A tale of two antibodies: obinutuzumabversusrituximab

Obinutuzumab in Refractory Membranous Nephropathy: A Case Series

Rationale & Objective

Membranous nephropathy (MN), recognized as an autoimmune kidney disease, responds well to anti-CD20 monoclonal antibodies. Obinutuzumab, a type Ⅱ humanized anti-CD20 and immunoglobulin G1 Fc-optimized monoclonal antibody, when compared with rituximab, has demonstrated superior efficacy in B-cell leukemia and lymphoma, especially in rituximab-resistant cases. However, the efficacy and safety of obinutuzumab in MN remain unclear.

Study Design

A case series study.

Setting & Participants

A total of 18 patients were diagnosed with MN and had received obinutuzumab at our center without secondary MN, undergoing dialysis, having a history of kidney transplantation, or infections requiring treatment.

Exposure

Obinutuzumab treatment.

Outcomes

Primary outcomes included remission rate, time to first remission, and first relapse-free survival time during the follow-up period.

Analytical Approach

Survival analysis was performed with Cox proportional hazards models, log-rank test, and Kaplan-Meier survival analysis.

Results

Patients with MN (median age of 52.5 years, 83.3% males) received an average dose of 2.1 ± 0.8 g of obinutuzumab during a median follow-up period of 13.6 months. During the follow-up, 17 patients (94.4%) achieved remission, with 12 patients (66.7%) achieving partial remission, and 5 patients (27.8%) achieving complete remission. The median time to first remission and first relapse-free survival time was 2.7 (1.0-6.1) months and 9.8 (2.6-11.2) months, respectively. Of 12 patients with previous rituximab treatment, all achieved remission successfully, with 8 (66.7%) achieving partial remission and 4 (33.3%) achieving complete remission. Adverse events were mostly mild, and no severe treatment-related adverse events were observed.

Limitations

Limited or missing data; risks of selection bias; or recall bias; underestimated first relapse-free survival time because of a limited follow-up period; unmonitored counts of CD19+ B-cells and other lymphocyte subsets.

Conclusions

Obinutuzumab demonstrated promising efficacy and safety in inducing remission in MN, particularly in patients with an unsatisfactory response to rituximab.

Obinutuzumab as Initial or Second-Line Therapy in Patients With Primary Membranous Nephropathy

Introduction

B-cell lymphocytes have been demonstrated to play a key role in the pathogenesis underlying membranous nephropathy (MN). The aim of this study was to evaluate the therapeutic efficacy and safety of Obinutuzumab, a glycoengineered type II anti-CD20 monoclonal antibody in individuals with MN.

Methods

We retrospectively analyzed data from 59 consecutive patients with primary MN who provided consent to receive Obinutuzumab and were followed for at least 6 months. The primary outcomes were complete (proteinuria <0.3 g/d) or partial (proteinuria <3.5 g/d with ≥ 50% reduction) remission of proteinuria.

Results

Twenty patients received Obinutuzumab as initial therapy, and 39 patients were previously treated with at least 1 immunosuppressant (second-line therapy). Fifty patients (84.7%) achieved complete remission (CR) or partial remission (PR) of proteinuria during the median follow-up of 9.4 months. The likelihood of remission was significantly higher when Obinutuzumab was used as initial therapy than as second-line therapy after adjusting for the baseline estimated glomerular filtration rate (eGFR), 24-hour urinary protein levels, and anti-phospholipase A2 receptor (PLA2R) status (adjusted hazard ratio [HR], 4.5; 95% confidence interval [CI]: 2.1-9.5, P < 0.001). Circulating CD19+ B-cell count decreased to <5 cells/μl in all patients within 2 weeks after infusion. Serum anti-PLA2R concentrations decreased to <14 relative units (RU)/ml in 43 of 48 patients with PLA2R-related MN. After Obinutuzumab administration, a significant reduction in 24-hour urine protein and increase in serum albumin were observed. No serious adverse events were observed.

Conclusion

Obinutuzumab may represent a promising and well-tolerated therapeutic option for individuals with primary MN. The potential of Obinutuzumab was highlighted as an initial therapy for primary MN.

New Therapies for Highly Sensitized Patients on the Waiting List

Exposure to HLA alloantigens through pregnancy, blood products, and previous transplantations induce powerful immunologic responses that create an immunologic barrier to successful transplantation. This is commonly detected through screening for HLA antibodies using Luminex beads coated with HLA antigens at transplant evaluation. Currently accepted approaches to desensitization include plasmapheresis/low-dose or high-dose intravenous Ig plus anti-CD20. However, these approaches are often unsuccessful because of the inability to remove high titer circulating HLA antibodies and limit rebound responses by long-lived anti-HLA antibody secreting plasma cells (PCs) and memory B cells (B MEM ). This is especially significant for patients with a calculated panel reactive antibody of 99%-100%. Newer desensitization approaches, such as imlifidase (IgG endopeptidase), rapidly inactivate IgG molecules and create an antibody-free zone by cleaving IgG into F(ab'2) and Fc fragments, thus eliminating complement and cell-mediated injury to the graft. This represents an important advancement in desensitization. However, the efficacy of imlifidase is limited by pathogenic antibody rebound, increasing the potential for antibody-mediated rejection. Controlling antibody rebound requires new strategies that address the issues of antibody depletion and inhibition of B MEM and PC responses. This will likely require a combination of agents that effectively and rapidly deplete pathogenic antibodies and prevent immune cell activation pathways responsible for antibody rebound. Here, using anti-IL-6 receptor (tocilizumab) or anti-IL-6 (clazakizumab) could offer long-term control of B MEM and PC donor-specific HLA antibody responses. Agents aimed at eliminating long-lived PCs (anti-CD38 and anti-B-cell maturation antigen×CD3) are likely to benefit highly HLA sensitized patients. Complement inhibitors and novel agents aimed at inhibiting Fc neonatal receptor IgG recycling will be important in desensitization. Administering these agents alone or in combination will advance our ability to effectively desensitize patients and maintain durable suppression post-transplant. After many years of limited options, advanced therapeutics will likely improve efficacy of desensitization and improve access to kidney transplantation for highly HLA sensitized patients.

Impact of leukemia-associated macrophages on the progression and therapy response of chronic lymphocytic leukemia

The treatment landscape of chronic lymphocytic leukemia (CLL) has advanced remarkably over the past decade. The advent and approval of the BTK inhibitor ibrutinib and BCL-2 inhibitor venetoclax, as well as monoclonal anti-CD20 antibodies rituximab and obinutuzumab, have resulted in deep remissions and substantially improved survival outcomes for patients. However, CLL remains a complex disease with many patients still experiencing relapse and unsatisfactory treatment responses. CLL cells are highly dependent on their pro-leukemic tumor microenvironment (TME), which comprises different cellular and soluble factors. A large body of evidence suggests that CLL-associated macrophages shaped by leukemic cells play a pivotal role in maintaining CLL cell survival. In this review, we summarize the pro-survival interactions between CLL cells and macrophages, as well as the impact of the current first-line treatment agents, including ibrutinib, venetoclax, and CD20 antibodies on leukemia-associated macrophages.

Acute acalculous cholecystitis following extended administration of nirmatrelvir/ritonavir for persistent SARS-CoV-2 infection

Immunocompromised patients with hematologic malignancies, particularly those treated with anti-CD20 antibodies such as rituximab and obinutuzumab, are known to be at risk of prolonged infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Prolonged administration or combination therapy with antiviral medications reportedly yields favorable outcomes in these patients. However, knowledge regarding the adverse events associated with such therapeutic approaches is limited. Herein, we report a case of acute acalculous cholecystitis (AAC) following extended administration of nirmatrelvir/ritonavir (NMV/r) in a 68-year-old Japanese man with persistent SARS-CoV-2 infection. The patient had received obinutuzumab and bendamustine for follicular lymphoma and was diagnosed with coronavirus disease 2019 (COVID-19) approximately one year after treatment initiation with these drugs. Subsequently, he was admitted to a different hospital, where he received antiviral drugs, monoclonal antibodies, and steroids. Despite these interventions, the patient relapsed and was subsequently transferred to our hospital due to persistent SARS-CoV-2 infection. Remdesivir administration was ineffective, leading to the initiation of extended NMV/r therapy. One week later, he exhibited elevated gamma-glutamyl transpeptidase (GGT) levels, and one month later, he developed AAC. Cholecystitis was successfully resolved via percutaneous transhepatic gallbladder drainage and administration of antibiotics. We speculate that extended NMV/r administration, in addition to COVID-19, may have contributed to the elevated GGT and AAC. During treatment of persistent SARS-CoV-2 infection with extended NMV/r therapy, patients should be carefully monitored for the appearance of findings suggestive of biliary stasis and the development of AAC.

