Anti-CD20 antibody therapy for B-cell lymphomas

Profiles of peripheral B cell subsets in a cohort of primary Sjögren's syndrome patients and their potential clinical significance

Background/purpose

Primary Sjögren's syndrome is a prototypical autoimmune disease, with B cell dysfunction as a dominant feature. Further insights into distribution of B cell subsets in primary Sjögren's syndrome are urgently required to identify the most appropriate target subpopulation. We aimed to evaluate the profiles of B lymphocyte subpopulations in primary Sjögren's syndrome patients and to investigate their clinical significance.

Materials and methods

Thirty primary Sjögren's syndrome patients and 15 age-and sex-matched healthy controls were recruited. Peripheral B cell subsets were analyzed by flow cytometry.

Results

Compared to healthy controls, circulating CD19+ B cells, CD19+CD20- B cells, CD19+CD27-IgD+ naïve B cells, CD19+IgD+CD38high plasmablasts, CD19+CD24highCD38high transitional B cells and CD19+CD20-CD27+CD38+ plasma cells were elevated in patients with primary Sjögren's syndrome, whereas CD19+CD27+ memory B cells, CD19+CD27-IgD- double negative B cells and CD19+CD24hiCD27+ Bregs were decreased. Furthermore, the percentage of circulating CD19+CD20-CD27+CD38+ plasma cells was positively correlated with serum IgG levels and the proportional area of lymphocytic infiltration of labial gland.

Conclusion

We identified a comprehensive B lymphocyte subset distribution profile in primary Sjögren's syndrome. Moreover, we detected a clinical significance of CD19+CD20-CD27+CD38+ plasma cells, suggesting that these cells might play a key role in disease pathology and represent potential therapeutic targets.

Promising immunotherapeutic approaches for primary effusion lymphoma

Primary effusion lymphoma (PEL) is a large B-cell neoplasm usually presenting as a serious effusion in body cavities without detectable tumor masses. It is an AIDS-related non-Hodgkin's lymphoma (HL) with human herpes virus 8 (HHV8)/Kaposi sarcoma-associated herpes virus (KSHV) infection. A combination antiretroviral therapy (cART) prolongs the lifespan of AIDS and AIDS-related malignant lymphoma patients, but PEL continues to have a dismal prognosis. PEL showed disappointing outcomes with standard chemotherapy such as CHOP or CHOP-like regimens. A PEL status highlights the urgent need for new therapeutic approaches and treatment strategies and improve clinical outcomes. This review discusses the current knowledge and some recent clinical trials for PEL in the platform of immunotherapy as well as promising future immunotherapeutic approaches for PEL.

A spatiotemporal map of co-receptor signaling networks underlying B cell activation

The B cell receptor (BCR) signals together with a multi-component co-receptor complex to initiate B cell activation in response to antigen binding. Here, we take advantage of peroxidase-catalyzed proximity labeling combined with quantitative mass spectrometry to track co-receptor signaling dynamics in Raji cells from 10 s to 2 h after BCR stimulation. This approach enables tracking of 2,814 proximity-labeled proteins and 1,394 phosphosites and provides an unbiased and quantitative molecular map of proteins recruited to the vicinity of CD19, the signaling subunit of the co-receptor complex. We detail the recruitment kinetics of signaling effectors to CD19 and identify previously uncharacterized mediators of B cell activation. We show that the glutamate transporter SLC1A1 is responsible for mediating rapid metabolic reprogramming and for maintaining redox homeostasis during B cell activation. This study provides a comprehensive map of BCR signaling and a rich resource for uncovering the complex signaling networks that regulate activation.

Results from a Phase 1 Study of ACTR707 in Combination with Rituximab in Patients with Relapsed or Refractory CD20+ B Cell Lymphoma

The antibody-coupled T cell receptor (ACTR) platform is an autologous engineered T cell therapy combining the cell-killing ability of T cells and the tumor-targeting ability of coadministered antibodies. Activation of the T cell product ACTR707 is dependent on the engagement of antibody bound to target cells via the CD16 domain of the chimeric receptor (CD16V-CD28-CD3ζ). ACTR707 in combination with the anti-CD20 monoclonal antibody rituximab was evaluated in the ATTCK-20-03 study, a multisite, single-arm, open-label phase I trial in B cell non-Hodgkin lymphoma (NHL). The primary objectives of this study were to evaluate the safety of the combination of ACTR707 and rituximab and to determine a recommended phase 2 dose (RP2D). Secondary objectives included evaluation of antitumor activity and ACTR T cell persistence. The study design included an ACTR707 cell dose escalation phase and an expansion phase at the RP2D. Escalating dose levels of ACTR707 in combination with rituximab were explored in 5 dose cohorts, with 25 subjects receiving study treatment. Subjects received lymphodepleting chemotherapy (cyclophosphamide 400 mg/m2/day and fludarabine 30 mg/m2/day) for 3 days, followed by rituximab 375 mg/m2 and, 24 to 48 hours later, a single dose of ACTR707. Additional doses of rituximab were administered every 3 weeks until disease progression, unacceptable toxicity, or investigator decision. Blood samples were collected at various time points to assess levels of rituximab, cytokines, inflammatory markers, and ACTR707 T cells. The overall response rate of ACTR707 plus rituximab was 56% (14 of 25) across all dose levels. Ten subjects (40.0%) achieved a complete response, with the longest duration of 586 days (range, 85 to 586 days), and 4 subjects (16.0%) experienced a partial response, with the longest duration of 130 days (range, 44 to 130 days). Only 1 case of cytokine release syndrome (grade 2) and no events of neurotoxicity were reported. There were no dose-limiting toxicities or events leading to death. ACTR707 plus rituximab resulted in only 1 adverse event (neutropenia), leading to study discontinuation of rituximab. The ATTCK-20-03 trial serves as proof of principle regarding the ACTR approach that potentially could be used with other antibodies targeting other markers in other malignancies. Although the ACTR707 program has been discontinued, these results may support other programs in the use of similar novel approaches of antibody-coupled T cell activation.

MHC-I upregulation safeguards neoplastic T cells in the skin against NK cell-mediated eradication in mycosis fungoides

Cancer-associated immune dysfunction is a major challenge for effective therapies. The emergence of antibodies targeting tumor cell-surface antigens led to advancements in the treatment of hematopoietic malignancies, particularly blood cancers. Yet their impact is constrained against tumors of hematopoietic origin manifesting in the skin. In this study, we employ a clonality-supervised deep learning methodology to dissect key pathological features implicated in mycosis fungoides, the most common cutaneous T-cell lymphoma. Our investigations unveil the prominence of the IL-32β-major histocompatibility complex (MHC)-I axis as a critical determinant in tumor T-cell immune evasion within the skin microenvironment. In patients' skin, we find MHC-I to detrimentally impact the functionality of natural killer (NK) cells, diminishing antibody-dependent cellular cytotoxicity and promoting resistance of tumor skin T-cells to cell-surface targeting therapies. Through murine experiments in female mice, we demonstrate that disruption of the MHC-I interaction with NK cell inhibitory Ly49 receptors restores NK cell anti-tumor activity and targeted T-cell lymphoma elimination in vivo. These findings underscore the significance of attenuating the MHC-I-dependent immunosuppressive networks within skin tumors. Overall, our study introduces a strategy to reinvigorate NK cell-mediated anti-tumor responses to overcome treatment resistance to existing cell-surface targeted therapies for skin lymphoma.

Using real-world data to inform dosing strategies of rituximab for pediatric patients with frequent-relapsing or steroid-dependent nephrotic syndrome: a prospective pharmacokinetic-pharmacodynamic study

Objectives: Rituximab is frequently used off-label for the treatment of frequent-relapsing/steroid-dependent nephrotic syndrome (FRNS/SDNS). However, the optimal dosing schedules remain undetermined. The objective of this study was to establish a population pharmacokinetic-pharmacodynamic (PK-PD) model in pediatric patients with FRNS/SDNS, and to investigate dosing regimens that provide adequate suppression of B lymphocytes. Methods: A prospective, open-label, single-center study was conducted in Nephrology Department at Children's Hospital of Fudan University, and a two-compartment PK model of rituximab in pediatric FRNS/SDNS has been developed previously by our group. CD19+ lymphocyte count profiles were obtained from these patients. The presence of anti-rituximab antibodies was assessed prior to medication in children who had previously received rituximab or during follow-up at the last sampling point for PK analysis. PK-PD analyses were performed to describe the changes of CD19+ lymphocytes, with rituximab assumed to increase their death rate. Monte Carlo simulation was conducted to evaluate different dosing regimens. Results: In total, 102 measurements of CD19+ lymphocyte counts were available for PK-PD analysis. No detectable levels of anti-rituximab antibodies were observed during the PK follow-up period. A turnover model with saturable stimulatory action of rituximab on the removal of lymphocytes best characterized the relationship between rituximab concentration and CD19+ lymphocyte counts, where the Emax and EC50 were estimated to be 99.6*106/L and 5.87 μg/mL, respectively. Simulations indicated that a single infusion of 750 mg/m2 and 2 infusions of 375 mg/m2 both yielded a 10-week suppression of CD19+ lymphocytes. Conclusion: This study represents a first attempt to quantitatively describe the PK-PD relationship of rituximab in pediatric patients with FRNS/SDNS, and provide a potential pathway for future precision dosing strategy for rituximab therapy. Further clinical studies are warranted to evaluate the efficacy and safety of different dosing schemes.

