Novel Methionine Aminopeptidase 2 Inhibitor M8891 Synergizes with VEGF Receptor Inhibitors to Inhibit Tumor Growth of Renal Cell Carcinoma Models

N-terminal processing by methionine aminopeptidases (MetAP) is a crucial step in the maturation of proteins during protein biosynthesis. Small-molecule inhibitors of MetAP2 have antiangiogenic and antitumoral activity. Herein, we characterize the structurally novel MetAP2 inhibitor M8891. M8891 is a potent, selective, reversible small-molecule inhibitor blocking the growth of human endothelial cells and differentially inhibiting cancer cell growth. A CRISPR genome-wide screen identified the tumor suppressor p53 and MetAP1/MetAP2 as determinants of resistance and sensitivity to pharmacologic MetAP2 inhibition. A newly identified substrate of MetAP2, translation elongation factor 1-alpha-1 (EF1a-1), served as a pharmacodynamic biomarker to follow target inhibition in cell and mouse studies. Robust angiogenesis and tumor growth inhibition was observed with M8891 monotherapy. In combination with VEGF receptor inhibitors, tumor stasis and regression occurred in patient-derived xenograft renal cell carcinoma models, particularly those that were p53 wild-type, had Von Hippel-Landau gene (VHL) loss-of-function mutations, and a mid/high MetAP1/2 expression score.

Activity of Tepotinib in Hepatocellular Carcinoma With High-Level MET Amplification: Preclinical and Clinical Evidence

PURPOSE

MET amplification (METamp) has been reported in 1%-5% of patients with hepatocellular carcinoma (HCC) and may be sensitive to MET inhibition. Tepotinib, a selective MET inhibitor, has shown promising activity in HCC with MET overexpression. We investigated the preclinical and clinical activity of tepotinib in HCC with METamp (MET gene copy number [GCN] ≥5), including high-level METamp (MET GCN ≥10).

METHODS

Preclinical antitumor activity of tepotinib 100 mg/kg (orally, days 1-5, every 7 days, 3-5 weeks; 3-12 replicates) was evaluated according to METamp status, as determined using the nCounter platform (NanoString), in 37 HCC patient-derived xenografts (PDXs) in immunodeficient mice. Clinical outcomes were evaluated in patients with METamp by fluorescence in situ hybridization who received tepotinib 500 mg (450 mg active moiety) in two phase Ib/II trials in HCC with MET overexpression.

RESULTS

Across the PDX models, tepotinib induced complete or near-complete tumor regression in the only two models with high-level METamp. Median tumor volume reductions were 100% and 99.8% in models with MET GCN 47.1 and 44.0, respectively. Across the two clinical trials, 15/121 patients had METamp. Disease control was achieved by 11/15 patients with METamp (complete response [CR], n = 1; partial response [PR], n = 4; stable disease [SD], n = 6) and 4/4 with high-level METamp (CR, n = 1; PR, n = 2; SD, n = 1). All three patients with high-level METamp and objective response received treatment for >1 year, including one patient who received first-line tepotinib for >6 years.

CONCLUSION

High-level METamp may be an oncogenic driver in HCC that is sensitive to MET inhibitors such as tepotinib.

Preclinical Pharmacokinetics and Translational Pharmacokinetic/Pharmacodynamic Modeling of M8891, a Potent and Reversible Inhibitor of Methionine Aminopeptidase 2

INTRODUCTION

M8891 is a selective and reversible inhibitor of methionine aminopeptidase 2 (MetAP2). We describe translational research to define the target pharmacokinetics (PK) of M8891 and associated pharmacodynamic (PD) levels, which were used to support efficacious dose selection in humans.

METHODS

In vitro and in vivo PK characteristics were investigated in animal species, and data integrated using in vitro-in vivo correlation and allometric methods to predict the clearance, volume of distribution, and absorption parameters of M8891 in humans. In parallel, inhibition of MetAP2 activity by M8891 was studied in renal cancer xenografts in mice by measuring accumulation of Met-EF1α, a substrate of MetAP2. The corresponding PD effect was described by a turnover and effect compartment model. This model was used to simulate PD at the M8891 dose showing in vivo efficacy, i.e. significant tumor growth inhibition. Simulations of M8891 PK and associated PD in humans were conducted by integrating predicted human PK parameters into the preclinical PK/PD model.

RESULTS

The target minimum PD level associated with efficacy was determined to be 125 µg Met-EF1α per mg protein. Integrating predicted human PK parameters into the preclinical PK/PD model defined a minimal M8891 concentration at steady-state (Ctrough) of 1500 ng/mL (3.9 µM) in humans as being required to produce the corresponding minimum target Met-EF1a level (125 µg per mg protein).

CONCLUSION

The defined target PK and PD levels supported the design of the clinical Phase Ia dose escalation study of M8891 (NCT03138538) and selection of the recommended Phase II dose.

The Preclinical Pharmacology of Tepotinib-A Highly Selective MET Inhibitor with Activity in Tumors Harboring MET Alterations

The mesenchymal-epithelial transition factor (MET) proto-oncogene encodes the MET receptor tyrosine kinase. MET aberrations drive tumorigenesis in several cancer types through a variety of molecular mechanisms, including MET mutations, gene amplification, rearrangement, and overexpression. Therefore, MET is a therapeutic target and the selective type Ib MET inhibitor, tepotinib, was designed to potently inhibit MET kinase activity. In vitro, tepotinib inhibits MET in a concentration-dependent manner irrespective of the mode of MET activation, and in vivo, tepotinib exhibits marked, dose-dependent antitumor activity in MET-dependent tumor models of various cancer indications. Tepotinib penetrates the blood-brain barrier and demonstrates strong antitumor activity in subcutaneous and orthotopic brain metastasis models, in-line with clinical activity observed in patients. MET amplification is an established mechanism of resistance to EGFR tyrosine kinase inhibitors (TKI), and preclinical studies show that tepotinib in combination with EGFR TKIs can overcome this resistance. Tepotinib is currently approved for the treatment of adult patients with advanced or metastatic non-small cell lung cancer harboring MET exon 14 skipping alterations. This review focuses on the pharmacology of tepotinib in preclinical cancer models harboring MET alterations and demonstrates that strong adherence to the principles of the Pharmacological Audit Trail may result in a successful discovery and development of a precision medicine.

