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Radiolabeled small-molecule DOTA-haptens can be combined with antitumor/anti-DOTA bispecific antibodies (BsAbs) for pretargeted radioimmunotherapy (PRIT). For optimized delivery of the theranostic γ- and ß-emitting isotope 177Lu with DOTA-based PRIT (DOTA-PRIT), bivalent Gemini (DOTA-Bn-thiourea-PEG4-thiourea-Bn-DOTA, aka (3,6,9,12-tetraoxatetradecane-1,14-diyl)bis(DOTA-benzyl thiourea)) was developed. Methods: Gemini was synthesized by linking 2 S-2-(4-isothiocyanatobenzyl)-DOTA molecules together via a 1,14-diamino-PEG4 linker. [177Lu]Lu-Gemini was prepared with no-carrier-added 177LuCl3 to a molar-specific activity of 123 GBq/µmol and radiochemical purity of more than 99%. The specificity of BsAb-177Lu-Gemini was verified in vitro. Subsequently, we evaluated biodistribution and whole-body clearance for [177Lu]Lu-Gemini and, for comparison, our gold-standard monovalent [177Lu]Lu-S-2-(4-aminobenzyl)-DOTA ([177Lu]Lu-DOTA-Bn) in naïve (tumor-free) athymic nude mice. For our proof-of-concept system, a 3-step pretargeting approach was performed with an established DOTA-PRIT regimen (anti-GPA33/anti-DOTA IgG-scFv BsAb, a clearing agent, and [177Lu]Lu-Gemini) in mouse models. Results: Initial in vivo studies showed that [177Lu]Lu-Gemini behaved similarly to [177Lu]Lu-DOTA-Bn, with almost identical blood and whole-body clearance kinetics, as well as biodistribution and mouse kidney dosimetry. Pretargeting [177Lu]Lu-Gemini to GPA33-expressing SW1222 human colorectal xenografts was highly effective, leading to absorbed doses of [177Lu]Lu-Gemini for blood, tumor, liver, spleen, and kidneys of 3.99, 455, 6.93, 5.36, and 14.0 cGy/MBq, respectively. Tumor-to-normal tissue absorbed-dose ratios (i.e., therapeutic indices [TIs]) for the blood and kidneys were 114 and 33, respectively. In addition, we demonstrate that the use of bivalent [177Lu]Lu-Gemini in DOTA-PRIT leads to improved TIs and augmented [177Lu]Lu-Gemini tumor uptake and retention in comparison to monovalent [177Lu]Lu-DOTA-Bn. Finally, we established efficacy in SW1222 tumor-bearing mice, demonstrating that a single injection of anti-GPA33 DOTA-PRIT with 44 MBq (1.2 mCi) of [177Lu]Lu-Gemini (estimated tumor-absorbed dose, 200 Gy) induced complete responses in 5 of 5 animals and a histologic cure in 2 of 5 (40%) animals. Moreover, a significant increase in survival compared with nontreated controls was noted (maximum tolerated dose not reached). Conclusion: We have developed a bivalent DOTA-radiohapten, [177Lu]Lu-Gemini, that showed improved radiopharmacology for DOTA-PRIT application. The use of bivalent [177Lu]Lu-Gemini in DOTA-PRIT, as opposed to monovalent [177Lu]Lu-DOTA-Bn, allows curative treatments with considerably less administered 177Lu activity while still achieving high TIs for both the blood (>100) and the kidneys (>30).
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Immunotherapy has emerged as an attractive option for patients with relapsed or refractory high-risk neuroblastoma (HRNB). Neuroblastoma (NB), a sympathetic nervous system cancer arising from an embryonic neural crest cell, is heterogeneous clinically, with outcomes ranging from an isolated abdominal mass that spontaneously regresses to a widely metastatic disease with cure rates of about 50% despite intensive multimodal treatment. Risk group stratification and stage-adapted therapy to achieve cure with minimal toxicities have accomplished major milestones. Targeted immunotherapeutic approaches including monoclonal antibodies, vaccines, adoptive cellular therapies, their combinations, and their integration into standard of care are attractive therapeutic options, although curative challenges and toxicity concerns remain. In this review, we provide an overview of immune approaches to NB and the tumor microenvironment (TME) within the clinical translational framework. We propose a novel T cell-based therapeutic approach that leverages the unique properties of tumor surface antigens such as ganglioside GD2, incorporating specific monoclonal antibodies and recent advancements in adoptive cell therapy.
