Biomarkers and coptis chinensis activity for rituximab-resistant diffuse large B-cell lymphoma: Combination of bioinformatics analysis, network pharmacology and molecular docking.

BACKGROUND: Rituximab resistance is one of the great challenges in the treatment of diffuse large B-cell lymphoma (DLBCL), but relevant biomarkers and signalling pathways remain to be identified. Coptis chinensis and its active ingredients have antitumour effects; thus, the potential bioactive compounds and mechanisms through which Coptis chinensis acts against rituximab-resistant DLBCL are worth exploring. OBJECTIVE: To elucidate the core genes involved in rituximab-resistant DLBCL and the potential therapeutic targets of candidate monomers of Coptis chinensis. METHODS: Using the Traditional Chinese Medicine System Pharmacology Database and Analysis Platform (TCMSP), the Similarity Ensemble Approach and Swiss Target Prediction, the main ingredients and pharmacological targets of Coptis chinensis were identified through database searches. Through the overlap between the pharmacological targets of Coptis chinensis and the core targets of rituximab-resistant DLBCL, we identified the targets of Coptis chinensis against rituximab-resistant DLBCL and constructed an active compound-target interaction network. The targets and their corresponding active ingredients of Coptis chinensis against rituximab-resistant DLBCL were molecularly docked. RESULTS: Berberine, quercetin, epiberberine and palmatine, the active components of Coptis chinensis, have great potential for improving rituximab-resistant DLBCL via PIK3CG. CONCLUSION: This study revealed biomarkers and Coptis chinensis-associated molecular functions for rituximab-resistant DLBCL.

Potential of the tumor­derived extracellular vesicles carrying the miR­125b­5p target TNFAIP3 in reducing the sensitivity of diffuse large B cell lymphoma to rituximab.

Diffuse large B­cell lymphoma (DLBCL) is the most common and aggressive form of non­Hodgkin's lymphoma. Extracellular vesicles (EVs) derived from cancer cells are known to modify the tumor microenvironment. The aim of the present study was to investigate the role of miR­125b­3p carried by EVs in DLBCL in vitro and in vivo. TNFAIP3 expression in patient lesions was measured and the upstream miR that regulates TNFAIP3 was predicted using the starBase database. EVs were isolated from DLBCL cells and identified. DLBCL cells were transfected with pcDNA to overexpress TNFAIP3 or inhibit miR­125b­5p expression, incubated with EVs, and treated with rituximab to compare cell growth and TNFAIP3/CD20 expression. DLBCL model mice were administered EVs, conditioned medium, and rituximab to observe changes in tumor size, volume, and weight. TNFAIP3 was downregulated in patients with DLBCL and its levels further decreased in patients with drug­resistant DLBCL. Overexpression of TNFAIP3 in DLBCL cells enhanced the inhibitory effect of rituximab and increased CD20 expression. miR­125b­5p targeted TNFAIP3. Inhibition of miR­125b­5p enhanced the inhibitory effect of rituximab in DLBCL cells. The EV­carried miR­125b­5p reduced the sensitivity of DLBCL cells to rituximab, which was averted by overexpression of TNFAIP3. EVs reduced the sensitivity of DLBCL model mice to rituximab via the miR­125b­5p/TNFAIP3 axis. The study findings indicate that the tumor­derived EVs carrying miR­125b­5p can enter DLBCL cells and target TNFAIP3, thus reducing the sensitivity of DLBCL to rituximab, which may provide a novel therapeutic approach for DLBCL.

Prognostic Impact of Age at the Time of Diagnosis in Korean Patients with Diffuse Large B-cell Lymphoma in the Rituximab Era: A Single Institution Study.

PURPOSE: In contrast to the Western diffuse large B-cell lymphoma (DLBCL), prognostic impact of age in a Korean population with DLBCL has not been fully evaluated. MATERIALS AND METHODS: Six hundred and eight DLBCL patients treated with rituximab-containing chemotherapeutic regimens from January 2002 to March 2012 in Asan Medical Center were enrolled. Survival models using the restricted cubic spine-transformed age variable were constructed to evaluate non-linear relationships between age and survival outcome. Finally, age was categorized according to the conventional international prognostic index (IPI), National Comprehensive Cancer Network (NCCN)-IPI, and Grupo Español de Linfomas/Trasplante Autólogo de Médula Ósea (GELTAMO)-IPI schemes and the prognostic implications were evaluated. RESULTS: The relative hazard did not change significantly during the first to fifth decades, but began to increase exponentially in patients aged over 62 years. This pattern or relationship was also retained in a multivariate model fitted to the age-adjusted IPI and relative dose intensity. Multivariate survival analysis revealed that age > 75 years, but not age > 60 years, was associated independently with poor overall and progression-free survival when the relative dose intensity and age-adjusted IPI were taken into account. CONCLUSION: The outcome of DLBCL in Korean populations may deteriorate rapidly as age exceeds 62 years. Therefore, a consensus cutoff value for age in Korean DLBCL patients should be determined to better predict prognosis.