Factors Affecting Health-Related Quality of Life among Survivors of Non-Hodgkin Lymphoma: A Population-Based Study

PURPOSE

To describe Health-Related Quality of Life (HRQoL) and to identify the association between sociodemographic, clinical and psychosocial factors, and self-reported HRQoL among NHL survivors.

METHODS

The data of the cancer registry specialized in hematological malignancies in Côte d'Or (France) were used to identify all patients diagnosed with follicular lymphoma (FL) and diffuse large B-cell lymphoma (DLBCL) from 2010 to 2017. Patients were invited to complete SF-12 and other questionnaires.

RESULTS

The HRQoL of NHL survivors was poorer than that of the French general population (p < 0.05) in vitality (48 vs. 56), general health (56 vs. 63), role physical scores (60 vs. 70), role emotional scores (64 vs. 72) and the Mental Component Scale (45 vs. 49). The mean difference in physical functioning decreased per unit increase in age (β = -1.1 (0.3); p < 0.001). Men had better vitality than women (β = 12.4 (6.1); p = 0.04) and the high education level was associated with greater role emotional scores (β = 14.1 (5.4); p = 0.01). Symptoms of anxiety and depression were associated with poorer HRQoL. The satisfaction of social support was associated with significantly greater scores on mental health (β = 17.3 (5.1); p = 0.001) and social functioning (β = 15.7 (7.8); p = 0.04). Socioeconomic deprivation was associated with poorer general health (β = -12.8 (5.2); p = 0.01).

CONCLUSIONS

From 3 to 11 years post-diagnosis, the main factors found to be associated with poor HRQoL of NHL survivors were age, sex, presence of anxiety, depression and economic problems. These findings suggest the need for supportive care to improve HRQOL and the consideration of these problems when developing care plans for NHL survivors.

Sequence enrichment profiles enable target-agnostic antibody generation for a broad range of antigens

Phenotypic drug discovery (PDD) enables the target-agnostic generation of therapeutic drugs with novel mechanisms of action. However, realizing its full potential for biologics discovery requires new technologies to produce antibodies to all, a priori unknown, disease-associated biomolecules. We present a methodology that helps achieve this by integrating computational modeling, differential antibody display selection, and massive parallel sequencing. The method uses the law of mass action-based computational modeling to optimize antibody display selection and, by matching computationally modeled and experimentally selected sequence enrichment profiles, predict which antibody sequences encode specificity for disease-associated biomolecules. Applied to a phage display antibody library and cell-based antibody selection, ∼10⁵ antibody sequences encoding specificity for tumor cell surface receptors expressed at 10³-10⁶ receptors/cell were discovered. We anticipate that this approach will be broadly applicable to molecular libraries coupling genotype to phenotype and to the screening of complex antigen populations for identification of antibodies to unknown disease-associated targets.

A Spatiotemporal Map of Co-Receptor Signaling Networks Underlying B Cell Activation

The B cell receptor (BCR) signals together with a multi-component co-receptor complex to initiate B cell activation in response to antigen binding. This process underlies nearly every aspect of proper B cell function. Here, we take advantage of peroxidase-catalyzed proximity labeling combined with quantitative mass spectrometry to track B cell co-receptor signaling dynamics from 10 seconds to 2 hours after BCR stimulation. This approach enables tracking of 2,814 proximity-labeled proteins and 1,394 quantified phosphosites and provides an unbiased and quantitative molecular map of proteins recruited to the vicinity of CD19, the key signaling subunit of the co-receptor complex. We detail the recruitment kinetics of essential signaling effectors to CD19 following activation, and then identify new mediators of B cell activation. In particular, we show that the glutamate transporter SLC1A1 is responsible for mediating rapid metabolic reprogramming immediately downstream of BCR stimulation and for maintaining redox homeostasis during B cell activation. This study provides a comprehensive map of the BCR signaling pathway and a rich resource for uncovering the complex signaling networks that regulate B cell activation.

Diagnosis and Treatment of Chronic Lymphocytic Leukemia: A Review

IMPORTANCE

Chronic lymphocytic leukemia (CLL), defined by a minimum of 5 × 109/L monoclonal B cells in the blood, affects more than 200 000 people and is associated with approximately 4410 deaths in the US annually. CLL is associated with an immunocompromised state and an increased rate of complications from infections.

OBSERVATIONS

At the time of diagnosis, the median age of patients with CLL is 70 years, and an estimated 95% of patients have at least 1 medical comorbidity. Approximately 70% to 80% of patients with CLL are asymptomatic at the time of diagnosis, and one-third will never require treatment for CLL. Prognostic models have been developed to estimate the time to first treatment and the overall survival, but for patients who are asymptomatic, irrespective of disease risk category, clinical observation is the standard of care. Patients with symptomatic disease who have bulky or progressive lymphadenopathy or hepatosplenomegaly and those with a low neutrophil count, anemia, or thrombocytopenia and/or symptoms of fever, drenching night sweats, and weight loss (B symptoms) should be offered treatment. For these patients, first-line treatment consists of a regimen containing either a covalent Bruton tyrosine kinase (BTK) inhibitor (acalabrutinib, zanubrutinib, or ibrutinib) or a B-cell leukemia/lymphoma 2 (BCL2) inhibitor (venetoclax). There is no evidence that starting either class before the other improves outcomes. The covalent BTK inhibitors are typically used indefinitely. Survival rates are approximately 88% at 4 years for acalabrutinib, 94% at 2 years for zanubrutinib, and 78% at 7 years for ibrutinib. Venetoclax is prescribed in combination with obinutuzumab, a monoclonal anti-CD20 antibody, in first-line treatment for 1 year (overall survival, 82% at 5-year follow-up). A noncovalent BTK inhibitor, pitobrutinib, has shown an overall response rate of more than 70% after failure of covalent BTK inhibitors and venetoclax. Phosphoinositide 3'-kinase (PI3K) inhibitors (idelalisib and duvelisib) can be prescribed for disease that progresses with BTK inhibitors and venetoclax, but patients require close monitoring for adverse events such as autoimmune conditions and infections. In patients with multiple relapses, chimeric antigen receptor T-cell (CAR-T) therapy with lisocabtagene maraleucel was associated with a 45% complete response rate. The only potential cure for CLL is allogeneic hematopoietic cell transplant, which remains an option after use of targeted agents.

CONCLUSIONS AND RELEVANCE

More than 200 000 people in the US are living with a CLL diagnosis, and CLL causes approximately 4410 deaths each year in the US. Approximately two-thirds of patients eventually need treatment. Highly effective novel targeted agents include BTK inhibitors such as acalabrutinib, zanubrutinib, ibrutinib, and pirtobrutinib or BCL2 inhibitors such as venetoclax.

Bispecific antibodies for the treatment of B-cell lymphoma: promises, unknowns, and opportunities

Treatment paradigms for B-cell non-Hodgkin lymphomas (B-NHL) have shifted dramatically in the last 2 decades following the introduction of highly active immunotherapies such as rituximab. Since then, the field has continued to witness tremendous progress with the introduction of newer, more potent immunotherapeutics, including chimeric antigen receptor T-cell therapy, which have received regulatory approval for and currently play a significant role in the treatment of these diseases. Bispecific antibodies (BsAb) are a novel class of off-the-shelf T-cell redirecting drugs and are among the most promising immunotherapeutics for lymphoma today. BsAb may target various cell-surface antigens and exist in different formats. Anti-CD20xCD3 BsAb have demonstrated remarkable single-agent activity in patients with heavily pretreated B-NHL with a manageable toxicity profile dominated by T-cell overactivation syndromes. Much work remains to be done to define the optimal setting in which to deploy these drugs for B-NHL treatment, their ideal combination partners, strategies to minimize toxicity, and, perhaps most importantly, pharmacodynamic biomarkers of response and resistance. In this review, we provide an update on BsAb development in B-NHL, from discovery to clinical applications, highlighting the achievements, limitations, and future directions of the field.

Drug-Resistance Mechanism and New Targeted Drugs and Treatments of Relapse and Refractory DLBCL

Diffuse large B-cell lymphoma (DLBCL) is the most common aggressive non-Hodgkin's lymphoma (NHL). 30 ~ 40% of DLBCL patients were resistant to the standard R-CHOP regimen or recurrence after remission. It is currently believed that drug resistance is the main cause of the recurrence and refractory of DLBCL (R/R DLBCL). With the increased understanding of DLBCL biology, tumor microenvironment and epigenetics, some new therapies and drugs like molecular and signal pathway target therapy, chimeric antigen receptor (CAR) T-cell therapy, immune checkpoint inhibitors, antibody drug-conjugate and tafasitamab have been used for R/R DLBCL. This article will review the drug resistance mechanism and novel targeted drugs and therapies of DLBCL.

