Efficacy of Bispecific Antibody Targeting EpCAM and CD3 for Immunotherapy in Ovarian Cancer Ascites:An Experimental Study

Objective This study aimed to explore the value of M701,targeting epithelial cell adhesion molecule(EpCAM)and CD3,in the immunotherapy of ovarian cancer ascites by the in vitro assay.Methods The expression of EpCAM in ovarian cancer tissues was analyzed by databases.The EpCAM expression and immune cell infiltration in different foci of ovarian cancer were detected by 8-channel flow cytometry.The toxic effect of M701 on OVCAR3 was tested using the in vitro cytotoxicity assay.The 3D cell culture and drug intervention experiments were performed to evaluate the therapeutic effect of M701 in ovarian cancer specimens.Flow cytometry was used to examine the effect of M701 on the binding of immune cells to tumor cells and the activation capacity of T cells.Results The results of the bioinformatic analysis showed that the expression of EpCAM in ovarian cancer tissue was significantly higher than that in normal ovarian tissue.The 8-channel flow cytometry of clinical samples showed that the EpCAM expression and lymphocyte infiltration were significantly heterogeneous among ovarian cancer patients and lesions at different sites.The in vitro experiment results showed that M701 had a significant killing effect on OVCAR3 cells.M701 also obviously killed primary tumor cells derived from some patients with ovarian cancer ascites.M701 could mediate the binding of CD3^(+)T cells to EpCAM^(+)tumor cells and induce T cell activation in a dose-dependent manner.Conclusion M701 showed significant inhibitory activity on tumor cells derived from ovarian cancer ascites,which had a promising application in immunotherapy for patients with ovarian cancer ascites.

Bispecific antibody drug conjugates:Making 1+1>2

Bispecific antibody‒drug conjugates(BsADCs)represent an innovative therapeutic category amalgamating the merits of antibody‒drug conjugates(ADCs)and bispecific antibodies(BsAbs).Positioned as the next-generation ADC approach,BsADCs hold promise for ameliorating extant clinical challenges associated with ADCs,particularly pertaining to issues such as poor internalization,off-target toxicity,and drug resistance.Presently,ten BsADCs are undergoing clinical trials,and initial findings underscore the imperative for ongoing refinement.This review initially delves into specific design considerations for BsADCs,encompassing target selection,antibody formats,and the linker–payload complex.Subsequent sections delineate the extant progress and challenges encountered by BsADCs,illustrated through pertinent case studies.The amalgamation of BsAbs with ADCs offers a prospective solution to prevailing clinical limitations of ADCs.Nevertheless,the symbiotic interplay among BsAb,linker,and payload necessitates further optimizations and coordination beyond a simplistic“1+1”to effectively surmount the extant challenges facing the BsADC domain.

Characterization of a novel bispecific antibody targeting tissue factor-positive tumors with T cell engagement

T cell engaging bispecific antibody(TCB)is an effective immunotherapy for cancer treatment.Through co-targeting CD3 and tumor-associated antigen(TAA),TCB can redirect CD3+T cells to eliminate tumor cells regardless of the specificity of T cell receptor.Tissue factor(TF)is a TAA that involved in tumor progression.Here,we designed and characterized a novel TCB targeting TF(TF-TCB)for the treatment of TF-positive tumors.In vitro,robust T cell activation,tumor cell lysis and T cell proliferation were induced by TF-TCB.The tumor cell lysis activity was dependent upon both CD3 and TF binding moieties of the TF-TCB,and was related to TF expression level of tumor cells.In vivo,in both tumor cell/human peripheral blood mononuclear cells(PBMC)co-grafting model and established tumor models with poor T cell infiltration,tumor growth was strongly inhibited by TF-TCB.T cell infiltration into tumors was induced during the treatment.Furthermore,efficacy of TF-TCB was further improved by combination with immune checkpoint inhibitors.For the first time,our results validated the feasibility of using TF as a target for TCB and highlighted the potential for TF-TCB to demonstrate efficacy in solid tumor treatment.

Bispecific antibodies targeting immunomodulatory checkpoints for cancer therapy

Advances in antibody engineering have led to the generation of more innovative antibody drugs,such as bispecific antibodies(bs Abs).Following the success associated with blinatumomab,bs Abs have attracted enormous interest in the field of cancer immunotherapy.By specifically targeting two different antigens,bs Abs reduce the distance between tumor and immune cells,thereby enhancing tumor killing directly.There are several mechanisms of action upon which bs Abs have been exploited.Accumulating experience on checkpoint-based therapy has promoted the clinical transformation of bs Abs targeting immunomodulatory checkpoints.Cadonilimab(PD-1×CTLA-4)is the first approved bs Ab targeting dual inhibitory checkpoints,which confirms the feasibility of bs Abs in immunotherapy.In this review we analyzed the mechanisms by which bs Abs targeting immunomodulatory checkpoints and their emerging applications in cancer immunotherapy.