Checkpoint inhibitor-related renal vasculitis and use of rituximab.

The percentage of patients with cancer eligible for checkpoint inhibitor (CPI) therapy has increased rapidly over the past few years and approaches 45%. As a result, more cases of CPI-related nephrotoxicity, including a rare subset with vasculitis, are being reported. To elucidate the clinical presentation of CPI-associated renal vasculitis and its possible mechanisms, treatment options and prognosis, we describe cases from a comprehensive cancer center and reviewed the literature for similar cases. We retrospectively reviewed the charts of all patients with cancer from 2014 to 2020 who were diagnosed with CPI-related nephrotoxicity and underwent a kidney biopsy. We identified five cases of renal vasculitis: three patients were diagnosed with seronegative antineutrophil cytoplasm antibody (ANCA)-associated vasculitis, one case with seropositive ANCA-associated vasculitis and one case was diagnosed with IgA vasculitis. Of these cases, four patients were receiving nivolumab, and one patient was receiving tremelimumab. All patients had microscopic hematuria, four out of five patients had negative ANCA serology, one patient had concurrent lung involvement and positive ANCA serology, and all had severe acute kidney injury with creatinine >4.50 mg/dL on diagnosis. All patients were treated by discontinuing CPI and initiating corticosteroids and rituximab. Three patients received plasmapheresis; two of these required renal replacement therapy including the patient with lung involvement. All patients after rituximab had a partial or complete renal response. Two patients died within 8 months of diagnosis due to malignancy progression. None of the patients had a relapse of vasculitis. We demonstrated that CPI can be associated with different types of renal vasculitis that are predominantly ANCA negative and manifest as severe acute kidney injury. Despite the lack of strong evidence, treatment similar to treatment of primary seropositive ANCA-associated vasculitis with corticosteroids and rituximab is well tolerated with favorable renal outcomes.

Are lupus animal models useful for understanding and developing new therapies for human SLE?

Systemic lupus erythematosus is a systemic autoimmune disease driven by a complex combination of genetic, environmental, and other immunoregulatory factors. The development of targeted therapies is complicated by heterogeneous clinical manifestations, varying organ involvement, and toxicity. Despite advances in understanding the mechanisms contributing to SLE, only one biologic drug, belimumab, is FDA-approved. The identification and development of potential therapies have largely been driven by studies in lupus animal models. Therefore, direct comparison of both the therapeutic and immunological findings in human and murine SLE studies is critical and can reveal important insights into indeed how useful and relevant are murine studies in SLE drug development. Studies involving belimumab, mycophenolate mofetil, abatacept, rituximab, and anti-interferon strategies generally demonstrated analogous findings in the attenuation of SLE manifestations and modulation of select immune cell populations in human and murine SLE. While further basic and translational studies are needed to identify SLE patient subsets likely to respond to particular therapeutic modalities and in dissecting complex mechanisms, we believe that despite some inherent weaknesses SLE mouse models will continue to be integral in developing targeted SLE therapies.

Developing a 3D B Cell Lymphoma Culture System to Model Antibody Therapy.