Translational PK/PD Modeling of Tumor Growth Inhibition and Target Inhibition to Support Dose Range Selection of the LMP7 Inhibitor M3258 in Relapsed/Refractory Multiple Myeloma

M3258 is an orally bioavailable, potent, selective, reversible inhibitor of the large multifunctional peptidase 7 (LMP7, β5i, PSMB8) proteolytic subunit of the immunoproteasome, a component of the cellular protein degradation machinery, highly expressed in malignant hematopoietic cells including multiple myeloma. Here we describe the fit-for-purpose pharmacokinetic (PK)/pharmacodynamic (PD)/efficacy modeling of M3258 based on preclinical data from several species. The inhibition of LMP7 activity (PD) and tumor growth (efficacy) were tested in human multiple myeloma xenografts in mice. PK and efficacy data were correlated yielding a free M3258 concentration of 45 nM for half-maximal tumor growth inhibition (KC₅₀). As M3258 only weakly inhibits LMP7 in mouse cells, both in vitro and in vivo bridging studies were performed in rats, monkeys, and dogs for translational modeling. These data indicated that the PD response in human xenograft models was closely reflected in dog PBMCs. A PK/PD model was established, predicting a free IC₅₀ value of 9 nM for M3258 in dogs in vivo, in close agreement with in vitro measurements. In parallel, the human PK parameters of M3258 were predicted by various approaches including in vitro extrapolation and allometric scaling. Using PK/PD/efficacy simulations, the efficacious dose range and corresponding PD response in human were predicted. Taken together, these efforts supported the design of a phase Ia study of M3258 in multiple myeloma patients (NCT04075721). At the lowest tested dose level, the predicted exposure matched well with the observed exposure while the duration of LMP7 inhibition was underpredicted by the model. SIGNIFICANCE STATEMENT: M3258 is a novel inhibitor of the immunoproteasome subunit LMP7. The human PK and human efficacious dose range of M3258 were predicted using in vitro-in vivo extrapolation and allometric scaling methods together with a fit-for-purpose PK/PD and efficacy model based on data from several species. A comparison with data from the Phase Ia clinical study showed that the human PK was accurately predicted, while the extent and duration of PD response were more pronounced than estimated.

Abstract P5-08-04: LMP7-specific inhibitor M3258 modulates the tumor microenvironment of aggressive breast cancer

Background: LMP7 (beta5i/PSMB8) is a proteolytic subunit of the immunoproteasome that is predominantly expressed in leukocytes and inflamed tissues. The immunoproteasome degrades ubiquitinated proteins for maintenance of cell homeostasis and generation of peptides for MHC class I presentation. LMP7 has been implicated in multiple myeloma, autoimmune and inflammatory diseases, and inflammation-related cancers. Here, we evaluated the effect of M3258, an orally bioavailable, highly-selective, and reversible inhibitor of LMP7, on the tumor microenvironment (TME) using in vitro and in vivo models of triple-negative breast cancer (TNBC) and inflammatory breast cancer (IBC). Methods: The proteolytic activity of M3258 was determined using the fluorogenic LMP7-specific peptidic substrate (Ac-ANW)2R110. Its anti-proliferation activity was determined using the CellTiter-Blue cell viability and sulforhodamine B staining assays. Expression of immunoproteasome subunits under different conditions was examined by Western blotting. All in vitro assessments were done with or without IFNγ, which is known to increase immunoproteasome expression. The in vivo anti-tumor efficacy of M3258 was evaluated using a SUM-149 PT TN-IBC xenograft mouse model implanted in humanized mice. Single-cell RNA sequencing (scRNA-seq) was used in this same study to examine the impact of M3258 on the TME. Results: M3258 inhibited LMP7 activity (IC50 = 6.5-212.8 nM) and had no effects on LMP7 protein expression in a panel of TNBC cells (DU4475, HCC1187), IBC cells (SUM190, IBC3, KPL4), and TN-IBC cells (SUM-149 PT, BCX-010, FC-IBC02). M3258 inhibited proliferation of TNBC and IBC cell lines in vitro (IC50 = 1-20 µM). In keeping with previous reports, IFNγ treatment strongly induced LMP7 expression and enhanced its proteolytic activity in these cell lines in vitro and increased M3258 sensitivity (2- to 5-fold). In the humanized SUM-149 PT xenograft mouse model, M3258 orally administered at 10 mg/kg significantly inhibited tumor growth versus vehicle (31.4%, P < 0.01) and was tolerated. ScRNA-seq analysis of the terminal tumor samples from this study revealed that M3258 reduced the abundance of CD4+ and CD8+ T cells, Tregs, M1 and M2 macrophages, and dendritic cells. Gene expression profiling indicated a particularly pronounced inhibitory effect of M3258 on M1 and M2 macrophages. Furthermore, M3258 treatment activated CD8+ T cells and suppressed expression of genes involved in inflammatory response, IFNα signaling, IFNγ signaling, and TNFα signaling in immune cells. In light of the scRNA-seq findings, we assessed the impact of M1 and M2 macrophages on the invasiveness of TN-IBC cells in vitro. Co-cultures with M1 or M2 macrophages enhanced invasiveness of SUM-149 PT cells (4.6-fold by M1, P < 0.001; 6.3-fold by M2, P < 0.01) and BCX-010 cells (2.1-fold by M1, P < 0.05; 4.0-fold by M2, P < 0.01). Since M2 macrophages showed a superior effect than M1 macrophages on TN-IBC cell invasiveness, we further assessed M3258’s ability to inhibit such activity. M3258 at 500 nM significantly inhibited M2 macrophage-induced invasion of SUM-149 PT cells (29.6%, P < 0.05) and BCX-010 (49.5%, P < 0.01). Conclusion: Using the exquisitely selective LMP7 inhibitor M3258, we were able to demonstrate for the first time that LMP7 plays an important role in the inflammatory microenvironment, proliferation and invasiveness of TNBC and IBC cells, in particular by modulating the pathogenic role of M2 macrophages. These data warrant future in vivo studies into the antitumor efficacy of M3258 when used with immunotherapy agents.

Citation Format: Xuemei Xie, Jangsoon Lee, Ganiraju C Manyam, Troy Pearson, Gina Walter-Bausch, Manja Friese-Hamim, Samantha M Goodstal, Debu Tripathy, Wang Jing, Michael Sanderson, Naoto T Ueno. LMP7-specific inhibitor M3258 modulates the tumor microenvironment of aggressive breast cancer [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P5-08-04.

M3258 Is a Selective Inhibitor of the Immunoproteasome Subunit LMP7 (β5i) Delivering Efficacy in Multiple Myeloma Models

Large multifunctional peptidase 7 (LMP7/β5i/PSMB8) is a proteolytic subunit of the immunoproteasome, which is predominantly expressed in normal and malignant hematolymphoid cells, including multiple myeloma, and contributes to the degradation of ubiquitinated proteins. Described herein for the first time is the preclinical profile of M3258; an orally bioavailable, potent, reversible and highly selective LMP7 inhibitor. M3258 demonstrated strong antitumor efficacy in multiple myeloma xenograft models, including a novel model of the human bone niche of multiple myeloma. M3258 treatment led to a significant and prolonged suppression of tumor LMP7 activity and ubiquitinated protein turnover and the induction of apoptosis in multiple myeloma cells both in vitro and in vivo Furthermore, M3258 showed superior antitumor efficacy in selected multiple myeloma and mantle cell lymphoma xenograft models compared with the approved nonselective proteasome inhibitors bortezomib and ixazomib. The differentiated preclinical profile of M3258 supported the initiation of a phase I study in patients with multiple myeloma (NCT04075721).

Structure-Based Optimization and Discovery of M3258, a Specific Inhibitor of the Immunoproteasome Subunit LMP7 (β5i)

Proteasomes are broadly expressed key components of the ubiquitin-dependent protein degradation pathway containing catalytically active subunits (β1, β2, and β5). LMP7 (β5i) is a subunit of the immunoproteasome, an inducible isoform that is predominantly expressed in hematopoietic cells. Clinically effective pan-proteasome inhibitors for the treatment of multiple myeloma (MM) nonselectively target LMP7 and other subunits of the constitutive proteasome and immunoproteasome with comparable potency, which can limit the therapeutic applicability of these drugs. Here, we describe the discovery and structure-based hit optimization of novel amido boronic acids, which selectively inhibit LMP7 while sparing all other subunits. The exploitation of structural differences between the proteasome subunits culminated in the identification of the highly potent, exquisitely selective, and orally available LMP7 inhibitor 50 (M3258). Based on the strong antitumor activity observed with M3258 in MM models and a favorable preclinical data package, a phase I clinical trial was initiated in relapsed/refractory MM patients.