Sequential administration of anti-complement component C5 eculizumab and type-2 anti-CD20 obinutuzumab for the treatment of early antibody-mediated rejection after kidney transplantation: A proof of concept

Kidney transplant (KT) candidates with donor-specific antibodies (DSA) exhibit exceedingly high antibody-mediated rejection (ABMR) and allograft loss rates. Currently, treatment of ABMR remains an unmet clinical need. We report the use of the anti-C5 eculizumab and the type-2 anti-CD20 obinutuzumab in two patients with early ABMR. Eculizumab (900 mg IV) led to complete inhibition of the terminal complement cascade (unremarkable AP50 and CH50 activity) and prompt stoppage of complement-dependent antibody-mediated allograft injury (clearance of intra-graft C4d and C5b-9 deposition). Despite complement inhibition, obinutuzumab (1000 mg IV) determined full and long-lasting peripheral B-cell depletion, with significant reduction in all DSA. Graft function improved, remaining stable up to three years of follow-up. No signs of active ABMR and rebound DSA were detected. Obinutuzumab B-cell depletion and inhibition of DSA production were not affected by complement blockage. Further studies are needed to confirm the potential benefit of obinutuzumab in association with complement inhibitors.

Membranous nephropathy: pathogenesis and treatments

Membranous nephropathy (MN), an autoimmune disease, can manifest at any age and is among the most common causes of nephrotic syndrome in adults. In 80% of cases, the specific etiology of MN remains unknown, while the remaining cases are linked to drug use or underlying conditions like systemic lupus erythematosus, hepatitis B virus, or malignancy. Although about one-third of patients may achieve spontaneous complete or partial remission with conservative management, another third face an elevated risk of disease progression, potentially leading to end-stage renal disease within 10 years. The identification of phospholipase A2 receptor as the primary target antigen in MN has brought about a significant shift in disease management and monitoring. This review explores recent advancements in the pathophysiology of MN, encompassing pathogenesis, clinical presentations, diagnostic criteria, treatment options, and prognosis, with a focus on emerging developments in pathogenesis and therapeutic strategies aimed at halting disease progression. By synthesizing the latest research findings and clinical insights, this review seeks to contribute to the ongoing efforts to enhance our understanding and management of this challenging autoimmune disorder.

Safety of Obinutuzumab in Children With Autoimmune Encephalitis and Early B-Cell Repopulation on Rituximab

BACKGROUND

Rituximab (RTX) resistance or early B-cells repopulation were observed in children but only few publications reported the use of Obinutuzumab and no recommendations were made concerning the dosage for children.

METHODS

This study was a single-center retrospective cohort study of all the children followed-up in the Pediatric Neurology Department of Necker-Enfants malades Hospital in Paris, France, and treated with obinutuzumab, between November 1, 2019, and November 1, 2021.

RESULTS

A total of eight children (three females, median age 4.5 years) were treated. Seven patients presented with autoimmune encephalitis and one with myeloradiculitis. The median delay of B-cell repopulation after a course of RTX was 87 days (range 41 to 160). A switch to obinutuzumab (anti-CD20) was performed for eight children. The median duration between the first RTX infusion and obinutuzumab administration was 6.6 months. The dosage regimen for obinutuzumab was one infusion of 1000 mg/1.73 m2, that is to say 580 mg/m2 (maximum 1000 mg/infusion), by extrapolation from the adult dosage. The median delay of B-cell repopulation after one course of obinutuzumab was 230 days (range 66 to 303 days) vs 87 days after one course of RTX (P < 0.01). None of the patients presented side effects with obinutuzumab treatment. All patients had a favorable evolution at the last-follow up. Median follow-up was 1.6 years.

CONCLUSIONS

This study reports the use of obinutuzumab in neurological inflammatory diseases in a pediatric population. Obinutuzumab seems to have a better biological efficacy than RTX with a longer time of B-cell repopulation.

Updates on the mechanisms of toxicities associated with monoclonal antibodies targeting growth factor signaling and immune cells in cancer

Monoclonal antibody (mAb)-based immunotherapy currently is considered to be an optimal therapeutic approach to cancer treatment, either in combination with surgery, radiation, and/or chemotherapy or alone. Various solid tumors and hematological malignancies have been characterized by distinct molecular targets, which could be utilized as innovative anticancer agents. Notably, receptor tyrosine kinases, including HER2, EGFR, VEGFR, and PDGFR, which act as receptors for growth factors, serve as crucial target proteins, expanding their role in the cancer therapeutic market. In contrast to conventional anticancer agents that directly target cancer cells, the advent of immunotherapy introduces novel approaches, such as immune checkpoint blockers (ICBs) and mAbs targeting surface antigens on immune cells in hematological malignancies and lymphomas. While these immunotherapies have mitigated the acquired resistance observed in traditional targeted therapies, they also exhibit diverse toxicities. Herein, this review focuses on describing the well-established toxicities and newly proposed mechanisms of monoclonal antibody toxicity in recent studies. Understanding these molecular mechanisms is indispensable to overcoming the limitations of mAbs-based therapies, facilitating the development of innovative anticancer agents, and uncovering novel indications for cancer treatment in the future.

Obinutuzumab in untreated primary membranous nephropathy: An observational case series

BACKGROUND

As an initial treatment for primary membranous nephropathy (PMN), there remains a significant proportion of patients for whom rituximab is not fully effective. Here, we aimed to assess the effectiveness and safety of obinutuzumab as initial treatment in patients with PMN.

METHODS

In this observational case series, patients diagnosed with PMN and treated with obinutuzumab as initial treatment were included. Treatment response was assessed by 24-h urine total protein (24 h UTP) and serum albumin, and immunologic remission was assessed by phospholipase A2 receptor (PLA2R) antibodies.

RESULTS

Twelve patients with PMN receiving obinutuzumab as initial treatment were included. Over 6 months, a statistically significant reduction in 24 h UTP levels (p = 0.003) and an increase in serum albumin levels were observed (p < 0.001). By the 6-month follow-up, two patients (16.7%) achieved complete remission, eight (66.6%) reached partial remission, and two (16.7%) showed no remission. Immunological remission was observed in 44.4% of evaluable patients (n = 9) after 3 months, increasing to 100% (6/6) at 6 months. Except for cases 1, 2, and 3, the total B cell counts in the remaining patients fell to less than 5 cells/μL before the administration of the second dose of obinutuzumab, including seven patients with counts as low as 0 cells/μL. Mild to moderate treatment-related adverse events (TRAEs) were reported in 58.3% (7/12) of the patients. No serious TRAEs were reported.

CONCLUSIONS

Obinutuzumab demonstrates promising potential as an initial treatment for PMN, with good effectiveness and a manageable safety profile. Further large-scale prospective studies are needed to confirm these findings.

T-cell help in the tumor microenvironment enhances rituximab-mediated NK-cell ADCC

ABSTRACT

Rituximab (RTX) and other monoclonal antibodies (mAbs) that bind directly to malignant cells are of great clinical value but are not effective for all patients. A major mechanism of action of RTX is antibody-dependent cellular cytotoxicity (ADCC) mediated by natural killer (NK) cells. Prior in vitro studies in our laboratory demonstrated that T cells contribute to maintaining the viability and cytotoxic potential of NK cells activated by anti-CD20-coated target B cells. Here, we conducted studies using a novel mouse model and clinical correlative analysis to assess whether T-cell help contribute to RTX-mediated NK-cell ADCC in the tumor microenvironment (TME) in vivo. A humanized mouse model was developed using Raji lymphoma cells and normal donor peripheral blood mononuclear cells that allows for control of T-cell numbers in the lymphoma TME. In this model, NK-cell viability and CD16 and CD25 expression dropped after RTX in the absence of T cells but increased in the presence of T cells. RTX therapy was more effective when T cells were present and was ineffective when NK cells were depleted. In patients with indolent lymphoma, fine needle aspirates were obtained before and ∼1 week after treatment with a RTX-containing regimen. There was a strong correlation between CD4+ T cells as well as total T cells in the pretherapy TME and an increase in NK-cell CD16 and CD25 expression after RTX. We conclude that T-cell help in the TME enhances RTX-mediated NK-cell viability and ADCC.