Diffuse large cell B cell lymphoma (DLBCL) accounts for approximately 30%-40% of all non-Hodgkin lymphoma (NHL) cases. Current first line DLBCL treatment results in long-term remission in more than 60% of cases. However, those patients with primary refractory disease or early relapse exhibit poor prognosis, highlighting a requirement for alternative therapies. Our aim was to develop a novel model of DLBCL that facilitates in vitro testing of current and novel therapies by replicating key components of the tumor microenvironment (TME) in a three-dimensional (3D) culture system that would enable primary DLBCL cell survival and study ex vivo. The TME is a complex ecosystem, comprising malignant and non-malignant cells, including cancer-associated fibroblasts (CAF) and tumor-associated macrophages (TAM) whose reciprocal crosstalk drives tumor initiation and growth while fostering an immunosuppressive milieu enabling its persistence. The requirement to recapitulate, at least to some degree, this complex, interactive network is exemplified by the rapid cell death of primary DLBCL cells removed from their TME and cultured alone in vitro. Building on previously described methodologies to generate lymphoid-like fibroblasts from adipocyte derived stem cells (ADSC), we confirmed lymphocytes, specifically B cells, interacted with this ADSC-derived stroma, in the presence or absence of monocyte-derived macrophages (MDM), in both two-dimensional (2D) cultures and a 3D collagen-based spheroid system. Furthermore, we demonstrated that DLBCL cells cultured in this system interact with its constituent components, resulting in their improved viability as compared to ex-vivo 2D monocultures. We then assessed the utility of this system as a platform to study therapeutics in the context of antibody-directed phagocytosis, using rituximab as a model immunotherapeutic antibody. Overall, we describe a novel 3D spheroid co-culture system comprising key components of the DLBCL TME with the potential to serve as a testbed for novel therapeutics, targeting key cellular constituents of the TME, such as CAF and/or TAM.

Human Serum Albumin-Based Drug-Free Macromolecular Therapeutics: Apoptosis Induction by Coiled-Coil-Mediated Cross-Linking of CD20 Antigens on Lymphoma B Cell Surface.

A therapeutic platform-drug-free macromolecular therapeutics (DFMT)-that induces apoptosis in B cells by cross-linking of CD20 receptors, without the need for low molecular weight cytotoxic drug, is developed. In this report, a DFMT system is synthesized and evaluated based on human serum albumin (HSA) and two complementary coiled-coil forming peptides, CCE and CCK. Fab' fragment of anti-CD20 monoclonal antibody rituximab is attached to CCE (Fab'-CCE); multiple grafts of CCK are conjugated to HSA (HSA-(CCK)7 ). The colocalization of both nanoconjugates at the surface of non-Hodgkin's lymphoma (NHL) Raji cells is demonstrated by confocal fluorescence microscopy. The colocalization leads to coiled-coil formation, CD20 cross-linking, and apoptosis induction. The apoptotic levels are evaluated by Annexin V, Caspase 3, and terminal deoxynucleotidyl transferase dUTP nick end labeling assays. Selective surface binding of DFMT to CD20+ cells is validated in experiments on a coculture of CD20+ (Raji) and CD20-(DG-75) cells. It is found that DFMT can trigger calcium influx only in Raji cells, but not in DG-75 cells. A highly specific treatment for NHL and other B cell malignancies with considerable translational potential is presented by HSA-based DFMT system.

Combination of 177 Lu-lilotomab with rituximab significantly improves the therapeutic outcome in preclinical models of non-Hodgkin's lymphoma.

OBJECTIVES: To investigate the therapeutic potential of the next-generation anti-CD37 radioimmunoconjugate 177 Lu-lilotomab satetraxetan (177 Lu-lilotomab) in combination with the anti-CD20 antibody rituximab for treatment of mice with non-Hodgkin's lymphoma (NHL) xenografts. METHODS: Nude mice with subcutaneous (s.c.) Burkitt's lymphoma Daudi xenografts and SCID mice intravenously (i.v.) injected with Mantle cell lymphoma Rec-1 cells were treated with either 177 Lu-lilotomab or rituximab alone or with the combination of both treatments. Tumour volume, body weight, blood counts and clinical status were monitored. CD20 expression was measured using flow cytometry with fluorescence-labelled rituximab. RESULTS: The combination of 177 Lu-lilotomab and rituximab was synergistic for treatment of nude mice with s.c. Daudi xenografts while it was additive for treatment of SCID mice with i.v. injected Rec-1 cells. Binding of rituximab to NHL cells in-vitro was increased by pretreatment with 177 Lu-lilotomab. CONCLUSIONS: Treatment of mice with NHL xenografts with 177 Lu-lilotomab synergistically increased tumour suppression of subsequent anti-CD20 immunotherapy and improved survival. If the same effect is confirmed in a recently started clinical study, it could change the way radioimmunotherapy and CD20 immunotherapy would be used in the future.

Granulocyte-Colony Stimulating Factor Nanocarriers for Stimulation of the Immune System (Part II): Dose-Dependent Biodistribution and In Vivo Antitumor Efficacy in Combination with Rituximab.