Challenges and strategies for next-generation bispecific antibody-based antitumor therapeutics

Bispecific antibodies(bsAbs)refer to a large family of molecules that recognize two different epitopes or antigens.Although a series of challenges,especially immunogenicity and chain mispairing issues,once hindered the development of bsAbs,they have been gradually overcome with the help of rapidly developing technologies in the past 5 decades.In the meantime,an increasing number of bsAb platforms have been designed to satisfy different clinical demands.Currently,numerous preclinical and clinical trials are underway,portraying a promising future for bsAb-based cancer treatment.Nevertheless,bsAb drugs still face enormous challenges in their application as cancer therapeutics,including tumor heterogeneity and mutational burden,intractable tumor microenvironment(TME),insufficient costimulatory signals to activate T cells,the necessity for continuous injection,fatal systemic side effects,and off-target toxicities to adjacent normal cells.Therefore,we provide several strategies as solutions to these issues,which comprise generating multispecific bsAbs,discovering neoantigens,combining bsAbs with other anticancer therapies,exploiting natural killer(NK)-cell-based bsAbs and producing bsAbs in situ.In this review,we mainly discuss previous and current challenges in bsAb development and underscore corresponding strategies,with a brief introduction of several typical bsAb formats.

Advanced cervix cancer patient with chemotherapy-induced grade IV myelosuppression achieved complete remission with cadonilimab:A case report

BACKGROUND The prognosis for patients with advanced metastatic cervix cancer(MCC)is poor,and this disease continues to pose a considerable therapeutic challenge.Despite the administration of first-line regimens consisting of cisplatin,paclitaxel,and bevacizumab,survival rates for patients with metastasis remain poor.The emergence of bispecific antibodies(BsAbs)offers a novel treatment option for patients diagnosed with MCC.CASE SUMMARY In this report,we present a patient with MCC who was treated with cadonilimab monotherapy at a dose of 6 mg/kg every two weeks after chemotherapy was proven to be intolerable.The patient exhibited a sustained complete response for a duration of 6 months,demonstrating an optimistic outlook.CONCLUSION This case illustrates the considerable efficacy of cadonilimab for treating advanced MCC.Therefore,BsAb therapy is a promising strategy for effectively treating patients with advanced MCC and should be considered as an option when patients are intolerant to standard chemotherapy.

Selection for Anti-transferrin Receptor Bispecific T-cell Engager in Different Molecular Formats

Selecting an ideal molecular format from diverse structures is a major challenge in developing a bispecific antibody(BsAb).To choose an ideal format of anti-CD3 x anti-transferrin receptor(TfR)bispecific antibodies for clinical application,we constructed TfR bispecific T-cell engager(BiTE)in two extensively applied formats,including single-chain tandem singlechain variable fragments(scFvs)and double-chain diabodies,and evaluated their functional characterizations in vitro.Results demonstrated that TfR-BiTE in both formats directed potent killing of TfR+HepG2 cells.However,compared to two・chain diabodies,scFvs were more efficient in antigen binding and TfR target killing.Furthermore,different domain orders in scFvs would also be evaluated because single-TfR-CD3-His was preferable to single-CD3-TfR-His in immunotherapeutic strategies.Thus,the single-chain tandem TfR-CD3 format was favored for further investigation in cancer therapy.

Preparation and Characterization for Bispecific Antibodies of Anti-CD3×Anti-Idiotype to BCellLym phocytic Leukem ia

Bispecific antibodies (BsAbs) of anti CD3×anti idiotype (Id) to B cell lymphocytic leukemia (CLL) were prepared by chemical conjugation and direct hybridization technique of hybridoma and hybridoma without screening markers. The specificity of BsAbs from culture supernatants or ascites was assayed by indirect ELISA and indirect immunoflurescence (IF). The results showed that BsAbs could specifically react with homologous serum IgM from patients with B CLL and cells carrying CD3 marker respectively. Cell combination test and LDH assay demonstrated that BsAb significantly increased the conjugate formation between lymphocyte activated kill (LAK) cells and Daudi cells, and enhanced the cytotoxic activity of LAK cells against Daudi cells.

