Objective To prepare CD318-specific monoclonal antibodies and evaluate their specificity, affinity, and application in immunological detection, laying the foundation for the development of CD318-targeted antibody drugs. MethodsCD318 protein was expressed and purified, and was used as an antigen to immunize mice, then mice with higher antiserum titers were screened. We prepared CD318-specific monoclonal antibodies through cell fusion and monoclonal screening, and the specificity, affinity, and application of the obtained monoclonal antibodies in immunological assays were evaluated. Then we constructed a CD318/CD3-targeting bispecific antibody and assessed its impact on T-cell cytotoxicity. Results Thirteen monoclonal antibodies were successfully generated, with the hybridoma clone 13-8-G2 exhibiting the highest titer, strongest specificity, and broadest applicability. The antibody was identified as an IgG1 isotype with a kappa light chain. The variable region of the light chain measured 318 bp, while the heavy chain variable region was 357 bp, yielding an affinity constant of approximately 7.68×10⁹. The specificity of CD318 was confirmed using flow cytometry and immunofluorescence assays. Additionally, a CD318/CD3-targeting bispecific antibody was constructed using the variable regions of this CD318 monoclonal antibody, which demonstrated enhanced T-cell cytotoxicity. Conclusion High-affinity and highly specific CD318 monoclonal antibodies were successfully prepared, laying a foundation for the development of therapeutic antibodies targeting CD318.
Animals ; Antibodies, Monoclonal/biosynthesis* ; Mice ; Antibodies, Bispecific/immunology* ; Humans ; Mice, Inbred BALB C ; Antibody Specificity/immunology* ; CD3 Complex/immunology* ; Antigens, CD/genetics* ; T-Lymphocytes/immunology* ; Hybridomas/immunology* ; Female

OBJECTIVES: To investigate the application value of thromboelastography (TEG) in assessing coagulation function in children with severe hemophilia A (HA) after emicizumab (EMI) therapy. METHODS: A retrospective analysis was performed on the activated partial thromboplastin time (APTT) and TEG testing results of 17 children with severe HA before and after EMI treatment at Shenzhen Children's Hospital from January 2023 to July 2024. Correlation analysis was conducted between coagulation factor VIII (FVIII) equivalent activity and reaction time (R value) measured by TEG. RESULTS: After EMI treatment, the mean bleeding rate for children with severe HA was 1.6 events per year, with 15 children (88%) without spontaneous bleeding or joint bleeding. The children with severe HA showed a significant reduction in APTT after EMI treatment (P<0.05), with a significantly shorter APTT than the normal control group (P<0.05). There was no correlation between APTT and FVIII equivalent activity after treatment (P>0.05). After EMI treatment, TEG parameters, including R value, kinetic time, alpha angle (α), maximum amplitude, clot strength, and coagulation index, shifted from a hypocoagulable state before treatment to a nearly normal state after treatment (P<0.05). The R value demonstrated a strong negative correlation with FVIII equivalent activity (r=-0.758, P<0.05). CONCLUSIONS The bleeding condition of children with severe HA can be effectively controlled after EMI treatment. Routine APTT testing cannot reflect true coagulation function, whereas TEG testing is clinically valuable in assessing the coagulation function of children with severe HA undergoing EMI treatment.
Humans ; Thrombelastography ; Hemophilia A/physiopathology* ; Male ; Child ; Antibodies, Bispecific/therapeutic use* ; Antibodies, Monoclonal, Humanized/therapeutic use* ; Blood Coagulation/drug effects* ; Child, Preschool ; Retrospective Studies ; Female ; Partial Thromboplastin Time ; Adolescent ; Infant

