approaches to lymphoma therapy

The CD20-directed monoclonal antibody rituximab established a new era in lymphoma therapy. Since then other epitopes on the lymphoma surface have been identified as potential targets for monoclonal antibodies (mAb). While most mAbs eliminate lymphoma cells mainly by antibody-dependent cellular cytotoxicity, complement-dependent cytotoxicity or direct cell death, others counter mechanisms utilized by malignant cells to evade immune surveillance. Expression of PD-L1 on malignant or stromal cells in the tumor environment for example leads to T-cell anergy. Targeting either PD-1 or PD-L1 via mAbs can indirectly eliminate cancer cells by unblocking the host intrinsic immune response. Yet another mechanism of targeted therapy with mAbs are bi-specific T-cell engagers (BiTE) such as blinatumomab, which directly engages the host immune cells. These examples highlight the broad spectrum of available therapies targeting the lymphoma surface with mAbs utilizing both passive and active immune pathways. Many of these agents have already demonstrated significant activity in clinical trials. In this review we will focus on novel CD20-directed antibodies as well as mAbs directed against newer targets like CD19, CD22, CD40, CD52 and CCR4. In addition we will review mAbs unblocking immune checkpoints and the BiTE blinatumomab. Given the success of mAbs and the expansion in active and passive immunotherapies, these agents will play an increasing role in the treatment of lymphomas.

Pro-apoptotic effect of an anti-CD37 scFv-Fc fusion protein, in combination with the anti-CD20 antibody, ofatumumab, on tumour cells from B-cell malignancies

SMIP-016, a new anti-tumour agent, is a mouse/human chimeric fusion protein built on the ADAPTIR™ (modular protein therapeutic) platform targeting human CD37. In this study, for the first time, we examined pro-apoptotic activity of SMIP-016 in combination with monoclonal anti-CD20 antibody, ofatumumab (HuMax-CD20) in de novo chronic lymphocytic leukaemia (CLL) cells and in different B-cell neoplasm-derived lines. In CLL cells SMIP-016 exerted significant cytotoxicity (versus control - p=0.01). In the in vitro models, SMIP-016 was also distinctly active against Raji line (Burkitt lymphoma; BL) (versus control - p=0.007), Riva-1 line (diffuse large B-cell lymphoma; DLBCL) (versus control - p=0.002) and RPMI 8226 line (multiple myeloma cells; MM) (versus control - p=0.03). In studies combining SMIP-016 and ofatumumab, the cytotoxicity against CLL cells was significantly higher than the agents used alone (p<0.03). Remarkably enhanced cytotoxic activity of SMIP-016 and ofatumumab in combination was also observed in Raji and Riva-1 cell lines (p<0.01 and p<0.003, respectively). Importantly, both agents induced cytotoxicity at very low concentrations which suggests that potential side-effects may be decreased in clinical practice. The mechanism responsible for cytotoxicity of SMIP-016 in all the examined models was connected with caspase-dependent apoptosis. In majority of cell types SMIP-016 induced overexpression of Bax protein, as well as downregulation of Bcl-2, cIAP1 (p<0.03) and Smac/DIABLO (p<0.003) apoptosis-regulating proteins. In conclusion, our study demonstrated high pro-apoptotic activity of SMIP-016, especially in combination with ofatumumab, against ex vivo CLL cells, and BL or DLBCL in vitro cell lines. Thus, further preclinical studies in in vivo models are warranted, as this combination may be a promising therapeutic concept for treatment of those malignancies.

A phase I study of PRO131921, a novel anti-CD20 monoclonal antibody in patients with relapsed/refractory CD20+ indolent NHL: correlation between clinical responses and AUC pharmacokinetics

PRO131921 is a third-generation, humanized anti-CD20 monoclonal antibody with increased antibody-dependent cytotoxicity and complement-dependent cytotoxicity compared to rituximab. In this phase I study, PRO131921 was administered as a single agent to patients with CD20+, relapsed or refractory, indolent non-Hodgkin lymphoma (NHL) who had been treated with a prior rituximab-containing regimen. The primary aim of this study was safety and tolerability of PRO131921. The secondary aim of the study, and focus of this report, was to determine the pharmacokinetics (PK) profile of PRO131921 and establish a correlation between drug exposure and clinical efficacy. Patients were treated with PRO131921 by intravenous infusion weekly for 4 weeks and the dose was escalated based on safety in a 3+3 design. Twenty-four patients were treated with PRO131921 at doses from 25mg/m(2) to 800 mg/m(2). Analysis of PK data demonstrated a correlation between higher normalized drug exposure (normalized AUC) and tumor shrinkage (p = .0035). Also, normalized AUC levels were higher among responders and subjects displaying tumor shrinkage versus subjects progressing or showing no regression (p = 0.030). In conclusion, PRO131921 demonstrated clinical activity in rituximab-relapsed and refractory indolent NHL patients. The observation that higher normalized AUC may be associated with improved clinical responses has potential implications in future trials of monoclonal antibody-based therapies, and emphasizes the importance of early PK studies to optimize antibody efficacy.