Results of a phase II study of bendamustine and ofatumumab in untreated indolent B cell non-Hodgkin's lymphoma

Phase 1 Study Evaluating Pharmacokinetics and Tolerability of Ofatumumab Combined With Bendamustine in Patients With Indolent B-Cell Non-Hodgkin's Lymphoma

The pharmacokinetics (PK) and safety of ofatumumab and bendamustine alone and in combination were evaluated in patients with treatment-naive or relapsed indolent B-cell non-Hodgkin lymphoma (iNHL). Patients were randomly assigned to ofatumumab and bendamustine or ofatumumab alone. Ofatumumab PK concentration profiles and parameters were similar, alone or in combination with bendamustine. A decrease of 14% in the maximum observed plasma concentration (C_max ) and 15% in the area under the plasma concentration-time curve (AUC) from time 0 to the last measurable concentration sampling time (AUC_last ) was observed for ofatumumab coadministered with bendamustine, which was not considered clinically relevant. Bendamustine PK concentration profiles and parameters were similar with or without ofatumumab. The most frequent treatment-related adverse event was infusion-related reaction in 53% in the combination arm and 47% in the ofatumumab arm. No relevant drug-drug interaction was observed between ofatumumab and bendamustine. Ofatumumab alone or in combination with bendamustine had a manageable safety profile.

PET/CT-Based Response Evaluation in Cancer-a Systematic Review of Design Issues

Positron emission tomography/x-ray computed tomography (PET/CT) has long been discussed as a promising modality for response evaluation in cancer. When designing respective clinical trials, several design issues have to be addressed, especially the number/timing of PET/CT scans, the approach for quantifying metabolic activity, and the final translation of measurements into a rule. It is unclear how well these issues have been tackled in quest of an optimised use of PET/CT in response evaluation. Medline via Ovid and Science Citation Index via Web of Science were systematically searched for articles from 2015 on cancer patients scanned with PET/CT before and during/after treatment. Reports were categorised as being either developmental or evaluative, i.e. focusing on either the establishment or the evaluation of a rule discriminating responders from non-responders. Of 124 included papers, 112 (90 %) were accuracy and/or prognostic studies; the remainder were response-curve studies. No randomised controlled trials were found. Most studies were prospective (62 %) and from single centres (85 %); median number of patients was 38.5 (range 5-354). Most (69 %) of the studies employed only one post-baseline scan. Quantification was mainly based on SUVmax (91 %), while change over time was most frequently used to combine measurements into a rule (79 %). Half of the reports were categorised as developmental, the other half evaluative. Most development studies assessed only one element (35/62, 56 %), most frequently the choice of cut-off points (25/62, 40 %). In summary, the majority of studies did not address the essential open issues in establishing PET/CT for response evaluation. Reasonably sized multicentre studies are needed to systematically compare the many different options when using PET/CT for response evaluation.

Efficacy and safety of ofatumumab and bendamustine followed by ofatumumab maintenance in patients with relapsed indolent non-Hodgkin lymphoma after prior rituximab

In indolent non-Hodgkin's lymphoma (iNHL), patients treated with rituximab, alone or in combination with various chemotherapeutic agents eventually relapse. This study evaluated the combination of ofatumumab and bendamustine, followed by maintenance ofatumumab in patients with relapsed iNHL with prior sensitivity to rituximab. Among the 49 patients enrolled, 24.5% achieved a complete response (CR) and 42.9% achieved a partial response (PR), with an overall response rate of 67.3% at the end of the induction therapy. Additionally, six patients with PR during induction phase achieved CR during the maintenance phase. Treatment-related adverse event was observed in 95.9% patients. The most common hematologic and biochemical abnormalities were decrease in lymphocytes (85.7%) and increase in glucose (91.8%), respectively. Overall, 42.9% progressed and 14.3% died during the study. Thus, ofatumumab in combination with bendamustine, followed by ofatumumab maintenance, was effective in the treatment of patients with iNHL with a manageable safety profile (NCT01294579).