Construction and evaluation of wild and mutant ofatumumab scFvs against the human CD20 antigen

Several monoclonal antibodies targeting the CD20 have been produced and Ofatumumab is a case in point. Although whole antibodies target cancer cells effectively, their applications are restricted in some ways. Single-chain fragment variable antibodies, rather than employing the entire structure of antibodies, have proven a practical approach for creating completely functional antigen-binding fragments. In current research, the DNA coding sequence of VL and VH of the wild and mutant forms of ofatumumab were joined with a flexible linker (GGGGS)3 separately. Using the E. coli BL21 (DE3) expression system, the VL-linker-VH genes were cloned into the pET-28 a (+), and the associated recombinant proteins were produced. Purified and refolded scFvs (scFv-C and scFv-V3) represented a concentration of around 0.7 mg/ml from 1 L of initial E. coli culture with a molecular weight of about 27 kDa. Affinity measurement disclosed anti-CD20 scFv-V3 possesses a higher affinity constant compared to anti-CD20 scFv-C. The recombinant scFvs exclusively attach to Raji cells but not to Jurkat cells, according to a cell-ELISA analysis. The MTT test signified anti-CD20 scFvs could affect cell viability in Raji cells but had no impact on Jurkat cells and also, Raji cells viability was affected more significantly by anti-CD20 scFv-V3.

Computational and Experimental Evaluation of Linker Peptides and Thioredoxin Fusion Tag in CD20-rituximab Specific Interactions

Background

Overexpression of CD20 protein on the surface of B cells in lymphoma can be targeted by several anti-CD20 molecules. The development of accessible interactive epitopes is more favorable than the full-length transmembrane CD20 in the affinity assessment of anti-CD20 monoclonal antibodies (mAbs).

Methods

The sequence of these epitopes was extracted, and the effects of different linker peptides and the location of histidine (His)-tag were computationally analyzed. The impact of thioredoxin (Trx)-tag on the folding of the selected construct and its interaction with rituximab was further investigated. The two final expression cassettes were expressed in Escherichia coli after optimization of culture conditions for incubation temperature, post-induction time, optical density at the induction time, and concentration of the inducer. ELISA evaluated the binding affinity of rituximab towards the recombinant proteins.

Results

By homology modeling studies, C-terminal His-tagged structures represented more desirable folded structures. Validation of the models revealed that CD20 extracellular domain linked by the G₄S polypeptide had better stereochemical quality and structural compatibility. It was selected due to its more effective interaction with rituximab showing the highest dissociation constant of 5.8E-09M, which improved after the fusion of Trx-tag (7.1E-10M). The most influential parameters in the expression of the two selected proteins were post-induction temperature and optical density at the induction time. Homemade ELISA assays revealed a slightly higher affinity of rituximab towards the Trx-CD20 protein than the CD20/G₄S molecule.

Conclusions

Experimental in vitro studies confirmed the computationally calculated affinity of rituximab towards the two designed CD20 constructs. Also, the cell-based binding assessment of anti-CD20 mAbs could be substituted by the engineered extracellular domain of human CD20 protein.

Update in Diagnosis and Management of Primary Cutaneous B-Cell Lymphomas

Primary cutaneous lymphomas are a rare group of diseases, with an estimated incidence of 0.5-1 case per 100,000 people per year. Primary cutaneous B-cell lymphomas (pCBCLs) represent 25-30% of all primary cutaneous lymphomas. There are three main subtypes of pCBCL: primary cutaneous marginal zone lymphoma, primary cutaneous follicle center lymphoma, and primary cutaneous diffuse large B-cell lymphoma, leg type. Cutaneous B-cell lymphomas have a broad spectrum of clinical presentations, which makes diagnostic and therapeutic strategies challenging. To date, treatment recommendations for cutaneous B-cell lymphomas have been largely based on small retrospective studies and institutional experience. Recently, the pharmacotherapeutic landscape has expanded to include drugs that may modify the underlying disease pathology of pCBCLs, representing new therapeutic modalities for this rare group of diseases. Novel therapies used for other systemic B-cell lymphomas show promise for the treatment of pCBCLs and are being increasingly considered. These new therapies are divided into five main groups: monoclonal antibodies, immune checkpoint inhibitors, small-molecule inhibitors, bispecific T-cell engaging, and chimeric antigen receptor T cell. In this review, we discuss the clinical, histopathological, molecular, and cytogenetic features of the most common pCBCL subtypes with a focus on current and innovative therapeutic developments in their management. These emerging treatment strategies for B-cell lymphomas and cutaneous B-cell lymphomas may represent novel first-line options for the management of these rare diseases.

Treating Autoimmune-Related Interstitial Lung Disease With B Cell Depletion

Autoimmune rheumatic diseases may affect vital organs with lung involvement being severe and difficult to treat manifestation. Systemic sclerosis (SSc) commonly affects the lung in the form of interstitial lung disease (ILD). ILD may be also seen in patients with rheumatoid arthritis (RA), Sjögren's syndrome (SS), systemic lupus erythematosus (SLE), inflammatory myositis (IM), antisynthetase syndrome (AS), and the ANCA-associated vasculitides (AAV). Rituximab (RTX) is an anti-CD20 B lymphocyte depleting mAb, often administered in the treatment of autoimmune rheumatic diseases. Although RTX is an off-label treatment for CTD–ILD, there are numerous reports providing data that is effective in improving both pulmonary function tests (PFTs) and chest computed tomography findings consistent with ILD. There are retrospective uncontrolled studies that assess RTX as a treatment of ILD in autoimmune diseases. These studies, apart from one, do not include patients with AAV-ILD. In SSc-ILD, in particular, there are both controlled and uncontrolled studies displaying encouraging results following B cell depletion. In addition, a number of retrospective uncontrolled studies and fewer prospective studies evaluate RTX in connective tissue diseases CTD–ILD. Although RTX is an approved treatment for AAV there are scarce only data focusing on patients with AAV-ILD specifically. The results of a handful of studies comparing treatment of CTD-ILD with RTX to treatment with other agents are in favor of RTX. Results from large, still ongoing controlled trials are awaited to ascertain RTX effects in ILD encountered in autoimmune rheumatic diseases. We review herein the results of the different RTX trials in patients with autoimmune disease–associated with ILD. Despite the heterogeneity of these studies, RTX may be considered an alternative and safe but still off-label treatment for patients with refractory CTD–ILD.

Targeting macrophages for enhancing CD47 blockade-elicited lymphoma clearance and overcoming tumor-induced immunosuppression

Tumor-associated macrophages (TAMs) are often the most abundant immune cells in the tumor microenvironment (TME). Strategies targeting TAMs to enable tumor cell killing through cellular phagocytosis have emerged as promising cancer immunotherapy. Although several phagocytosis checkpoints have been identified, the desired efficacy has not yet been achieved by blocking such checkpoints in preclinical models or clinical trials. Here, we showed that late-stage non-Hodgkin lymphoma (NHL) was resistant to therapy targeting phagocytosis checkpoint CD47 due to the compromised capacity of TAMs to phagocytose lymphoma cells. Via a high-throughput screening of the US Food and Drug Administration-approved anticancer small molecule compounds, we identified paclitaxel as a potentiator that promoted the clearance of lymphoma by directly evoking phagocytic capability of macrophages, independently of paclitaxel's chemotherapeutic cytotoxicity toward NHL cells. A combination with paclitaxel dramatically enhanced the anticancer efficacy of CD47-targeted therapy toward late-stage NHL. Analysis of TME by single-cell RNA sequencing identified paclitaxel-induced TAM populations with an upregulation of genes for tyrosine kinase signaling. The activation of Src family tyrosine kinases signaling in macrophages by paclitaxel promoted phagocytosis against NHL cells. In addition, we identified a role of paclitaxel in modifying the TME by preventing the accumulation of a TAM subpopulation that was only present in late-stage lymphoma resistant to CD47-targeted therapy. Our findings identify a novel and effective strategy for NHL treatment by remodeling TME to enable the tumoricidal roles of TAMs. Furthermore, we characterize TAM subgroups that determine the efficiency of lymphoma phagocytosis in the TME and can be potential therapeutic targets to unleash the antitumor activities of macrophages.

Establishment of Membrane-Bound IgA1-Specific Antibody Possessing Antibody-Dependent Cellular Cytotoxicity Activity

Therapeutic agents targeting B cells, such as rituximab, have been proven to be effective in several diseases. However, since this therapy targets the whole B cell population, there are still concerns about critical adverse events. Therefore, a new type of antibody that can specifically deplete a particular type of B cell may have the potential to become an efficient and safer therapy. Membrane-bound IgA1 (mIgA1) is expressed on soluble IgA1 (sIgA1) producing B cells and/or their precursor, B cells. Although most of the amino acid sequence in the N-terminal regions of the extracellular domains of mIgA1 and sIgA1 is shared, there is a membrane type-specific region, named the membrane-bound immunoglobulin isotype-specific (migis-α) region, at the membrane-proximal region of mIgA1. We hypothesized that the migis-α region would be a suitable antigen for therapeutic antibodies to target mIgA1-expressing B cells without binding to sIgA1, which may cause undesired adverse effects and poor pharmacokinetics (PK). We established two anti-migis-α monoclonal antibodies (mAbs), KM4641 and KM4644, by immunization of the synthetic peptide corresponding to an migis-α region. These mAbs both showed robust binding to mIgA1-expressing transfectant cells. As we expected, neither mAbs bound to sIgA1 and we found that the mAbs recognized different seven to eight amino acid sequences within the migis-α region. Furthermore, the rat-human chimeric type of both mAbs showed antibody-dependent cellular cytotoxicity against mIgA1-expressing transfectant cells. Taken together, this study showed that established mAbs have therapeutic potential in IgA-related diseases, such as IgA nephropathy.