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Children are surviving cancer in greater numbers than ever. Over the last 50 years, substantial advancements in pediatric cancer treatment have resulted in an 85% 5-year survival rate. Nonetheless, a notable 10%-15% of patients encounter relapse or develop refractory disease, leading to significantly lower survival. Recent attempts to further intensify cytotoxic chemotherapy have failed due to either severe toxicities or ineffectiveness, highlighting the need for new treatment strategies. Immunotherapies are emerging and expanding their clinical application to a wide array of cancers, including those affecting children. In pediatric cancers, monoclonal antibodies targeting GD2 have demonstrated durable radiographic and histologic responses in neuroblastoma (NB), and CD19-targeted bispecific antibodies (BsAbs) and chimeric antigen receptor (CAR) T cells have likewise changed the outlook for refractory acute lymphoblastic leukemia (ALL) in children. This review discusses the clinical development of immunotherapies for pediatric cancers, focusing on pediatric ALL and NB, two major pediatric cancers transformed by immunotherapy, updates on the recent advancements in immunotherapies, and further discusses the future directions of immunotherapy for pediatric cancers.
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INTRODUCTION: Data on ovarian function in neuroblastoma survivors are limited. We sought to determine the prevalence of ovarian dysfunction in a cohort of high-risk neuroblastoma survivors and compare outcomes among survivors treated with and without autologous stem cell rescue (ASCR) preceded by myeloablative chemotherapy. METHODS: Retrospective review of female survivors of high-risk neuroblastoma ≥5 years from diagnosis, diagnosed between 1982 and 2014, and followed in a tertiary cancer center. Participants were divided into two groups: individuals treated with conventional chemotherapy ± radiation ("non-ASCR") (n = 32) or with chemotherapy ± radiation followed by myeloablative chemotherapy with ASCR ("ASCR") (n = 51). Ovarian dysfunction was defined as follicle-stimulating hormone ≥15 mU/mL, while premature ovarian insufficiency (POI) was defined as persistent ovarian dysfunction requiring hormone replacement therapy. Poisson models were used to determine prevalence ratios of ovarian dysfunction and POI. RESULTS: Among 83 females (median attained age: 19 years [range, 10-36]; median follow-up: 15 years [range, 7-36]), 49 (59%) had ovarian dysfunction, and 34 (41%) developed POI. Survivors treated with ASCR were 3.2-fold more likely to develop ovarian dysfunction (95% CI: 1.8-6.0; p < 0.001) and 4.5-fold more likely to develop POI (95% CI: 1.7-11.7; p = 0.002) when compared with those treated with conventional chemotherapy, after adjusting for attained age. Two participants in the non-ASCR group and six in the ASCR group achieved at least one spontaneous pregnancy. DISCUSSION: Ovarian dysfunction is prevalent in female high-risk neuroblastoma survivors, especially after ASCR. Longitudinal follow-up of larger cohorts is needed to inform counseling about the risk of impaired ovarian function after neuroblastoma therapy.
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Sobreviventes de Câncer , Neuroblastoma , Insuficiência Ovariana Primária , Humanos , Feminino , Neuroblastoma/terapia , Adolescente , Estudos Retrospectivos , Sobreviventes de Câncer/estatística & dados numéricos , Adulto , Criança , Adulto Jovem , Insuficiência Ovariana Primária/epidemiologia , Insuficiência Ovariana Primária/etiologia , Insuficiência Ovariana Primária/induzido quimicamente , Seguimentos , Ovário/efeitos dos fármacos , Ovário/fisiopatologia , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Transplante AutólogoRESUMO
BACKGROUND: EGFR and/or HER2 expression in pancreatic cancers is correlated with poor prognoses. We generated homodimeric (EGFRxEGFR or HER2xHER2) and heterodimeric (EGFRxHER2) T cell-engaging bispecific antibodies (T-BsAbs) to direct polyclonal T cells to these antigens on pancreatic tumors. METHODS: EGFR and HER2 T-BsAbs were constructed using the 2 + 2 IgG-[L]-scFv T-BsAbs format bearing two anti-CD3 scFvs attached to the light chains of an IgG to engage T cells while retaining bivalent binding to tumor antigens with both Fab arms. A Fab arm exchange strategy was used to generate EGFRxHER2 heterodimeric T-BsAb carrying one Fab specific for EGFR and one for HER2. EGFR and HER2 T-BsAbs were also heterodimerized with a CD33 control T-BsAb to generate 'tumor-monovalent' EGFRxCD33 and HER2xCD33 T-BsAbs. T-BsAb avidity for tumor cells was studied by flow cytometry, cytotoxicity by T-cell mediated 51Chromium release, and in vivo efficacy against cell line-derived xenografts (CDX) or patient-derived xenografts (PDX). Tumor infiltration by T cells transduced with luciferase reporter was quantified by bioluminescence. RESULTS: The EGFRxEGFR, HER2xHER2, and EGFRxHER2 T-BsAbs demonstrated high avidity and T cell-mediated cytotoxicity against human pancreatic ductal adenocarcinoma (PDAC) cell lines in vitro with EC50s in the picomolar range (0.17pM to 18pM). They were highly efficient in driving human polyclonal T cells into subcutaneous PDAC xenografts and mediated potent T cell-mediated anti-tumor effects. Both EGFRxCD33 and HER2xCD33 tumor-monovalent T-BsAbs displayed substantially reduced avidity by SPR when compared to homodimeric EGFRxEGFR or HER2xHER2 T-BsAbs (â¼150-fold and â¼6000-fold respectively), tumor binding by FACS (8.0-fold and 63.6-fold), and T-cell mediated cytotoxicity (7.7-fold and 47.2-fold), while showing no efficacy against CDX or PDX. However, if either EGFR or HER2 was removed from SW1990 by CRISPR-mediated knockout, the in vivo efficacy of heterodimeric EGFRxHER2 T-BsAb was lost. CONCLUSION: EGFR and HER2 were useful targets for driving T cell infiltration and tumor ablation. Two arm Fab binding to either one or both targets was critical for robust anti-tumor effect in vivo. By engaging both targets, EGFRxHER2 heterodimeric T-BsAb exhibited potent anti-tumor effects if CDX or PDX were EGFR+HER2+ double-positive with the potential to spare single-positive normal tissue.