Translational pharmacokinetic-pharmacodynamic modeling of preclinical and clinical data of the oral MET inhibitor tepotinib to determine the recommended phase II dose

Tepotinib is a highly selective and potent MET inhibitor in development for the treatment of patients with solid tumors. Given the favorable tolerability and safety profiles up to the maximum tested dose in the first‐in‐human (FIH) trial, an efficacy‐driven translational modeling approach was proposed to establish the recommended phase II dose (RP2D). To study the in vivo pharmacokinetics (PKs)/target inhibition/tumor growth inhibition relationship, a subcutaneous KP‐4 pancreatic cell‐line xenograft model in mice with sensitivity to MET pathway inhibition was selected as a surrogate tumor model. Further clinical PK and target inhibition data (derived from predose and postdose paired tumor biopsies) from a FIH study were integrated with the longitudinal PKs and target inhibition profiles from the mouse xenograft study to establish a translational PK/pharmacodynamic (PD) model. Preclinical data showed that tumor regression with tepotinib treatment in KP‐4 xenograft tumors corresponded to 95% target inhibition. We therefore concluded that a PD criterion of sustained, near‐to‐complete (>95%) phospho‐MET inhibition in tumors should be targeted for tepotinib to be effective. Simulations of dose‐dependent target inhibition profiles in human tumors that exceeded the PD threshold in more than 90% of patients established an RP2D of tepotinib 500 mg once daily. This translational mathematical modeling approach supports an efficacy‐driven rationale for tepotinib phase II dose selection of 500 mg once daily. Tepotinib at this dose has obtained regulatory approval for the treatment of patients with non‐small cell lung cancer harboring MET exon 14 skipping.

Activity of tepotinib in hepatocellular carcinoma (HCC) with high-level MET amplification (METamp): Preclinical and clinical evidence

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Background: Tepotinib, a potent and highly selective MET inhibitor, showed promising activity in advanced HCC with MET overexpression in two Phase Ib/II trials, which both met their primary endpoints. One trial enrolled Asian patients (pts) without prior systemic therapy (first line [1L]; NCT01988493) and one enrolled US/European pts with prior sorafenib (second line [2L]; NCT02115373). By investigator assessment, objective response rates and disease control rates with tepotinib in Phase II were 15.8% and 60.5% in 1L (n = 38), and 8.2% and 57.1% in 2L (n = 49). Outcomes appeared better in pts with METamp. Thus, we further investigated the preclinical and clinical activity of tepotinib in HCC, focusing on high-level METamp, which could be an oncogenic driver in this tumor type. Methods: Preclinical activity was assessed in 37 HCC pt-derived xenografts (PDXs) in nude mice treated with tepotinib (100 mg/kg, Days 1–5, every 7 days for five cycles; 6–12 replicates per PDX). Clinical activity was assessed by analyzing pts with METamp or high-level METamp (defined as mean MET gene copy number [GCN] ≥5 and ≥10, respectively; by fluorescence in situ hybridization), who received tepotinib 500 mg in Phase Ib or II of the 1L and 2L trials (n = 121). In the Phase Ib part of the 1L trial, pts could have received prior treatment. Results: Molecular profiling revealed high-level METamp in two of 37 HCC PDXs: LIM612 ( MET GCN 47.1) and LIPF210 ( MET GCN 44). Tepotinib induced significant tumor regression in both of these high-level METamp HCC PDX models (mean tumor volume reduction: 97% and 96%, respectively). Across the two trials, 15 pts treated with tepotinib 500 mg had METamp, of whom five had an objective response (one complete response [CR] and four partial responses [PRs]) and six had stable disease (SD) as best overall response. Four pts had high-level METamp (mean MET GCN 14.3, 18.1, 30.2, and 36.2), with best overall response of CR in one pt, PR in two pts and SD in one pt (Table). One pt with high-level METamp (mean MET GCN 14.3) treated with 1L tepotinib was still receiving treatment as of Sept 2020 (total tepotinib treatment duration: > 45 months). Conclusions: High-level METamp may be an oncogenic driver in HCC that sensitizes tumors to MET inhibition with tepotinib. Compared with MET overexpression, high-level METamp could be a better predictive biomarker for MET inhibitors in this setting. Clinical trial information: NCT01988493, NCT02115373. [Table: see text]

First-in-Man Phase I Trial of the Selective MET Inhibitor Tepotinib in Patients with Advanced Solid Tumors

PURPOSE

Tepotinib is an oral, potent, highly selective MET inhibitor. This first-in-man phase I trial investigated the MTD of tepotinib to determine the recommended phase II dose (RP2D).

PATIENTS AND METHODS

Patients received tepotinib orally according to one of three dose escalation regimens (R) on a 21-day cycle: R1, 30-400 mg once daily for 14 days; R2, 30-315 mg once daily 3 times/week; or R3, 300-1,400 mg once daily. After two cycles, treatment could continue in patients with stable disease until disease progression or unacceptable toxicity. The primary endpoint was incidence of dose-limiting toxicity (DLT) and treatment-emergent adverse events (TEAE). Secondary endpoints included safety, tolerability, pharmacokinetics, pharmacodynamics, and antitumor effects.

RESULTS

One hundred and forty-nine patients received tepotinib (R1: n = 42; R2: n = 45; R3: n = 62). Although six patients reported DLTs [one patient in R1 (115 mg), three patients in R2 (60, 100, 130 mg), two patients in R3 (1,000, 1,400 mg)], the MTD was not reached at the highest tested dose of 1,400 mg daily. The RP2D of tepotinib was established as 500 mg once daily, supported by translational modeling data as sufficient to achieve ≥95% MET inhibition in ≥90% of patients. Treatment-related TEAEs were mostly grade 1 or 2 fatigue, peripheral edema, decreased appetite, nausea, vomiting, and lipase increase. The best overall response in R3 was partial response in two patients, both with MET overexpression.

CONCLUSIONS

Tepotinib was well tolerated with clinical activity in MET-dysregulated tumors. The RP2D of tepotinib was established as 500 mg once daily. MET abnormalities can drive tumorigenesis. This first-in-man trial demonstrated that the potent, highly selective MET inhibitor tepotinib can reduce or stabilize tumor burden and is well tolerated at doses up to 1,400 mg once daily. An RP2D of 500 mg once daily, as determined from translational modeling and simulation integrating human population pharmacokinetic and pharmacodynamic data in tumor biopsies, is being used in ongoing clinical trials.