The purpose of immuno-modulation is to increase or restore the action of immunocompetent cells against tumors with or without the use of monoclonal antibodies. The innate immune system is a key player in various pathological situations, but cells of this system appear to be inhibited or insufficiently active in malignancy or severe infectious diseases. The present study was designed to investigate therapeutic value of nanoparticles (NPs) coupled with bioactive hematopoietic growth factors acting on the innate immune system. The use of nanoparticles (NPs) allowing multimodal detection and multifunctional grafting are currently of great interest for theranostic purposes. In the present work, we have evaluated the impact of the number of granulocyte-colony stimulating factor (G-CSF) grafted on the surface on the NPs on the biodistribution in mice thanks to indium 111 radiolabeling. Furthermore, we have investigated whether grafted G-CSF NPs could stimulate the immune innate system and enhance the therapeutic efficacy of the monoclonal antibody rituximab in mice bearing human lymphoma xenografts. Following intravenous (i.v.) administration of NP-DTPA and NP-DTPA/G-CSF-X high levels of radioactivity were observed in the liver. Furthermore, spleen uptake was correlated with the number of G-CSF molecules grafted on the surface of the NPs. Combining NP-DTPA/G-CSF-34 with rituximab strongly reduced RL tumor growth compared to rituximab alone or in combination with conventional G-CSF + rituximab. The use of highly loaded G-CSF NPs as immune adjuvants could enhance the antitumor activity of therapeutic monoclonal antibodies by amplifying tumor cell destruction by innate immune cells.

Outcome of patients older than 80 years with diffuse large B-cell lymphoma (DLBCL) treated with "standard" immunochemotherapy: A large retrospective study from 4 institutions.

Little information is available on the very elderly patients with diffuse large B-cell lymphoma (DLBCL). We performed a retrospective analysis of 281 patients >80 years old with newly diagnosed DLBCL treated in 4 referral institutions in Switzerland and Northern Italy. Primary end points were overall survival, progression-free survival, and cause-specific survival. Systemic chemotherapy was given to 239 patients, and 119 of them received rituximab in their initial treatment. At a median follow-up of 5.5 years, 5-year progression-free survival was 26% (95% confidence interval [CI], 20-32%), 5-year overall survival was 31% (95% CI, 25-37%), and 5-year cause-specific survival was 48% (95% CI, 41-55%) for the entire cohort. Rituximab and/or anthracyclines as part of initial treatment were associated with improved outcome. Cause-specific survival in patients receiving both agents approximated 60% at 5 years. At multivariate analysis, rituximab use maintained a significant prognostic impact after controlling for age, performance status, stage, haemoglobin, and lactate dehydrogenase levels. The International Prognostic Index as well as the more recently proposed revised-International Prognostic Index and National Comprehensive Cancer Center Network-International Prognostic Index could discriminate patients with significantly different outcomes. Albeit very elderly and potentially frail, there may be a potential for cure in fit DLBCL patients ≥80 years old. Accurate selection of patients able to tolerate proper immunochemotherapy is crucial.

Thrombotic thrombocytopenic purpura.

Thrombotic thrombocytopenic purpura (TTP; also known as Moschcowitz disease) is characterized by the concomitant occurrence of often severe thrombocytopenia, microangiopathic haemolytic anaemia and a variable degree of ischaemic organ damage, particularly affecting the brain, heart and kidneys. Acute TTP was almost universally fatal until the introduction of plasma therapy, which improved survival from <10% to 80-90%. However, patients who survive an acute episode are at high risk of relapse and of long-term morbidity. A timely diagnosis is vital but challenging, as TTP shares symptoms and clinical presentation with numerous conditions, including, for example, haemolytic uraemic syndrome and other thrombotic microangiopathies. The underlying pathophysiology is a severe deficiency of the activity of a disintegrin and metalloproteinase with thrombospondin motifs 13 (ADAMTS13), the protease that cleaves von Willebrand factor (vWF) multimeric strings. Ultra-large vWF strings remain uncleaved after endothelial cell secretion and anchorage, bind to platelets and form microthrombi, leading to the clinical manifestations of TTP. Congenital TTP (Upshaw-Schulman syndrome) is the result of homozygous or compound heterozygous mutations in ADAMTS13, whereas acquired TTP is an autoimmune disorder caused by circulating anti-ADAMTS13 autoantibodies, which inhibit the enzyme or increase its clearance. Consequently, immunosuppressive drugs, such as corticosteroids and often rituximab, supplement plasma exchange therapy in patients with acquired TTP.

Saponins from Saponaria officinalis L. Augment the Efficacy of a Rituximab-Immunotoxin.