Screening Protein Prognostic Biomarkers for Stomach Adenocarcinoma Based on The Cancer Proteome Atlas

The objective was to construct a prognostic risk model of stomach adenocarcinoma (STAD) based on The Cancer Proteome Atlas (TCPA) to search for prognostic biomarkers. Protein data and clinical data on STAD were downloaded from the TCGA database, and differential expressions of proteins between carcinoma and para-carcinoma tissues were screened using the R package. The STAD data were randomly divided into a training set and a testing set in a 1:1 ratio. Subsequently, a linear prognostic risk model of proteins was constructed using Cox regression analysis based on training set data. Based on the scores of the prognostic model, sampled patients were categorized into two groups: a high-risk group and a low-risk group. Using the testing set and the full sample, ROC curves and K-M survival analysis were conducted to measure the predictive power of the prognostic model. The target genes of proteins in the prognostic model were predicted and their biological functions were analyzed. A total of 34 differentially expressed proteins were screened (19 up-regulated, 15 down-regulated). Based on 176 cases in the training set, a prognostic model consisting of three proteins (COLLAGEN VI, CD20, TIGAR) was constructed, with moderate prediction accuracy (AUC=0.719). As shown by the Kaplan-Meier and survival status charts, the overall survival rate of the low-risk group was better than that of the high-risk group. Moreover, a total of 48 target proteins were identified to have predictive power, and the level of proteins in hsa05200 (Pathways in cancer) was the highest. According to the results of the Univariate and multivariate COX analysis, tri-protein was identified as an independent prognostic factor. Therefore, the tri-protein prognostic risk model can be used to predict the likelihood of STAD and guide clinical treatment.

B cell-directed therapies: a new era in Multiple Sclerosis treatment

Multiple sclerosis (MS) is a chronic autoimmune demyelinating disease of the central nervous system (CNS) that often progresses to severe disability. Previous studies have highlighted the role of T cells in disease pathophysiology; however, the success of B-cell-targeted therapies has led to an increased interest in how B cells contribute to disease immunopathology. In this review, we summarize evidence of B-cell involvement in MS disease mechanisms, starting with pathology and moving on to review aspects of B cell immunobiology potentially relevant to MS. We describe current theories of critical B cell contributions to the inflammatory CNS milieu in MS, namely (i) production of autoantibodies, (ii) antigen presentation, (iii) production of proinflammatory cytokines (bystander activation), and (iv) EBV involvement. In the second part of the review, we summarize medications that have targeted B cells in patients with MS and their current position in the therapeutic armamentarium based on clinical trials and real-world data. Covered therapeutic strategies include the targeting of surface molecules such as CD20 (rituximab, ocrelizumab, ofatumumab, ublituximab) and CD19 (inebilizumab), and molecules necessary for B-cell activation such as B cell activating factor (BAFF) (belimumab) and Bruton's Tyrosine Kinase (BTK) (evobrutinib). We finally discuss the use of B-cell-targeted therapeutics in pregnancy.

Safety and Efficacy of Engineered Toxin Body MT-3724 in Relapsed or Refractory B-cell Non-Hodgkin's Lymphomas and Diffuse Large B-cell Lymphoma

MT-3724, a novel engineered toxin body comprised of an anti-CD20 single-chain variable fragment genetically fused to Shiga-like Toxin A subunit, is capable of binding to and internalizing against CD20, inducing cell killing via permanent ribosomal inactivation. This study evaluated MT-3724 in patients with relapsed/refractory B-cell non-Hodgkin lymphoma (r/rNHL). This open-label, multiple-dose phase Ia/b trial included a dose escalation in patients with r/rNHL according to a standard 3+3 design. Primary objectives were to determine the MTD and pharmacokinetics/pharmacodynamics. In a dose expansion study at MTD in serum rituximab-negative patients with diffuse large B-cell lymphoma (DLBCL), primary objectives were safety, tolerability, and pharmacokinetics/pharmacodynamics. Twenty-seven patients enrolled. MTD was 50 μg/kg/dose with 6,000 μg/dose cap. Thirteen patients experienced at least one grade ≥3 treatment-related adverse events; the most common grade ≥3 event was myalgia (11.1%). Two patients (75 μg/kg/dose) experienced grade 2 treatment-related capillary leak syndrome. Overall objective response rate was 21.7%. In serum rituximab-negative patients with DLBCL or composite DLBCL (n = 12), overall response rate was 41.7% (complete response, n = 2; partial response, n = 3). In patients with detectable baseline peripheral B cells, treatment resulted in dose-dependent B-cell depletion. The proportion of patients with anti-drug antibodies (ADA) increased during treatment and the majority appeared to be neutralizing based on an in vitro assay; nevertheless, tumor regression and responses were observed. MT-3724 demonstrated efficacy at the MTD in this population of previously treated patients with r/rDLBCL, with mild-to-moderate immunogenic safety events.

Significance

This work describes the safety and efficacy of a new pharmaceutical pathway that could provide a treatment option for a subset of patients with a critical unmet therapeutic need. The study drug, MT-3724, is capable of targeting B-cell lymphomas via a unique, potent cell-killing mechanism that appears to be promising.

Does the Number of Bifunctional Chelators Conjugated to a mAb Affect the Biological Activity of Its Radio-Labeled Counterpart? Discussion Using the Example of mAb against CD-20 Labeled with 90Y or 177Lu

There has been considerable interest in developing a monoclonal antibody (mAb) against-CD-20 (for example, Rituximab) modified by bifunctional chelating agents (BCA) for non-Hodgkin's lymphoma radioimmunotherapy. Therefore, many researchers have modified this monoclonal antibody by attaching different BCA moieties and evaluated their biological activities in terms of in vitro study and in vivo study in healthy and tumor xenografted rodents. This mini-perspective reviews the in vitro studies, the immunoreactivity and physiological distribution studies: organ-to-blood and the tumor-to-organ ratio of conjugates with different numbers of chelators per mAb. We set up a null hypothesis that states there is no statistical significance between the biological activity of monoclonal antibody (Rituximab) and the number of conjugated bifunctional chelators. Overall, we have concluded that there is no strong evidence for this hypothesis. However, the literature data should be questioned due to the potential lack of uniform study methodology.

Effectiveness of Anti-Cluster of Differentiation 20 as a Disease-Modifying Therapy in Multiple Sclerosis Across Its Different Phenotypes at the University Hospital of Caen

Background

Multiple sclerosis is a chronic, demyelinating disorder occurring primarily as two main forms of relapsing-remitting multiple sclerosis (RRMS) found predominantly in women, and primary progressive multiple sclerosis (PPMS) occurring predominantly in men. In this retrospective single-center study, we aimed to explore the effects of anti-cluster of differentiation (CD)20 treatment for both relapsing-remitting and primary progressive forms of multiple sclerosis (MS) in a population-based cohort treated at the university hospital. 

Methodology

The diagnostic factors being assessed were forms of multiple sclerosis (MS), age at first relapse, whereas therapeutic factors were age at first disease-modifying therapy (DMT), age at starting anti-CD20, reason to switch to anti-CD20 and the duration of anti-CD20 treatment. Primary outcomes measured were number of relapses and progression in disability as measured by the Expanded Disability Status Scale, while secondary outcomes measures being assessed number of cerebral lesions on MRI and level of IgG at the beginning and end of the 12-month treatment.

Results

Treatment with anti-CD20 demonstrated a reduction in number of relapses 12 months after treatment, no change in the progression of disability in RRMS type, but an increase in PPMS type. No change was observed in cerebral MRI lesions at the end of treatment after 12 months. A statistically significant reduction in serum IgG value was observed after 12 months from the start of treatment, where only one out of 26 (3.8%) patients developed hypogammaglobulinemia with IgG less than 6 g/L but none developed hypogammaglobulinemia of less than 5 g/L.

Conclusion

Anti-CD20 antibodies as disease-modifying therapy can profoundly impact the course and progression of MS in both its forms if utilized at an earlier stage in patients and therefore greatly improve the quality of life in patients living with multiple sclerosis.

Novel In Vivo and In Vitro Pharmacokinetic/Pharmacodynamic-Based Human Starting Dose Selection for Glofitamab

We present a novel approach for first-in-human (FIH) dose selection of the CD20xCD3 bispecific antibody, glofitamab, based on pharmacokinetic/pharmacodynamic (PKPD) assessment in cynomolgus monkeys to select a high, safe starting dose, with cytokine release (CR) as the PD endpoint. Glofitamab pharmacokinetics were studied in mice and cynomolgus monkeys; PKPD of IL-6, TNF-α and interferon-γ release following glofitamab, with/without obinutuzumab pretreatment (Gpt) was studied in cynomolgus monkeys. Potency differences for CR between cynomolgus monkeys and humans were determined by glofitamab incubation in whole blood of both species. The PKPD model for CR was translated to humans to project a starting dose that did not induce CR exceeding a clinically-predefined threshold. In cynomolgus monkeys, glofitamab showed a species-specific atypical high clearance, with and without B-cell debulking by Gpt. CR was related to glofitamab serum levels and B-cell counts. B-cell reduction by Gpt led to a marked decrease in CR. FIH starting dose (5 µg) was selected based on IL-6 release considering the markedly higher glofitamab in vitro potency in human vs monkey blood. This is a novel PKPD-based approach for selection of FIH starting dose for a CD20xCD3 bispecific antibody in B-cell lymphoma, evidenced in the glofitamab study, NP30179 (NCT03075696).