Targeting the MET Receptor Tyrosine Kinase as a Strategy for Radiosensitization in Locoregionally Advanced Head and Neck Squamous Cell Carcinoma

Radiotherapy (RT) along with surgery is the mainstay of treatment in head and neck squamous cell carcinoma (HNSCC). Radioresistance represents a major source of treatment failure, underlining the urgent necessity to explore and implement effective radiosensitization strategies. The MET receptor widely participates in the acquisition and maintenance of an aggressive phenotype in HNSCC and modulates the DNA damage response following ionizing radiation (IR). Here, we assessed MET expression and mutation status in primary and metastatic lesions within a cohort of patients with advanced HNSCC. Moreover, we investigated the radiosensitization potential of the MET inhibitor tepotinib in a panel of cell lines, in vitro and in vivo, as well as in ex vivo patient-derived organotypic tissue cultures (OTC). MET was highly expressed in 62.4% of primary tumors and in 53.6% of lymph node metastases (LNM), and in 6 of 9 evaluated cell lines. MET expression in primaries and LNMs was significantly associated with decreased disease control in univariate survival analyses. Tepotinib abrogated MET phosphorylation and to distinct extent MET downstream signaling. Pretreatment with tepotinib resulted in variable radiosensitization, enhanced DNA damage, cell death, and G₂-M-phase arrest. Combination of tepotinib with IR led to significant radiosensitization in one of two tested in vivo models. OTCs revealed differential patterns of response toward tepotinib, irradiation, and combination of both modalities. The molecular basis of tepotinib-mediated radiosensitization was studied by a CyTOF-based single-cell mass cytometry approach, which uncovered that MET inhibition modulated PI3K activity in cells radiosensitized by tepotinib but not in the resistant ones.

Abstract 3075: Antitumor activity of M8891, a potent and reversible inhibitor of methionine aminopeptidase 2

N-terminal cleavage of methionine by methionine aminopeptidases is a crucial step in the maturation of proteins during protein biosynthesis. MetAP2, one of the two methionine aminopeptidases expressed in mammalian cells, has been identified as the target of the highly potent and irreversible inhibitor fumagillin to which antiangiogenic and antitumoral properties have been ascribed. This and other findings support the rationale to develop MetAP2 inhibitors for cancer therapy. The fumagillin derivative TNP-470 has been evaluated in several clinical trials, but development was discontinued following demonstration of unfavorable pharmacokinetics and side effects likely attributed to the reactivity of the compound. We have developed M8891, an orally bioavailable, potent, and reversible inhibitor of MetAP2. M8891 inhibited growth of primary endothelial cells as well as patient-derived tumor cells and demonstrated antiangiogenic and antitumoral activity in mouse models. Accumulation of an unprocessed MetAP2 substrate, methionylated elongation factor 1 α, Met-EF1a, was observed upon treatment with M8891 in vitro as well as in vivo confirming that MetAP2 can be effectively inhibited with this compound. In combination with sunitinib, M8891 demonstrated strong and durable antitumor activity in a cohort of patient-derived renal cancer xenografts at well-tolerated exposure levels. Predictive biomarker hypotheses generated from CRISPR sensitivity/resistance screens as well as analyses of molecular profiling data from PDX tumors are currently being evaluated in further nonclinical studies. A dose-escalation phase 1 study in patients with advanced solid tumors is currently ongoing.

Citation Format: Manja Friese-Hamim, Olga Bogatyrova, Maria J. Ortiz, Dirk Wienke, Timo Heinrich, Felix Rohdich, Klaus Duecker, Christoph Schultes, Bayard Huck, Frank T. Zenke, Andree Blaukat. Antitumor activity of M8891, a potent and reversible inhibitor of methionine aminopeptidase 2 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3075.

The selective c-Met inhibitor tepotinib can overcome epidermal growth factor receptor inhibitor resistance mediated by aberrant c-Met activation in NSCLC models

Non-small cell lung cancer (NSCLC) sensitive to first-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) often acquires resistance through secondary EGFR mutations, including the T790M mutation, aberrant c-Met receptor activity, or both. We assessed the ability of the highly selective c-Met inhibitor tepotinib to overcome EGFR TKI resistance in various xenograft models of NSCLC. In models with EGFR-activating mutations and low c-Met expression (patient explant-derived LU342, cell line PC-9), EGFR TKIs caused tumors to shrink, but growth resumed upon cessation of treatment. Tepotinib combined with EGFR TKIs delayed tumor regrowth, while tepotinib alone was ineffective. In patient explant-derived LU858, which has an EGFR-activating mutation and expresses high levels of c-Met/HGF, EGFR TKIs had no effect on tumor growth. Tepotinib combined with EGFR TKIs caused complete tumor regression and tepotinib alone caused tumor stasis. In cell line DFCI081 (activating EGFR mutation, c-Met amplification), EGFR TKIs were ineffective, whereas tepotinib alone induced complete tumor regression. Finally, in a 'double resistant' EGFR T790M-positive, high c-Met model (cell line HCC827-GR-T790M), the EGFR TKIs erlotinib, afatinib, and rociletinib, as well as tepotinib as a single agent or in combination with erlotinib or afatinib, slowed tumor growth, but only tepotinib in combination with rociletinib induced complete tumor regression. We conclude that tepotinib can overcome acquired resistance to EGFR TKIs. Based on these data, clinical trials of tepotinib in combination with EGFR TKIs in patients with NSCLC with acquired resistance to first-generation EGFR TKIs are warranted.

Abstract 4663: Combination of c-Met inhibitor tepotinib (MSC2156119J) and a third-generation EGFR inhibitor can overcome double resistance mediated by EGFR T790M mutation and c-Met amplification in non-small cell lung cancer models

In clinical practice, acquired resistance to EGFR tyrosine kinase inhibitors (TKIs) in EGFR-mutant non-small cell lung cancer (NSCLC) causes EGFR TKI treatment failure. Several resistance mechanisms have been identified; EGFR T790M mutation and aberrant activation of c-Met through c-Met gene amplification and/or HGF upregulation are the two most common mechanisms. We have previously shown that combining the highly selective c-Met inhibitor tepotinib with 1st or 2nd-generation EGFR TKIs overcomes gefitinib resistance caused only by c-MET amplification. Third-generation EGFR TKIs such as rociletinib have been developed specifically to overcome T790M-mediated resistance to EGFR TKIs. We hypothesized that combining a 3rd-generation EGFR TKI with tepotinib could overcome resistance to a 1st or 2nd-generation EGFR TKI (e.g. gefitinib) regardless of the mechanism of resistance.

We assessed the efficacy of tepotinib and a Merck-synthesized version of rociletinib (MSR) as monotherapy or in combination in a NSCLC cell line xenograft model (HCC827-GR-T790M) with an EGFR del 19 mutation, c-Met amplification, and exogenous T790M expression, and in a patient-derived xenograft model (DFCI081) with an EGFR del 19 mutation and c-Met amplification, but not a T790M mutation.

Single-agent tepotinib, erlotinib, and afatinib did not show antitumor activity in HCC827-GR-T790M xenografts and tumors progressed on treatment (median tumor volume [TV] changes >73%). The combinations of tepotinib + erlotinib and tepotinib + afatinib delayed tumor regrowth more than single-agent therapy, but were no more effective than single-agent MSR. In contrast, the combination of tepotinib + MSR had strong antitumor activity in this model with double resistance due to c-Met amplification and exogenous T790M expression, resulting in complete tumor regression (median TV change -97%).

In the patient-derived xenograft model DFCI081, tumors progressed under single-agent therapy with the EGFR TKIs erlotinib, afatinib, and MSR, as expected given that this cell line expresses c-Met. In contrast, tepotinib induced complete tumor regression as monotherapy and when combined with each of the EGFR TKIs (median TV change -100%). Complete regression was maintained until the end of the 60-day observation period after treatment termination.