Triterpenoidal saponins are synthesized in the roots of Saponaria officinalis L. The same plant is also a source for the toxin Saporin, which is a ribosome-inactivating protein. Triterpenoidal saponins are known to increase the cytotoxicity of Saporin by modulating its intracellular trafficking. Here, we investigated if the combinatorial effects elicited by purified saponins and Saporin can be applied to increase the therapeutic efficacy of the immunotoxin Saporin-Rituximab. First, saponins were purified by high-performance liquid chromatography. Thereafter, their intrinsic cytotoxicity was evaluated on Ramos cells with no observed effect up to 5 µg/mL, however, saponins increased the cytotoxicity of Saporin, while no influence was observed on its N-glycosidase activity. Saporin-Rituximab bound to CD20 in Ramos cells and, in the absence of saponins, had a GI50 (concentration inhibiting cell growth to 50 %) of 7 nM. However, in the presence of a nontoxic concentration of saponins, the GI50 of Saporin-Rituximab was 0.01 nM, a nearly 700-fold increase in efficacy. Moreover, two further immunotoxins, namely Saporin-anti-CD22 and Saporin-anti-CD25, were tested in combination with saponins yielding enhancement factors of 170-fold and 25-fold, respectively. All three receptors are present in Ramos cells and the differences in cytotoxicity enhancement may be explained by the differing expression levels of the cellular receptors. The application of purified saponins from S. officinalis L. is therefore a new strategy to potentially improve the cytotoxicity and therapeutic efficacy of Rituximab-immunotoxins for the treatment of B-cell lymphoma.

Antibody-Mediated Blockade of Phosphatidylserine Enhances the Antitumor Effect of Sorafenib in Hepatocellular Carcinomas Xenografts.

BACKGROUND: Currently, the only FDA-approved systemic therapy for hepatocellular carcinoma (HCC) is the multi-receptor tyrosine kinase inhibitor, sorafenib, which provides only modest clinical benefit. We recently showed that treatment with a phosphatidylserine (PS) targeting agent suppresses tumor growth by targeting tumor vasculature and reactivating antitumor immunity. METHODS: We tested the hypothesis that sorafenib increases PS exposure on tumor vasculature, thereby enhancing the antitumor efficacy of PS targeting. We evaluated the efficacy of combining a PS targeting agent (2aG4) with sorafenib in murine xenograft models of human HCC. RESULTS: Our results demonstrate that combination of 2aG4 and sorafenib had a superior therapeutic effect over single agent therapy. Mechanistic studies showed that sorafenib significantly increased PS exposure on tumor vasculature; the percentage of PS-positive vessels increased from 19 to 52, 23 to 68, and 30 to 55 % in PLC/PRF/5, C3A, and Huh7 tumors, respectively. Combination therapy significantly decreased tumor microvessel density and the level of M2 macrophages, while increasing the apoptotic index of tumor endothelial cells and the frequency of M1 macrophages. Furthermore, we report the findings of a Phase I clinical study of bavituximab, a chimeric version of 2aG4, combined with sorafenib in HCC patients. The Phase I results demonstrate the appropriate dose of bavituximab to be given with sorafenib in future clinical trials. CONCLUSIONS: Overall, these results strongly support the combination of bavituximab with sorafenib as a promising systemic therapeutic strategy for the treatment for advanced HCC patients.

The preclinical discovery of rituximab for the treatment of non-Hodgkin's lymphoma.

INTRODUCTION: Monoclonal antibodies (MoAbs) were developed in the 1980s in order to treat malignancies. An important target for MoAbs was the CD20 B-cell lineage antigen. Rituximab (RTX) is a chimeric mouse anti-human MoAb that targets the CD20 antigen on the surface of malignant and normal B lymphocytes, and has rapidly become the widest used immunotherapeutic drug. RTX has had a significant impact on how B-cell non-Hodgkin's lymphomas (NHLs) and chronic lymphocytic leukemia is now treated. AREAS COVERED: In this review, the authors demonstrate the mechanisms of action of RTX, and the preclinical data that have led to clinical trials and its final approval for the treatment of B-cell NHLs. EXPERT OPINION: The discovery of RTX opened a new era for treatment of B-cell malignancies and became the starting point for the development of new, more active classes of anti-CD20 agents. Furthermore, it has contributed to the construction of a number of MoAbs specific for other antigens that target different types of neoplastic cells.

Ofatumumab Exhibits Enhanced In Vitro and In Vivo Activity Compared to Rituximab in Preclinical Models of Mantle Cell Lymphoma.