OBJECTIVE: To retrospectively analyze the clinical characteristics of 15 children with B-cell acute lymphoblastic leukemia (B-ALL) treated with blinatumomab, and summarize the efficacy and safety of blinatumomab in the treatment of pediatric B-ALL. METHODS: Fifteen children who received treatment with blinatumomab from February 2022 to January 2023 were enrolled in this study. One course (28 days) of blinatumomab concurrent with intrathecal chemotherapy was given according to the standard regimen, except for 2 cases who had shortened course of treatment due to hematopoietic stem cell transplantation (HSCT) and did not receive combined intrathecal chemotherapy, and 1 case had a shortened course of treatment due to economic problems. The efficacy and safety of the treatment were evaluated. RESULTS: In terms of efficacy, for the children who had achieved complete molecular remission (CMR) before treatment, blinatumomab treatment could effectively maintain CMR status; For the children who did not achieve CMR, the CMR rate after one standard course of treatment with blinatumomab reached 66.7%(4/6); For the children with relapsed/refractory ALL (R/R ALL) who had minimal residual disease (MRD), the MRD clearance rate reached 75.0%(3/4). The statistical results of the incidence of adverse events showed that 13.3%(2/15) of the children did not experience any adverse events. The most common adverse events were cytokine release syndrome (CRS) (73.3%, 11/15) and transaminase elevation (26.7%, 4/15); 33.3%(5/15) of the children experienced grade 3 or higher adverse events. All the adverse events were resolved after symptomatic treatment.The level of IgG decreased significantly after 4-7 weeks of treatment with blinatumomab, and gradually recovered after 8 weeks of treatment. CONCLUSION Blinatumomab can be used as a safe and effective treatment for inducing deep remission in pediatric R/R-ALL patients and as a bridge therapy for the pediatric ALL patients who are intolerant to chemotherapy.
Humans ; Antibodies, Bispecific/therapeutic use* ; Child ; Retrospective Studies ; Female ; Male ; Precursor Cell Lymphoblastic Leukemia-Lymphoma/drug therapy* ; Remission Induction ; Treatment Outcome ; Child, Preschool ; Adolescent ; Precursor B-Cell Lymphoblastic Leukemia-Lymphoma/drug therapy*

Bispecific antibody drugs have enhanced efficacy and safety compared with therapeutic monoclonal antibody drugs, gradually becoming a new generation of effective therapies. With the development of genetic engineering and the maturity of the industry, increasing studies have been carried out on bispecific and multi-specific antibody drugs, and the application indications of these drugs are expanding, which lays a foundation for satisfying the clinical needs and creating clinical values. This paper provides a comprehensive review of the development stages, indications, target combinations, structural formats, and mechanisms of bispecific and multi-specific antibody drugs. It also discusses key points and strategies for differentiated drug discovery, facilitating the rapid development of innovative therapies, providing theoretical support for the clinical translation of these drugs, and offering more precise and effective treatment options for clinical practice.
Antibodies, Bispecific/biosynthesis* ; Humans ; Drug Discovery ; Antibodies, Monoclonal/biosynthesis*

This article reports two cases of children with B-cell acute lymphoblastic leukemia (B-ALL) complicated by invasive fungal disease (IFD) who received bridging treatment using blinatumomab. Case 1 was a 4-month-old female infant who experienced recurrent high fever and limb weakness during chemotherapy. Blood culture was negative, and next-generation sequencing (NGS) of peripheral blood, bronchoalveolar lavage fluid, and cerebrospinal fluid were all negative. Chest CT and cranial MRI revealed obvious infection foci. Case 2 was a 2-year-old male patient who experienced recurrent high fever with multiple inflammatory masses during chemotherapy. Candida tropicalis was detected in peripheral blood and abscess fluid using NGS, while blood culture and imaging examinations showed no obvious abnormalities. After antifungal and blinatumomab therapy, both cases showed significant improvement in symptoms, signs, and imaging, and B-ALL remained in continuous remission. The report indicates that bridging treatment with blinatumomab in children with B-ALL complicated by IFD can rebuild the immune system and control the underlying disease in the presence of immunosuppression and severe fungal infection.
Child, Preschool ; Female ; Humans ; Infant ; Male ; Antibodies, Bispecific/therapeutic use* ; Invasive Fungal Infections/drug therapy* ; Precursor B-Cell Lymphoblastic Leukemia-Lymphoma/drug therapy* ; Remission Induction

OBJECTIVES: To study the safety and short-term effectiveness of blinatumomab in the treatment of childhood relapsed/refractory acute lymphoblastic leukemia (R/R-ALL). METHODS: Six children with R/R-ALL who received blinatumomab treatment from August 2021 to August 2022 were included as subjects, and a retrospective analysis was performed for their clinical data. RESULTS: Among the six children, there were three boys and three girls, with a median age of 10.5 (5.0-13.0) years at the time of inclusion. Of all six children, one had refractory ALL and did not achieve remission after several times of chemotherapy, and 5 relapsed for the first time, with a median time of 30 (9-60) months from diagnosis to relapse. Minimal residual disease (MRD) before treatment was 15.50% (0.08%-78.30%). Three children achieved complete remission after treatment, among whom two had negative conversion of MRD. Five children had cytokine release syndrome (CRS), among whom 3 had grade 1 CRS and 2 had grade 2 CRS. Four children were bridged to allogeneic hematopoietic stem cell transplantation, with a median interval of 50 (40-70) days from blinatumomab treatment to transplantation. The six children were followed up for a median time of 170 days, and the results showed an overall survival rate of 41.7% (95%CI: 5.6%-76.7%) and a median survival time of 126 (95%CI: 53-199) days. CONCLUSIONS Blinatumomab has good short-term safety and effectiveness in the treatment of childhood R/R-ALL, and its long-term effectiveness needs to be confirmed by studies with a larger sample size.
Male ; Child ; Female ; Humans ; Adolescent ; Antineoplastic Agents ; Retrospective Studies ; Precursor B-Cell Lymphoblastic Leukemia-Lymphoma/drug therapy* ; Antibodies, Bispecific/adverse effects*