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Anticorpos Biespecíficos , Carcinoma Ductal Pancreático , Receptores ErbB , Neoplasias Pancreáticas , Receptor ErbB-2 , Linfócitos T , Anticorpos Biespecíficos/uso terapêutico , Anticorpos Biespecíficos/imunologia , Anticorpos Biespecíficos/farmacologia , Humanos , Animais , Neoplasias Pancreáticas/imunologia , Neoplasias Pancreáticas/terapia , Linfócitos T/imunologia , Carcinoma Ductal Pancreático/imunologia , Carcinoma Ductal Pancreático/terapia , Camundongos , Receptores ErbB/imunologia , Receptor ErbB-2/imunologia , Linhagem Celular Tumoral , Dimerização , Ensaios Antitumorais Modelo de Xenoenxerto , Camundongos SCIDRESUMO
BACKGROUND: Post-traumatic stress disorder (PTSD) is a well-documented psychiatric outcome in patients who experience physical trauma. The phenomenon is less studied in the staff involved in caring for such patients. The aim was to investigate the prevalence of PTSD in visiting international surgeons undergoing elective trauma training and to compare to local and international rates. METHODS: A trauma screening questionnaire (TSQ) survey was conducted among surgeons completing their elective trauma service placements in the Pietermaritzburg Metropolitan Trauma Service. RESULTS: Nineteen surveys were completed (32% response rate). Mean age was 38.9 (SD 6.5). Median postgraduate working experience was 5 (2-10) years. Median time of stay in South Africa was 6 (1-72) months. Compared to preelective experience, there was a five-fold increase in the level of trauma resuscitation experience reported during elective placement. 10.5% of surgeons scored > 5 in the TSQ suggesting probable PTSD. No statistical differences in age, years of prior experience, prior trauma rotation, number of major resuscitations, or length of stay in South Africa were observed in those scoring positive versus negative screening in the TSQ questionnaire. CONCLUSION: Despite being exposed to increased levels of trauma related injury, we observed low rates of positive screening for PTSD in our cohort of visiting international surgeons involved in elective trauma service placements. Investigation of potential protective factors against PTSD in this South African tertiary trauma centre is warranted.
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Transtornos de Estresse Pós-Traumáticos , Cirurgiões , Adulto , Humanos , África do Sul/epidemiologia , Transtornos de Estresse Pós-Traumáticos/epidemiologia , Transtornos de Estresse Pós-Traumáticos/etiologia , Centros de TraumatologiaRESUMO
BACKGROUND: The survival benefit observed in children with neuroblastoma (NB) and minimal residual disease who received treatment with anti-GD2 monoclonal antibodies prompted our investigation into the safety and potential clinical benefits of anti-CD3×anti-GD2 bispecific antibody (GD2Bi) armed T cells (GD2BATs). Preclinical studies demonstrated the high cytotoxicity of GD2BATs against GD2+cell lines, leading to the initiation of a phase I/II study in recurrent/refractory patients. METHODS: The 3+3 dose escalation phase I study (NCT02173093) encompassed nine evaluable patients with NB (n=5), osteosarcoma (n=3), and desmoplastic small round cell tumors (n=1). Patients received twice-weekly infusions of GD2BATs at 40, 80, or 160×106 GD2BATs/kg/infusion complemented by daily interleukin-2 (300,000 IU/m2) and twice-weekly granulocyte macrophage colony-stimulating factor (250 µg/m2). The phase II segment focused on patients with NB at the dose 3 level of 160×106 GD2BATs/kg/infusion. RESULTS: Of the 12 patients enrolled, 9 completed therapy in phase I with no dose-limiting toxicities. Mild and manageable cytokine release syndrome occurred in all patients, presenting as grade 2-3 fevers/chills, headaches, and occasional hypotension up to 72 hours after GD2BAT infusions. GD2-antibody-associated pain was minimal. Median overall survival (OS) for phase I and the limited phase II was 18.0 and 31.2 months, respectively, with a combined OS of 21.1 months. A phase I NB patient had a complete bone marrow response with overall stable disease. In phase II, 10 of 12 patients were evaluable: 1 achieved partial response, and 3 showed clinical benefit with prolonged stable disease. Over 50% of evaluable patients exhibited augmented immune responses to GD2+targets post-GD2BATs, as indicated by interferon-gamma (IFN-γ) EliSpots, Th1 cytokines, and/or chemokines. CONCLUSIONS: This study demonstrated the safety of GD2BATs up to 160×106 cells/kg/infusion. Coupled with evidence of post-treatment endogenous immune responses, our findings support further investigation of GD2BATs in larger phase II clinical trials.