Advancements in cancer immunotherapies targeting CD20: from pioneering monoclonal antibodies to chimeric antigen receptor-modified T cells

CD20 located predominantly on the B cells plays a crucial role in their development, differentiation, and activation, and serves as a key therapeutic target for the treatment of B-cell malignancies. The breakthrough of monoclonal antibodies directed against CD20, notably exemplified by rituximab, revolutionized the prognosis of B-cell malignancies. Rituximab, approved across various hematological malignancies, marked a paradigm shift in cancer treatment. In the current landscape, immunotherapies targeting CD20 continue to evolve rapidly. Beyond traditional mAbs, advancements include antibody-drug conjugates (ADCs), bispecific antibodies (BsAbs), and chimeric antigen receptor-modified (CAR) T cells. ADCs combine the precision of antibodies with the cytotoxic potential of drugs, presenting a promising avenue for enhanced therapeutic efficacy. BsAbs, particularly CD20xCD3 constructs, redirect cytotoxic T cells to eliminate cancer cells, thereby enhancing both precision and potency in their therapeutic action. CAR-T cells stand as a promising strategy for combatting hematological malignancies, representing one of the truly personalized therapeutic interventions. Many new therapies are currently being evaluated in clinical trials. This review serves as a comprehensive summary of CD20-targeted therapies, highlighting the progress and challenges that persist. Despite significant advancements, adverse events associated with these therapies and the development of resistance remain critical issues. Understanding and mitigating these challenges is paramount for the continued success of CD20-targeted immunotherapies.

Advances in desensitization for human leukocyte antigen incompatible kidney transplantation

PURPOSE OF REVIEW

Human leukocyte antigen (HLA) sensitization is a major barrier to kidney transplantation induced by exposure to alloantigens through pregnancy, blood product exposure and previous transplantations. Desensitization strategies are undertaken to improve the chances of finding compatible organ offers. Standard approaches to desensitization include the use of plasmapheresis/low dose intravenous immunoglobulin (IVIG) or high dose IVIG plus anti-CD20. However, current methods to reduce HLA antibodies are not always successful, especially in those with calculated panel reactive antibody 99-100%.

RECENT FINDINGS

Newer desensitization strategies such as imlifidase [immunoglobulin G (IgG) endopeptidase] rapidly inactivates IgG molecules and creates an "antibody-free zone", representing an important advancement in desensitization. However, pathogenic antibodies rebound, increasing allograft injury that is not addressed by imlifidase. Here, use of anti-IL-6R (tocilizumab) or anti-interleukin-6 (clazakizumab) could offer long-term control of B-memory and plasma cell DSA responses to limit graft injury. Agents aimed at long-lived plasma cells (anti-CD38 and anti-BCMAxCD3) could reduce or eliminate HLA-producing plasma cells from marrow niches. Other agents such as complement inhibitors and novel agents inhibiting the Fc neonatal receptor (FcRn) mediated IgG recycling will likely find important roles in desensitization.

SUMMARY

Use of these agents alone or in combination will likely improve the efficacy and durability of desensitization therapies, improving access to kidney transplantation for immunologically disadvantaged patients.

An Updated Review of Membranous Nephropathy

Membranous nephropathy (MN) is one of the most common causes of nephrotic syndrome in adults. The discovery of phospholipase A2 receptor (PLA2R) as a target antigen has led to a paradigm shift in the understanding and management of MN. At present, serum PLA2R antibodies are used for diagnosis, prognostication, and guiding treatment. Now, with the discovery of more than 20 novel target antigens, antigen mapping is almost complete. The clinical association of certain antigens provides clues for clinicians, such as the association of nerve epidermal growth factor-like 1 with malignancies and indigenous medicines. Serum antibodies are detected for most target antigens, except exostosin 1 and 2 and transforming growth factor-beta receptor 3, but their clinical utility is yet to be defined. Genome-wide association studies and studies investigating environmental factors, such as air pollution, shed more light on the underpinnings of MN. The standard therapy of MN diversified from cyclical cyclophosphamide and steroids to include rituximab and calcineurin inhibitors over the past decades. Here, we provide a cutting-edge review of MN, focusing on genetics, immune system and environmental factors, novel target antigens and their clinical characteristics, and currently available and emerging novel therapies in MN.

Management of the sensitized pediatric renal transplant candidate

Kidney transplantation is the treatment of choice for patients with ESRD as it is associated with improved patient survival and better quality of life, especially in children. There are several barriers to a successful transplant including organ shortage, anatomic barriers, and immunologic barriers. One of the biggest immunologic barriers that precludes transplantation is sensitization, when patients have antibodies prior to transplantation, resulting in positive crossmatches with donor. 30%-40% of adult patients on the wait list are sensitized. There is a growing number of pediatric patients on the wait list who are sensitized. This poses a unique challenge to the pediatric transplant community. Therefore, attempts to perform desensitization to remove or suppress pathogenic HLA antibodies resulting in acceptable crossmatches, and ultimately a successful transplant, while reducing the risk of acute rejection, are much needed in these children. This review article aims to address the management of such patients both prior to transplantation, with strategies to overcome sensitization, and after transplantation with monitoring for allograft rejection and other complications.

An international multicenter study comparing COVID-19 omicron outcomes in patients with hematological malignancies treated with obinutuzumab versus rituximab

OBJECTIVES

Hematological malignancy (HM) patients treated with anti-CD20 monoclonal antibodies are at higher risk for severe COVID-19. A previous single-center study showed worse outcomes in patients treated with obinutuzumab compared to rituximab. We examined this hypothesis in a large international multicenter cohort.

METHODS

We included HM patients from 15 centers, from five countries treated with anti-CD20, comparing those treated with obinutuzumab (O-G) to rituximab (R-G) between December 2021 and June 2022, when Omicron lineage was dominant.

RESULTS

We collected data on 1048 patients. Within the R-G (n = 762, 73%), 191 (25%) contracted COVID-19 compared to 103 (36%) in the O-G. COVID-19 patients in the O-G were younger (61 ± 11.7 vs. 64 ± 14.5, p = 0.039), had more indolent HM diagnosis (aggressive lymphoma: 3.9% vs. 67.0%, p < 0.001), and most were on maintenance therapy at COVID-19 diagnosis (63.0% vs. 16.8%, p < 0.001). Severe-critical COVID-19 occurred in 31.1% of patients in the O-G and 22.5% in the R-G. In multivariable analysis, O-G had a 2.08-fold increased risk for severe-critical COVID-19 compared to R-G (95% CI 1.13-3.84), adjusted for Charlson comorbidity index, sex, and tixagevimab/cilgavimab (T-C) prophylaxis. Further analysis comparing O-G to R-G demonstrated increased hospitalizations (51.5% vs. 35.6% p = 0.008), ICU admissions (12.6% vs. 5.8%, p = 0.042), but the nonsignificant difference in COVID-19-related mortality (n = 10, 9.7% vs. n = 12, 6.3%, p = 0.293).

CONCLUSIONS

Despite younger age and a more indolent HM diagnosis, patients receiving obinutuzumab had more severe COVID-19 outcomes than those receiving rituximab. Our findings underscore the need to evaluate the risk-benefit balance when considering obinutuzumab therapy for HM patients during respiratory viral outbreaks.

Negative Impact of Gemtuzumab Ozogamicin on CD33-Positive Early T-Cell Precursor Acute Lymphoblastic Leukemia: A Case Report

Introduction

Early T-cell precursor acute lymphoblastic leukemia (ETP-ALL) is a rare subtype of T-cell leukemia that phenotypically expresses mature T-cell markers and immature myeloid markers such as CD33. Gemtuzumab ozogamicin (GO) is a novel agent for the CD33 molecular targeting antibody conjugated to the cytotoxic agent calicheamicin. GO is anticipated to be effective against ETP-ALL. In vivo studies promise antileukemic effects in cell lines; however, clinical reports to support this research are lacking. We treated a patient who suffered from CD33-positive ETP-ALL using GO.