Humans ; Antibodies, Bispecific/therapeutic use* ; Hematologic Neoplasms/therapy* ; Immunotherapy ; Neoplasms

Humans ; Treatment Outcome ; Antibodies, Bispecific/adverse effects* ; Precursor Cell Lymphoblastic Leukemia-Lymphoma/drug therapy* ; Antineoplastic Agents/adverse effects* ; Precursor B-Cell Lymphoblastic Leukemia-Lymphoma

The drugs of programmed cell death 1 and its ligand 1 immune checkpoint inhibitors have ushered in a new era of anti-tumor immunotherapy, which has shown outstanding efficacy in some tumors, such as Hodgkin lymphoma, but there is still low response rate in some kinds of tumors. In recent years, bispecific antibodies prepared by cell fusion, recombinant DNA, protein engineering and other technologies can specifically bind two antigens or epitopes at the same time or successively, play a synergistic role in tumor treatment, can effectively inhibit tumor immune escape, and improve the effect of anti-tumor treatment has become a hot spot in tumor research. This paper will summarize the clinical research and development of bispecific antibodies, to provide reference for the industry.
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Antibodies, Bispecific/therapeutic use* ; Antineoplastic Agents ; DNA, Recombinant ; Epitopes ; Humans ; Immune Checkpoint Inhibitors ; Immunotherapy ; Ligands ; Lung Neoplasms/drug therapy* ; Neoplasms ; Research

BACKGROUND: Epidermal growth factor receptor (EGFR) and cellular-mesenchymal to epithelial transition factor (c-Met) are widely expressed on cancer cells. There is a synergistic effect of EGFR and HGF/c-Met pathways on proliferation, downstream activation of signal transduction and an additive effect. Studies show that combination of both signaling pathways could potentially be targeted in a synergistic fashion. Amivantamab, a bispecific monoclonal antibody targeting EGFR and c-Met, yielded robust and durable responses in a variety of clinicals trials. However, few researches have reported its efficacy in Chinese non-small cell lung cancer (NSCLC) patients. This study was conducted to evaluate the effectiveness and tolerance of Amivantamab in NSCLC patients with EGFR/MET gene abnormalities at Peking University Cancer Hospital. METHODS: The study enrolled NSCLC patients who received Amivantamab in our hospital between August 2020 and December 2021, and analyzed the response, survival, and treatment-related adverse events. RESULTS: Fifteen patients were enrolled in this research, and six of them received Amivantamab treatment and the other nine patients received Amivantamab plus Lazertinib treatment. The rates of partial response (PR), stable disease (SD), and progressive disease (PD) were 46.7% (7/15), 46.7% (7/15) and 6.7% (1/15), respectively. The overall response rate (ORR) and disease control rate (DCR) were 28.6% (2/7) and 100.0% (7/7) in seven patients with EGFR exon 20 insertion, respectively. The ORR and DCR were 40.0% (2/5) and 100.0% (5/5) in five post-osimertinib EGFR-mutant patients, respectively. After a median follow-up of 8.7 months, the median progression-free survival and overall survival were not reached. The most common treatment-related adverse events were rash (86.7%), paronychia (80.0%), and infusion-related reactions (60.0%), and most of them were graded as 1 to 2. Grade 3 to 4 adverse events included rash (33.3%), alanine aminotransferase elevation (13.3%), gamma-glutamyl transpeptidase elevation (13.3%), peripheral edema (6.7%), thromboembolism (6.7%), interstitial lung disease (6.7%), and thrombocytopenia (6.7%). CONCLUSIONS Amivantamab was effective in Chinese NSCLC patients with EGFR exon 20 insertion and post-Osimertinib EGFR-mutant patients, similar to the results of clinical trials conducted in western countries. Amivantamab was well tolerated and emphases should be put on adverse events such as rash, paronychia, and infusion-related reactions.
Antibodies, Bispecific ; Carcinoma, Non-Small-Cell Lung/genetics* ; ErbB Receptors/genetics* ; Exanthema/drug therapy* ; Humans ; Lung Neoplasms/genetics* ; Mutation ; Paronychia/drug therapy* ; Protein Kinase Inhibitors/therapeutic use*