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Antineoplásicos , Neuroblastoma , Osteossarcoma , Criança , Humanos , Linfócitos T/patologia , Neuroblastoma/patologia , Anticorpos Monoclonais/farmacologia , Anticorpos Monoclonais/uso terapêutico , Antineoplásicos/uso terapêutico , Osteossarcoma/tratamento farmacológicoRESUMO
Rationale: The in vivo dynamics of CAR-T cells remain incompletely understood. Novel methods are urgently needed to longitudinally monitor transferred cells non-invasively for biodistribution, functionality, proliferation, and persistence in vivo and for improving their cytotoxic potency in case of treatment failure. Methods: Here we engineered CD19 CAR-T cells ("Thor"-cells) to express a membrane-bound scFv, huC825, that binds DOTA-haptens with picomolar affinity suitable for labeling with imaging or therapeutic radionuclides. We assess its versatile utility for serial tracking studies with PET and delivery of α-radionuclides to enhance anti-tumor killing efficacy in sub-optimal adoptive cell transfer in vivo using Thor-cells in lymphoma models. Results: We show that this reporter gene/probe platform enables repeated, sensitive, and specific assessment of the infused Thor-cells in the whole-body using PET/CT imaging with exceptionally high contrast. The uptake on PET correlates with the Thor-cells on a cellular and functional level. Furthermore, we report the ability of Thor-cells to accumulate cytotoxic alpha-emitting radionuclides preferentially at tumor sites, thus increasing therapeutic potency. Conclusion: Thor-cells are a new theranostic agent that may provide crucial information for better and safer clinical protocols of adoptive T cell therapies, as well as accelerated development strategies.
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Antineoplásicos , Radioimunoterapia , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Distribuição Tecidual , Imunoterapia Adotiva/métodos , Radioisótopos/metabolismo , Antineoplásicos/metabolismo , Linfócitos T/metabolismoRESUMO
Antibodies that bind peptide-MHC (pMHC) complex in a manner akin to T cell receptor (TCR) have not only helped in understanding the mechanism of TCR-pMHC interactions in the context of T cell biology but also spurred considerable interest in recent years as potential cancer therapeutics. Traditional methods to generate such antibodies using hybridoma and B cell sorting technologies are sometimes inadequate, possibly due to the small contribution of peptide to the overall B cell epitope space on the surface of the pMHC complex (typical peptide MW = 1 kDa versus MHC MW = 45 kDa) and to the multiple efficiency limiting steps inherent in these methods. In this chapter we describe phage display approaches, including a cell panning strategy, for the rapid generation of such antibodies with high specificity and affinity.
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Anticorpos , Bacteriófagos , Linfócitos B , Movimento Celular , Técnicas de Visualização da Superfície Celular , Antígenos de HistocompatibilidadeRESUMO
The cure rate for metastatic or relapsed osteosarcoma has not substantially improved over the past decades despite the exploitation of multimodal treatment approaches, allowing long-term survival in less than 30% of cases. Patients with osteosarcoma often develop resistance to chemotherapeutic agents, where personalized targeted therapies should offer new hope. T cell immunotherapy as a complementary or alternative treatment modality is advancing rapidly in general, but its potential against osteosarcoma remains largely unexplored. Strategies incorporating immune checkpoint inhibitors (ICIs), chimeric antigen receptor (CAR) modified T cells, and T cell engaging bispecific antibodies (BsAbs) are being explored to tackle relapsed or refractory osteosarcoma. However, osteosarcoma is an inherently heterogeneous tumor, both at the intra- and inter-tumor level, with no identical driver mutations. It has a pro-tumoral microenvironment, where bone cells, stromal cells, neovasculature, suppressive immune cells, and a mineralized extracellular matrix (ECM) combine to derail T cell infiltration and its anti-tumor function. To realize the potential of T cell immunotherapy in osteosarcoma, an integrated approach targeting this complex ecosystem needs smart planning and execution. Herein, we review the current status of T cell immunotherapies for osteosarcoma, summarize the challenges encountered, and explore combination strategies to overcome these hurdles, with the ultimate goal of curing osteosarcoma with less acute and long-term side effects.