Case Presentation

We treated an 81-year-old man who suffered from ETP-ALL. The patient's leukemia expressed T cell and myeloid markers including cyCD3, CD5, CD7, CD33, and HLA-DR. Initially, the patient was treated using a standard chemotherapy regimen for acute lymphoblastic leukemia comprising cyclophosphamide, daunorubicin, vincristine, l-asparaginase, and prednisolone. The induction chemotherapy produced the expected complete hematological response; however, bone marrow blasts remained. Following consolidation chemotherapy, the patient maintained a full hematological response. Thereafter, we changed the consolidation regimen to nelarabine, which did not reduce bone marrow blasts effectively. After two courses of nelarabine therapy, we finally used GO at an 8 mg/m2 weekly dose after confirming that CD33 expression was still positive in the patient's residual leukemic cells. GO was ineffective in treating the patient's leukemia, and peripheral blasts increased 30 days following treatment. The patient died 81 days after initiating GO therapy.

Conclusion

This is the first clinical case of GO having a negative impact on ETP-ALL. Because the GO resistance mechanism for ETP-ALL has not been fully elucidated, treatment modification should be considered to achieve optimal clinical efficacy.

Obinutuzumab in Frequently Relapsing and Steroid-Dependent Nephrotic Syndrome in Children

BACKGROUND

B-cell depletion with rituximab induces sustained remission in children with steroid-dependent or frequently relapsing nephrotic syndrome. However, most patients relapse after B-cell recovery, and some patients do not achieve B-cell depletion. Obinutuzumab is a second-generation anti-CD20 antibody designed to overcome such situations in B-cell malignancies and was recently reported to be safe and effective in other autoimmune diseases affecting the kidneys.

METHODS

We retrospectively report 41 children with steroid-dependent or frequently relapsing nephrotic syndrome treated with a single low-dose infusion of obinutuzumab at Robert-Debre Hospital between April 2018 and December 2020. Participants were treated because of rituximab resistance or relapse after rituximab and received a single infusion of 300 mg/1.73 m 2 obinutuzumab with cessation of oral immunosuppressors within 2 months.

RESULTS

B-cell depletion was achieved in all participants and lasted a median of 8.3 months (interquartile range, 6.4-11.1), a duration exceeding that for last rituximab treatment. At 12 and 24 months, 92% (38/41) and 68% (28/41) of patients, respectively, were in sustained remission. Mild infusion reactions occurred in five participants (12%) and neutropenia in nine (21%). No significant decrease in IgG level was reported during treatment, and whereas IgM levels decreased in 34 patients (83%), they were normal at last follow-up in 32 (78%).

CONCLUSIONS

These results identified low-dose obinituzumab as a promising treatment option in children with steroid-dependent or frequently relapsing nephrotic syndrome, including those resistant to rituximab. The tolerance profile of obinutuzumab was similar to that of rituximab, but hemogram and immunoglobulin levels should be monitored.

Immunotherapeutic approaches for systemic lupus erythematosus: early overview and future potential

Systemic lupus erythematosus (SLE) is a complex autoimmune disease. Current SLE therapies include immunosuppressants, antimalarial drugs, non-steroidal anti-inflammatory drugs (NSAIDs), and corticosteroids, but these treatments can cause substantial toxicities to organs and may not be effective for all patients. In recent years, significant progress has been made in the treatment of SLE using immunotherapy, including Benlysta and Saphnelo. These advances in immunotherapy hold promise for SLE patients, providing new therapeutic options that may offer better clinical benefit and effectiveness. Simultaneously, several new biological therapies focusing on cytokines, peptides, targeted antibodies, and cell-based approaches are under clinical evaluation and have shown immense potential for the treatment of SLE. However, the complexity of SLE immunopathogenesis and disease heterogeneity present significant challenges in the development of effective immunological therapies. This review aims to discuss past experiences and understanding of diverse immunological targeting therapies for SLE and highlight future perspectives for the development of novel immunological therapies.

Biomanufacturing of glycosylated antibodies: Challenges, solutions, and future prospects

Traditionally, recombinant protein production has been done in several expression hosts of bacteria, fungi, and majorly CHO (Chinese Hamster Ovary) cells; few have high production costs and are susceptible to harmful toxin contamination. Green algae have the potential to produce recombinant proteins in a more sustainable manner. Microalgal diversity leads to offer excellent opportunities to produce glycosylated antibodies. An antibody with humanized glycans plays a crucial role in cellular communication that works to regulate cells and molecules, to control disease, and to stimulate immunity. Therefore, it becomes necessary to understand the role of abiotic factors (light, temperature, pH, etc.) in the production of bioactive molecules and molecular mechanisms of product synthesis from microalgae which would lead to harnessing the potential of algal bio-refinery. However, the potential of microalgae as the source of bio-refinery has been less explored. In the present review, omics approaches for microalgal engineering, methods of humanized glycoproteins production focusing majorly on N-glycosylation pathways, light-based regulation of glycosylation machinery, and production of antibodies with humanized glycans in microalgae with a major emphasis on modulation of post-translation machinery of microalgae which might play a role in better understanding of microalgal potential as a source for antibody production along with future perspectives.

Efficacy of retreatment with polatuzumab vedotin in combination with rituximab in polatuzumab vedotin-resistant DLBCL models

Polatuzumab vedotin (Pola) was approved for first-line and relapsed/refractory (r/r) diffuse large B-cell lymphoma (DLBCL) in many countries. This means that retreatment with Pola for r/r DLBCL could be considered after first-line Pola treatment; however, there is currently no evidence on the effectiveness of Pola-retreatment. To address this, we established two Pola-resistant cells from DLBCL cells (SU-DHL-4 and STR-428) and evaluated the combination efficacy of Pola plus rituximab (Rit), the key component of DLBCL therapy. MDR1 overexpression and decreased Bim expression were suggested to be the resistant mechanisms to Pola in Pola-resistant SU-DHL-4 and Pola-resistant STR-428, respectively. In these cells, Pola significantly increased Rit-induced CDC sensitivity either with increased MAC formation or reduced Mcl-1 expression. Additionally, treatment with Pola + Rit significantly enhanced antitumor activity in Pola-resistant STR-428 xenograft mouse models. Based on these results, Pola + Rit retreatment could have preserved efficacy because of the effect of Pola on sensitizing cells to Rit.

Simulating Interclonal Interactions in Diffuse Large B-Cell Lymphoma

Diffuse large B-cell lymphoma (DLBCL) is one of the most common types of cancers, accounting for 37% of B-cell tumor cases globally. DLBCL is known to be a heterogeneous disease, resulting in variable clinical presentations and the development of drug resistance. One underexplored aspect of drug resistance is the evolving dynamics between parental and drug-resistant clones within the same microenvironment. In this work, the effects of interclonal interactions between two cell populations-one sensitive to treatment and the other resistant to treatment-on tumor growth behaviors were explored through a mathematical model. In vitro cultures of mixed DLBCL populations demonstrated cooperative interactions and revealed the need for modifying the model to account for complex interactions. Multiple best-fit models derived from in vitro data indicated a difference in steady-state behaviors based on therapy administrations in simulations. The model and methods may serve as a tool for understanding the behaviors of heterogeneous tumors and identifying the optimal therapeutic regimen to eliminate cancer cell populations using computer-guided simulations.

NETosis: an emerging therapeutic target in renal diseases

Introduction

Neutrophil extracellular traps (NETs) are web-like structures composed of nuclear and granular components. The primary role of NETS is to prevent the dissemination of microbes and facilitate their elimination. However, this process is accompanied by collateral proinflammatory adverse effects when the NET release becomes uncontrollable, or clearance is impaired. Although NET-induced organ damage is conducted primarily and indirectly via immune complexes and the subsequent release of cytokines, their direct effects on cells are also remarkable. NETosis plays a critical pathogenic role in several renal disorders, such as the early phase of acute tubular necrosis, anti-neutrophil cytoplasmic antibody-mediated renal vasculitis, lupus nephritis, thrombotic microangiopathies, anti-glomerular basement membrane disease, and diabetic nephropathy. Their substantial contribution in the course of these disorders makes them a desirable target in the therapeutic armamentarium. This article gives an in-depth review of the heterogeneous pathogenesis and physiological regulations of NETosis and its pivotal role in renal diseases. Based on the pathogenesis, the article also outlines the current therapeutic options and possible molecular targets in the treatment of NET-related renal disorders.

