The prostate‐specific membrane antigen (PSMA) has been demonstrated in numerous studies to be expressed specifically on prostate carcinoma cells and on the neovasculature of several other cancer ...entities. However, the simultaneous expression of PSMA on both, tumor cells as well as tumor vessels remains unclear, even if such “dual” expression would constitute an important asset to facilitate sufficient influx of effector cells to a given tumor site. We report here on the generation of a PSMA antibody, termed 10B3, which exerts superior dual reactivity on sections of prostate carcinoma and squamous cell carcinoma of the lung. 10B3 was used for the construction of T‐cell recruiting bispecific PSMAxCD3 antibodies in Fab‐ and IgG‐based formats, designated Fabsc and IgGsc, respectively. In vitro, both molecules exhibited comparable activity. In contrast, only the larger IgGsc molecule induced complete and durable elimination of established tumors in humanized mice due to favorable pharmacokinetic properties. Upon treatment of three patients with metastasized prostate carcinoma with the IgGsc reagent, marked activation of T cells and rapid reduction of elevated PSA levels were observed.
Synopsis
Insufficient penetration of immune cells and therapeutic antibodies into the tumor core is a major limitation in the immunotherapy field. This study reports the development of a novel bispecific antibody, named CC‐1, for improved dual targeting of tumor‐ and vascular cells in PSMA positive tumors.
A novel PSMA antibody (10B3) exhibiting enhanced reactivity with tumor‐ and vascular cells in samples from prostate carcinoma and squamous cell carcinoma of the lung was generated.
Two different bispecific antibodies comprising 10B3 and anti‐CD3 single chain in a Fabsc‐ and IgGsc‐format were constructed and characterized.
In vivo application of both bispecific antibodies revealed that only the IgGsc‐molecule localized at a given tumor site, resulting in effective tumor cell destruction.
A first‐in‐man application of the IgGsc‐molecule, designated CC‐1, in three patients with metastasized prostate carcinoma, demonstrated profound T cell activation and a rapid decline of elevated PSA levels.
A first‐in‐man clinical study in patients with prostate carcinoma is currently ongoing (NCT04104607).
Insufficient penetration of immune cells and therapeutic antibodies into the tumor core is a major limitation in the immunotherapy field. This study reports the development of a novel bispecific antibody, named CC‐1, for improved dual targeting of tumor‐ and vascular cells in PSMA positive tumors.
FLT3 is a receptor-tyrosine-kinase that is expressed on leukemic cells of the myeloid and lymphoid lineage rather specifically. We here report on the construction and selection of bispecific FLT3 X ...CD3 antibodies in a new recombinant format, termed Fabsc, that resembles the normal antibody structure more closely than the well-established bispecific single chain (bssc)-format. Our preferred antibody, which emerged from an initial selection procedure utilizing different FLT3- and CD3-antibodies, contains the FLT3-antibody 4G8 and the CD3-antibody UCHT1. The 4G8 X UCHT1 Fabsc-antibody was found to be superior to a bssc-antibody with identical specificities with respect to (i) affinity to the target antigen FLT3, (ii) production yield by transfected cells, and (iii) the diminished formation of aggregates. T-cell activation in the presence and absence of cultured leukemic cells and killing of these cells was comparable for both molecules. In addition, the 4G8 X UCHT1 Fabsc-antibody was found to induce T-cell activation and efficient killing of leukemic blasts in primary peripheral blood mononuclear cell (PBMC) cultures of acute myeloid leukemia (AML) patients. In these experiments, the bispecific molecule was clearly superior to an Fc-optimized monospecific FLT3-antibody described previously, indicating that within PBMC of AML patients the recruitment of T cells is more effective than that of natural killer cells.