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Neoplasias Ósseas , Osteossarcoma , Humanos , Linfócitos T , Ecossistema , Recidiva Local de Neoplasia , Imunoterapia , Osteossarcoma/genética , Neoplasias Ósseas/genética , Microambiente Tumoral , Imunoterapia AdotivaRESUMO
Patients with stage 4N neuroblastoma (distant metastases limited to lymph nodes) stand out as virtually the only survivors of high-risk neuroblastoma (HR-NB) before myeloablative therapy (MAT) and immunotherapy with anti-GD2 monoclonal antibodies (mAbs) became standard. Because no report presents more recent results with 4N, we analyzed our large 4N experience. All 51 pediatric 4N patients (<18 years old) diagnosed 1985 to 2021 were reviewed. HR-NB included MYCN-nonamplified 4N diagnosed at age ≥18 months and MYCN-amplified 4N. Among 34 MYCN-nonamplified high-risk patients, 20 are relapse-free 1.5+ to 37.5+ (median 12.5+) years post-diagnosis, including 13 without prior MAT and 5 treated with little (1 cycle; n = 2) or no mAb (n = 3), while 14 patients (7 post-MAT, 8 post-mAbs) relapsed (all soft tissue). Of 15 MYCN-amplified 4N patients, 7 are relapse-free 2.1+ to 26.4+ (median 11.6+) years from the start of chemotherapy (all received mAbs; 3 underwent MAT) and 4 are in second remission 4.2+ to 21.8+ years postrelapse (all soft tissue). Statistical analyses showed no significant association of survival with either MAT or mAbs for MYCN-nonamplified HR-NB; small numbers prevented these analyses for MYCN-amplified patients. The two patients with intermediate-risk 4N (14-months-old) are relapse-free 7+ years postresection of primary tumors; distant disease spontaneously regressed. The natural history of 4N is marked by NB confined to soft tissue without early relapse in bones or bone marrow, where mAbs have proven efficacy. These findings plus curability without MAT, as seen elsewhere and at our center, support consideration of treatment reduction for MYCN-nonamplified 4N.
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Recidiva Local de Neoplasia , Neuroblastoma , Criança , Humanos , Lactente , Adolescente , Prognóstico , Proteína Proto-Oncogênica N-Myc/genética , Estadiamento de Neoplasias , Recidiva Local de Neoplasia/terapia , Recidiva Local de Neoplasia/patologia , Neuroblastoma/genética , Neuroblastoma/terapia , ImunoterapiaRESUMO
Desmoplastic small round cell tumor (DSRCT) is a rare pediatric cancer caused by the EWSR1-WT1 fusion oncogene. Despite initial response to chemotherapy, DSRCT has a recurrence rate of over 80% leading to poor patient prognosis with a 5-year survival rate of only 15-25%. Owing to the rarity of DSRCT, sample scarcity is a barrier in understanding DSRCT biology and developing effective therapies. Utilizing a novel pair of primary and recurrent DSRCTs, we present the first map of DSRCT genomic breakpoints and the first comparison of gene expression alterations between primary and recurrent DSRCT. Our genomic breakpoint map includes the lone previously published DSRCT genomic breakpoint, the breakpoint from our novel primary/recurrent DSRCT pair, as well as the breakpoints of five available DSRCT cell lines and five additional DSRCTs. All mapped breakpoints were unique and most breakpoints included a 1-3 base pair microhomology suggesting microhomology-mediated end-joining as the mechanism of translocation fusion and providing novel insights into the etiology of DSRCT. Through RNA-sequencing analysis, we identified altered genes and pathways between primary and recurrent DSRCTs. Upregulated pathways in the recurrent tumor included several DNA repair and mRNA splicing-related pathways, while downregulated pathways included immune system function and focal adhesion. We further found higher expression of the EWSR1-WT1 upregulated gene set in the recurrent tumor as compared to the primary tumor and lower expression of the EWSR1-WT1 downregulated gene set, suggesting the EWSR1-WT1 fusion continues to play a prominent role in recurrent tumors. The identified pathways including upregulation of DNA repair and downregulation of immune system function may help explain DSRCT's high rate of recurrence and can be utilized to improve the understanding of DSRCT biology and identify novel therapies to both help prevent recurrence and treat recurrent tumors.