Methods

We carried out thorough literature research published in PubMed and Google Scholar, including a comprehensive review and analysis of the classification, pathomechanisms, and a broad spectrum of NET-related kidney disorders.

Conclusions

NETosis plays a pivotal role in certain renal diseases. It initiates and maintains inflammatory and autoimmune disorders, thus making it a desirable target for improving patient and renal outcomes. Better understanding and clinical translation of the pathogenesis are crucial aspects to treatment, for improving patient, and renal outcomes.

Unlocking the Power of Complement-Dependent Cytotoxicity: Engineering Strategies for the Development of Potent Therapeutic Antibodies for Cancer Treatments

The complement system is a crucial part of the innate immune response, providing defense against invading pathogens and cancer cells. Recently, it has become evident that the complement system plays a significant role in anticancer activities, particularly through complement-dependent cytotoxicity (CDC), alongside antibody-dependent cell-mediated cytotoxicity (ADCC) and antibody-dependent cell-mediated phagocytosis (ADCP). With the discovery of new roles for serum complement molecules in the human immune system, various approaches are being pursued to develop CDC-enhanced antibody therapeutics. In this review, we focus on successful antibody engineering strategies for enhancing CDC, analyzing the lessons learned and the limitations of each approach. Furthermore, we outline potential pathways for the development of antibody therapeutics specifically aimed at enhancing CDC for superior therapeutic efficacy in the future.

Control of acute myeloid leukemia by a trifunctional NKp46-CD16a-NK cell engager targeting CD123

CD123, the alpha chain of the IL-3 receptor, is an attractive target for acute myeloid leukemia (AML) treatment. However, cytotoxic antibodies or T cell engagers targeting CD123 had insufficient efficacy or safety in clinical trials. We show that expression of CD64, the high-affinity receptor for human IgG, on AML blasts confers resistance to anti-CD123 antibody-dependent cell cytotoxicity (ADCC) in vitro. We engineer a trifunctional natural killer cell engager (NKCE) that targets CD123 on AML blasts and NKp46 and CD16a on NK cells (CD123-NKCE). CD123-NKCE has potent antitumor activity against primary AML blasts regardless of CD64 expression and induces NK cell activation and cytokine secretion only in the presence of AML cells. Its antitumor activity in a mouse CD123+ tumor model exceeds that of the benchmark ADCC-enhanced antibody. In nonhuman primates, it had prolonged pharmacodynamic effects, depleting CD123+ cells for more than 10 days with no signs of toxicity and very low inflammatory cytokine induction over a large dose range. These results support clinical development of CD123-NKCE.

Future landscape for the management of membranous nephropathy

Among all glomerular diseases, membranous nephropathy (MN) is perhaps the one in which major progress has been made in recent decades, in both the understanding of the pathogenesis and treatment. Despite the overall significant response rates to these therapies-particularly rituximab and cyclical regimen based on corticosteroids and cyclophosphamide-cumulative experience over the years has shown, however, that 20%-30% of cases may confront resistant disease. Thus, these unmet challenges in the treatment of resistant forms of MN require newer approaches. Several emerging new agents-developed primarily for the treatment of hematological malignancies or rheumatoid diseases-are currently being evaluated in MN. Herein we conducted a narrative review on future therapeutic strategies in the disease. Among the different novel therapies, newer anti-CD20 agents (e.g. obinutuzumab), anti-CD38 (e.g. daratumumab, felzartamab), immunoadsorption or anti-complement therapies (e.g. iptacopan) have gained special attention. In addition, several technologies and innovations developed primarily for cancer (e.g. chimeric antigen receptor T-cell therapy, sweeping antibodies) seem particularly promising. In summary, the future therapeutic landscape in MN seems encouraging and will definitely move the management of this disease towards a more precision-based approach.

Treatment Approaches to Granulomatosis with Polyangiitis and Microscopic Polyangiitis

We have made significant headway in our ability to induce and maintain remission in patients with granulomatosis with polyangiitis and microscopic polyangiitis. With increased understanding of the pathogenesis of antineutrophilic cytoplasmic antibody-associated vasculitides (AAV), therapeutic targets have been identified and studied in clinical trials. From initial induction strategies including glucocorticoids and cyclophosphamide, we have discovered effective induction regimens with rituximab and complement inhibition that can significantly decrease the glucocorticoid cumulative doses in patients with AAV. There are many trials underway evaluating management strategies for refractory patients and exploring new and old therapies that may help to continuously improve outcomes for patients with AAV.

Hypogammaglobulinemia, late-onset neutropenia, and infections following rituximab

Rituximab is a chimeric anti-CD20 monoclonal antibody that targets CD20-expressing B lymphocytes, has a well-defined efficacy and safety profile, and is broadly used to treat a wide array of diseases. In this review, we cover the mechanism of action of rituximab and focus on hypogammaglobulinemia and late-onset neutropenia-2 immune effects secondary to rituximab-and subsequent infection. We review risk factors and highlight key considerations for immunologic monitoring and clinical management of rituximab-induced secondary immune deficiencies. In patients treated with rituximab, monitoring for hypogammaglobulinemia and infections may help to identify the subset of patients at high risk for developing poor B cell reconstitution, subsequent infections, and adverse complications. These patients may benefit from early interventions such as vaccination, antibacterial prophylaxis, and immunoglobulin replacement therapy. Systematic evaluation of immunoglobulin levels and peripheral B cell counts by flow cytometry, both at baseline and periodically after therapy, is recommended for monitoring. In addition, in those patients with prolonged hypogammaglobulinemia and increased infections after rituximab use, immunologic evaluation for inborn errors of immunity may be warranted to further risk stratification, increase monitoring, and assist in therapeutic decision-making. As the immunologic effects of rituximab are further elucidated, personalized approaches to minimize the risk of adverse reactions while maximizing benefit will allow for improved care of patients with decreased morbidity and mortality.

Recent advances in immunotherapies for lupus nephritis

Childhood-onset systemic lupus erythematosus (SLE) is characterized by increased rates of kidney involvement, termed lupus nephritis. Despite the significant morbidity and mortality associated with this disease, lupus nephritis trials have been plagued by repeated failures to meet clinical endpoints. However, improvements in trial design and the development of targeted approaches have begun to yield promising results, including two new FDA-approved lupus nephritis treatments since 2020. These include belimumab, a monoclonal antibody targeting the B cell survival cytokine BAFF (B cell activating factor), and voclosporin, a cyclosporin analog with improved pharmacokinetic characteristics. In this review, we will summarize the data supporting regulatory approval for these agents in lupus nephritis and highlight ongoing clinical trials targeting the diverse immunologic drivers of renal inflammation in SLE. While pediatric patients remain underrepresented in lupus clinical trials, given the increased severity of childhood-onset SLE and need for long-term protection from kidney damage, we anticipate the need for off-label use of these targeted therapies in the pediatric population. Future studies are needed to define optimal patient selection, drug combinations, and treatment duration in pediatric lupus nephritis.

Characterization and exploration of an artifact in the reducing capillary electrophoresis-sodium dodecyl sulfate analysis of the 'me-too' drug zuberitamab related to rituximab

For monoclonal antibody (mAb) drugs, the 'me-too' drug is a pharmacologically active compound that is structurally similar to the first-in-class drugs, acting on the same target and is used for the same therapeutic purposes, but it may differ in drug-drug interactions and adverse drug reactions. Capillary electrophoresis-sodium dodecyl sulfate (CE-SDS) has been widely used for quality evaluation of mAb drugs. The properties of the detected substances can interfere with the credibility and accuracy of the method. In the routine comparison analysis for both innovator rituximab and 'me-too' drug zuberitamab samples, an uncommon artifact related to the heavy chain (HC) of zuberitamab was observed in reducing CE-SDS and interfered with our identification of the purity of samples. In this work, the overall hydrophobicity of the HCs of rituximab, zuberitamab, and several other common mAbs was characterized and determined by reversed-phase high-performance liquid chromatography. Additionally, the local hydrophobicity and surface charge were compared using Expasy ProtScale and PyMOL software simulations. We concluded that noncovalent protein aggregation can be related to strong hydrophobicity and low electrostatic repulsion of local amino acid regions, which complicates drug quality control. These findings shed light on the relationship between protein aggregation and the local hydrophobicity region, and broaden the way to analyze the detection 'artifacts' in reducing CE-SDS studies of therapeutic proteins.