A phase II trial of bendamustine in combination with ofatumumab in patients with relapsed or refractory marginal zone B-cell lymphomas

Marginal zone lymphomas (MZLs) are indolent yet incurable lymphomas with frequent relapses following therapy. For patients with relapsed/refractory disease, no standard therapies exist. Here we report results of an exploratory phase II study aimed at assessing the efficacy and safety of the alkylator agent bendamustine in combination with the second-generation anti-CD20 monoclonal antibody, ofatumumab, in patients with relapsed or refractory MZL. Patients with MZL and previously treated with at least one line of systemic therapy were eligible. Treatment consisted in bendamustine (90 mg/m² on days 1 and 2) and ofatumumab (1000 mg on day 1) in 28-day cycles for up to six cycles. Sixteen patients were included in the trial. In one patient, the diagnosis was revised after two cycles of treatment and was excluded from the efficacy analysis. Among 15 patients with MZL, 14 were evaluable for response: the overall and complete response rates were 92.9% and 57.1%, respectively. The median duration of response was 30.4 months (95% confidence interval [CI], 15.5 -not estimable) and 2-years progression-free survival 77% (95% CI, 43%-92%). Fifteen patients (94%) experienced grade 3-4 adverse events. Toxicity was mostly hematological. Neutropenia grade ≥3 was recorded in 27% of patients, lymphocytopenia in 93%, and infections and febrile neutropenia each in 13%. One patient discontinued treatment due to myocardial infarction; no treatment-related deaths occurred. The combination of bendamustine with ofatumumab was active with an acceptable toxicity profile in this small phase II trial and can be considered for further investigation in relapsed/refractory MZL patients.

Risk Factors for Skin Toxicities Associated with Bendamustine-Based Chemotherapy in Patients with Non-Hodgkin Lymphoma

Bendamustine plays an especially important role as a treatment for non-Hodgkin lymphoma (NHL). However, patients administered bendamustine alone or in combination with rituximab (BR) may experience drug-associated skin toxicities that can profoundly impact their health-related QOL through both physical discomfort and psychological distress. Moreover, worsening skin symptoms may lead to dose reduction or termination in the management of cancer chemotherapy. We retrospectively investigated patient backgrounds and pretreatment characteristics from medical records of NHL patients treated with bendamustine alone or BR therapy and identified predictive factors for skin toxicities at the start of chemotherapy. Patients were eligible for the study if they were 20 years older, diagnosed with NHL, and received bendamustine alone or BR therapy at the Department of Hematology, Kobe City Medical Center General Hospital, between April 1, 2011, and March 31, 2018. This study included 95 patients with newly diagnosed or refractory or relapsed NHL. Multivariate stepwise logistic regression analysis with backward selection revealed that baseline non-prior chemotherapy (odds ratio (OR), 15.72; 95% confidence interval (CI), 4.24-83.13, p < 0.001) was a significant factor influencing the occurrence of skin toxicity. Our results demonstrated that non-prior chemotherapy was a significant risk factor for skin toxicities in patients with NHL receiving bendamustine alone or BR therapy. No patient experience serious side effects of grade 3 or higher and that bendamustine is very useful as a first-line treatment.

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.

Nitrogen Mustards as Anticancer Chemotherapies: Historic Perspective, Current Developments and Future Trends

Nitrogen mustards, a family of DNA alkylating agents, marked the start of cancer pharmacotherapy. While traditionally characterized by their dose-limiting toxic effects, nitrogen mustards have been the subject of intense research efforts, which have led to safer and more effective agents. Even though the alkylating prodrug mustards were first developed decades ago, active research on ways to improve their selectivity and cytotoxic efficacy is a currently active topic of research. This review addresses the historical development of the nitrogen mustards, outlining their mechanism of action, and discussing the improvements on their therapeutic profile made through rational structure modifications. A special emphasis is made on discussing the nitrogen mustard prodrug category, with Cyclophosphamide (CPA) serving as the main highlight. Selected insights on the latest developments on nitrogen mustards are then provided, limiting such information to agents that preserve the original nitrogen mustard mechanism as their primary mode of action. Additionally, future trends that might follow in the quest to optimize these invaluable chemotherapeutic medications are succinctly suggested.

Randomized trial of ofatumumab and bendamustine versus ofatumumab, bendamustine, and bortezomib in previously untreated patients with high-risk follicular lymphoma: CALGB 50904 (Alliance)

BACKGROUND

This multicenter, randomized phase 2 trial evaluated complete responses (CRs), efficacy, and safety with ofatumumab and bendamustine and with ofatumumab, bendamustine, and bortezomib in patients with untreated, high-risk follicular lymphoma (FL).