BackgroundIn lymphoid malignancies, the introduction of chimeric antigen receptor T (CAR-T) cells and bispecific antibodies (bsAbs) has achieved remarkable clinical success. However, such ...immunotherapeutic strategies are not yet established for acute myeloid leukemia (AML), the most common form of acute leukemia in adults. Common targets in AML such as CD33, CD123, and CLEC12A are highly expressed on both AML blasts and on normal myeloid cells and hematopoietic stem cells (HSCs), thereby raising toxicity concerns. In B-cell acute lymphoblastic leukemia (B-ALL), bsAbs and CAR-T therapy targeting CD19 and CD22 have demonstrated clinical success, but resistance via antigen loss is common, motivating the development of agents focused on alternative targets. An attractive emerging target is FLT3, a proto-oncogene expressed in both AML and B-ALL, with low and limited expression on myeloid dendritic cells and HSCs.MethodsWe developed and characterized CLN-049, a T cell-activating bsAb targeting CD3 and FLT3, constructed as an IgG heavy chain/scFv fusion. CLN-049 binds the membrane proximal extracellular domain of the FLT3 protein tyrosine kinase, which facilitates the targeting of leukemic blasts regardless of FLT3 mutational status. CLN-049 was evaluated for preclinical safety and efficacy in vitro and in vivo.ResultsCLN-049 induced target-restricted activation of CD4+ and CD8+ T cells. AML cell lines expressing a broad range of surface levels of FLT3 were efficiently lysed on treatment with subnanomolar concentrations of CLN-049, whereas FLT3-expressing hematopoietic progenitor cells and dendritic cells were not sensitive to CLN-049 killing. Treatment with CLN-049 also induced lysis of AML and B-ALL patient blasts by autologous T cells at the low effector-to-target ratios typically observed in patients with overt disease. Lysis of leukemic cells was not affected by supraphysiological levels of soluble FLT3 or FLT3 ligand. In mouse xenograft models, CLN-049 was highly active against human leukemic cell lines and patient-derived AML and B-ALL blasts.ConclusionsCLN-049 has a favorable efficacy and safety profile in preclinical models, warranting evaluation of its antileukemic activity in the clinic.
T cell-recruiting bispecific antibodies (bsAbs) are successfully used for the treatment of cancer. However, effective treatment with bsAbs is so far hampered by severe side effects, i.e., potentially ...life-threatening cytokine release syndrome. Off-target T cell activation due to binding of bispecific CD3 antibodies to T cells in the absence of target cells may contribute to excessive cytokine release. We report here, in an in vitro setting, that off-target T cell activation is induced by bsAbs with high CD3 binding affinity and increased by endothelial- or lymphoid cells that act as stimulating bystander cells. Blocking antibodies directed against the adhesion molecules CD18/CD54 or CD2/CD58 markedly reduced this type of off-target T cell activation. CD18 blockade-in contrast to CD2-did not affect the therapeutic activity of various bsAbs. Since CD18 antibodies have been shown to be safely applicable in patients, blockade of this integrin holds promise as a potential target for the prevention of unwanted off-target T cell activation and allows the application of truly effective bsAb doses.
This essay argues that to assess the likelihood that incumbent firms will successfully make the required transformations to their strategy and operations in the face of technological transformations, ...it is not sufficient to investigate their dynamic capabilities. Whether an incumbent is likely to succeed in its effort to change itself via dynamic capabilities depends also on how quickly start-ups or diversifying entrants can build ordinary capabilities to offer the new technology at scale. We offer a framework to assess dynamic competition that integrates both ordinary and dynamic capabilities into the analysis by systematically comparing incumbents, start-ups, and diversifying entrants. We illustrate the framework with a case study of electric vehicles and aim to show how crucial such comparative analyses are for making well-founded predictions about the likelihood that incumbents will be able to maintain their leadership positions in the future.
Short-term infusions of single vasodilators, usually given in a fixed dose, have not improved outcomes in patients with acute heart failure (AHF).
To evaluate the effect of a strategy that emphasized ...early intensive and sustained vasodilation using individualized up-titrated doses of established vasodilators in patients with AHF.
Randomized, open-label blinded-end-point trial enrolling 788 patients hospitalized for AHF with dyspnea, increased plasma concentrations of natriuretic peptides, systolic blood pressure of at least 100 mm Hg, and plan for treatment in a general ward in 10 tertiary and secondary hospitals in Switzerland, Bulgaria, Germany, Brazil, and Spain. Enrollment began in December 2007 and follow-up was completed in February 2019.
Patients were randomized 1:1 to a strategy of early intensive and sustained vasodilation throughout the hospitalization (n = 386) or usual care (n = 402). Early intensive and sustained vasodilation was a comprehensive pragmatic approach of maximal and sustained vasodilation combining individualized doses of sublingual and transdermal nitrates, low-dose oral hydralazine for 48 hours, and rapid up-titration of angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, or sacubitril-valsartan.