Prolonged SARS-CoV-2 Infection and Organizing Pneumonia in a Patient with Follicular Lymphoma, Treated with Obinutuzumab—Challenging Recognition and Treatment

A Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causing coronavirus disease 2019 (COVID-19) led to a pandemic outbreak in 2019. COVID-19’s course and its treatment in immunocompromised patients are uncertain. Furthermore, there is a possibility of protracted SARS-CoV-2 infection and the need for repeated antiviral treatment. Monoclonal antibodies against CD20, which are used, among other things, in the therapy of chronic lymphocytic leukaemia and follicular lymphoma, can induct immunosuppression. We present a case report of a patient with follicular lymphoma, treated with obinutuzumab, who was diagnosed with prolonged, ongoing SARS-CoV-2 infection and related organizing pneumonia. The recognition and the treatment were challenging which makes this case noteworthy. Antiviral therapy with several medications was administrated to our patient and their temporary, positive effect was observed. Moreover, high-dose intravenous immunoglobulin was applied, because slowly decreasing IgM and IgG levels were observed. The patient also received standard treatment of organizing pneumonia. We believe that such a complex approach can create an opportunity for recovery. Physicians should be conscious of the course and treatment possibilities facing similar cases.

Cellular and humoral immunotherapy in children, adolescents and young adults with non-Hodgkin lymphoma

The prognosis is dismal (2-year overall survival less than 25%) for childhood, adolescent, and young adult (CAYA) with relapsed and/or refractory (R/R) non-Hodgkin lymphoma (NHL). Novel targeted therapies are desperately needed for this poor-risk population. CD19, CD20, CD22, CD79a, CD38, CD30, LMP1 and LMP2 are attractive targets for immunotherapy in CAYA patients with R/R NHL. Novel anti-CD20 monoclonal antibodies, anti-CD38 monoclonal antibody, antibody drug conjugates and T and natural killer (NK)-cell bispecific and trispecific engagers are being investigated in the R/R setting and are changing the landscape of NHL therapy. A variety of cellular immunotherapies such as viral activated cytotoxic T-lymphocyte, chimeric antigen receptor (CAR) T-cells, NK and CAR NK-cells have been investigated and provide alternative options for CAYA patients with R/R NHL. Here, we provide an update and clinical practice guidance of utilizing these cellular and humoral immunotherapies in CAYA patients with R/R NHL.

Anti-HLA antibodies in recipients of CD19 versus BCMA-targeted CAR T-cell therapy

Antibodies against foreign human leukocyte antigen (HLA) molecules are barriers to successful organ transplantation. B cell-depleting treatments are used to reduce anti-HLA antibodies but have limited efficacy. We hypothesized that the primary source for anti-HLA antibodies is long-lived plasma cells, which are ineffectively targeted by B cell depletion. To study this, we screened for anti-HLA antibodies in a prospectively enrolled cohort of 49 patients who received chimeric antigen receptor T-cell therapy (CARTx), targeting naïve and memory B cells (CD19-targeted, n = 21) or plasma cells (BCMA-targeted, n = 28) for hematologic malignancies. Longitudinal samples were collected before and up to 1 year after CARTx. All individuals were in sustained remission. We identified 4 participants with anti-HLA antibodies before CD19-CARTx. Despite B cell depletion, anti-HLA antibodies and calculated panel reactive antibody scores were stable for 1 year after CD19-CARTx. Only 1 BCMA-CARTx recipient had pre-CARTx low-level anti-HLA antibodies, with no follow-up samples available. These data implicate CD19neg long-lived plasma cells as an important source for anti-HLA antibodies, a model supported by infrequent HLA sensitization in BCMA-CARTx subjects receiving previous plasma cell-targeted therapies. Thus, plasma cell-targeted therapies may be more effective against HLA antibodies, thereby enabling improved access to organ transplantation and rejection management.

CARs and Drugs: Pharmacological Ways of Boosting CAR-T-Cell Therapy

The development of chimeric antigen receptor T cells (CAR-T cells) has marked a new era in cancer immunotherapy. Based on a multitude of durable complete remissions in patients with hematological malignancies, FDA and EMA approval was issued to several CAR products targeting lymphoid leukemias and lymphomas. Nevertheless, about 50% of patients treated with these approved CAR products experience relapse or refractory disease necessitating salvage strategies. Moreover, in the vast majority of patients suffering from solid tumors, CAR-T-cell infusions could not induce durable complete remissions so far. Crucial obstacles to CAR-T-cell therapy resulting in a priori CAR-T-cell refractory disease or relapse after initially successful CAR-T-cell therapy encompass antigen shutdown and CAR-T-cell dysfunctionality. Antigen shutdown predominately rationalizes disease relapse in hematological malignancies, and CAR-T-cell dysfunctionality is characterized by insufficient CAR-T-cell proliferation and cytotoxicity frequently observed in patients with solid tumors. Thus, strategies to surmount those obstacles are being developed with high urgency. In this review, we want to highlight different approaches to combine CAR-T cells with drugs, such as small molecules and antibodies, to pharmacologically boost CAR-T-cell therapy. In particular, we discuss how certain drugs may help to counteract antigen shutdown and CAR-T-cell dysfunctionality in both hematological malignancies and solid tumors.

B cell depletion and inhibition in systemic lupus erythematosus

INTRODUCTION

Systemic lupus erythematosus (SLE) is characterized by autoantibody expression and aberrant autoreactive B cells contribute to disease progression; therefore, B cell inhibition has been an attractive target for novel therapies. However, after more than two decades of research and over 40 randomized clinical trials, only one such therapy, belimumab, has been approved for use in SLE.

AREAS COVERED

In this review, we discuss the evidence for B cell-targeted therapies in SLE and lupus nephritis. Belimumab has been successful in several large clinical trials and is approved in several countries for use in SLE and lupus nephritis. Despite a lack of supporting phase III evidence, rituximab is used off-label in SLE. Several other B cell-targeted therapies have failed to meet their end points in late-stage clinical trials. Successful phase II trials have recently been reported for obinutuzumab and telitacicept with larger confirmatory trials currently underway.

EXPERT OPINION

Refinements in pharmaceutical mechanisms of action, trial design, and patient selection have resulted in recent preliminary successes, offering renewed optimism for B-cell targeted therapeutics in SLE management.

Anti-CD20-atezolizumab-polatuzumab vedotin in relapsed/refractory follicular and diffuse large B-cell lymphoma

PURPOSE

New therapies are needed for relapsed/refractory (R/R) B-cell non-Hodgkin lymphoma. This phase 1b, open-label trial evaluated two anti-CD20-based triplet combinations.

METHODS

Patients with R/R follicular lymphoma (FL; n = 13) were treated with obinutuzumab, atezolizumab, and polatuzumab vedotin (G-atezo-pola; 1.4 mg/kg/1.8 mg/kg) and patients with R/R diffuse large B-cell lymphoma (DLBCL; n = 23) received rituximab (R)-atezo-pola. The primary efficacy endpoint was complete response (CR) at end of induction (EOI) by PET-CT (investigator assessed; modified Lugano 2014 criteria). Safety endpoints were also assessed.

