An Evidence-based Review of Anti-CD20 Antibody-containing Regimens for the Treatment of Patients With Relapsed or Refractory Chronic Lymphocytic Leukemia, Diffuse Large B-cell Lymphoma, or Follicular Lymphoma

Multispecific CAR T Cells Deprive Lymphomas of Escape via Antigen Loss

Chimeric antigen receptor (CAR) modified T cell therapy has transformed the management of relapsed/refractory B cell malignancies. Despite high overall response rates, relapse post CAR T treatment remains a clinical challenge. Loss of target antigen, specifically CD19, is one well-defined mechanism of disease relapse. The mechanism of CD19 loss and which patients are at higher risk of CD19 loss remain poorly understood. To overcome CD19 loss, CARs targeting multiple antigens are being tested in clinical trials. CD19/20 and CD19/22 bispecific CARs demonstrate cytotoxicity against CD19-negative cells in preclinical studies. These CARs have also shown efficacy, safety, and a relatively low rate of CD19-negative relapse in phase I trials. These small studies suggest that multispecific CAR T cells can deprive lymphomas of escape via antigen loss. However, the selection of an ideal target, the right CAR construct, and whether these multispecific CARs can induce long-term remissions are still under investigation.

Management of relapsed or refractory large B-cell lymphoma in patients ineligible for CAR-T cell therapy

INTRODUCTION

Chimeric antigen receptor T (CAR-T) therapy has revolutionized the treatment of relapsed/refractory large B-cell lymphoma (LBCL). However, patients who are excluded or have no access to CAR-T represent a challenge for clinicians and have generally a dismal outcome. The landscape for this category of patients is constantly evolving: new agents have been approved in the last 2-3 years, alone or in combination, and novel treatment modalities are under investigations.

AREAS COVERED

Thereafter, we reviewed the currently available therapeutic strategies: conventional chemotherapy, Antibody-drug conjugate ADC (mainly polatuzumab and loncastuxumab), bispecific antibodies (CD19/CD3 and focus on novel CD20/CD3 Abs), immunomodulatory drugs (covering tafasitamab and lenalidomide, checkpoint inhibitors mainly in PMBL), small molecules (selinexor, BTK and PI3K inhibitors), and the role of radiotherapy.

EXPERT OPINION

Navigating this scenario, will uncover new challenges, including identifying an ideal sequence for these therapies, the most effective combinations, and search for consistent predictive factors to help selecting the appropriate population of LBCL patients. At present, supporting clinical research for CAR-T ineligible patients, a new and challenging group, must remain a major focus that is complementary to advances in CAR T-cell therapy.

Monoclonal Antibodies, Bispecific Antibodies and Antibody-Drug Conjugates in Oncohematology

Background:

The therapeutic outcomes and the prognosis of patients with various hematologic malignancies are not always ideal with the current standard of care.

Objective:

The aim of this study is to analyze the results of the use of monoclonal antibodies, bispecific antibodies and antibody-drug conjugates for the therapy of malignant hemopathies.

Methods:

A mini-review was achieved using the articles published in Web of Science and PubMed between January 2017 and January 2020 and the new patents were made in this field.

Results:

Naked monoclonal antibodies have improved the therapeutic results obtained with standard of care, but they also have side effects and the use of some of them can lead to the loss of the target antigen through trogocytosis, which explains the resistance that occurs during therapy. The results obtained with naked monoclonal antibodies have been improved by a better monoclonal antibody preparation, the use of bispecific antibodies (against two antigens on the target cell surface or by binding both surface antigen on target cells and T-cell receptor complex, followed by cytotoxic T-lymphocytes activation and subsequent cytolysis of the target cell), the use of monoclonal or bispecific constructs in frontline regimens, combining immunotherapy with chemotherapy, including through the use of antibody-drug conjugates (which provides a targeted release of a chemotherapeutic agent).

Conclusion:

Immunotherapy and immuno-chemotherapy have improved the outcome of the patients with malignant hemopathies through a targeted, personalized therapy, with reduced systemic toxicity, which in some cases can even induce deep complete remissions, including minimal residual disease negativity.