Chronic lymphocytic leukemia: 2022 update on diagnostic and therapeutic procedures

DISEASE OVERVIEW

Chronic lymphocytic leukemia (CLL) is one of the most frequent types of leukemia. It typically occurs in elderly patients and has a highly variable clinical course. Leukemic transformation is initiated by specific genomic alterations that interfere with the regulation of proliferation and of apoptosis in clonal B-cells.

DIAGNOSIS

The diagnosis is established by blood counts, blood smears, and immunophenotyping of circulating B-lymphocytes, which identify a clonal B-cell population carrying the CD5 antigen as well as typical B-cell markers.

PROGNOSIS AND STAGING

The clinical staging systems provide prognostic information by using the results of physical examination and blood counts. Various biological and genetic markers provide additional prognostic information. Deletions of the short arm of chromosome 17 (del[17p]) and/or mutations of the TP53 gene predict resistance to chemoimmunotherapy and a shorter time to progression with most targeted therapies. The CLL international prognostic index integrates genetic, biological, and clinical variables to identify distinct risk groups of patients with CLL.

THERAPY

Only patients with active or symptomatic disease or with advanced Binet or Rai stages require therapy. When treatment is indicated, several therapeutic options exist: a combination of the B-cell lymphoma 2 (BCL2) inhibitor venetoclax with obinutuzumab, monotherapy with inhibitors of Bruton tyrosine kinase (BTK) such as ibrutinib and acalabrutinib, or chemoimmunotherapy. At relapse, the initial treatment may be repeated, if the treatment-free interval exceeds 3 years. If the disease relapses earlier, therapy should be changed using an alternative regimen. Patients with a del(17p) or TP53 mutation are usually resistant to chemotherapy and should, therefore, be treated with targeted agents.

FUTURE CHALLENGES

Combinations of targeted agents are now being investigated to create efficient, potentially curative therapies of CLL with fixed duration. One of the most relevant questions currently addressed in clinical trials is the comparison of monotherapies with BTK inhibitors with fixed duration combination therapies. Moreover, the optimal sequencing of targeted therapies remains to be determined. Alternative therapies are needed for patients with BTK and BCL2 inhibitor double-refractory disease.

Case series: MRD negativity assessment using 11C-Acetate PET with 3-weekly daratumumab-based quadruplet induction in newly diagnosed multiple myeloma

Complete response (CR) is an important favorable factor for survival in multiple myeloma (MM). However, CR patients continue to relapse, especially in the presence of minimal residual disease (MRD). Bone marrow (BM) MRD is predictive of progression-free survival (PFS) in MM. However, myeloma outside the BM aspiration site may result in subsequent relapse despite MRD-negativity. Therefore, positron emission tomography-computed tomography (PET-CT) based on F-fluorodeoxyglucose (FDG) is a complementary tool to monitor residual disease in MM. However, FDG may miss myeloma lesions that are not FDG-avid. On the other hand, ¹¹C-Acetate (ACT) has been found to be a more sensitive and specific tracer than FDG in MM. Recently, the addition of daratumumab to bortezomib, thalidomide, dexamethasone (VTd) or bortezomib, lenalidomide, dexamethasone (VRd) backbone has been proven to improve outcomes. Herein, we report three newly-diagnosed MM patients achieving deep responses with imaging CR using ACT PET in addition to conventional immunofixation CR and MRD-negative CR after a 3-weekly daratumumab-based quadruplet induction regimen.

3-weekly daratumumab-lenalidomide/pomalidomide-dexamethasone is highly effective in relapsed and refractory multiple myeloma

OBJECTIVES

Myeloma relapse remains challenging. Daratumumab (dara) with immunomodulatory agents (IMiD) and dexamethasone (dex) was proven highly effective in relapsed or refractory multiple myeloma (RRMM) in randomized controlled trials. The recommended schedule of dara is weekly for eight doses, followed by 2-weekly for eight doses, and then every 4-weekly thereafter. However, the cost of daratumumab is daunting, precluding widespread and prolonged use in some countries. In this study, we aimed to evaluate the efficacy of using a 3-weekly daratumumab regimen in RRMM.

METHODS

Thirteen RRMM patients were treated with dara-IMiD-dex till maximal response, followed by single-agent IMiD maintenance until disease progression. Dara (every 6 weekly) would be added upon significant biochemical disease progression.

RESULTS

After a median of four daratumumab infusions (range: 3-10), the best responses included complete response (CR) in seven patients (53.8%), very good partial response (VGPR) in four patients (30.8%), and partial response (PR) in two patients (15.4%). The median time to VGPR was four weeks. At 10 months, the overall survival was 90%, and progression-free survival was 54.7%. Two of three patients tested achieved MRD-ve CR. Another patient, who had PET-CT reassessment, showed PET-ve CR.

DISCUSSION

Despite less frequent daratumumab use, we reported rapid responses with a median time to VGPR of only four weeks, and a response rate of 100% including CR rate of 54%. Despite less frequent daratumumab use, grade ¾ neutropenia remained common with a frequency comparable to that observed in Pollux.

CONCLUSION

This 3-weekly dara-IMiD-dex regimen preserves a high efficacy with rapid, deep responses including MRD-ve and PET-ve CR, hence a cost-effective regimen.

The future of antibody therapy in chronic lymphocytic leukemia

INTRODUCTION

Outcomes in chronic lymphocytic leukemia (CLL) have been dramatically improved with the addition of anti-CD20 antibodies to chemotherapy, defining a new standard of care for many years. More recently, therapies targeting fundamental signaling and anti-apoptotic pathways within the CLL cell have demonstrated dramatic clinical responses, including in patients with high-risk prognostic markers, thus emerging as preferred therapy for many patients. While the addition of anti-CD20 antibodies to traditional chemotherapy resulted in significant improvements in outcomes, the role of monoclonal antibodies in the era of targeted agents remains an active area of investigation. Furthermore, since the advent of next-generation anti-CD20 antibodies, the role of specific anti-CD20 antibodies remains an open question.

AREAS COVERED

In this review, we highlight the important role that anti-CD20 antibody therapy has had in the field of CLL, both when used with chemotherapy and in combination with targeted therapy, as well as the current studies that are further exploring this treatment paradigm in the modern era.

EXPERT OPINION

While anti-CD20 antibodies have played a pivotal role in the treatment of CLL, additional studies will be required to determine the optimal application of these therapies in combination with targeted therapy.

Nuclear and stromal expression of Manic fringe in renal cell carcinoma

Renal cell carcinoma (RCC) is the most common type of kidney cancer and has the highest mortality rate among genitourinary cancers. Despite the advances in molecular targeted therapies to treat RCC, the inevitable emergence of resistance has delineated the need to uncover biomarkers to prospectively identify patient response to treatment and more accurately predict patient prognosis. Fringe is a fucose specific β1, 3N-acetylglucosaminyltransferase that modifies the Notch receptors. Given the link between its function and aberrant Notch activation in RCC, Fringe may be implicated in this disease. The Fringe homologs comprise of Lunatic fringe (LFng), Manic fringe (MFng) and Radical fringe (RFng). MFng has been reported to play a role in cancer. MFng is also essential in the development of B cells. However, the expression profile and clinical significance of MFng, and its association with B cells in RCC are unknown. CD20 is a clinically employed biomarker for B cells. This pilot study aimed to determine if MFng protein expression can be utilized as a prospective biomarker for therapeutics and prognosis in RCC, as well as to determine its association with CD20+ B cells. Analysis of publicly available MFng gene expression datasets on The Cancer Genome Atlas Netlwork (TCGA) identified MFng gene expression to be up-regulated in Kidney Clear Cell Renal Carcinoma (KIRC) patients. However there was no significant association between the patient survival probability and the level of MFng expression in this cohort. Immunohistochemistry performed on a tissue microarray containing cores from 64 patients revealed an elevated MFng protein expression in the epithelial and stromal tissues of RCC compared to the normal kidney, suggesting a possible role in tumorigenesis. Our study describes for the first time to our knowledge, the protein expression of MFng in the nuclear compartment of normal kidney and RCC, implicating a prospective involvement in gene transcription. At the cellular level, cytoplasmic MFng was also abundant in the normal kidney and RCC. However, MFng protein expression in the malignant epithelial and stromal tissue of RCC had no positive correlation with the patients' overall survival, progression-free survival and time to metastasis, as well as the gender, age, tumor stage and RCC subtype, indicating that MFng may not be an appropriate prognostic marker. The association between CD20+ B cells and epithelial MFng was found to approach borderline insignificance. Nonetheless, these preliminary findings may provide valuable information on the suitability of MFng as a potential therapeutic molecular marker for RCC, thus warrants further investigation using a larger cohort.

Combined therapy of adenovirus vector mediated IGF-1 gene with anti-CD20 mAbs exerts potential beneficial role on type 1 diabetes in nonobese diabetic mice

AIMS

To assess the protective effects of combined treatment with anti-CD20 monoclonal antibody (mAb) and adenovirus mediated mouse insulin-like growth factor 1 (Adv-mIGF-1) gene on type 1 diabetes (T1D) in nonobese diabetic (NOD) mice at early stage.