RESULTS

13 FL patients were treated and evaluable for safety; 2/23 DLBCL patients did not receive treatment and were not included in the safety population. Median observation time was 23.3 and 5.7 months in the FL and DLBCL cohorts, respectively. At EOI, CR rates in FL patients treated with G-atezo-pola at pola doses of 1.4 mg/kg (N = 3) and 1.8 mg/kg (N = 7) were 33% and 14%, respectively. In DLBCL patients receiving R-atezo-pola, the CR rate at EOI was 13%. In the FL cohort, 62% of patients experienced a grade 3-5 adverse event (AE; including two deaths) and 31% developed a serious AE (SAE). In DLBCL patients, R-atezo-pola was associated with a lower incidence of grade 3-5 AEs (24%; one death) and SAEs (10%). In both cohorts, the most common grade 3-5 AEs were hematologic toxicities.

CONCLUSION

Based on these safety issues, considered as related specifically to G-atezo-pola, and limited efficacy, no further development of either combination is planned.

TRIAL REGISTRATION

NCT02729896; Date of registration: April 6, 2016.

Leveraging Natural Killer Cell Innate Immunity against Hematologic Malignancies: From Stem Cell Transplant to Adoptive Transfer and Beyond

Numerous recent advancements in T-cell based immunotherapies have revolutionized the treatment of hematologic malignancies. In the race towards the first approved allogeneic cellular therapy product, there is growing interest in utilizing natural killer (NK) cells as a platform for off-the-shelf cellular therapies due to their scalable manufacturing potential, potent anti-tumor efficacy, and superior safety profile. Allogeneic NK cell therapies are now being actively explored in the setting of hematopoietic stem cell transplantation and adoptive transfer. Increasingly sophisticated gene editing techniques have permitted the engineering of chimeric antigen receptors, ectopic cytokine expression, and tumor recognition signals to improve the overall cytotoxicity of NK cell therapies. Furthermore, the enhancement of antibody-dependent cellular cytotoxicity has been achieved through the use of NK cell engagers and combination regimens with monoclonal antibodies that act synergistically with CD16-expressing NK cells. Finally, a greater understanding of NK cell biology and the mechanisms of resistance have allowed the preclinical development of NK checkpoint blockade and methods to modulate the tumor microenvironment, which have been evaluated in early phase trials. This review will discuss the recent clinical advancements in NK cell therapies in hematologic malignancies as well as promising avenues of future research.

Case report: Eculizumab plus obinutuzumab induction in a deceased donor kidney transplant recipient with DEAP-HUS

The wide-spread use of the anti-complement component 5 monoclonal antibody (moAb) eculizumab has greatly reduced the incidence of relapsing atypical hemolytic uremic syndrome (aHUS) after kidney transplantation (KT). However, the optimal management of aHUS transplant candidates with anti-Complement Factor H (CFH) antibodies remains debated. In these patients, the benefits of chronic eculizumab administration should be weighed against the risk of fatal infections, repeated hospital admissions, and excessive costs. We report the case of a 45-year-old female patient with CFHR1/CFHR3 homozygous deletion-associated aHUS who underwent deceased-donor KT despite persistently elevated anti-CFH antibody titers. As induction and aHUS prophylaxis, she received a combination of eculizumab and obinutuzumab, a humanized type 2 anti-CD20 moAb. The post-operative course was uneventful. After 1-year of follow-up, she is doing well with excellent allograft function, undetectable anti-CFH antibodies, sustained B-cell depletion, and no signs of aHUS activity. A brief review summarizing current literature on the topic is also included. Although anecdotal, our experience suggests that peri-operative obinutuzumab administration can block anti-CFH antibodies production safely and effectively, thus ensuring long-lasting protection from post-transplant aHUS relapse, at a reasonable cost. For the first time, we have demonstrated in vivo that obinutuzumab B-cell depleting properties are not significantly affected by eculizumab-induced complement inhibition.

Potent immunomodulatory and antitumor effect of anti-CD20-IL2no-alpha tri-functional immunocytokine for cancer therapy

Introduction

The anti-CD20 antibody rituximab (RTX) has substantially improved outcomes of patients with B-cell lymphomas, although more efficient therapies are needed for refractory or relapsing lymphomas. An approach to increase the clinical effectiveness of anti-tumor therapy is the use of antibody-cytokine fusion proteins (immunocytokines (ICKs)) to deliver at the tumor site the antibody effector functions and cytokines that trigger anti-tumor activities. In particular, IL-2-based ICKs have shown significant results in preclinical studies but not in clinical trials due to the toxicity profile associated to high doses IL-2 and the undesired expansion of Tregs.

Methods

To improve the efficacy of RTX therapy, we fused a murine (mIgG2a) or a human (hIgG1) version of RTX to a mutated IL-2 (no-alpha mutein), which has a disrupted affinity for the high affinity IL-2 receptor (IL-2R) to prevent the stimulation of Tregs and reduce the binding to endothelial cells expressing CD25, the α chain of high affinity IL-2R. Characterization of anti-CD20-IL2no-alpha ICKs was performed by SDS-PAGE, Western-blotting and SEC-HPLC and also by several functional in vitro techniques like T-cell proliferation assays, apoptosis, CDC and ADCC assays. The in vivo activity was assessed by using murine tumor cells expressing huCD20 in C57/Bl6 mice.

Results

Both ICKs exhibited similar in vitro specific activity of their IL2no-alpha mutein moieties and kept CD20-binding capacity. Anti-CD20-IL2no-alpha (hIgG1) retained antibody effector functions as complement-dependent cytotoxicity and enhanced direct apoptosis, NK cell activation and antibody-dependent cellular cytotoxicity relative to RTX. In addition, both ICKs demonstrated a higher antitumor efficacy than parental molecules or their combination in an EL4-huCD20 tumor model in immunocompetent mice. Anti-CD20-IL2no-alpha (hIgG1) strongly expanded NK and CD8+ T cells but not Tregs in tumor-bearing mice.

Discussion

These findings suggest that anti-CD20-IL2no-alpha could represent an alternative treatment for B cell lymphoma patients, mainly those refractory to RTX therapy.

Acquired B-cell deficiency secondary to B-cell-depleting therapies

The advantage of the newer biological therapies is that the immunosuppressive effect is targeted, in contrast, to the standard, traditional immunomodulatory agents, which have a more global effect. However, there are unintended targets and consequences, even to these "precise" therapeutics, leading to acquired or secondary immunodeficiencies. Besides depleting specific cellular immune subsets, these biological agents, which include monoclonal antibodies against biologically relevant molecules, often have broader functional immune consequences, which become apparent over time. This review focuses on acquired B-cell immunodeficiency, secondary to the use of B-cell depleting therapeutic agents. Among the many adverse consequences of B-cell depletion is the risk of hypogammaglobulinemia, failure of B-cell recovery, impaired B-cell differentiation, and risk of infections. Factors, which modulate the outcomes of B-cell depleting therapies, include the intrinsic nature of the underlying disease, the concomitant use of other immunomodulatory agents, and the clinical status of the patient and other co-existing morbidities. This article seeks to explore the mechanism of action of B-cell depleting agents, the clinical utility and adverse effects of these therapies, and the relevance of systematic and serial laboratory immune monitoring in identifying patients at risk for developing immunological complications, and who may benefit from early intervention to mitigate the secondary consequences. Though these biological drugs are gaining widespread use, a harmonized approach to immune evaluation pre-and post-treatment has not yet gained traction across multiple clinical specialties, because of which, the true prevalence of these adverse events cannot be determined in the treated population, and a systematic and evidence-based dosing schedule cannot be developed. The aim of this review is to bring these issues into focus, and initiate a multi-specialty, data-driven approach to immune monitoring.

Efficacy and safety of obinutuzumab in systemic lupus erythematosus patients with secondary non-response to rituximab

OBJECTIVES

Secondary inefficacy with infusion reactions and anti-drug antibodies (secondary non-depletion nonresponse, 2NDNR) occurs in 14% of SLE patients receiving repeated rituximab courses. We evaluated baseline clinical characteristics, efficacy and safety of obinutuzumab, a next-generation humanized type-2 anti-CD20 antibody licensed for haematological malignancies in SLE patients with 2NDNR to rituximab.

METHODS

We collated data from SLE patients receiving obinutuzumab for secondary non-response to rituximab in BILAG centres. Disease activity was assessed using BILAG-2004, SLEDAI-2K and serology before, and 6 months after, obinutuzumab 2× 1000 mg infusions alongside methylprednisolone 100 mg.