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Epithelial ovarian cancer (EOC) is often asymptomatic and presents clinically in an advanced stage as widespread peritoneal microscopic disease that is generally considered to be surgically incurable. Targeted α-therapy with the α-particle-emitting radionuclide 225Ac (half-life, 9.92 d) is a high-linear-energy-transfer treatment approach effective for small-volume disease and even single cells. Here, we report the use of human epidermal growth factor receptor 2 (HER2) 225Ac-pretargeted radioimmunotherapy (PRIT) to treat a mouse model of human EOC SKOV3 xenografts growing as peritoneal carcinomatosis (PC). Methods: On day 0, 105 SKOV3 cells transduced with a luciferase reporter gene were implanted intraperitoneally in nude mice, and tumor engraftment was verified by bioluminescent imaging (BLI). On day 15, treatment was started using 1 or 2 cycles of 3-step anti-HER2 225Ac-PRIT (37 kBq/cycle as 225Ac-Proteus DOTA), separated by a 1-wk interval. Efficacy and toxicity were monitored for up to 154 d. Results: Untreated PC-tumor-bearing nude mice showed a median survival of 112 d. We used 2 independent measures of response to evaluate the efficacy of 225Ac-PRIT. First, a greater proportion of the treated mice (9/10 1-cycle and 8/10 2-cycle; total, 17/20; 85%) survived long-term compared with controls (9/27, 33%), and significantly prolonged survival was documented (log-rank [Mantel-Cox] P = 0.0042). Second, using BLI, a significant difference in the integrated BLI signal area to 98 d was noted between controls and treated groups (P = 0.0354). Of a total of 8 mice from the 2-cycle treatment group (74 kBq total) that were evaluated by necropsy, kidney radiotoxicity was mild and did not manifest itself clinically (normal serum blood urea nitrogen and creatinine). Dosimetry estimates (relative biological effectiveness-weighted dose, where relative biological effectiveness = 5) per 37 kBq administered for tumors and kidneys were 56.9 and 16.1 Gy, respectively. One-cycle and 2-cycle treatments were equally effective. With immunohistology, mild tubular changes attributable to α-toxicity were observed in both therapeutic groups. Conclusion: Treatment of EOC PC-tumor-bearing mice with anti-HER2 225Ac-PRIT resulted in histologic cures and prolonged survival with minimal toxicity. Targeted α-therapy using the anti-HER2 225Ac-PRIT system is a potential treatment for otherwise incurable EOC.
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Neoplasias Peritoneais , Radioimunoterapia , Humanos , Animais , Camundongos , Radioimunoterapia/métodos , Camundongos Nus , Neoplasias Peritoneais/diagnóstico por imagem , Neoplasias Peritoneais/radioterapia , Neoplasias Peritoneais/tratamento farmacológico , Radioisótopos/uso terapêutico , Linhagem Celular TumoralRESUMO
T cell-engaging bispecific antibodies (T-BsAbs) are in various stages of preclinical development and clinical testing for solid tumors. Factors such as valency, spatial arrangement, interdomain distance, and Fc mutations affect the anti-tumor efficacy of these therapies, commonly by influencing the homing of T cells to tumors, which remains a major challenge. Here, we describe a method to transduce activated human T cells with luciferase, allowing in vivo tracking of T cells during T-BsAb therapy studies. The ability of T-BsAbs to redirect T cells to tumors can be quantitatively evaluated at multiple time points during treatment, allowing researchers to correlate the anti-tumor efficacy of T-BsAbs and other interventions with the persistence of T cells in tumors. This method alleviates the need to sacrifice animals during treatment to histologically assess T cell infiltration and can be repeated at multiple time points to determine the kinetics of T cell trafficking during and after treatment.
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Anticorpos Biespecíficos , Neoplasias , Animais , Humanos , Anticorpos Biespecíficos/farmacologia , Anticorpos Biespecíficos/uso terapêutico , Linfócitos T , Neoplasias/terapiaRESUMO
Patients with high-risk neuroblastoma generally present with widely metastatic disease and often relapse despite intensive therapy. As most studies to date focused on diagnosis-relapse pairs, our understanding of the genetic and clonal dynamics of metastatic spread and disease progression remain limited. Here, using genomic profiling of 470 sequential and spatially separated samples from 283 patients, we characterize subtype-specific genetic evolutionary trajectories from diagnosis through progression and end-stage metastatic disease. Clonal tracing timed disease initiation to embryogenesis. Continuous acquisition of structural variants at disease-defining loci (MYCN, TERT, MDM2-CDK4) followed by convergent evolution of mutations targeting shared pathways emerged as the predominant feature of progression. At diagnosis metastatic clones were already established at distant sites where they could stay dormant, only to cause relapses years later and spread via metastasis-to-metastasis and polyclonal seeding after therapy.