METHODS

Patients with grade 1 to 3a FL and either a Follicular Lymphoma International Prognostic Index (FLIPI) score of 2 with 1 lymph node >6 cm or an FLIPI score of 3 to 5 were randomized to arm A (ofatumumab, bendamustine, and maintenance ofatumumab) or to arm B (ofatumumab, bendamustine, bortezomib, and maintenance ofatumumab and bortezomib).

RESULTS

One hundred twenty-eight patients (66 in arm A and 62 in arm B) received treatment. The median age was 61 years, and 61% had disease >6 cm; 29% had an FLIPI score of 2, and 71% had an FLIPI score of 3 to 5. In arm A, 86% completed induction, and 64% completed maintenance. In arm B, 66% and 52% completed induction and maintenance, respectively. Dose modifications were required in 65% and 89% in arms A and B, respectively. Clinically significant grade 3 to 4 toxicities included neutropenia (A, 36%; B, 31%), nausea/vomiting (A, 0%; B, 8%), diarrhea (A, 5%; B, 11%), and sensory neuropathy (A, 0%; B, 5%). The estimated CR rates were 62% (95% confidence interval [CI], 50%-74%) and 60% (95% CI, 47%-72%) in arms A and B, respectively (P = .68). With a median follow-up of 3.3 years, the estimated 2-year progression-free survival (PFS) and overall survival (OS) rates were 80% and 97%, respectively, for arm A and 76% and 91%, respectively, for arm B.

CONCLUSIONS

The CR rates, PFS, and OS were not improved with the addition of bortezomib to ofatumumab and bendamustine in patients with high-risk FL. Although grade 3 to 4 toxicities were similar, more patients treated with bortezomib required dose modifications and early discontinuation.

Phase 2 multicentre study of single-agent ofatumumab in previously untreated follicular lymphoma: CALGB 50901 (Alliance)

Rituximab monotherapy has proven efficacy in treatment-naïve, asymptomatic advanced-stage follicular lymphoma (FL). Ofatumumab is a fully humanized anti-CD20 monoclonal antibody with increased CD20 affinity and complement-dependent cytotoxicity. This phase 2 trial (NCT01190449) evaluated ofatumumab in patients with untreated, low/intermediate-risk FL International Prognostic Index (FLIPI), advanced-stage FL to determine single-agent efficacy. Patients with measurable disease in stages III/IV or bulky stage II, regardless of Groupe d'Etude des Lymphomes Folliculaires criteria, received 4 weekly 1000 mg doses followed by four extended induction doses once every 8 weeks. Primary endpoint was overall response rate (ORR) to 1000 mg; secondary endpoints were progression-free survival (PFS) and safety. Fifty-one patients were enrolled. Fifteen patients were randomized to 500 mg prior to discontinuing that arm for slow accrual. Among 36 patients on the 1000 mg arm, ORR was 84%, median PFS was 1·9 years and median response duration was 23·7 months. All patients remain alive. No grade 4 infusion reactions or grade 3/4 infections occurred. Grade 3 infusion reactions occurred in 25% in the 1000 mg arm only (all first infusion); all but two patients continued on study. Discontinuation was 6% for the total study population. Ofatumumab monotherapy administered by extended induction in untreated, low/intermediate-risk FLIPI, advanced-stage FL is well tolerated and active. Activity appears similar to that reported with single-agent rituximab.

Past, Present, and Future of Rituximab-The World's First Oncology Monoclonal Antibody Therapy