Baseline SUVmax is related to tumor cell proliferation and patient outcome in follicular lymphoma

Follicular lymphoma (FL) is the most common indolent lymphoma. Despite the clear benefit of CD20-based therapy, a subset of FL patients still progress to aggressive lymphoma. Thus, identifying early biomarkers that incorporate PET metrics could be helpful to identify patients with a high risk of treatment failure with Rituximab. We retrospectively included a total of 132 untreated FL patients separated into training and validation cohorts. Optimal threshold of baseline SUVmax was first determined in the training cohort (n=48) to predict progression-free survival (PFS). The PET results were investigated along with the tumor and immune microenvironment, which were determined by immunochemistry and transcriptome studies involving gene set enrichment analyses and immune cell deconvolution, together with the tumor mutation profile. We report that baseline SUVmax >14.5 was associated with poorer PFS than baseline SUVmax ≤14.5 (HR=0.28; p=0.00046). Neither immune T-cell infiltration nor immune checkpoint expression were associated with baseline PET metrics. By contrast, FL samples with Ki-67 staining ≥10% showed enrichment of cell cycle/DNA genes (p=0.013) and significantly higher SUVmax values (p=0.007). Despite similar oncogenic pathway alterations in both SUVmax groups of FL samples, 4 out of 5 cases harboring the infrequent FOXO1 transcription factor mutation were seen in FL patients with SUVmax >14.5. Thus, high baseline SUVmax reflects FL tumor proliferation and, together with Ki-67 proliferative index, can be used to identify patients at risk of early relapse with R-chemotherapy.

Leveraging Heterogeneity in Systemic Lupus Erythematosus for New Therapies

Systemic lupus erythematosus (SLE) is a multisystem, chronic autoimmune disease where treatment varies by patient and disease activity. Strong preclinical results and clinical correlates have motivated development of many drugs, but many of these have failed to achieve efficacy in clinical trials. FDA approval of belimumab in 2011 was the first successful SLE drug in nearly six decades. In this article, we review insights into the molecular and clinical heterogeneity of SLE from transcriptomics studies and detail their potential impact on drug development and clinical practices. We critically examine the pipeline of SLE drugs, including past failures and their associated lessons and current promising approaches. Finally, we identify opportunities for integrating these findings and drug development with new multidisciplinary advances to enhance future SLE treatment.

Pre-Therapeutic Total Lesion Glycolysis on [18F]FDG-PET Enables Prognostication of 2-Year Progression-Free Survival in MALT Lymphoma Patients Treated with CD20-Antibody-Based Immunotherapy

PURPOSE

Standardized uptake values (SUV), total metabolic tumor volumes (TMTV), and total lesion glycolysis (TLG) based on positron emission tomography with 2-deoxy-2-[¹⁸F]fluoro-D-glucose ([¹⁸F]FDG/positron emission tomography (PET) are established outcome predictors in FDG-avid lymphomas. We therefore investigated whether these biomarkers also have prognostic value in extranodal marginal zone B cell lymphoma of the mucosa-associated lymphoid tissue (MALT lymphoma), with a focus on patients treated with anti-CD20 antibody-based immunotherapy.

PROCEDURES

Pre-therapeutic [¹⁸F]FDG/PET scans of 61 treatment-naïve MALT lymphoma patients, including 35 scheduled for anti-CD20 antibody-based immunotherapy, were included in this retrospective study. SUVmean, SUVmax, TMTV, and TLG were measured and tested for 2-year progression-free survival (PFS) prognostication, using Cox regression analyses. Receiver operating characteristic curves were used to determine optimal cutoffs for prognostic [¹⁸F]FDG/PET parameters, and Kaplan-Meier estimates with log rank tests were performed.

