CARD-CC complexes involving BCL10 and MALT1 are major cellular signaling hubs. They govern NF-κB activation through their scaffolding properties as well as MALT1 paracaspase function, which cleaves substrates involved in NF-κB regulation. In human lymphocytes, gain-of-function defects in this pathway lead to lymphoproliferative disorders. CARD10, the prototypical CARD-CC protein in non-hematopoietic cells, is overexpressed in several cancers and has been associated with poor prognosis. However, regulation of CARD10 remains poorly understood. Here, we identified CARD10 as the first MALT1 substrate in non-hematopoietic cells and showed that CARD10 cleavage by MALT1 at R587 dampens its capacity to activate NF-κB. Preventing CARD10 cleavage in the lung tumor A549 cell line increased basal levels of IL-6 and extracellular matrix components in vitro, and led to increased tumor growth in a mouse xenograft model, suggesting that CARD10 cleavage by MALT1 might be a built-in mechanism controlling tumorigenicity.

Activation of p53 by blocking p53-Mdm2 interaction using small-molecule inhibitors is being pursued as a promising cancer therapeutic strategy in p53 wild-type tumors. Here, we report the identification of NVP-HDM201, a novel, highly potent and selective inhibitor of the p53-Mdm2 interaction, with optimized drug-like properties allowing a versatile use with regard to route of administration, dose and scheduling. We determined the pharmacokinetics, pharmacodynamics and efficacy relationship of NVP-HDM201 with various dosing schedules in xenograft bearing mouse and rat models. NVP-HDM201 administered either daily at a low dose or once at a high dose revealed a differentiated engagement of the p53 molecular response. In contrast to the daily low dose treatment regimen, the single high dose NVP-HDM201 regimen resulted in a rapid and dramatic induction of p53-dependent PUMA expression and apoptosis. This was consistent with the finding that a single high dose NVP-HDM201 treatment, administered orally or intravenously, resulted in a robust and sustained tumor regression. Overall, both daily and once every 3 weeks dosing regimen showed comparable long term efficacy in preclinical studies. The ongoing clinical trial is currently designed to compare both dosing regimens with regard to efficacy and tolerability. Citation Format: Stéphane Ferretti, Ramona Rebmann, Marjorie Berger, Francesca Santacroce, Geneviève Albrecht, Kerstin Pollehn, Dario Sterker, Markus Wartmann, Andreas Hueber, Marion Wiesmann, Michael R. Jensen, Francesco Hofmann, William R. Sellers, Philipp Holzer, Sébastien Jeay. Insights into the mechanism of action of NVP-HDM201, a differentiated and versatile Next-Generation small-molecule inhibitor of Mdm2, under evaluation in phase I clinical trials. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1224.

Although functional inactivation of the tumor suppressor p53 is a frequent genetic event, half of all human tumors express wild-type p53. Stabilization of p53 by antagonizing its negative regulator mouse double minute 2 (Mdm2) leads to selective induction of the p53 pathway, thus offering a promising therapeutic opportunity. NVP-CGM097 binds in the p53 pocket on the surface of Mdm2 and effectively disrupts the interaction between p53 and Mdm2. The aim of this study was to determine the pharmacokinetic (PK), pharmacodynamic (PD) and efficacy profile of this novel p53-Mdm2 inhibitor in mouse models of human cancer. During the medicinal chemistry discovery efforts, the compound series was optimized for oral administration. The selected compound, NVP-CGM097, was well absorbed in mice where the maximum plasma concentration (Tmax) was observed about 3 hours post dose followed by a prolonged absorption phase. PD effects were determined by measuring the expression levels of p53 target genes including p21, PUMA and Mdm2 in tumors. The expression levels of p53 target genes correlated with the concentrations of NVP-CGM097 demonstrating a good PK/PD relationship. Optimal treatment schedules were investigated in the Mdm2-amplified, p53 wild-type osteosarcoma xenograft model SJSA-1. Interestingly, various schedules were highly efficacious at well-tolerated dose levels. Tumor regression was observed when NVP-CGM097 was administered in schedules ranging from daily to twice per week with no adverse effects. Following dose optimization studies, potent anti-tumor efficacy was observed in a range of p53 wild-type expressing xenograft models including Mdm2 non-amplified orthotopic AML as well as well-differentiated (WDLPS) and dedifferentiated (DDLPS) liposarcomas. Overall, we demonstrate that the novel p53-Mdm2 inhibitor NVP-CGM097 has a good PK profile and affects PD markers in human tumors leading to tumor regression at well-tolerated dose levels. These data strongly support clinical development of NVP-CGM097. Citation Format: Stéphane Ferretti, Marjorie Berger, Ramona Rebmann, Francesca Santacroce, Dario Sterker, Michael Jensen, Keiichi Masuya, Sébastien Jeay. NVP-CGM097: a novel p53-Mdm2 inhibitor exhibiting potent antitumor activity in mouse models of human cancer. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 4638. doi:10.1158/1538-7445.AM2014-4638

Rapid development in nanotechnology allows the incorporation of multiple therapeutic agents (e.g. liposomes) into nanoparticle with a size range from 1 to 1000 nm. These nanocarrier systems provide new approaches to treat aggressive malignancy. Nano-based delivery systems hold an advantage over traditional small molecule therapy in that they can deliver drugs preferentially to tumors due to the enhanced permeability and retention (EPR) effect. On one hand, high permeability of the tumor vessels and a lack of functional lymphatic vessels results in the EPR effect, driving nanoparticle extravasation. On the other hand, these phenomena lead to high interstitial fluid pressure (IFP), limiting nanoparticle extravasation. In this study, we have used dynamic-contrast enhanced (DCE) MRI with small (Dotarem, 5 nm) and large (Vistarem, 25 nm) contrast agents (CAs) to examine tumor vessel permeability in SJSA-1 osteosarcoma tumor-bearing rats. An inversion-recovery true fast imaging with steady state precession (TrueFISP) was employed to determine the transfer constant Ktrans in subcutaneous and intra-tibia tumor models. When the tumor cells were injected in both niches within the same animal, Ktrans was significantly lower in intra-tibia tumors with both CAs, and blood vessels significantly less and larger compared to subcutaneous tumors. Moreover, Ktrans negatively correlated with tumor bioluminescence for the intra-tibia model, suggesting that EPR decreased inversely with tumor size, while the opposite was noticed for the subcutaneous tumors. These data demonstrate for the first time that the EPR of tumors with a similar size within the same animal can be influenced by the microenvironment. Moreover, they show that the therapeutic index of a nanotherapeutics may be different if it's determined with either an orthotopic or ectopic model. Citation Format: Stephane Ferretti, Nicolau Beckmann, laura Holzer, Michael Obrecht, Marjorie Berger, Michael Rugaard Jensen. The tumor microenvironment of preclinical tumor models may have an impact on the therapeutic index of nanotherapeutics [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 2111.