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Recidiva Local de Neoplasia , Neuroblastoma , Humanos , Recidiva Local de Neoplasia/genética , Neuroblastoma/genética , Evolução Clonal , Mutação , Metástase NeoplásicaRESUMO
BACKGROUND: This paper reviews our experience with management of renal injuries in children and adolescents with a focus on the outcome of non-operative management (NOM). METHODS: Retrospective review of the clinical characteristics, injury grade (I-III, low grade and IV and V high grade), management and outcomes of children ≤ 18 years old with renal trauma presenting to a major trauma centre in South Africa between December 2012 and October 2020. RESULTS: Sixty-one children with a renal injury were identified with a median age of 13 (range 0-18) years. Forty-five were boys; blunt and penetrating mechanisms of trauma were sustained by 55 (90%) and six (10%) children, respectively. The median American Association for the Surgery of Trauma (AAST) grade of renal injury was 3 (range 1-5): this included eight (13%) with grade I, six (10%) with grade II, 17 (28%) with grade III, 20 (46%) with grade IV and 10 (16%) with grade V injuries. Forty children (66%) were successfully managed non-operatively and 21 required a laparotomy; of these six (28%) required nephrectomy. The overall renal salvage rate was 55/61 (90%). Children who required laparotomy were significantly more likely to have sustained a penetrating mechanism of injury (24% vs 2%) and have greater length of hospital stay (median 9 vs 3 days) compared to children managed non-operatively (p < 0.05). Children who underwent a nephrectomy had a significantly greater length of hospital stay (median 9 vs 4 days, p = 0.03); however, their demographics, outcomes developed complications. Two children (3%) died; one managed non-operatively and one with a laparotomy. CONCLUSION: Paediatric renal trauma can be successfully managed non-operatively in over two-thirds of cases in this middle-income country. High grade of renal injury does not absolutely predict need for surgery or nephrectomy and can be managed non-operatively.
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Ferimentos não Penetrantes , Masculino , Humanos , Criança , Adolescente , Recém-Nascido , Lactente , Pré-Escolar , Feminino , Ferimentos não Penetrantes/diagnóstico , Ferimentos não Penetrantes/terapia , Escala de Gravidade do Ferimento , Rim , Nefrectomia , Estudos Retrospectivos , Centros de TraumatologiaRESUMO
BACKGROUND: Music is played in operating theatres (OTs) throughout the world, though controversy around its use exists. While some clinicians may find background music favourable to the theatre mood and a way to augment surgical performance, there is concern raised over its distracting and noise-creating properties. METHODS: In this prospective observational study, between August and December 2021, 110 surgeons and registrars in South Africa responded to a survey investigating the way they use music, and their perceptions and attitudes towards its effect on the OT environment. RESULTS: In this cohort, 66% were male, 29% were consultants and the most common age range was 30-39 years old. Eighty per cent of respondents reported that music was played at least "sometimes", with 74% reporting that they enjoyed it. Easy Listening was the most played and preferred genre followed by Top 40/Billboard hits. Overwhelmingly, respondents reported that background music in the OT improved temperament, focus, mood, and performance, though over a quarter felt it worsened communication. Thirty-one per cent of respondents reported that the choice of music depended on the type of operation, and 70% would turn music down or off during crises. Those who enjoyed music in their spare time were significantly more likely to enjoy music in the OT and perceive it positively. CONCLUSION: This study provides a window into the surgeons' use of and attitudes to intraoperative music in South Africa. While overall, music is viewed positively by this cohort, some concerns remain regarding communication and distractedness. Further interventional and qualitative studies would be useful.
Assuntos
Música , Humanos , Masculino , Adulto , Feminino , África do Sul , Atitude do Pessoal de Saúde , Salas Cirúrgicas , Inquéritos e QuestionáriosRESUMO
Background: Development of successful antibody-based immunotherapeutic and radioimmunotherapeutic strategies rely on the identification of cell surface tumor-associated antigens (TAA) with restricted expression on normal tissues. Desmoplastic small round cell tumor (DSRCT) is a rare and generally neglected malignancy that primarily affects adolescent and young adult males. New therapies capable of treating disseminated disease are needed for DSRCT, which is often widespread at diagnosis. Methods: We used immunohistochemistry (IHC) on fresh frozen surgical specimens and patient-derived xenograft (PDX) tumors and flow cytometry on DSRCT cell lines to evaluate expression of TAAs in these tumors. In vitro cytotoxicity assays were used to evaluate the efficacy of T cell-engaging bispecific antibodies (T-BsAbs) directed at these targets. In vivo, we used an intraperitoneal xenograft mouse model of DSRCT to test T-BsAbs against several TAAs. Results: In DSRCT specimens we found widespread expression of B7-H3, EGFR, GD2, HER2, mesothelin, and polysialic acid, clinical targets for which specific antibody therapeutics are available. The expression of B7-H3, EGFR, HER2, and mesothelin was confirmed on the cell surface of DSRCT cell lines. In vitro cytotoxicity assays confirmed the efficacy of T cell-engaging bispecific antibodies (T-BsAbs) directed at these targets against DSRCT cells. Remarkably, a HER2xCD3 T-BsAb was capable of completely shrinking established tumors in an intraperitoneal mouse model of DSRCT. Conclusions: We propose that these TAAs should be further investigated in preclinical models as targets for immunotherapy and radioimmunotherapy with the hope of providing a rationale to extend these therapies to patients with advanced DSRCT.