These findings are compatible with the hypothesis that combining tepotinib with a 3rd-generation EGFR TKI to overcome double resistance to 1st and 2nd-generation TKIs mediated by T790M and c-Met in NSCLC is more effective than using either agent alone. Furthermore, whereas EGFR TKIs were not effective in tumor models showing c-Met amplification and EGFR del 19 mutation but not T790M mutation, ie resistance is c-Met mediated, tepotinib monotherapy induced complete tumor regression.

Citation Format: Manja Friese-Hamim, Giuseppe Locatelli, Friedhelm Bladt. Combination of c-Met inhibitor tepotinib (MSC2156119J) and a third-generation EGFR inhibitor can overcome double resistance mediated by EGFR T790M mutation and c-Met amplification in non-small cell lung cancer models. [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 4663.

Abstract 2591: Activity of MSC2156119J in non-small cell lung cancer models with activating EGFR mutation

The therapeutic success of EGFR tyrosine kinase inhibitors (TKIs) in EGFR-mutant non-small cell lung cancer (NSCLC) is hampered in a subset of patients by the development of drug resistance through the EGFR T790M ‘gate keeper’ mutation. Recent investigations suggest that aberrant activation of the c-Met receptor through c-Met amplification and/or HGF upregulation may be an additional mechanism for acquired resistance. Combination of an EGFR TKI with a c-Met inhibitor could, therefore, delay and/or prevent the emergence of c-Met-driven resistance.

The aim of our study was to evaluate the efficacy of MSC2156119J, a highly selective small molecule c-Met inhibitor, as monotherapy or in combination with EGFR TKIs (erlotinib, gefitinib and afatinib) in human xenograft models transplanted with two different primary NSCLC explants, LU342 and LU0858. While both tumors express the activated EGFR mutant form, LU342 expresses low levels of c-Met, while LU0858 expresses high levels of c-Met and carries an amplified c-Met locus.

Single-agent MSC2156119J was inactive against the low c-Met-expressing LU342 explant and tumors progressed on treatment (median tumor volume [TV] change >73%). Erlotinib treatment resulted in tumor regression, with median TV change of -93% and tumor growth delay (TGD) of 56 days. The combination of MSC2156119J and erlotinib was more active, delaying tumor regrowth by 73 days compared to erlotinib monotherapy. Administration of afatinib at 5mg/kg was highly active in this model, inducing complete tumor regression (median TV change -100%), similar to the combination of afatinib and MSC2156119J.

In contrast, the LU0858 explant, which carries an amplified c-Met locus, was sensitive to MSC2156119J at a dose of 100mg/kg 5 days on and 2 days off (5 on/2 off), inducing tumor stasis with a median TV change of 19% and TGD of 34 days. While gefitinib and afatinib alone at doses of 150mg/kg 5 on/2 off and 5mg/kg 5 on/2 off, respectively, were inactive (median TV changes >73%), in combination with MSC2156119J tumor growth inhibition was enhanced, resulting in tumor regression (median TV changes of -64% and -85%, respectively). In comparison, tumors treated with platinum-based doublet chemotherapy (cisplatin 5mg/kg QW/pemetrexed 200mg/kg QW) progressed, with TGD of 16 days. When MSC2156119J was combined with cisplatin/pemetrexed, antitumor activity was not significantly enhanced compared to single-agent MSC2156119J (median TV change -32%, TGD 30 days).

Together, these findings are compatible with the hypothesis that inhibition of the c-Met pathway prevents and/or delays the emergence of c-Met-driven resistance in EGFR-mutant NSCLC. Furthermore, the enhancement of antitumor activity in the low c-Met-expressing LU342 model when MSC2156119J was combined with erlotinib suggests that the combination of an EGFR TKI + MSC2156119J may also be active in tumors with low levels of c-Met expression.

Citation Format: Friedhelm Bladt, Manja Friese-Hamim, Andree Blaukat. Activity of MSC2156119J in non-small cell lung cancer models with activating EGFR mutation. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 2591. doi:10.1158/1538-7445.AM2015-2591

Abstract 2724: Development of a sensitive assay for measuring pharmacodynamic modulation of c-Met in biopsies

Introduction: MSC2156119J, a highly selective, potent, reversible, ATP-competitive c-Met inhibitor currently under clinical testing, efficiently inhibits c-Met phosphorylation and downstream signaling in vivo and induces regression of established tumors in xenograft models in preclinical studies (Bladt et al. Clin Cancer Res. 2013;19:2941-51). One initial event following c-Met activation is Y1234/35 phosphorylation in the activation loop of the kinase domain. This results in kinase activation and triggers phosphorylation of tyrosine residues in the c-Met C-terminal tail (eg, Y1349), creating multifunctional docking sites for intracellular adapters. The development of an assay allowing the measurement of these phospho-c-Met epitopes in tumor biopsies will be crucial for establishing an optimal biologic dose for MSC2156119J. Methods: We describe here the development of a highly sensitive Luminex assay that can reliably and reproducibly measure the phosphorylation state of Y1234/35 and Y1349 residues of the c-Met receptor. The high sensitivity of the assay was confirmed by measuring the phospho-c-Met levels in biopsies from patients before and during MSC2156119J treatment. Results: We first assessed the stability of phosphorylated Y1234/35 and Y1349 epitopes in preclinical tumor samples. Analyses revealed that the total c-Met protein is rather stable over time, while the phospho-c-Met epitopes Y1234/35 and Y1349 are relatively unstable; their detection requires rapid processing of tumor samples derived from preclinical tumors or from patients. In tumor samples derived from human xenografts treated with MSC2156119J, Y1349 phosphorylation inhibition varied in different tumor models and did not show strong dose dependence. In contrast, phosphorylation of Y1234/35 residues was effectively inhibited by MSC2156119J in all tumor models tested. Based on these findings, phosphorylation of c-Met Y1234/35 was also assessed in tumor biopsies from patients treated with MSC2156119J in the first-in-man trial (NCT01014936; Falchook et al. J Clin Oncol. 2013;31(suppl):2506). When compared to pretreatment tumor biopsies, on-treatment samples showed effective, dose-dependent inhibition of >90% of c-Met Y1234/35 phosphorylation. Conclusions: We successfully developed an assay capable of detecting phosphorylation of the c-Met Y1234/35 epitope, which is crucial for c-Met activation. Using this assay on tumor samples from xenograft models and on patient-derived tumor biopsies, we demonstrated that MSC2156119J inhibits phosphorylation of c-Met Y1234/35 in a dose-dependent fashion. Therefore, phosphorylation of c-Met Y1234/35 can be used as a pharmacodynamic biomarker of c-Met inhibition and will be an important and valuable element for the selection of the optimal biologic dose of MSC2156119J.