Construction,expression and binding specificity of bispecific CD3×VEGFR-2 and CD3×NCAM antibodies in the single chain and diabody format

Bispecific antibodies are recombinant proteins with novel immunological properties and therapeutic potential. Recombinant protein quality and activity of several bispecific antibodies comprising different variable domain combinations with respect to the parental monospecific single chain fragments (scFv) were evaluated after expression in bacteria or mammalian cells. The parental scFv proteins humanized anti-NCAM scFv, murine anti-VEGFR-2 scFv, murine and humanized anti-CD3 scFv, respectively, could successfully be expressed in E. coli, whereas the murine anti-NCAM scFv version could not be reliably detected. Bispecific CD3 × VEGFR-2 and CD3 × NCAM anti-bodies were expressed in the bispecific single chain and the single chain diabody format. However, the diabody derived from the murine anti-NCAM scFv could not efficiently be expressed in E. coli or in mammalian cells. Significant binding of the CD3 × NCAM single chain diabody comprising the humanized version of anti-CD3 and humanized version of anti-NCAM was efficient to both antigens. Nevertheless, binding of the bispecific single chain version to the NCAM antigen was inefficient in comparison to CD3 binding. In conclusion, the data could indicate that the result of scFv expression in bacteria may be predictive for the chances of success for functional expression of more complex bispecific derivatives.

Recent advances in treatment of nodal and gastrointestinal follicular lymphoma

Follicular lymphoma(FL)is the most common low-grade lymphoma,and although nodal FL is highly responsive to treatment,the majority of patients relapse repeatedly,and the disease has been incurable with a poor prognosis.However,primary FL of the gastrointestinal tract has been increasingly detected in Japan,especially due to recent advances in small bowel endoscopy and increased opportunities for endoscopic examinations and endoscopic diagnosis.However,many cases are detected at an early stage,and the prognosis is good in many cases.In contrast,in Europe and the United States,gastrointestinal FL has long been considered to be present in 12%-24%of Stage-IV patients,and the number of advanced gastrointestinal cases is expected to increase.This editorial provides an overview of the recent therapeutic advances in nodal FL,including antibody-targeted therapy,bispecific antibody therapy,epigenetic modulation,and chimeric antigen receptor T-cell therapy,and reviews the latest therapeutic manuscripts published in the past year.Based on an understanding of the therapeutic advances in nodal FL,we also discuss future possibilities for gastroenterologists to treat gastrointestinal FL,especially in advanced cases.

SPECT imaging of distribution and retention of a brain-penetrating bispecific amyloid-β antibody in a mouse model of Alzheimer's disease

Background:Alzheimer's disease(AD)immunotherapy with antibodies targeting amyloid-B(AB)has been extensively explored in clinical trials.The aim of this study was to study the long-term brain distribution of two radiolabeled monoclonal Aβ antibody variants-RmAb158,the recombinant murine version of BAN2401,which has recently demonstrated amyloid removal and reduced cognitive decline in AD patients,and the bispecific RmAb158-scFv8D3,which has been engineered for enhanced brain uptake via transferrin receptor-mediated transcytosis.Methods:A single intravenous injection of iodine-125(251)-labeled RmAb158-scFv8D3 or RmAb158 was administered to AD transgenic mice(tg-ArcSwe).In vivo single photon emission computed tomography was used to investigate brain retention and intrabrain distribution of the antibodies over a period of 4 weeks.Activity in blood and brain tissue was measured ex vivo and autoradiography was performed in combination with Aβand CD31 immunostaining to investigate the intrabrain distribution of the antibodies and their interactions with AB.Results:Despite faster blood clearance,[125]RmAb158-scFv8D3 displayed higher brain exposure than[25]RmAb158 throughout the study.The brain distribution of[l25]RmAb158-scFv8D3 was more uniform and coincided with parenchymal Aβ pathology,while[2 I]RmAb158 displayed a more scattered distribution pattern and accumulated in central parts of the brain at later times.Ex vivo autoradiography indicated greater vascular escape and parenchymal Aβ interactions for[25]RmAb158-scFv8D3,whereas[25]RmAb158 displayed retention and Aβ interactions in lateral ventricles.Conclusions:The high brain uptake and uniform intrabrain distribution of RmAb158-scFv8D3 highlight the benefits of receptor-mediated transcytosis for antibody-based brain imaging.Moreover,it suggests that the alternative transport route of the bispecific antibody contributes to improved efficacy of brain-directed immunotherapy.