Rituximab is a chimeric mouse/human monoclonal antibody (mAb) therapy with binding specificity to CD20. It was the first therapeutic antibody approved for oncology patients and was the top-selling oncology drug for nearly a decade with sales reaching $8.58 billion in 2016. Since its initial approval in 1997, it has improved outcomes in all B-cell malignancies, including diffuse large B-cell lymphoma, follicular lymphoma, and chronic lymphocytic leukemia. Despite widespread use, most mechanistic data have been gathered from in vitro studies while the roles of the various response mechanisms in humans are still largely undetermined. Polymorphisms in Fc gamma receptor and complement protein genes have been implicated as potential predictors of differential response to rituximab, but have not yet shown sufficient influence to impact clinical decisions. Unlike most targeted therapies developed today, no known biomarkers to indicate target engagement/tumor response have been identified, aside from reduced tumor burden. The lack of companion biomarkers beyond CD20 itself has made it difficult to predict which patients will respond to any given anti-CD20 antibody. In the past decade, two new anti-CD20 antibodies have been approved: ofatumumab, which binds a distinct epitope of CD20, and obinutuzumab, a mAb derived from rituximab with modifications to the Fc portion and to its glycosylation. Both are fully humanized and have biological activity that is distinct from that of rituximab. In addition to these new anti-CD20 antibodies, another imminent change in targeted lymphoma treatment is the multitude of biosimilars that are becoming available as rituximab's patent expires. While the widespread use of rituximab itself will likely continue, its biosimilars will increase global access to the therapy. This review discusses current research into mechanisms and potential biomarkers of rituximab response, as well as its biosimilars and the newer CD20 binding mAb therapies. Increased ability to assess the effectiveness of rituximab in an individual patient, along with the availability of alternative anti-CD20 antibodies will likely lead to dramatic changes in how we use CD20 antibodies going forward.

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 370 patients with mantle cell lymphoma treated with ibrutinib: a pooled analysis from three open-label studies

Ibrutinib is highly active in treating mantle cell lymphoma (MCL), an aggressive B-cell lymphoma. We pooled data from three ibrutinib studies to explore the impact of baseline patient characteristics on treatment response. Patients with relapsed/refractory MCL (n = 370) treated with ibrutinib had an objective response rate (ORR) of 66% (20% complete response; 46% partial response); median duration of response (DOR), progression-free survival (PFS) and overall survival (OS) were 18·6, 12·8 and 25·0 months, respectively. Univariate analyses showed patients with one versus >one prior line of therapy had longer OS. Multivariate analyses identified that one prior line of therapy affected PFS; Eastern Cooperative Oncology Group (ECOG) performance status, simplified MCL international prognostic index (sMIPI) score, bulky disease, and blastoid histology affected OS and PFS. Patients with blastoid versus non-blastoid histology had similar time to best response, but lower ORR, DOR, PFS and OS. OS and PFS were longer in patients with better sMIPI, patients with ECOG performance status 0-1, non-bulky disease and non-blastoid histology. Additionally, the proportion of patients with poor prognostic factors increased with increasing lines of therapy. Together, results suggest that patient outcomes following treatment failure with ibrutinib are related to the natural biological evolution of the disease.

Impact of obinutuzumab alone and in combination for follicular lymphoma

Although rituximab-based chemoimmunotherapy prolongs the survival of patients with follicular lymphoma (FL), this disease is considered incurable in most patients. Thus, new therapies are needed not only for those in the relapsed/refractory setting, but also for initial treatment. Obinutuzumab (G, GA101) is a third-generation, fully humanized type II glycoengineered, anti-CD20 monoclonal antibody that results in increased direct cell death and antibody-dependent, cell-mediated cytotoxicity/phagocytosis compared to rituximab. Obinutuzumab has significant antitumor activity when used alone or in combinations in untreated or relapsed refractory FL patients. Studies have demonstrated its ability to prolong progression-free survival and, in some cases, overall survival, and to eliminate minimal residual disease. Several ongoing trials are investigating combinations with chemotherapy, immunomodulators, targeted drugs, and immunotherapy agents. G is generally well tolerated, with associated adverse effects including infusion-related reactions, neutropenia, thrombocytopenia, and reactivation of hepatitis B virus. Future studies with this antibody should focus on identifying predictive markers and developing chemotherapy-free combinations that will improve the outcome of patients with FL.

A pilot phase II study of ofatumumab monotherapy for extranodal marginal zone B-cell lymphoma of the mucosa-associated lymphoid tissue (MALT) lymphoma