RESULTS

All nine patients included in the study received obinutuzumab with concomitant oral immunosuppression. At 6 months post-obinutuzumab, there were significant reductions in median SLEDAI-2K from 12 to 6 (P = 0.014) and total BILAG-2004 score from 21 to 2 (P = 0.009). Complement C3 and dsDNA titres improved significantly (both P = 0.04). Numerical, but not statistically significant improvements were seen in C4 levels. Of 8/9 patients receiving concomitant oral prednisolone at baseline (all >10 mg/day), 5/8 had their dose reduced at 6 months. Four of nine patients were on 5 mg/day and were in Lupus Low Disease Activity State following obinutuzumab. After obinutuzumab, 6/9 patients with peripheral B cell data achieved complete depletion, including 4/4 assessed with highly sensitive assays. Of the nine patients, one obinutuzumab non-responder required CYC therapy. One unvaccinated patient died from COVID-19.

CONCLUSIONS

Obinutuzumab appears to be effective and steroid-sparing in renal and non-renal SLE patients with secondary non-response to rituximab. These patients have severe disease with few treatment options but given responsiveness to B cell depletion, switching to humanized type-2 anti-CD20 therapy is a logical approach.

Therapeutic Antibodies in Cancer Treatment in the UK

The growing understanding of the molecular mechanisms of carcinogenesis accelerated the development of monoclonal therapeutic antibodies to specifically target multiple cancer pathways. Recombinant protein therapeutics now constitute a large proportion of yearly approved medicines. Oncology, autoimmune diseases and to a smaller degree the prophylaxis of organ transplant rejection are their main application areas. As of the date of this review, 37 monoclonal antibody products are approved for use in cancer treatments in the United Kingdom. Currently, the antibody therapeutics market is dominated by monoclonal immunoglobulins (IgGs). New types of recombinant antibody therapeutics developed more recently include bispecific recombinant antibodies and other recombinantly produced functional proteins. This review focuses on the approved therapeutic antibodies used in cancer treatment in the UK today and describes their antigen targets and molecular mechanisms involved. We provide convenient links to the relevant databases and other relevant resources for all antigens and antibodies mentioned. This review provides a comprehensive summary of the different monoclonal antibodies that are currently in clinical use primarily in malignancy, including their function, which is of importance to those in the medical field and allied specialties.

Anti-viral efficacy of a next-generation CD4-binding site bNAb in SHIV-infected animals in the absence of anti-drug antibody responses

Broadly neutralizing antibodies (bNAbs) against HIV-1 are promising immunotherapeutic agents for treatment of HIV-1 infection. bNAbs can be administered to SHIV-infected rhesus macaques to assess their anti-viral efficacy; however, their delivery into macaques often leads to rapid formation of anti-drug antibody (ADA) responses limiting such assessment. Here, we depleted B cells in five SHIV-infected rhesus macaques by pretreatment with a depleting anti-CD20 antibody prior to bNAb infusions to reduce ADA. Peripheral B cells were depleted following anti-CD20 infusions and remained depleted for at least 9 weeks after the 1^st anti-CD20 infusion. Plasma viremia dropped by more than 100-fold in viremic animals after the initial bNAb treatment. No significant humoral ADA responses were detected for as long as B cells remained depleted. Our results indicate that transient B cell depletion successfully inhibited emergence of ADA and improved the assessment of anti-viral efficacy of a bNAb in a SHIV-infected rhesus macaque model.

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Highly potent CD4bs bNAb reduces viremia up to 4 log₁₀ in SHIV-infected animals

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Sustained B cell depletion prevents development of ADA responses

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Lack of ADA enables multiple bNAb infusions over 12 weeks

Novel and emerging treatment strategies for lupus nephritis

INTRODUCTION

Lupus nephritis (LN) is a key predictor for kidney failure and death in patients with systemic lupus erythematosus (SLE). While conventional immunosuppressive treatments have improved the outcome of LN, novel therapies continue to emerge. These new agents target specific immune-reactive cells (B cell repertoire or T lymphocytes) and crucial cytokines/signalling pathways in LN pathogenesis.

AREAS COVERED

New therapeutic approaches that target specific immune-reactive cells (B cell repertoire or T lymphocytes), crucial cytokines and their signalling pathways in LN pathogenesis.

EXPERT OPINION

Although earlier studies of rituximab fail to show benefit, a newer generation anti-CD20 biologic, obinutuzumab, is promising in LN. Inhibition of B-cell activating factor by belimumab confers superior renal response when added to the standard of care (SOC) regimens, leading to its recent approval for LN. Therapies targeting plasma cells (proteasome inhibitors, anti-CD38) in LN are being developed. A newer generation calcineurin inhibitor, voclosporin, when combined with SOC, results in better renal responses in LN. Other innovative strategies include targeting type I interferon, co-stimulatory signals, complement cascade (anti-C5b) and intracellular proliferation signals (e.g. mTOR, JAK1/2, BTK). While these novel agents improve the short-term renal responses without increased toxicities, long-term data on disease progression and safety remain to be established. Patient stratification by clinical phenotypes, biomarkers and molecular profiles helps enhance the efficacy and cost-effectiveness of novel therapies of LN.

Overlapping Autoimmune Neurological Syndrome: A Case Report of Triple-Positive Antibody

The presentation of several autoimmune neurological disorders in a single patient is rare and often debilitating. However, early diagnosis and efficacious treatment can lead to a significant recovery. Here, we present an interesting case of a triple antibody-positive autoimmune neurological syndrome patient who manifested the clinical features of neuromyelitis optica (NMO) spectrum disorder (NMOSD), N-methyl-D-aspartate (NMDA) receptor (NMDAR) encephalitis, and myasthenia gravis (MG). Hence, the patient manifested both central and peripheral nervous system immune-mediated neurological syndromes. A middle-aged female with a history of seropositive aquaporin-4 (AQP4) NMOSD on mycophenolate 1 g twice daily presented with severe fatigue and right eye ptosis (three months since NMOSD diagnosis) and tested positive for acetylcholine receptor (AchR) binding antibody, consistent with MG. Six months after the patient’s NMOSD diagnosis, she began to experience subacute progressive cognitive decline, behavioral changes, imbalance, anxiety/panic attacks, and paranoid delusions. NMDAR encephalitis was suspected, and she tested positive for cerebrospinal fluid NMDAR antibodies. After treatment with steroids failed, she was given two doses of rituximab 1 g, two weeks apart, and reported improvement in her symptoms shortly after the second dose.

Adverse Renal Effects of Anticancer Immunotherapy: A Review

Simple Summary

The immune system has a natural ability to work against cancer cells; however, in many cases this ability is insufficient, and cancers develop methods enabling them to escape from the supervision of immune cells. Novel therapeutic methods used in neoplastic diseases are based on encouraging immune cells to fight against cancer. In some cases, boosted by this approach, the immune system may damage not only tumor cells, but also other cells, tissues and organs in the human body. Kidney involvement, for example, is directly dangerous for patients’ health and may have an impact on human body homeostasis and the excretion of xenobiotics. However, renal function impairment in patients treated with immunotherapy is thought to be relatively rare but may be severe. Knowledge of early diagnosis and proper management are essential for physicians utilizing immunotherapy in daily clinical practice.

Abstract

Modern oncological therapy utilizes various types of immunotherapy. Immune checkpoint inhibitors (ICIs), chimeric antigen receptor T cells (CAR-T) therapy, cancer vaccines, tumor-targeting monoclonal antibodies (TT-mAbs), bispecific antibodies and cytokine therapy improve patients’ outcomes. However, stimulation of the immune system, beneficial in terms of fighting against cancer, generates the risk of harm to other cells in a patient’s body. Kidney damage belongs to the relatively rare adverse events (AEs). Best described, but still, superficially, are renal AEs in patients treated with ICIs. International guidelines issued by the European Society for Medical Oncology (ESMO) and the American Society of Clinical Oncology (ASCO) cover the management of immune-related adverse events (irAEs) during ICI therapy. There are fewer data concerning real occurrence and possible presentations of renal adverse drug reactions of other immunotherapeutic methods. This implies the need for the collection of safety data during ongoing clinical trials and in the real-life world to characterize the hazard related to the use of new immunotherapies and management of irAEs.