PURPOSE: Mantle cell lymphoma (MCL) is a mature B-cell lymphoma considered to be incurable with current treatments, including first-line rituximab in combination with multiagent chemotherapy and for those eligible, high-dose chemotherapy and stem cell support or rituximab maintenance. On the other hand, achieving a complete remission by high-sensitive flow cytometry is associated with prolonged duration of remission, stressing the need to develop and/or incorporate novel agents into the management of MCL. To this end, we examined the activity of ofatumumab, an anti-CD20 monoclonal antibody with distinct binding and immunologic properties compared to rituximab, in MCL preclinical models. EXPERIMENTAL DESIGN: MCL cells were labeled with (51)Cr before incubation with rituximab or ofatumumab (10 µg/mL) plus human serum or effector cells. (51)Cr-release was measured and the percentage of lysis was calculated. Surface CD20, CD55, and CD59 were measured by Imagestream analysis. SCID mice inoculated subcutaneously with Z138 cells were assigned to control versus four doses of ofatumumab or rituximab (10 mg/kg/dose). RESULTS: Ofatumumab exhibited enhanced in vitro complement-dependent cytotoxicity activity compared with rituximab in MCL cell lines, despite a high degree of in vitro resistance to rituximab associated with low CD20 levels and/or high expression of complement inhibitory proteins. Ofatumumab also delayed tumor progression and prolonged survival in a murine model of MCL. CONCLUSIONS: Our results demonstrate that ofatumumab is more effective than rituximab in MCL preclinical models, including in the presence of rituximab resistance, and support the clinical investigation of ofatumumab in combination with standard systemic chemotherapy in MCL (NCT01527149).

Thyroid-specific changes following treatment with biological therapies in patients with rheumatic diseases.

Biological anti-rheumatic agents (BAA) may induce autoimmune phenomena. Evidence on thyroid-specific effects of these agents is relatively limited. We studied prospectively, over 3 years, 36 rheumatic patients treated with BAA (18 Infliximab and 18 Rituximab) and no prior exposure to biological therapies (group-1), with respect to their thyroid function, thyroid antibody titers, and thyroid ultrasonographic parameters, such as left inferior thyroid artery peak systolic velocity (ITA PSV), left thyroid lobe vascularity index (TL VI), and echogenicity. Twenty-eight rheumatic patients treated with disease-modifying anti-rheumatic drugs and/or glucocorticoids (group-2), 21 rheumatic patients not receiving any treatment (group-3), and 49 healthy individuals (group-4) were used for comparison. Thyroid function and autoantibody titers were not significantly altered at any stage irrespectively of the administered BAA, previously unknown autoimmune thyroid disease (AITD) status, and/or concomitant treatment with glucocorticoids. Left ITA PSV was significantly increased in group-1 patients (mean ± SD start: 25.5 ± 14.1 cm/s vs. end: 29.8 ± 11.1 cm/s, p = 0.038 and p < 0.001, respectively). Six group-1, 7 group-2, and 3 group-3 patients developed reduced thyroid echogenicity during follow-up (start: p = 0.003 and end: p < 0.001). Left ITA PSV, left TL VI, and echogenicity changes were not related to alterations in thyroid volume, thyrotropin hormone levels, and/or underlying AITD. Infliximab and Rituximab do not cause any alterations in thyroid function and/or autoimmunity, even in patients with previously undiagnosed AITD. Elevated left ITA PSV and reduced thyroid echogenicity may be early features signaling progression to AITD in patients treated with BAA.

Target-directed development and preclinical characterization of the proposed biosimilar rituximab GP2013.

Biosimilar development involves a target-directed iterative process to ensure a similar product to the originator. Here we report the preclinical development of the proposed biosimilar rituximab (GP2013). Post-translational modifications and bioactivities of GP2013 versus originator rituximab were engineered and monitored to ensure similar pharmacological profiles. Antibody-dependent cellular cytotoxicity (ADCC) was used to illustrate how different glycosylation patterns and structure-function relationships were controlled during process development. Pharmacological comparability between GP2013 and originator rituximab were confirmed in preclinical studies using clinical scale drug product. Similar in vitro ADCC potency was demonstrated when compared in a dose-response manner against two lymphoma cell lines using freshly purified human natural killer (NK) cells. In vivo efficacy was demonstrated in two well characterized mouse xenograft models, testing at sensitive sub-therapeutic dose levels. Pharmacokinetics and pharmacodynamics (CD20 cell depletion) were likewise comparable in cynomolgus monkeys. This preclinical comparability exercise confirms that GP2013 and originator rituximab are pharmacologically similar.