METHODS

To simultaneously restore the proportion of Th cells and block the interaction of B cells, NOD model mice were assigned to four groups which received PBS, Adv-mIGF-1 gene and anti-CD20 mAbs alone or combination, respectively. After 16 weeks of therapeutic intervention, blood samples and pancreatic tissues of mice were measured via the methods of ELISA, RT-PCR, western blotting, H&E staining, TUNEL and immunohistochemistry assays.

KEY FINDINGS

Chronic combination intervention with Adv-mIGF-1 gene and anti-CD20 mAbs reduced the T1D-related morbidity, promoted the secretion of insulin, controlled the blood glucose levels (BGLs) and alleviated insulitis of experimental mice. In addition, current combination intervention also protected the pancreatic β cells via suppressing the expression of Fas and TNF-α, inhibiting Caspase-3/8 related apoptotic pathway, and activating the Bcl-2-related antiapoptotic pathway. Furthermore, current combination therapy also increased the expression levels of PDX-1 and CK-19 genes, and finally accelerated the proliferation and differentiation of pancreatic β-cells. In addition, combination therapy could also ameliorate the pathological characteristics of diabetic nephropathy in NOD mice.

CONCLUSION

Combination treatment with Adv-mIGF-1 gene and anti-CD20 mAbs may exert a potential beneficial role on T1D in NOD mice.

Optimizing the treatment of acute lymphoblastic leukemia in younger and older adults: new drugs and evolving paradigms

In the past decade, the available treatments for patients with acute lymphoblastic leukemia (ALL) have rapidly expanded, in parallel with an increased understanding of the genomic features that impact the disease biology and clinical outcomes. With the development of the anti-CD22 antibody-drug conjugate inotuzumab ozogamicin, the CD3-CD19 bispecific T-cell engager antibody blinatumomab, CD19 chimeric antigen receptor T-cell therapy, and the potent BCR-ABL1 tyrosine kinase inhibitor ponatinib, the outlook of ALL in both younger and older adults has substantially improved. The availability of highly effective drugs raised important questions concerning the optimal combination and sequence of these agents, their incorporation into frontline regimens, and the role of hematopoietic stem cell transplantation. In this review, we discuss the rapidly evolving paradigms in the treatment of ALL, highlighting both established and effective regimens, as well as promising new therapies that are being evaluated in ongoing clinical trials. We specifically focus on novel combination regimens in both the frontline and salvage settings that are leading to new standards of care in the treatment of ALL.

Co-Stimulatory versus Cell Death Aspects of Agonistic CD40 Monoclonal Antibody Selicrelumab in Chronic Lymphocytic Leukemia

Simple Summary

Previous observations have shown that CD40 activation of CLL cells via coculture with CD40L-expressing fibroblasts increases sensitivity to cell death by CD20 mAbs rituximab and obinutuzumab. We studied the activity of the fully human-agonistic CD40 mAb selicrelumab in primary CLL cells in relation to cell activation, induced pro-survival profile and sensitization for cell death by aCD20 mAbs. We found that the pro-survival effect of selicrelumab is minimal, while cell death by combined selicrelumab plus anti-CD20 antibody treatment is maintained. Thus, further investigation of applying selicrelumab combined with anti-CD20 mAbs in a therapeutic setting might be considered.

Abstract

Objectives: Chronic lymphocytic leukemia (CLL) is a common form of leukemia with a heterogeneous clinical course that remains incurable due to the development of therapy resistance. In lymph node proliferation centers, signals from the microenvironment such as CD40 ligation through interaction with follicular T helper cells shield CLL cells from apoptosis. Previous observations have shown that, despite CD40-induced changes in apoptotic mediators resulting in cell survival, CD40 activation also increases sensitivity to cell death by CD20 mAbs rituximab and obinutuzumab. To further investigate these observations, we here studied the activity of the fully human agonistic CD40 mAb selicrelumab in primary CLL cells in relation to cell activation, induced pro-survival profile, and sensitization for cell death by aCD20 mAbs, in vitro. Methods: CLL cells from peripheral blood were isolated by the Ficoll density method. The expression of activation markers and cytokine production following CD40 stimulation was quantified by flow cytometry and ELISA. The anti-apoptotic profile of CLL induced by stimulation was evaluated by the expression of BCL-2 proteins with Western blot, and resistance to venetoclax with flow cytometry. Cell death induced by the combination of selicrelumab and aCD20 mAbs was quantified by flow cytometry. Results: CLL cells treated with selicrelumab upregulated co-stimulatory molecules such as CD86, TNF-α and death receptor CD95/Fas. In contrast to the CD40 ligand-transfected NIH3T3 cells, induction of resistance to venetoclax by selicrelumab was very moderate. Importantly, selicrelumab stimulation positively sensitized CLL cells to CD20-induced cell death, comparable to CD40 ligand-transfected NIH3T3 cells. Conclusions: Taken together, these novel insights into selicrelumab-stimulatory effects in CLL may be considered for developing new therapeutic strategies, particularly in combination with obinutuzumab.

Fatal Hepatitis C after Chemotherapy in a Patient with Malignant Lymphoma: Possible Reactivation of Seronegative Occult Hepatitis C Virus Infection Due to Chemotherapy

A 79-year-old man with lymphoma who tested negative for anti-hepatitis C virus (HCV) antibody received rituximab-containing chemotherapy. Liver dysfunction of unknown cause had persisted since the second cycle of chemotherapy. Ten months after treatment, he rapidly developed massive ascites and atrophy of the liver, and we detected HCV RNA in his serum using real time polymerase chain reaction. Furthermore, medical interviews showed that the patient had no episodes for acute HCV infection, but he did have a history of unspecified liver dysfunction. These findings support the possibility of the reactivation of seronegative occult HCV infection due to chemotherapy in a cancer patient.

Failed, Interrupted, or Inconclusive Trials on Immunomodulatory Treatment Strategies in Multiple Sclerosis: Update 2015-2020

In the past decades, multiple sclerosis (MS) treatment has experienced vast changes resulting from major advances in disease-modifying therapies (DMT). Looking at the overall number of studies, investigations with therapeutic advantages and encouraging results are exceeded by studies of promising compounds that failed due to either negative or inconclusive results or have been interrupted for other reasons. Importantly, these failed clinical trials are informative experiments that can help us to understand the pathophysiological mechanisms underlying MS. In several trials, concepts taken from experimental models were not translatable to humans, although they did not lack a well-considered pathophysiological rationale. The lessons learned from these discrepancies may benefit future studies and reduce the risks for patients. This review summarizes trials on MS since 2015 that have either failed or have been interrupted for various reasons. We identify potential causes of failure or inconclusiveness, looking at the path from basic animal experiments to clinical trials, and discuss the implications for our current view on MS pathogenesis, clinical practice, and future study designs. We focus on anti-inflammatory treatment strategies, without including studies on already approved and effective DMT. Clinical trials addressing neuroprotective and alternative treatment strategies are presented in a separate article.

The clinical efficacy of Rituximab administration in autoimmunity disorders, primary immunodeficiency diseases and malignancies

Rituximab (RTX), as a monoclonal antibody-based immunotherapeutic intervention targeting CD20 on B cells, has proven efficacy in the treatment of patients with some immune-mediated diseases. In the present review, we provided information on the immunobiological mechanisms of signaling for RTX and its clinical applications, according to the immune-pathophysiology involved in the microenvironment of multiple diseases. We highlighted combination therapy, dose schedules, and laboratory monitoring, as well as the associated common and rare side effects to avoid. We also discussed the efficacy and safety of RTX-based therapeutic strategies and whether RTX therapy can be used as a promising treatment regimen for autoimmune diseases, primary immunodeficiency diseases, and malignancies. Our review highlights and supports the importance of collaboration between basic medical researchers and clinical specialists when considering the use of RTX in the treatment of various immune-mediated disorders.

Biosimilar or Not: Physicochemical and Biological Characterization of MabThera and Its Two Biosimilar Candidates

The development of therapeutic biosimilar antibodies has become an important driving force of the modern biopharmaceutical industry. In this study, physiochemical characteristics (amino acid sequence, intact/subunit molecular weight, isoelectric point, post-translation modification, and disulfide linkage pattern), purity (charge variants, high and low molecular weight variants), antigen binding activity, Fc receptor binding affinity and Fc-effector function (CDC and ADCC) were analyzed by using an extensive set of state-of-the-art and orthogonal analytical technologies to provide a comprehensive characterization of the innovative product rituximab and two biosimilar candidates. The similarity study showed that biosimilar candidate 1 (BC1) and the reference product (RP) MabThera had an identical protein amino acid sequences and highly similar primary structures along with similar purity, heterogeneity profiles, antigen binding activity, Fc receptor binding affinity, and Fc-effector functions. Biosimilar candidate 2 (BC2), which had an amino acid replacement at a constant region, a different N-glycosylation profiling, and purity, was not analytically similar to RP. Although BC2 showed improvement such as an increased level of afucose, another IgG1 allotype, and similar biological activities, it was not recommended to be applied as a biosimilar compound in drug registration because the biosimilar manufacturer must first show that its primary structure was identical to that of RP. Our physicochemical characterizations and bioassay comparability study provided a deepened understanding of the structure-function relationship of quality attributes.