RESULTS

After 2 years, progression had occurred in 12/61 patients (CD20-anitbody group 6/35). TLG emerged as the only significant prognostic factor for 2-year PFS in the multivariate analyses with forward selection, both in entire cohort (hazard ratio HR, 1.001; 95 % CI, 1.001-1.002; P < 0.0001) and in the CD20-antibody group (HR, 1.001; 95 % CI, 1.001-1.002; P = 0.001). However, in the entire population, where 8/26 patients with a TLG > 90 (30.8 %) vs. 4/35 patients with a TLG ≤ 90 (11.4 %) showed progression within the 2-year observation period, TLG-based separation of risk groups failed (HR, 0.35; 95 % CI, 0.10-1.15; P = 0.069); whereas in the CD20-antibody group, where 6/16 patients with a TLG > 90 (37.5 %) vs. 0/19 patients with a TLG ≤ 90 (0.0 %) showed progression, risk group separation was successful (HR, 0.010; 95 % CI, 0.0001-8.068; P = 0.003).

CONCLUSIONS

TLG may improve early risk stratification of MALT lymphoma patients treated with CD20-antibody-based immunotherapy.

Rituximab treatment for IgA vasculitis: A systematic review

BACKGROUND

Immunoglobulin A vasculitis (IgAV) is a systemic small vessel vasculitis for which treatment of severe cases is usually based on glucocorticoids and other conventional immunosuppressive drugs. The role of rituximab for resistant or refractory cases has been explored in isolated case reports and small series.

AIMS

To perform a literature review of all pediatric and adult patients with IgAV treated with rituximab (RTX) and to assess disease characteristics, RTX efficacy and safety.

METHODS

We conducted a systematic literature review according to PRISMA guidelines by selecting articles with information on IgAV and RTX up to October 2019. We extracted data on patient characteristics, disease course, RTX efficacy and tolerance. The resulting database was analyzed with statistical software package SPSS v 22.0.

RESULTS

Among the initial 161 articles found, 20 studies including 35 well-characterized IgAV patients treated with RTX were finally analyzed. Distribution by sex was similar, and the median age at diagnosis was 26 (range: 2 months to 70 years). Patients included were equally diagnosed at pediatric age and in the adulthood. Almost 90% of patients had renal involvement before RTX treatment and resistant or refractory disease to glucocorticoids or other immunosuppressive agents, mainly with renal impairment, was the reason for RTX administration in 85.7% of patients. RTX was used because of contraindication to these previous agents in 8.6% of patients, and as first line therapy in 5.7% of them. With regard to RTX response, 94.3% of patients presented clinical improvement of any type and 74.3% achieved sustained remission at the end of follow-up. Among the 13 (37.1%) patients who experienced a disease relapse, 11 (31.4%) were treated with a new RTX dose, with good disease control in all cases. In terms of treatment requirements, glucocorticoids and additional immunosuppressants were significantly lower after RTX administration. No deaths were observed and the rate of minor RTX-associated adverse effects was of 8.6%.

CONCLUSION

RTX seems to be a safe and useful agent in inducing disease remission and reducing previous immunosuppressive treatment in IgAV pediatric and adult patients resistant or refractory to glucocorticoids or other immunosuppressive drugs, and in those patients in whom these agents are contraindicated. Nevertheless, controlled clinical trials in are still warranted to clarify the role of RTX in IgAV.

Monoclonal Antibody Therapies in Multiple Myeloma: A Challenge to Develop Novel Targets

The treatment options in multiple myeloma (MM) has changed dramatically over the past decade with the development of novel agents such as proteasome inhibitors (PIs); bortezomib and immunomodulatory drugs (IMiDs); thalidomide, and lenalidomide which revealed high efficacy and improvement of overall survival (OS) in MM patients. However, despite these progresses, most patients relapse and become eventually refractory to these therapies. Thus, the development of novel, targeted immunotherapies has been pursued aggressively. Recently, next-generation PIs; carfilzomib and ixazomib, IMiD; pomalidomide, histone deacetylase inhibitor (HDADi); panobinostat and monoclonal antibodies (MoAbs); and elotuzumab and daratumumab have emerged, and especially, combination of mAbs plus novel agents has led to dramatic improvements in the outcome of MM patients. The field of immune therapies has been accelerating in the treatment of hematological malignancies and has also taken center stage in MM. This review focuses on an overview of current status of novel MoAb therapy including bispecific T-cell engager (BiTE) antibody (BsAb), antibody-drug conjugate (ADC), and chimeric antigen receptor (CAR) T cells, in relapsed or refractory MM (RRMM). Lastly, investigational novel MoAb-based therapy to overcome immunotherapy resistance in MM is shown.