Citation Format: Friedhelm Bladt, Frank Jaehrling, Manja Friese-Hamim, Gerald S. Falchook, Hesham M. Amin, Manfred B. Klevesath, Andree Blaukat. Development of a sensitive assay for measuring pharmacodynamic modulation of c-Met in biopsies. [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 2724. doi:10.1158/1538-7445.AM2014-2724

The c-Met Inhibitor MSC2156119J Effectively Inhibits Tumor Growth in Liver Cancer Models

The mesenchymal-epithelial transition factor (c-Met) is a receptor tyrosine kinase with hepatocyte growth factor (HGF) as its only high-affinity ligand. Aberrant activation of c-Met is associated with many human malignancies, including hepatocellular carcinoma (HCC). We investigated the in vivo antitumor and antimetastatic efficacy of the c-Met inhibitor MSC2156119J (EMD 1214063) in patient-derived tumor explants. BALB/c nude mice were inoculated with MHCC97H cells or with tumor fragments of 10 patient-derived primary liver cancer explants selected according to c-Met/HGF expression levels. MSC2156119J (10, 30, and 100 mg/kg) and sorafenib (50 mg/kg) were administered orally as single-agent treatment or in combination, with vehicle as control. Tumor response, metastases formation, and alpha fetoprotein (AFP) levels were measured. MSC2156119J inhibited tumor growth and induced complete regression in mice bearing subcutaneous and orthotopic MHCC97H tumors. AFP levels were undetectable after 5 weeks of MSC2156119J treatment, and the number of metastatic lung foci was reduced. Primary liver explant models with strong c-Met/HGF activation showed increased responsiveness to MSC2156119J, with MSC2156119J showing similar or superior activity to sorafenib. Tumors characterized by low c-Met expression were less sensitive to MSC2156119J. MSC2156119J was better tolerated than sorafenib, and combination therapy did not improve efficacy. These findings indicate that selective c-Met/HGF inhibition with MSC2156119J is associated with marked regression of c-Met high-expressing tumors, supporting its clinical development as an antitumor treatment for HCC patients with active c-Met signaling.

Association of EGFR expression level and cetuximab activity in patient-derived xenograft models of human non-small cell lung cancer

PURPOSE

To explore in a panel of patient-derived xenograft models of human non-small cell lung cancer (NSCLC) whether high EGFR expression, was associated with cetuximab activity.

EXPERIMENTAL DESIGN

NSCLC patient-derived xenograft models (n=45) were implanted subcutaneously into panels of nude mice and randomization cohorts were treated with either cetuximab, cisplatin, cisplatin plus cetuximab, vehicle control, or else were left untreated. Responses according to treatment were assessed at week 3 by analyzing the relative change in tumor volume and an experimental analogue of the Response Evaluation Criteria in Solid Tumors (RECIST) guidelines. An EGFR IHC score was calculated for each patient-derived xenograft model and response was assessed according to EGFR expression level.

RESULTS

When tumors were stratified into high and low EGFR expression groups (IHC score threshold 200; scale 0-300), a stronger antitumor activity was seen in the high EGFR expression group compared with the low EGFR expression group in both the cetuximab monotherapy and cisplatin plus cetuximab combination therapy settings. For tumors treated with cisplatin plus cetuximab, the objective response rate was significantly higher in the high EGFR expression group compared with the low EGFR expression group (68% vs. 29%). Objective response rates were similar in high and low expression groups for tumors treated with cisplatin alone (27% vs. 24%, respectively).

CONCLUSION

Cetuximab activity in NSCLC patient-derived xenograft models was demonstrated clearly only in tumors that expressed high levels of EGFR, as defined by an IHC score of ≥200.

Abstract 925: The c-Met inhibitor MSC2156119J effectively inhibits growth of liver cancer models

The mesenchymal-epithelial transition factor (c-Met) receptor, also known as hepatocyte growth factor receptor (HGFR), controls morphogenesis, a process physiologically required for embryonic development and tissue repair. Aberrant c-Met activation is associated with human malignancies, including hepatocellular carcinomas (HCC). The aim of this study was to evaluate the effect of a novel, highly selective c-Met inhibitor, MSC2156119J (EMD 1214063), in hepatocellular cancer models.

MHCC97H is a human HCC cell line co-expressing c-Met and HGF, and exhibiting high metastatic potential. The effect of MSC2156119J on MHCC97H was evaluated in a Balb/c nu/nu murine xenograft model in a subcutaneous and orthotopic setting. Tumor-bearing mice were orally treated with 100 mg/kg MSC2156119J (5 days on/2 days off). In the subcutaneous setting, MSC2156119J resulted in tumor regression in 10/10 mice, achieving tumor eradication in 9/10 mice. In the orthotopic model, MHCC97H tumor fragments proliferate in the liver and invariably metastasize to the lung (100%). MSC2156119J treatment started 7 days after tumor fragment implantation. After 5 weeks of treatment, mice were necropsied and a series of parameters were assessed. Primary tumor size and weight, and circulating Alpha-Feto-Protein levels were significantly lower in mice treated with MSC2156119J compared to controls (p<0.001). Notably, treatment with MSC2156119J resulted in a reduced number of mice with visible lung metastasis (6/9), and correlated with a significantly lower number of metastatic foci in the lungs compared to control mice (p<0.01).

To better predict the clinical efficacy of MSC2156119J, 9 patient-derived primary HCC explants models were used. The explants were subdivided into 3 groups, based on their c-Met levels and HGF expression. Each group comprised 3 tumors expressing high, intermediate, and low levels of c-Met and HGF, respectively. Mice were treated with MSC2156119J, sorafenib, or a combination of both.

MSC2156119J (100 mg/kg/5 out of 7 days) strongly inhibited tumor growth in 4/9 models (TGD range of 370% to 41%). Analysis of intratumoral c-Met, phospho c-Met and HGF levels indicated that explants with high levels of c-Met and HGF were more sensitive to MSC2156119J than low-expressing models. In 3/4 responsive models, MSC2156119J exhibited a better anti-tumor activity than sorafenib, while sorafenib was more efficacious in a model characterized by intermediate c-Met/HGF expression. MSC2156119J was not efficacious in models exhibiting low or no signs of c-Met signalling. When used in combination, MSC2156119J did not enhance the activity of sorafenib. MSC2156119J monotherapy was well tolerated while sorafenib alone and in combination with MSC2156119J induced significant body weight loss.

Overall, these data indicate that MSC2156119J may be a valuable therapeutic option for liver cancers with high levels of c-Met expression/activation.

Citation Format: Friedhelm Bladt, Andree Blaukat, Dieter Dorsch, Manja Friese-Hamim, Michael Meyring, Oliver Schadt. The c-Met inhibitor MSC2156119J effectively inhibits growth of liver cancer models. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 925. doi:10.1158/1538-7445.AM2013-925

EMD 1214063 and EMD 1204831 constitute a new class of potent and highly selective c-Met inhibitors

PURPOSE

The mesenchymal-epithelial transition factor (c-Met) receptor, also known as hepatocyte growth factor receptor (HGFR), controls morphogenesis, a process that is physiologically required for embryonic development and tissue repair. Aberrant c-Met activation is associated with a variety of human malignancies including cancers of the lung, kidney, stomach, liver, and brain. In this study, we investigated the properties of two novel compounds developed to selectively inhibit the c-Met receptor in antitumor therapeutic interventions.

EXPERIMENTAL DESIGN

The pharmacologic properties, c-Met inhibitory activity, and antitumor effects of EMD 1214063 and EMD 1204831 were investigated in vitro and in vivo, using human cancer cell lines and mouse xenograft models.

