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Supplementary Figure Legend from Assessing the Activity of Cediranib, a VEGFR-2/3 Tyrosine Kinase Inhibitor, against VEGFR-1 and Members of the Structurally Related PDGFR Family

Supplementary Tables 1-3 from Assessing the Activity of Cediranib, a VEGFR-2/3 Tyrosine Kinase Inhibitor, against VEGFR-1 and Members of the Structurally Related PDGFR Family

Supplementary Figure 1 from Assessing the Activity of Cediranib, a VEGFR-2/3 Tyrosine Kinase Inhibitor, against VEGFR-1 and Members of the Structurally Related PDGFR Family

Cediranib is a potent inhibitor of the VEGF receptor (VEGFR)-2 and VEGFR-3 tyrosine kinases. This study assessed the activity of cediranib against the VEGFR-1 tyrosine kinase and the platelet-derived growth factor receptor (PDGFR)-associated kinases c-Kit, PDGFR-α, and PDGFR-β. Cediranib inhibited VEGF-A–stimulated VEGFR-1 activation in AG1-G1-Flt1 cells (IC50 = 1.2 nmol/L). VEGF-A induced greatest phosphorylation of VEGFR-1 at tyrosine residues Y1048 and Y1053; this was reversed by cediranib. Potency against VEGFR-1 was comparable with that previously observed versus VEGFR-2 and VEGFR-3. Cediranib also showed significant activity against wild-type c-Kit in cellular phosphorylation assays (IC50 = 1–3 nmol/L) and in a stem cell factor–induced proliferation assay (IC50 = 13 nmol/L). Furthermore, phosphorylation of wild-type c-Kit in NCI-H526 tumor xenografts was reduced markedly following oral administration of cediranib (≥1.5 mg/kg/d) to tumor-bearing nude mice. The activity of cediranib against PDGFR-β and PDGFR-α was studied in tumor cell lines, vascular smooth muscle cells (VSMC), and a fibroblast line using PDGF-AA and PDGF-BB ligands. Both receptor phosphorylation (IC50 = 12–32 nmol/L) and PDGF-BB–stimulated cellular proliferation (IC50 = 32 nmol/L in human VSMCs; 64 nmol/L in osteosarcoma cells) were inhibited. In vivo, ligand-induced PDGFR-β phosphorylation in murine lung tissue was inhibited by 55% following treatment with cediranib at 6 mg/kg but not at 3 mg/kg or less. In contrast, in C6 rat glial tumor xenografts in mice, ligand-induced phosphorylation of both PDGFR-α and PDGFR-β was reduced by 46% to 61% with 0.75 mg/kg cediranib. Additional selectivity was showed versus Flt-3, CSF-1R, EGFR, FGFR1, and FGFR4. Collectively, these data indicate that cediranib is a potent pan-VEGFR kinase inhibitor with similar activity against c-Kit but is significantly less potent than PDGFR-α and PDGFR-β. Mol Cancer Ther; 10(5); 861–73. ©2011 AACR.

Supplementary Tables S1-S2.

Supplemental Figure 3. Mean (SD) TIRA plasma concentration. Cycle 1 Day 8 data are shown in patients receiving TIRA monotherapy with A) TIRA/IDELA, and B) TIRA/ENTO*

Supplemental Table 1 summarizes study inclusion and exclusion criteria. Supplemental Table 2 shows the doses and dose-escalation strategy used in this study. Supplemental Table 3 defines the dose-limiting toxicities that guided dose escalation. Supplemental Table 4 lists the number of patients by disease in the dose expansion phase. Supplemental Table 5 summarizes study drug exposure. Supplemental Table 6 lists TEAEs and laboratory abnormalities of interest that occurred during the study. Supplemental Table 7 shows responders and nonresponders according to biomarker risk groups. Supplemental Table 8 shows best overall response and gene aberration status as measured by FISH and NGS. Supplemental Table 9 provides tirabrutinib peak plasma concentrations. Supplemental Table 10 summarizes tirabrutinib, idelalisib, and entospletinib plasma exposure (AUC) and maximum plasma concentrations (Cmax). Supplemental Table 11 shows patients with free BTK below the lower limit of quantitation. Supplemental Figure 1 graphically illustrates the design of the study. Supplemental Figure 2 illustrates the disposition of patients over the course of the study. Supplemental Figure 3 shows line graphs illustrating tirabrutinib plasma concentrations over time. Supplemental Figure 4 shows box plots representing BTK levels at baseline and trough tirabrutinib concentrations.

PDF file - 63KB, This figure describes the relationship between time and circulating biomarkers of VEGFR and KIT inhibition.