These are the final results of the Ofatumumab in MALT lymphoma study (O-MA 1), a pilot phase II trial evaluating the capacity and safety of ofatumumab to induce objective responses in patients with Helicobacter pylori eradication refractory or extragastric MALT lymphoma. Ofatumumab was given at 4 weekly doses (1000 mg) followed by 4 doses at 2-month intervals starting at week 8. According to protocol, a total of 16 patients were recruited (median age 69 years; range 38-85). Thirty one percent (5/16) of patients had primary gastric MALT lymphoma while the remaining 69% (11/16) presented with extragastric manifestations. Seventy-five percent (12/16) had localized lymphoma and 4 patients disseminated disease. The overall response rate to treatment with ofatumumab was 81% (13/16), with the median time to best response being 5.5 months. In detail, 50% (8/16) achieved complete remission; 31% (5/16), partial remission; and 19% (3/16), disease stabilization as best response. However, 1 patient with gastric lymphoma and complete remission at second restaging had a relapse at final assessment but ongoing complete remission during further follow-up. Tolerability was excellent accept low-grade infusion reactions occurring in 86% (14/16). At a median follow-up time of 25 months only 1 patient has relapsed suggesting durable responses in the majority of patients. This pilot trial shows clearly that ofatumumab is active and safe for the treatment of MALT lymphoma.

Once-weekly ofatumumab in untreated or relapsed Waldenström's macroglobulinaemia: an open-label, single-arm, phase 2 study

BACKGROUND

The development of more effective and safer treatments, especially non-chemotherapeutics, is needed for patients with Waldenström's macroglobulinaemia. The aim of the study was to assess the safety and clinical activity of intravenous ofatumumab monotherapy for untreated and relapsed Waldenström's macroglobulinaemia.

METHODS

We did a phase 2, open-label, single-arm study at six centres (hospitals and cancer clinics) in the USA. Patients aged at least 18 years who were diagnosed with untreated or relapsed Waldenström's macroglobulinaemia and required treatment, received up to three cycles of weekly ofatumumab for 5 weeks. For cycle 1, patients received one of two treatment regimens. Group A received ofatumumab 300 mg during week 1 followed by 1000 mg during weeks 2-4. Because of the acceptable safety of the 1000 mg dose in treatment group A and clinical activity of the 2000 mg dose established in chronic lymphocytic leukaemia, the study was amended on Dec 9, 2009, to change cycle 1 for group B who received ofatumumab 300 mg during week 1 and 2000 mg during weeks 2-5. We followed up patients during weeks 5-16 for treatment group A and during weeks 6-16 for treatment group B (no treatment was given during this follow-up). Patients in both groups with stable disease or a minor response after 16 weeks were eligible to then receive a redosing cycle of ofatumumab 300 mg during week 1 and 2000 mg during weeks 2-5. We followed up patients during weeks 6-16 after the redosing cycle (no treatment was given during this follow-up). Patients responding to cycle 1 or the redosing cycle who developed disease progression within 36 months could receive cycle 2 of ofatumumab 300 mg during week 1 and 2000 mg during weeks 2-5. The primary endpoint for this study was the proportion of patients who achieved an overall response (complete responses plus partial responses plus minor responses) after each treatment cycle in the intent-to-treat population every 4 weeks starting at week 8. This trial is registered at www.ClinicalTrials.gov, NCT00811733, and is now complete.

FINDINGS

Between March 17, 2009, and Feb 24, 2011, we enrolled and assigned 37 patients to treatment (15 in treatment group A and 22 in treatment group B). All 37 were included in the efficacy and safety analyses. 19 (51%, 95% CI 34·4-68·1) of 37 patients achieved an overall response after cycle 1 and 22 (59%, 42·1-75·2) of 37 achieved an overall response after the redosing cycle; 15 (41%) with partial responses, seven (19%) with minor responses. 13 patients received treatment cycle 2; ten (77%) of the 13 achieved a response. All 37 patients had at least one adverse event; 16 (43%) patients had events of grade 3 or more (30 grade 3, one grade 4). The most common grade 3 or 4 adverse events were infusion reactions (four [11%] of 37), chest pain (two [5%] of 37), haemolysis (two [5%] of 37), and neutropenia (two [5%] of 37). Two (9%) of 22 patients (both in treatment group B) had an IgM flare. 12 patients reported serious adverse events; haemolysis and pyrexia were the most common (each occurring in two [5%] of 37 patients).

INTERPRETATION

A high proportion of patients achieved an overall response with ofatumumab monotherapy and this treatment was well tolerated, with a low incidence of IgM flare. This therapy might be a non-chemotherapeutic treatment option for patients with Waldenström's macroglobulinaemia, especially those with high IgM concentrations.

FUNDING

GlaxoSmithKline and Genmab.