RESULTS

EMD 1214063 and EMD 1204831 selectively suppressed the c-Met receptor tyrosine kinase activity. Their inhibitory activity was potent [inhibitory 50% concentration (IC50), 3 nmol/L and 9 nmol/L, respectively] and highly selective, when compared with their effect on a panel of 242 human kinases. Both EMD 1214063 and EMD 1204831 inhibited c-Met phosphorylation and downstream signaling in a dose-dependent fashion, but differed in the duration of their inhibitory activity. In murine xenograft models, both compounds induced regression of human tumors, regardless of whether c-Met activation was HGF dependent or independent. Both drugs were well tolerated and induced no substantial weight loss after more than 3 weeks of treatment.

CONCLUSIONS

Our results indicate selective c-Met inhibition by EMD 1214063 and EMD 1204831 and strongly support clinical testing of these compounds in the context of molecularly targeted anticancer strategies.

Abstract 1787: The c-Met inhibitors EMD 1214063 and EMD 1204831 are effective in combination with EGFR and VEGF inhibitors in NSCLC models

c-Met is a receptor tyrosine kinase that has hepatocyte growth factor as its ligand. Evidence from biochemical and human genetic studies indicate that c-Met is one of the most frequently activated tyrosine kinases in human cancer. Dysregulated c-Met signaling can result in the development of tumors highly dependent on c-Met. Furthermore, enhanced c-Met signaling is likely involved in conferring resistance to epidermal growth factor receptor (EGFR) and vascular endothelial growth factor (VEGF) inhibitors. The orally available EMD 1214063 and EMD 1204831 inhibit c-Met activity in a potent and highly selective fashion, and are currently being evaluated in cancer patients. Here we report the activity of these compounds in combination with inhibitors of EGFR and VEGF in various tumor xenograft models. EMD 1214063 was tested alone and in combination with EGFR inhibitors (erlotinib and cetuximab) in xenografts of erlotinib-resistant tumor cells, namely the lung cancer H1975 and the NCI-H441 non-small-cell lung cancer (NSCLC) cell lines. The H1975 cell line expresses moderate amounts of c-Met, and EMD 1214063 was inactive as a single agent (treatment group/control group [T/C] 78%; tumor growth delay [TGD] 2 days). Cetuximab was active with a T/C of 13% inducing a TGD of 21 days. The combination of EMD 1214063 and cetuximab was active with a T/C of α1% and a TGD of 42 days. The NCI-H441 cell line is characterized by constitutive c-Met overexpression and is sensitive to c-Met inhibitors in vivo. EMD 1214063 (100 mg/kg) was active inducing a T/C of 20%, while erlotinib alone (30 mg/kg) was not efficacious. However, the combination of EMD 1214063 with erlotinib enhanced tumor growth inhibition, induced partial tumor regression in 2/9 mice, and delayed tumor re-growth. These data are compatible with the hypothesis that cMet pathway activation confers resistance to EGFR inhibitors. We additionally investigated the combination of either EMD 1214063 or EMD 1204831 with VEGF inhibitors in NSCLC models. In NCI-H441 xenografts, EMD 1204831 produced a modest T/C (66%) at the suboptimal dose of 25 mg/kg/bid, similarly to aflibercept at 40 mg/kg (T/C 55%). In contrast, the combination of both compounds yielded a T/C of 1% with partial responses in 2/10 mice. In the EBC-1 model, treatment with EMD 1214063 (10 mg/kg) or with the antiVEGF antibody B20-4.1 (20 mg/kg) as single agents resulted in a T/C of β21% (with partial regression in 1/10 mice) and 19%, respectively. In contrast, the combination of EMD 1214063 and B20-4.1 exhibited enhanced anti-tumor activity with a T/C of −72% and partial regressions in 10/10 mice. These data support the hypothesis that EMD 1214063 or EMD 1204831 may be effective in NSCLC patients in combination with VEGF-targeting agents. In conclusion, our findings provide a rationale to evaluate the efficacy of the combination of EMD 1214063 or EMD 1204831 with EGFR and VEGF inhibitors in NSCLC patients.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 1787. doi:1538-7445.AM2012-1787

Abstract 2786: Identification and preclinical characterization of EMD 1204831 – A selective c-Met kinase inhibitor in clinical phase 1

The involvement of the mesenchymal endothelial transition factor (c-Met) in the primary event of oncogenic transformation and the secondary ability to mediate metastatic spread has been convincingly demonstrated in preclinical and early clinical settings. The clinical benefits of c-Met kinase inhibitors with various modes of actions and selectivity profiles are currently under investigation hoping that inhibitors of c-Met might emerge as valuable cancer therapeutics in the future. During an HTS run 3-(diethylamino)propyl N-[3-[[5-(3,4-dimethoxyphenyl)-2-oxo-6H-1,3,4-thiadiazin-3-yl]methyl]phenyl]carbamate was identified as an attractive lead structure with an interesting overall profile (clogD (7.4): 2.5, S (pH 7.4): >100 µg/ml, IC50 (cMet enzyme): 30 nM, IC50 (cMet A549): 800 nM) providing a valid starting point. The co-crystal structure of 1 revealed the binding mode and the essential structural features. The initial HTS hit was bound in a DFG-in conformation interacting with the main chain nitrogen atom of Met1160 within the hinge region and with the main chain nitrogen of Asp1222. After subsequent optimization of potency, efficacy, PK properties and the safety profile of thiadiazinone 1, EMD1204831 was identified as development compound. EMD1204831 is currently being investigated in a phase 1 clinical trial. The pyridazinone EMD1204831 inhibits enzymatic and cellular c-Met kinase activity with IC50 values of 12 nM and 15 nM, respectively. EMD1204831 displayed an exquisite selectivity when tested in vitro against a panel of more than 400 potential off-targets, including kinases, GPCRs, ion channels, transporters and various enzymes. EMD 1204831 demonstrated excellent anti-tumor activity in vivo in a variety of xenograft models, including U87-MG glioblastoma cells (autocrine HGF expression), TPR-Met-transformed mouse fibroblasts (oncogenic Met fusion protein) or Hs746T gastric cancer cells (c-Met gene amplification and HGF-independent activation). Depending on the particular model, complete regressions were observed with doses as low as 6 mg/kg/d administered per os. PK/PD analysis revealed efficient, dose- and time-dependent inhibition of c-Met phosphorylation, reduction of IL-8 and cyclin D1 expression as well as an induction of the cell cycle inhibitor p27. The overall profile of EMD1204831 including first time structural disclosure, some structure activity relationships, in vitro potency, selectivity profile and in-vivo data will be presented.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 2786. doi:10.1158/1538-7445.AM2011-2786

Abstract 3622: Preclinical characterization of EMD1214063, a potent and highly selective inhibitor of the c-Met kinase in Phase I clinical trials

c-Met, the receptor for hepatocyte growth factor (HGF), is a well characterized receptor tyrosine kinase, which is crucial for cell functions, such as survival, proliferation, motility and migration. Activating point mutations of c-Met have been identified in human malignancies, including renal carcinoma and lung cancer and constitutive activation of the HGF/c-Met pathway leads to tumor development and progression in cancer animal models. In the light of these findings, c-Met has become a key target for oncology therapeutics.