RESUMO
BACKGROUND: Success of T cell immunotherapy hinges on the tumor microenvironment (TME), and abnormal tumor vasculature is a hallmark of most solid tumors and associated with immune evasion. The efficacy of T cell engaging bispecific antibody (BsAb) treatment relies on the successful trafficking and cytolytic activity of T cells in solid tumors. Normalization of tumor vasculature using vascular endothelial growth factor (VEGF) blockades could improve efficacy of BsAb-based T cell immunotherapy. METHODS: Anti-human VEGF (bevacizumab, BVZ) or anti-mouse VEGFR2 antibody (DC101) was used as VEGF blockade, and ex vivo armed T cells (EATs) carrying anti-GD2, anti-HER2, or anti-glypican3 (GPC3) IgG-(L)-scFv platformed BsAb were used. BsAb-driven intratumoral T cell infiltration and in vivo antitumor response were evaluated using cancer cell line-derived xenografts (CDXs) or patient-derived xenografts (PDXs) carried out in BALB-Rag2 -/-IL-2R-γc-KO (BRG) mice. VEGF expression on human cancer cell lines was analyzed by flow cytometry, and VEGF levels in mouse serum were measured using VEGF Quantikine ELISA Kit. Tumor infiltrating lymphocytes (TILs) were evaluated using flow cytometry and by bioluminescence; both TILs and tumor vasculature were studied using immunohistochemistry. RESULTS: VEGF expression on cancer cell lines increased with seeding density in vitro. BVZ significantly reduced serum VEGF levels in mice. BVZ or DC101 increased high endothelial venules (HEVs) in the TME and substantially enhanced (2.1-8.1 fold) BsAb-driven T cell infiltration into neuroblastoma and osteosarcoma xenografts, which was preferential for CD8(+) TILs versus CD4(+) TILs, leading to superior antitumor effects in multiple CDX and PDX tumor models without added toxicities. CONCLUSIONS: VEGF blockade using specific antibodies against VEGF or VEGFR2 increased HEVs in the TME and cytotoxic CD8(+) TILs, significantly improving the therapeutic efficacy of EAT strategies in preclinical models, supporting the clinical investigation of VEGF blockades to further enhance BsAb-based T cell immunotherapies.
Assuntos
Anticorpos Biespecíficos , Linfócitos T , Animais , Camundongos , Humanos , Fator A de Crescimento do Endotélio Vascular , Anticorpos Biespecíficos/farmacologia , Anticorpos Biespecíficos/uso terapêutico , Linfócitos do Interstício Tumoral , Imunoterapia , GlipicanasRESUMO
INTRODUCTION: This study reviews our cumulative experience with the management of patients presenting with a retained knife following an abdominal stab wound (SW). METHODS: A retrospective study was conducted at a major trauma centre in South Africa over a 15-year period from July 2006 to December 2020 including all patients who presented with a retained knife in the abdomen following a SW. RESULTS: A total of 42 cases were included: 37 males (93%) with a mean age of 26 years. A total of 18 knives (43%) were in the anterior abdomen and 24 were posterior abdomen. Plain radiography was performed in 88% (37/42) of cases and computed tomography was performed in 81% (34/42); 90% (38/42) underwent extraction in the operating theatre. Laparotomy was performed in 62% (26/42). Of all the laparotomies performed, 77% (20/26) were positive for intra-abdominal organ or visceral injury. Overall morbidity was 31%. There were two mortalities (5%). Laparotomy was less commonly required for the posterior abdomen (33% (8/24) vs 100% (18/18), p<0.001). For retained knives in the anterior abdomen, 72% (13/18) of the laparotomies were positive for intra-abdominal organ or visceral injury. For the posterior abdomen, 7 of the 8 (88%) were positive for intra-abdominal organ or visceral injury. There were no differences in the need for intensive care unit admission, length of hospital stay, morbidities or mortalities. CONCLUSIONS: Uncontrolled extraction of a retained knife in the abdomen outside of the operating theatre must be avoided. Retained knives in the anterior abdomen usually require formal laparotomy, but this is generally not required for posterior abdomen.