Type I IFN Activating Type I Dendritic Cells for Antitumor Immunity

Immune checkpoint inhibitors are successful immunotherapy modalities that enhance CD8⁺ T-cell responses. Although T cells are initially primed in draining lymph nodes, the mechanisms that underlie their reactivation inside the tumor microenvironment are less clear. Recent studies have found that not only is the cross-priming of conventional type 1 dendritic cells (cDC1) required to initiate CD8⁺ T-cell responses during tumor progression, but it also plays a central role in immunotherapy-mediated reactivation of tumor-specific CD8⁺ T cells for tumor regression. Moreover, many cancer treatment modalities trigger type I IFN responses, which play critical roles in boosting cDC1 cross-priming and CD8⁺ T-cell reactivation. Inducing type I IFNs within tumors can overcome innate immune resistance and activate antitumor adaptive immunity. Here, we review recent studies on how type I IFN-cDC1 cross-priming reactivates CD8⁺ T cells and contributes to tumor control by cancer immunotherapy.

Coiled coil-based therapeutics and drug delivery systems

Coiled coils are characterized by an arrangement of two or more α-helices into a superhelix and one of few protein motifs where the sequence-to-structure relationship to a large extent have been decoded and understood. The abundance of both natural and de novo designed coil coils provides a rich molecular toolbox for self-assembly of elaborate bespoke molecular architectures, nanostructures, and materials. Leveraging on the numerous possibilities to tune both affinities and preferences for polypeptide oligomerization, coiled coils offer unique possibilities to design modular and dynamic assemblies that can respond in a predictable manner to biomolecular interactions and subtle physicochemical cues. In this review, strategies to use coiled coils in design of novel therapeutics and advanced drug delivery systems are discussed. The applications of coiled coils for generating drug carriers and vaccines, and various aspects of using coiled coils for controlling and triggering drug release, and for improving drug targeting and drug uptake are described. The plethora of innovative coiled coil-based molecular systems provide new knowledge and techniques for improving efficacy of existing drugs and can facilitate development of novel therapeutic strategies.

Immunomodulation Induced During Interferon-α Therapy Impairs the Anti-HBV Immune Response Through CD24+CD38hi B Cells

Type I interferon is widely used for antiviral therapy, yet has yielded disappointing results toward chronic HBV infection. Here we identify that PEG-IFNα-2b therapy toward persistent infection in humans is a double-edged sword of both immunostimulation and immunomodulation. Our studies of this randomised trial showed persistent PEG-IFNα-2b therapy induced large number of CD24⁺CD38^hi B cells and launched a CD24⁺CD38^hi B cells centered immunosuppressive response, including downregulating functions of T cells and NK cells. Patients with low induced CD24⁺CD38^hi B cells have achieved an improved therapeutic effect. Specifically, using the anti-CD24 antibody to deplete CD24⁺CD38^hi B cells without harming other B cell subsets suggest a promising strategy to improve the therapeutic effects. Our findings show that PEG-IFNα-2b therapy toward persistent infection constitutes an immunomodulation effect, and strategies to identifying the molecular basis for the antiviral versus immunomodulatory effects of PEG-IFNα-2b to selectively manipulate these opposing activities provide an opportunity to ameliorate anti-virus immunity and control viral infection.

A population-based study on different regimens of R-CHOP in patients with newly diagnosed DLBCL in The Netherlands

Randomized controlled trials have studied different dose-intensity and dose-interval regimens of R-CHOP for patients with diffuse large B-cell lymphoma (DLBCL). This study was undertaken to confirm these results in a population-based setting, with special emphasis on the value of 6xR-CHOP21 among patients aged 18-64 years. Two thousand three hundred and thirty-eight stage II-IV DLBCL patients, ≥18 years, we confirmed the similar efficacy of six versus eight cycles of R-CHOP and of R-CHOP21 versus R-CHOP14 regimens across all age groups on overall survival (median follow-up 36.4 (1.3-167.6) months). Nevertheless, overall survival decreased with older age. Interestingly, in patients 18-64 years, the adjusted risk of mortality among recipients of 6xR-CHOP21 compared to other R-CHOP regimens seems to be similar (HR 0.62; 95%CI: 0.38-1.02; p= .059). Although this finding might suggest that 6xR-CHOP21 could be considered as first-line regimen for all stage II-IV DLBCL patients, it should be confirmed in forthcoming population-based studies with larger patient numbers and longitudinal follow-up.

The Pharmacogenetics of Rituximab: Potential Implications for Anti-CD20 Therapies in Multiple Sclerosis

There are a broad range of disease-modifying therapies (DMTs) available in relapsing-remitting multiple sclerosis (RRMS), but limited biomarkers exist to personalise DMT choice. All DMTs, including monoclonal antibodies such as rituximab and ocrelizumab, are effective in preventing relapses and preserving neurological function in MS. However, each agent harbours its own risk of therapeutic failure or adverse events. Pharmacogenetics, the study of the effects of genetic variation on therapeutic response or adverse events, could improve the precision of DMT selection. Pharmacogenetic studies of rituximab in MS patients are lacking, but pharmacogenetic markers in other rituximab-treated autoimmune conditions have been identified. This review will outline the wider implications of pharmacogenetics and the mechanisms of anti-CD20 agents in MS. We explore the non-MS rituximab literature to characterise pharmacogenetic variants that could be of prognostic relevance in those receiving rituximab, ocrelizumab or other monoclonal antibodies for MS.

The Potential Action of Thomsen-Friedenreich Monoclonal Antibody (A78-G/A7) in Thyroid Cancer

Background

Thomsen–Friedenreich antibody (TF-Ab) is a specific antibody against the Thomsen–Friedenreich antigen (TF-Ag). At present, studies on a number of other tumors have shown that TF-Ab can effectively inhibit metastasis and induce apoptosis in tumor cells. However, the role of TF-Ab in thyroid cancer (TC) remains unclear.

Materials and Methods

Normal subjects and patients with primary papillary TC with or without lymph node metastasis were tested for TF-Ab expression by enzyme-linked immunosorbent assays (ELISAs). Immunofluorescence was used to assess the expression of TF-Ag in thyroid papillary carcinoma with or without lymph node metastasis and undifferentiated cancer tissues. To evaluate the role of TF-Ab in TC, the effects of TF monoclonal antibody (mAb A78-G/A7) on cell biological function were investigated by MTT assays, flow cytometry, adhesion assays and transwell experiments.

Results

Compared with normal individuals, TF-Ab levels in patients with TC were decreased, but no changes were observed with respect to lymph node metastasis. The expression of TF-Ag in TC tissues was relatively higher than that detected in adjacent tissues, but it was not affected by the presence or absence of lymph node metastasis. Upon treatment mAb A78-G/A7 treating, TC cell cycles were affected, meanwhile the abilities to adhere, invade and migrate were also significantly reduced.

Conclusion

The results of the present study showed that mAb A78-G/A7 could affect the invasion and migration of all assayed TC cell lines. The effects of mAb A78-G/A7 on the cell cycle, adhesion, invasion and migration of TC cells were more significant than those observed for proliferation and apoptosis.

Well-Orientation Strategy for Direct Immobilization of Antibodies: Development of the Immunosensor Using the Boronic Acid-Modified Magnetic Graphene Nanoribbons for Ultrasensitive Detection of Lymphoma Cancer Cells

This work presents an effective strategy for the well-oriented immobilization of antibodies in which boronic acid is directly attached to the surface and with no need of the long and flexible spacer. A magnetic graphene nanoribbon-boronic-acid-based immunosensor was developed and tested for the impedimetric detection of lymphoma cancer cells, a blood cancer biomarker. Magnetic graphene nanoribbons (MGNRs) were modified with boronic acid (BA) to create a supporting matrix that is utilized by immobilizing anti-CD20 antibodies with good orientation. The prepared biosensing layer (MGNR/BA/Ab) with well-oriented antibodies was premixed into whole blood samples to interact with lymphoma cancer cell receptors. In the presence of target cell receptors, an immunocomplex was formed between anti-CD20 antibodies and lymphoma cancer cell receptors. Then, the biosensing layer was magnetically collected on a screen-printed carbon electrode (SPCE) and placed in a homemade electrochemical cell configuration to measure impedimetric signals. The fabrication steps of the immunosensor were characterized by various techniques, such as resonance light scattering, fluorescence, electrochemical impedance spectroscopy, and cyclic voltammetry. The assay is highly sensitive: the calculated limit of detection of lymphoma cancer cells was as low as 38 cells/mL, and the detection was linear from 100 to 1 000 000 cells/mL. The specificity of the immunosensor is also very high, and there is no interference effect with several potential interferents, such as the breast cancer (MCF-7), human embryonic kidney (HEK293), and leukemia (HL-60 and KCL-22) cell lines. The performance of the immunosensor for lymphoma cancer cells in clinical blood samples is consistent with that of commercial flow cytometric assays.

Sirt6 promotes tumorigenesis and drug resistance of diffuse large B-cell lymphoma by mediating PI3K/Akt signaling

Background

Sirtuin 6 (Sirt6) is a highly conserved ADP-ribosylase and NAD+ dependent deacylase, involved in broad cellular processes. This molecule possesses contradictory roles in carcinogenesis, as it has been documented to both suppressing and augmenting tumor growth. This project aimed to explore the expression and functions of Sirt6 in diffuse large B-cell lymphoma (DLBCL), especially with regards to the regulatory role of OSS_128167, a novel small molecular inhibitor targeting Sirt6.