Cerebrospinal fluid and blood biomarkers in the diagnostic assays of Alzheimer's disease

The anti-amyloid-j(anti-Aβ)fibrils and soluble oligomers antibody aducanumab were approved to effectively slow down the progression of A lzheimer's disease(AD)at higher doses in 2019,reaffirming the therapeutic effects of targeting the core pathology of AD.A timely and accurate diagnosis in the prodromal or pre-dementia stage of AD is essential for patient recruitment,stratifcation,and monitoring of treat ment effects.A D core biomarkers amyloid-B(Aβ1-42),total tau(t-tau),and phosphorylated tau(p-tau)have been clinically validated to reflect AD-type pathological changes through cerebrospinal fuid(CSF)measurement or positron-emission to-mography(PET)and found to have high diagnostic performance for AD identification in the stage of mild cognitive impairment.The development of ultrasensitive immunoassay technology enables AD pathological proteins such as tau and neurofilament light(NFL)to be measured in blood samples.However,combined biomarker detection or targeting multiple biomarkers in immunoassays will increase detection sensitivity and specifcity and improve diagnostic accuracy..This review summarizes and analyzes the performance of current detection methods for early diagnosis of AD,and provides a concept of detection method based on multiple biomarkers instead of a single target,which may become a potential tool for early diagnosis of AD in the future.

Modified Therapeutic Antibodies: Improving Efficacy

The prosperity of the biotherapeutics market reflects the feasibility and effectiveness of therapeutic antibodies for the treatment of cancers,inflammatory disorders,and refractory infections.As drawbacks emerge in clinical trials and practice,such as impeded binding,reduced effector functions,and frequent adverse reactions,modifications of therapeutic antibodies are unprecedently burgeoning in research and development(R&D).These modifications include:①modified glycosylation;②fragment of crystallizable domain(Fc)amino acid alterations;③cross-isotype or cross-subclass exchanges;④antibody–drug conjugates(ADCs);⑤single chain of variable region fragment(scFv)for chimeric antigen receptor T(CAR-T)cells;and⑥bispecific antibodies(bsAbs)in order to promote binding affinity,half-life in circulation,effectiveness toward target cells and,ultimately,to achieve overall improved efficacy.While many achievements have been made around the world in the past decades,China has been playing an active role in this realm,with its great demand for biotherapeutics with R&D potential.This review recapitulates the international progress that has been achieved with modified therapeutic antibodies,and then focuses on that of China in an independent section.

Bispecific antibodies in cancer therapy:Target selection and regulatory requirements

In recent years,the development of bispecific antibodies(bsAbs)has been rapid,with many new structures and target combinations being created.The boom in bsAbs has led to the successive issuance of industry guidance for their development in the US and China.However,there is a high degree of similarity in target selection,which could affect the development of diversity in bsAbs.This review presents a classification of various bsAbs for cancer therapy based on structure and target selection and examines the advantages of bsAbs over monoclonal antibodies(mAbs).Through database research,we have identified the preferences of available bsAbs combinations,suggesting rational target selection options and warning of potential wastage of medical resources.We have also compared the US and Chinese guidelines for bsAbs in order to provide a reference for their development.

Current status and future perspectives of bispecific antibodies in the treatment of lung cancer

Monoclonal antibodies have been successfully incorporated into the current therapeutical landscape of lung cancer in the last decades.Recently,with technological advances,bispecific antibodies(bsAbs)have also shown robust efficacy in the treatment of malignant cancers,including lung cancer.These antibodies target two independent epitopes or antigens and have been extensively explored in translational and clinical studies in lung cancer.Here,we outline the mechanisms of action of bsAbs,related clinical data,ongoing clinical trials,and potent novel compounds of various types of bsAbs in clinical studies,especially in lung cancer.We also propose future directions for the clinical development of bsAbs,which might bring a new era of treatment for patients with lung cancer.