Immunotherapy in Hodgkin Lymphoma: Present Status and Future Strategies

Although classical Hodgkin lymphoma (cHL) is usually curable, 20-30% of the patients experience treatment failure and most of them are typically treated with salvage chemotherapy and autologous stem cell transplantation (autoSCT). However, 45-55% of that subset further relapse or progress despite intensive treatment. At the advanced stage of the disease course, recently developed immunotherapeutic approaches have provided very promising results with prolonged remissions or disease stabilization in many patients. Brentuximab vedotin (BV) has been approved for patients with relapsed/refractory cHL (rr-cHL) who have failed autoSCT, as a consolidation after autoSCT in high-risk patients, as well as for patients who are ineligible for autoSCT or multiagent chemotherapy who have failed ≥ two treatment lines. However, except of the consolidation setting, 90-95% of the patients will progress and require further treatment. In this clinical setting, immune checkpoint inhibitors (CPIs) have produced impressive results. Both nivolumab and pembrolizumab have been approved for rr-cHL after autoSCT and BV failure, while pembrolizumab has also been licensed for transplant ineligible patients after BV failure. Other CPIs, sintilimab and tislelizumab, have been successfully tested in China, albeit in less heavily pretreated populations. Recent data suggest that the efficacy of CPIs may be augmented by hypomethylating agents, such as decitabine. As a result of their success in heavily pretreated disease, BV and CPIs are moving to earlier lines of treatment. BV was recently licensed by the FDA for the first-line treatment of stage III/IV Hodgkin lymphoma (HL) in combination with AVD (only stage IV according to the European Medicines Agency (EMA)). CPIs are currently being evaluated in combination with AVD in phase II trials of first-line treatment. The impact of BV and CPIs was also investigated in the setting of second-line salvage therapy. Finally, combinations of targeted therapies are under evaluation. Based on these exciting results, it appears reasonable to predict that an improvement in survival and a potential increase in the cure rates of cHL will soon become evident.

Immunotherapy in Hodgkin Lymphoma: Present Status and Future Strategies

Although classical Hodgkin lymphoma (cHL) is usually curable, 20-30% of the patients experience treatment failure and most of them are typically treated with salvage chemotherapy and autologous stem cell transplantation (autoSCT). However, 45-55% of that subset further relapse or progress despite intensive treatment. At the advanced stage of the disease course, recently developed immunotherapeutic approaches have provided very promising results with prolonged remissions or disease stabilization in many patients. Brentuximab vedotin (BV) has been approved for patients with relapsed/refractory cHL (rr-cHL) who have failed autoSCT, as a consolidation after autoSCT in high-risk patients, as well as for patients who are ineligible for autoSCT or multiagent chemotherapy who have failed ≥ two treatment lines. However, except of the consolidation setting, 90-95% of the patients will progress and require further treatment. In this clinical setting, immune checkpoint inhibitors (CPIs) have produced impressive results. Both nivolumab and pembrolizumab have been approved for rr-cHL after autoSCT and BV failure, while pembrolizumab has also been licensed for transplant ineligible patients after BV failure. Other CPIs, sintilimab and tislelizumab, have been successfully tested in China, albeit in less heavily pretreated populations. Recent data suggest that the efficacy of CPIs may be augmented by hypomethylating agents, such as decitabine. As a result of their success in heavily pretreated disease, BV and CPIs are moving to earlier lines of treatment. BV was recently licensed by the FDA for the first-line treatment of stage III/IV Hodgkin lymphoma (HL) in combination with AVD (only stage IV according to the European Medicines Agency (EMA)). CPIs are currently being evaluated in combination with AVD in phase II trials of first-line treatment. The impact of BV and CPIs was also investigated in the setting of second-line salvage therapy. Finally, combinations of targeted therapies are under evaluation. Based on these exciting results, it appears reasonable to predict that an improvement in survival and a potential increase in the cure rates of cHL will soon become evident.

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.