In order to develop c-Met specific inhibitors, we have conducted a biochemical HTS run with the recombinant kinase domain of c-Met. This approach has enabled us to identify a new class of c-Met inhibitors. Our report will focus on pharmacological and pre-clinical data, characterising EMD1214063, a promising therapeutic candidate currently under clinical testing.

Inhibition of the c-Met kinase by EMD1214063 was potent and highly selective. In in vitro kinase reactions and binding assays, EMD1214063 at a dose of 1μM, inhibited only 5 additional kinases in a panel of more than 250 different potential off-targets more than 50%. In vitro, EMD1214063 interfered with survival, anchorage-independent growth and HGF-induced migration of tumor cells, by blocking HGF-dependent as well as constitutive phosphorylation of c-Met.

In vivo, oral administration of EMD1214063 resulted in a strong inhibition - ranging from delayed growth to complete regression - of HGF-dependent and -independent c-Met driven tumor xenografts. Such anti-tumor activity was observed at a broad dose range, suggesting that EMD1214063 has a wide therapeutic index. The inhibitor was well tolerated, as indicated by the lack of significant weight loss in treated mice. The mechanism of action of EMD1214063 was investigated in vivo in a series of PK/PD studies. Administration of a single dose of EMD1214063 induced a complete and long-lasting inhibition of c-Met phosphorylation in the tumor xenografts. Furthermore, it strongly reduced the plasma levels of tumor-derived IL-8. c-Met phosphorylation and plasma IL-8 levels decreased as a function of the drug concentration in the tumor and plasma.

Taken together, the high c-Met selectivity, potency and in vivo efficacy of EMD1214063 render this compound a very promising candidate for the treatment of patients bearing c-Met-driven tumors.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 3622.

Abstract 5777: EMD 1214063, an exquisitely selective c-Met kinase inhibitor in clinical phase 1

The role of the receptor tyrosin kinase c-Met in tumor progression, metastasis and aggressiveness has been convincingly demonstrated in preclinical and early clinical settings. Several compounds with different selectivity profiles inhibiting c-Met are currently under preclinical/clinical investigation and might emerge as valuable cancer therapeutics in the future. During an HTS run N-(3-(3,6-Dihydro-5-(3,4-dimethoxyphenyl)-2-oxo-2H-1,3,4-thiadiazin-3-ylmethyl)-phenyl)-carbaminic acid-(3-(N,N-diethylamino)-propylester) (1) was identified as an attractive lead structure with an interesting overall profile (clogD (7.4): 2.5, S (pH 7.4): >100 µg/ml, IC50 (c-Met in vitro): 30 nM, IC50 (c-Met cellular): 800 nM) providing a valid starting point for lead optimization. The co-crystal structure of 1 revealed the binding mode and the essential structural features. The initial HTS hit was bound in a DFG-in conformation interacting namely with the main chain nitrogen atom of methionine 1160 within the hinge region and with the main chain nitrogen of aspartic acid 1222. After subsequent optimization of potency, efficacy, PK properties and the safety profile of thiadiazinone 1, EMD1214063 was identified as candidate for further development and is currently investigated in a phase 1 clinical trial. The pyridazinone EMD1214063 inhibits enzymatic and cellular c-Met kinase activity with IC50 values in the low nanomolar range. This compound displayed an exquisite selectivity when tested in vitro against a panel of more than 250 potential off-targets, including kinases, GPCRs, ion channels, transporters and various enzymes and demonstrated excellent anti-tumor activity in vivo in a variety of xenograft models. Depending on the particular model, complete regressions were observed with doses as low as 6 mg/kg/d administered per os. The overall profile of EMD1214063 including first time disclosure of the precise structure, synthesis, structure activity relationships, in vitro potency, selectivity profile, pharmacokinetic and in vivo data will be discussed.

Note: This abstract was not presented at the AACR 101st Annual Meeting 2010 because the presenter was unable to attend.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 5777.

Abstract B252: Identification of a new class of highly potent and selective c-Met kinase inhibitors

The role of the receptor tyrosin kinase c-Met in tumor progression and metastasis has been shown in preclinical studies and in early clinical settings. Several c-Met inhibitors with different selectivity profiles are currently in preclinical/clinical investigation and might provide effective cancer therapeutics in the future.

A biochemical HTS run using the recombinant kinase domain of c-Met enabled us to identify N-(3-(3,6-Dihydro-5-(3,4-dimethoxyphenyl)-2-oxo-2H-1,3,4-thiadiazin-3-ylmethyl)-phenyl)-carbaminic acid-(3-(N,N-diethylamino)-propylester) representing as new chemical class of kinase inhibitors. This HTS hit inhibited c-Met in vitro kinase activity and HGF-induced c-Met phosphorylation in A459 lung cancer cells with IC50 values well below 1 µM. The analysis of co-crystal structures defined the molecular requirements for potency and selectivity and guided the subsequent chemical optimization. As a result of the lead optimization process, two candidate compounds with distinct pharmacological properties were synthesized, EMD 1214063 and EMD 1204831. Both compounds are highly potent and efficient inhibitors of c-Met in vitro kinase activity and c-Met auto-phosphorylation induced in vitro by HGF stimulation or by c-Met overexpression. Both compounds displayed an exquisite selectivity profile when tested in vitro against a panel of more than 250 potential off-targets, including kinases, GPCRs, ion channels, transporters and various enzymes.

EMD 1214063 and EMD 1204831 exhibited excellent anti-tumor activity in vivo in a variety of xenograft models, including U87-MG glioblastoma cells (autocrine HGF production), TPR-Met-transformed mouse fibroblasts (oncogenic Met fusion protein) or Hs746T gastric and EBC-1 lung cancer cells (c-Met gene amplification and HGF-independent activation).

In c-Met-driven models complete regressions were observed with doses as low as 6 mg/kg/d administered per os. PK/PD analysis revealed efficient, dose- and time-dependent inhibition of c-Met phosphorylation, reduction of IL-8 and cyclin D1 expression as well as an induction of the cell cycle inhibitor p27. The pharmacodynamic effects of EMD 1214063 were longlasting and allowed various schedule variations without compromising its anti-tumor activity, while c-Met inhibition by EMD 1204831 was rather transient, allowing optimal anti-tumor activity when the compound was applied once or twice daily.

The profile of EMD 1214063 and EMD 1204831 including synthesis, structure activity relationships, X-ray structures and a comprehensive pharmacological in vitro and in vivo characterization will be presented. Furthermore, potential pharmacodynamic and predictive biomarkers will be discussed.

Citation Information: Mol Cancer Ther 2009;8(12 Suppl):B252.

Pinpointing phosphotyrosine-dependent interactions downstream of the collagen receptor DDR1

Activation of the receptor tyrosine kinase DDR1 by collagen results in robust and sustained phosphorylation, however little is known about its downstream mediators. Using phosphopeptide mapping and site-directed mutagenesis, we here identified multiple tyrosine phosphorylation sites within DDR1. We found that Nck2 and Shp-2, two SH2 domain-containing proteins, bind to DDR1 in a collagen-dependent manner. The binding site of Shp-2 was mapped to tyrosine-740 of DDR1 within an ITIM-consensus sequence. Lastly, ablation of DDR1 in the mouse mammary gland resulted in delocalized expression of Nck2, suggesting that defects observed during alveologenesis are caused by the lack of the DDR1-Nck2 interaction.