Current status of novel biologics and small molecule drugs in the individualized treatment of inflammatory bowel disease

Treatment strategies for inflammatory bowel disease(IBD)are rapidly evolving with the development of biologics and small molecule drugs(SMDs).However,these drugs are not guaranteed to be effective in all patients,and a“ceiling effect”of biologic monotherapy may occur.This issue highlights an unmet need for optimizing the use of biologics and predicting therapeutic responses.Thus,the development of new drugs with novel mechanisms of action is urgently needed for patients with primary nonresponse and secondary loss of response to conventional biologics and SMDs.In addition,combining different biologics or SMDs has been proposed as a novel strategy to enhance treatment efficacy in IBD,which theoretically has multidimensional anti-inflammatory potential.Based on the current evidence available for IBD,dual targeted therapy may be a promising strategy for refractory IBD patients who have failed in multiple biologic treatments or who have extraintestinal manifestation.Additionally,identifying the subgroup of IBD patients who are responding to biological combination therapies is also equally important in stable disease remission.In this review,we summarize the newly developed biologics and SMDs and the current status of biologics/SMDs to highlight the development of individualized treatment in IBD.

Preclinical characterization and comparison between CD3/CD19 bispecific and novel CD3/CD19/CD20 trispecific antibodies against B-cell acute lymphoblastic leukemia:targeted immunotherapy for acute lymphoblastic leukemia

The CD19-targeting bispecific T-cell engager blinatumomab has shown remarkable efficacy in patients with relapsed/refractory B-cell precursor acute lymphoblastic leukemia.However,several studies showed that blinatumomab has a short plasma half-life due to its low molecular weight,and thus its clinical use is limited.Furthermore,multiple trials have shown that approximately 30%of blinatumomab-relapsed cases are characterized by CD19 negative leukemic cells.Here,we design and characterize two novel antibodies,A-319 and A-2019.Blinatumomab and A-319 are CD3/CD19 bispecific antibodies with different molecular sizes and structures,and A-2019 is a novel CD3/CD19/CD20 trispecific antibody with an additional anti-CD20 function.Our in vitro,ex vivo,and in vivo experiments demonstrated that A-319 and A-2019 are potent antitumor agents and capable of recruiting CD3 positive T cells,enhancing T-cell function,mediating B-cell depletion,and eventually inhibiting tumor growth in Raji xenograft models.The two molecules are complementary in terms of efficacy and specificity profile.The activity of A-319 demonstrated superior to that of A-2019,whereas A-2019 has an additional capability to target CD20 in cells missing CD19,suggesting its potential function against CD19 weak or negative CD20 positive leukemic cells.

Targeting tumor microenvironment for non-small cell lung cancer immunotherapy

The tumor microenvironment(TME)is composed of different cellular and non-cellular elements.Constant inter-actions between tumor cells and the TME are responsible for tumor initiation,tumor progression,and responses to therapies.Immune cells in the TME can be classified into two broad categories,namely adaptive and innate immunity.Targeting these immune cells has attracted substantial research and clinical interest.Current research focuses on identifying key molecular players and developing targeted therapies.These approaches may offer more efficient ways of treating different cancers.In this review,we explore the heterogeneity of the TME in non-small cell lung cancer,summarize progress made in targeting the TME in preclinical and clinical studies,discuss the potential predictive value of the TME in immunotherapy,and highlight the promising effects of bispecific antibodies in the era of immunotherapy.

Building on the backbone of CD47-based therapy in cancer:Combination strategies,mechanisms,and future perspectives

Described as a“don't eat me”signal,CD47 becomes a vital immune checkpoint in cancer.Its interaction with signal regulatory protein alpha(SIRPa)prevents macrophage phagocytosis.In recent years,a growing body of evidences have unveiled that CD47-based combination therapy exhibits a superior anti-cancer effect.Latest clinical trials about CD47 have adopted the regimen of collaborating with other therapies or developing CD47-directed bispecific antibodies,indicating the combination strategy as a general trend of the future.In this review,clinical and preclinical cases about the current combination strategies targeting CD47 are collected,their underlying mechanisms of action are discussed,and ideas from future perspectives are shared.

Emerging immunological strategies: recent advances and future directions

mmunotherapy plays a compelling role in cancer treatment and has already made remarkable progress.However,many patients receiving immune checkpoint inhibitors fail to achieve clinical benefits,and the response rates vary among tumor types.New approaches that promote anti-tumor immunity have recently been developed,such as small molecules,bispecific antibodies,chimeric antigen receptor T cell products,and cancer vaccines.Small molecule drugs include agonists and inhibitors that can reach the intracellular or extracellular targets of immune cells participating in innate or adaptive immune pathways.Bispecific antibodies,which bind two different antigens or one antigen with two different epitopes,are of great interest.Chimeric antigen receptor T cell products and cancer vaccines have also been investigated.This review explores the recent progress and challenges of different forms of immunotherapy agents and provides an insight into future immunotherapeutic strategies.