Health-related quality of life and symptoms in patients with rituximab-refractory indolent non-Hodgkin lymphoma treated in the phase III GADOLIN study with obinutuzumab plus bendamustine versus bendamustine alone

We present health-related quality of life (HRQoL) data from GADOLIN, comparing bendamustine (B) alone or combined with obinutuzumab (G-B) in rituximab-refractory indolent non-Hodgkin lymphoma patients. The Functional Assessment of Cancer Treatment-Lymphoma (FACT-Lym) questionnaire was administered on day 1 of cycles 1, 3, and 5 during treatment, at end of induction (EOI), bi-monthly for 2 years during maintenance/follow-up, and annually during extended follow-up until progression/death. Time to first ≥6-point worsening from baseline in the FACT-Lym trial outcome index (TOI) was estimated. Minimally important differences at individual subscale and total score level were used to define the proportion of patients reporting improvement on the FACT-Lym lymphoma-specific subscale (≥3 points), FACT-Lym TOI (≥6 points), and FACT-Lym total score (≥7 points). Overall, 396 patients were randomized. Analysis was conducted when 175 Independent Review Committee-assessed progression-free survival (PFS) events were observed. Questionnaire completion rates were generally balanced between arms at baseline, EOI, and final follow-up. Median time to ≥6-point worsening from baseline on the FACT-Lym TOI was 8.0 months in the G-B arm and 4.6 months in the B arm (HR 0.74; 95% CI 0.56-0.98). More G-B patients reported meaningful improvements on the FACT-Lym questionnaire subscales. Results were similar when follicular lymphoma patients were analyzed separately. The delayed time to worsening and greater proportion of patients reporting meaningful improvement in HRQoL in the G-B arm suggest that benefit in PFS is not at the expense of an increase in treatment-related toxicity that could lead to reduced HRQoL.

Reappraising the timing of transplant for indolent non-Hodgkin lymphomas

INTRODUCTION

Indolent non-Hodgkin lymphomas (iNHL) remain incurable with standard approaches. The timing of autologous stem cell transplant (ASCT) is changing following the introduction of new drugs that can potentially defer the transplant, improved reduced intensity conditioning (RIC) and haploidentical allogeneic SCT (allo-SCT).

AREAS COVERED

The most relevant aspects concerning the role of hematopoietic stem cell transplantation in the management of iNHL are discussed. Literature search methodology included examination of PubMed index and meeting presentations. Expert commentary: ASCT is not currently employed as consolidation in first-line, being reserved to patients with refractory/relapsed disease. The curative potential of graft-versus-lymphoma (GVL) after RIC allo-SCT could be particularly beneficial in patients with iNHL relapsing after ASCT. This scenario could be modified in the near future by better definition of high-risk patients at diagnosis, by the improvement of minimal residual disease (MRD) evaluation and by the introduction of new drugs in the therapeutic algorithm.

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.

Novel Targeted Agents in Hodgkin and Non-Hodgkin Lymphoma Therapy

There has been a recent emergence of novel targeted agents for treatment of Hodgkin and non-Hodgkin lymphoma. In particular, antibodies and antibody-drug conjugates directed against surface antigens, agents that block immune checkpoint pathways, and small molecule inhibitors directed against cell signaling pathways have shown significant promise in patients with relapsed and refractory disease and in the frontline setting. With the development of these new therapies, cytotoxic chemotherapy may be avoided entirely in some clinical settings. This review will present the latest information on these novel treatments in Hodgkin and non-Hodgkin lymphoma and will discuss both recently approved agents as well as drugs currently being studied in clinical trials.

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.

Action and resistance of monoclonal CD20 antibodies therapy in B-cell Non-Hodgkin Lymphomas

Anti-CD20 monoclonal antibodies (mAbs) have improved patient's survival with Non-Hodgkin Lymphoma, when combined with chemotherapy. Several mechanisms of action have been reported, including antibody-dependent cellular cytotoxicity, complement-dependent cytotoxicity and induction of apoptosis. Despite the large amount of studies and published data, the role each mechanism played in vivo is not fully understood. Furthermore, the reason why a significant percentage of patients are refractory or resistant remains unknown. Several activated intracellular signaling pathways have been implicated in the mechanisms of resistance of rituximab. In the present manuscript, we review those mechanisms and new anti-CD20 mAbs, as well as the efforts being accomplished to overcome it, focusing on new drugs targeting pathways implicated in resistance to rituximab.

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.