The primary end point was a composite of all-cause mortality or rehospitalization for AHF at 180 days.
Among 788 patients randomized, 781 (99.1%; median age, 78 years; 36.9% women) completed the trial and were eligible for primary end point analysis. Follow-up at 180 days was completed for 779 patients (99.7%). The primary end point, a composite of all-cause mortality or rehospitalization for AHF at 180 days, occurred in 117 patients (30.6%) in the intervention group (including 55 deaths 14.4%) and in 111 patients (27.8%) in the usual care group (including 61 deaths 15.3%) (absolute difference for the primary end point, 2.8% 95% CI, -3.7% to 9.3%; adjusted hazard ratio, 1.07 95% CI, 0.83-1.39; P = .59). The most common clinically significant adverse events with early intensive and sustained vasodilation vs usual care were hypokalemia (23% vs 25%), worsening renal function (21% vs 20%), headache (26% vs 10%), dizziness (15% vs 10%), and hypotension (8% vs 2%).
Among patients with AHF, a strategy of early intensive and sustained vasodilation, compared with usual care, did not significantly improve a composite outcome of all-cause mortality and AHF rehospitalization at 180 days.
ClinicalTrials.gov Identifier: NCT00512759.
Chemoresistance and advanced tumour stage at time of diagnosis are the major reasons for poor treatment results in hepatoblastoma (HB) and paediatric hepatocellular carcinoma (HCC). Positive results ...with transplantation of liver and bone marrow revealed the impact of the immune system on the treatment of liver malignancies. Cytotoxic-immune-cells-like natural killer (NK) and T cells are major player in the defence against developing tumours. This study aimed to specifically analyse the ability of ex-vivo expanded gamma delta T cells to recognise and lyse HB and HCC cell lines in coculture assays. Cell viability after treatment with gamma delta T cells was evaluated with two HB (HUH6 and HepT1) and one HCC cell line (HC-AFW1) using a MTT-based cytotoxicity assay. The binding of T cells to target cells was monitored using immunofluorescence microscopy. Incubation of hepatic tumour cell lines with gamma delta T cells led to a significant decrease in tumour cell viability. This was enhanced by zoledronic acid and histone deacetylase inhibitors. MT110, an EpCAM/CD3-bispecific BiTE antibody could bluntly enhance tumour cell lysis close to completion. gamma delta T cells efficiently interacted with HB and HCC cells in a spheroid culture model. Bispecific antibodies such as MT110 might be used to intensify the antitumoural effect of gamma delta T cells in context of adoptive immune cell transfer. Optimised immunotherapeutic strategies might therefore improve the outcome of high risk hepatoblastoma and hepatocellular carcinoma.
Background
Chemoresistance and advanced tumour stage at time of diagnosis are the major reasons for poor treatment results in hepatoblastoma (HB) and paediatric hepatocellular carcinoma (HCC). ...Positive results with transplantation of liver and bone marrow revealed the impact of the immune system on the treatment of liver malignancies.
Aim
Cytotoxic‐immune‐cells‐like natural killer (NK) and T cells are major player in the defence against developing tumours. This study aimed to specifically analyse the ability of ex‐vivo expanded γδ T cells to recognise and lyse HB and HCC cell lines in coculture assays.
Methods
Cell viability after treatment with γδ T cells was evaluated with two HB (HUH6 and HepT1) and one HCC cell line (HC‐AFW1) using a MTT‐based cytotoxicity assay. The binding of T cells to target cells was monitored using immunofluorescence microscopy.
Results
Incubation of hepatic tumour cell lines with γδ T cells led to a significant decrease in tumour cell viability. This was enhanced by zoledronic acid and histone deacetylase inhibitors. MT110, an EpCAM/CD3‐bispecific BiTE antibody could bluntly enhance tumour cell lysis close to completion. γδ T cells efficiently interacted with HB and HCC cells in a spheroid culture model.
Conclusion
Bispecific antibodies such as MT110 might be used to intensify the antitumoural effect of γδ T cells in context of adoptive immune cell transfer. Optimised immunotherapeutic strategies might therefore improve the outcome of high risk hepatoblastoma and hepatocellular carcinoma.
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