Methods

Immunohistochemistry (IHC) was conducted to assess the expression of Sirt6 on paraffin-embedded tissues. Microarray dataset GSE32918 and GSE83632 were obtained from Gene Expression Omnibus and survival analysis was performed. Lentivirus vectors either encoding shSirt6, lvSirt6 or empty lentiviral vector were stably transfected into DLBCL cells. LY1 cell transfected with shSirt6 were performed RNA-sequencing (RNA-seq) analysis, functional enrichment analyses of gene ontology (GO) and gene set enrichment analysis (GSEA). DLBCL cells were subcutaneously injected to SCID beige mice to establish xenograft models.

Results

Sirt6 is found to be overexpressed in DLBCL, and is related to poor prognosis. Sirt6-deprived DLBCL cells displayed augmented sensitivity towards chemotherapy, higher rates of apoptosis, dysfunctional cell proliferation, and arrested cell cycle progression between the G2 and M phases. Selective OSS_128167-mediated Sirt6 blockage resulted in similar anti-lymphoma effects when compared to Sirt6 knocked-down DLBCL cells. PI3K signaling along with phosphorylation of its downstream targets was reduced upon Sirt6 downregulation. Xenograft models subjected to either OSS_128167 treatment or Sirt6-knockdown showed suppressed tumor growth and lower Ki-67 level.

Conclusions

These findings provide mechanistic insights into the oncogenic activity of Sirt6 in DLBCL for the first time and highlighted the potency of OSS_128167 for novel therapeutic strategies in DLBCL.

HDAC inhibitors overcome immunotherapy resistance in B-cell lymphoma

Immunotherapy has been applied successfully to treat B-cell lymphomas in preclinical models or clinical settings. However, immunotherapy resistance is a major challenge for B-cell lymphoma treatment. To overcome this issue, combinatorial therapeutic strategies have been pursued to achieve a better efficacy for treating B-cell lymphomas. One of such strategies is to combine immunotherapy with histone deacetylase (HDAC) inhibitors. HDAC inhibitors can potentially increase tumor immunogenicity, promote anti-tumor immune responses, or reverse immunosuppressive tumor environments. Thus, the combination of HDAC inhibitors and immunotherapy has drawn much attention in current cancer treatment. However, not all HDAC inhibitors are created equal and their net effects are highly dependent on the specific inhibitors used and the HDACs they target. Hence, we suggest that optimal treatment efficacy requires personalized design and rational combination based on prognostic biomarkers and unique profiles of HDAC inhibitors. Here, we discuss the possible mechanisms by which B-cell lymphomas acquire immunotherapy resistance and the effects of HDAC inhibitors on tumor cells and immune cells that could help overcome immunotherapy resistance.

Patients with systemic lupus erythematosus show increased proportions of CD19+CD20- B cells and secretion of related autoantibodies

BACKGROUND

At present, anti-CD20 monoclonal antibody treatments targeting systemic lupus erythematosus (SLE) are complex, variable, and often have disappointing outcomes. High levels of programmed cell death-1 (PD-1) and its ligands (PD-L1, PD-L2) or CD80/CD86 on B cell surfaces are markers of increased B cell activity. However, their expression levels on CD19⁺CD20^+/- B cells and their clinical significance for SLE dynamics have not been carefully investigated.

METHODS

Flow cytometry was used to detect the expression levels of PD-1, PD-L1, PD-L2, CD80, and CD86 on CD19⁺CD20^+/- B cells in peripheral blood from SLE patients and healthy controls (HCs). The amount of anti-dsDNA and immunoglobin G (IgG) secreted by CD19⁺CD20^+/- B cells was measured by enzyme-linked immunosorbent assay.

RESULTS

CD19⁺CD20^- B cell frequency was significantly higher in SLE patients than in HCs (P < 0.001), and was positively correlated with disease activity. In SLE patients, frequencies of PD-1, PD-L1, PD-L2, and CD86 on CD19⁺CD20^- B cells were significantly higher than CD19⁺CD20⁺ B cells (P ≤ 0.002) and were significantly correlated with individual laboratory and clinically based parameters (P < 0.05). In vitro tests, we found that the levels of anti-dsDNA and IgG secreted by CD19⁺CD20^- B cells from patients with SLE were significantly higher than the HC group (P < 0.05).

CONCLUSIONS

We found abnormal frequency of CD19⁺CD20^- B cells and increased expression of surface markers on these cells from SLE patients. And the CD19⁺CD20^- B cells had the ability to proliferate and secrete anti-dsDNA and IgG. Additionally, our results suggested that CD19⁺CD20^- B cells from SLE patients may be the activated B cells and caused poor efficacy of rituximab. Key Points • CD19⁺CD20^- B cell frequencies were significantly higher in SLE patients. • Frequencies of PD-1 and its ligands on CD19⁺CD20^- B cells increased significantly in SLE patients. • CD19⁺CD20^- B cells in SLE patients had the ability to secrete anti-dsDNA and IgG. • CD19⁺CD20^- B cells in SLE patients may be the activated B cells and caused poor efficacy of rituximab.

Evolving therapy of adult acute lymphoblastic leukemia: state-of-the-art treatment and future directions

Recent years have witnessed major advances that have improved outcome of adults with acute lymphoblastic leukemia (ALL). The emergence of the concept of measurable residual disease has fine-tuned our prognostic models and guided our treatment decisions. The treatment paradigms of ALL have been revolutionized with the advent of tyrosine kinase inhibitors targeting BCR-ABL1, monoclonal antibodies targeting CD20 (rituximab), antibody-drug conjugates targeting CD22 (inotuzumab ozogamicin), bispecific antibodies (blinatumomab), and CD19 chimeric antigen receptor T cell therapy (tisagenlecleucel). These highly effective new agents are allowing for novel approaches that reduce reliance on intensive cytotoxic chemotherapy and hematopoietic stem cell transplantation in first remission. This comprehensive review will focus on the recent advances and future directions in novel therapeutic strategies in adult ALL.

Immunohistochemical CD20-negative change in B-cell non-Hodgkin lymphomas after rituximab-containing therapy

CD20^- change after rituximab-containing therapy is considered one of the main reasons of rituximab resistance of B-cell non-Hodgkin lymphomas (B-NHLs). However, the clinicopathological characteristics of B-NHL with CD20^- change are not entirely understood. In this study, 252 B-NHL patients who were CD20⁺ at initial diagnosis, whose diseases relapsed or were refractory after rituximab-containing therapy, and who were re-biopsied between 2000 and 2018, were included. The median number of rituximab administration was 11 (range, 1-48). Completely negative (cCD20^-) and partially negative (pCD20^-) change of CD20 was observed in 49 (20%) and 16 (6%) cases, respectively. Among cCD20^- and pCD20^- cases, 74% and 62% of the cases changed to CD20^- at the second relapse or later, respectively. Overall survival was significantly shorter in cCD20^- follicular lymphoma (FL) cases than in CD20⁺ FL cases. Seven histopathological patterns, such as CD20^- change without histological change, histological transformation (HT) to CD20^- diffuse large B-cell lymphoma, and proliferation of plasmablastic/plasmacytoid tumor cells, were associated with CD20^- change. HT occurred more frequently in FLs with CD20^- change than in FLs continuously expressing CD20 (P < 0.0001), regardless of the timing of HT. Nine out of 25 cases (36%) showed regain or heterogeneous regain of CD20 expression. In conclusion, 20% and 6% of the 252 B-NHL cases show cCD20^- and pCD20^- changes with 7 histological patterns after rituximab-containing therapy. Because changes in morphology and CD20 expression after rituximab-containing therapy vary, and recovery of CD20 expression is not rare, careful follow-up and re-biopsy in B-NHL patients are recommended.

Smart Biomimetic Nanocomposites Mediate Mitochondrial Outcome through Aerobic Glycolysis Reprogramming: A Promising Treatment for Lymphoma

Toxicity and drug resistance caused by chemotherapeutic drugs have become bottlenecks in treating tumors. The delivery of anticancer drugs based on nanocarriers is regarded as an ideal way to solve the aforementioned problems. In this study, a new antilymphoma nanodrug CD20 aptamer-RBCm@Ag-MOFs/PFK15 (A-RAMP) is designed and constructed, and it consists of two parts: (1) metal-organic frameworks Ag-MOFs (AM) loaded with tumor aerobic glycolysis inhibitor PFK15 (P), forming a core part (AMP); (2) targeted molecule CD20 aptamer (A) is inserted into the red blood cell membrane (RBCm) to form the shell part (A-R). A-RAMP under the guidance of CD20 aptamer actively targets B-cell lymphoma both in vitro and in vivo. As a result, A-RAMP not only significantly inhibits the effect on tumor growth but also shows no obvious side effects on the treated nude mice, indicating that A-RAMP can accurately target tumor cells, reprogram aerobic glycolysis, and exert synergistic antitumor effect by Ag⁺ and PFK 15. Furthermore, the antitumor mechanism of A-RAMP in vivo by apoptotic pathway and targeting metabonomics are explored. These results suggest that A-RAMP has a promising application prospect as an smart, safe, effective, and synergistic antilymphoma agent.