Purpose: Vascular endothelial growth factor (VEGF) signaling is key to tumor angiogenesis and is an important target in the development of anticancer drugs. However, VEGF receptor (VEGFR) expression in human cancers, particularly the relative expression of VEGFR-2 and VEGFR-3 in tumor vasculature versus tumor cells, is poorly defined.Experimental Design: VEGFR-2– and VEGFR-3–specific antibodies were identified and used in the immunohistochemical analysis of human primary cancers and normal tissue. The relative vascular localization of both receptors in colorectal and breast cancers was determined by coimmunofluorescence with vascular markers.Results: VEGFR-2 and VEGFR-3 were expressed on vascular endothelium but not on malignant cells in 13 common human solid tumor types (n > 400, bladder, breast, colorectal, head and neck, liver, lung, skin, ovarian, pancreatic, prostate, renal, stomach, and thyroid). The signal intensity of both receptors was significantly greater in vessels associated with malignant colorectal, lung, and breast than adjacent nontumor tissue. In colorectal cancers, VEGFR-2 was expressed on both intratumoral blood and lymphatic vessels, whereas VEGFR-3 was found predominantly on lymphatic vessels. In breast cancers, both receptors were localized to and upregulated on blood vessels.Conclusions: VEGFR-2 and VEGFR-3 are primarily localized to, and significantly upregulated on, tumor vasculature (blood and/or lymphatic) supporting the majority of solid cancers. The primary clinical mechanism of action of VEGF signaling inhibitors is likely to be through the targeting of tumor vessels rather than tumor cells. The upregulation of VEGFR-3 on tumor blood vessels indicates a potential additional antiangiogenic effect for dual VEGFR-2/VEGFR-3–targeted therapy. Clin Cancer Res; 16(14); 3548–61. ©2010 AACR.

Purpose: Cediranib is a potent VEGF signaling inhibitor with activity against all three VEGF receptors and KIT. This phase II study evaluated the antitumor activity of cediranib in patients with metastatic gastrointestinal stromal tumor (GIST) resistant/intolerant to imatinib, or metastatic soft-tissue sarcomas (STS; ClinicalTrials.gov, NCT00385203).Experimental Design: Patients received cediranib 45 mg/day. Primary objective was to determine the antitumor activity of cediranib according to changes in 2[18F]fluoro-2-deoxy-D-glucose positron emission tomography (18FDG-PET) tumor uptake in patients with GIST using maximum standardized uptake values (SUVmax). Secondary objectives included objective tumor response and tolerability in patients with GIST/STS.Results: Thirty-four of 36 enrolled patients were treated (GIST n = 24; STS n = 10). At day 29, five patients had confirmed decreases in SUVmax (≥10% from day 8) and two had confirmed partial metabolic responses (≥25% decrease), but arithmetic mean percentage changes in SUVmax, averaged across the cohort, were not significant at day 8 [6.8%; 95% confidence interval (CI), 19.95–33.54) or day 29 (4.6%; 95% CI, 8.05–17.34). Eleven patients with GIST achieved a best objective tumor response of stable disease; eight achieved stable disease ≥16 weeks. In patients with STS, four of six with alveolar soft-part sarcoma (ASPS) achieved confirmed and durable partial responses. The commonest adverse events were diarrhea (85%), fatigue (74%), and hypertension (68%).Conclusions: In patients progressing on imatinib/sunitinib, cediranib 45 mg/day demonstrated evidence of activity by 18FDG-PET, but did not reduce average SUVmax. Evidence of antitumor activity was seen in ASPS. Clin Cancer Res; 20(13); 3603–12. ©2014 AACR.

Supplemental Figure 2. Patient disposition

Purpose:Bruton tyrosine kinase (BTK) inhibition alone leads to incomplete responses in chronic lymphocytic leukemia (CLL). Combination therapy may reduce activation of escape pathways and deepen responses. This open-label, phase Ib, sequential dose-escalation and dose-expansion study evaluated the safety, tolerability, pharmacokinetics, and preliminary efficacy of the selective BTK inhibitor tirabrutinib alone, in combination with the PI3K delta (PI3Kδ) inhibitor idelalisib, or with the spleen tyrosine kinase (SYK) inhibitor entospletinib in patients with relapsed/refractory CLL.Patients and Methods:Patients received either tirabrutinib monotherapy (80 mg every day) or tirabrutinib 20–150 mg every day in combination with either idelalisib (50 mg twice a day or 100 mg every day) or entospletinib (200 mg or 400 mg every day).Results:Fifty-three patients were included. Systemic tirabrutinib exposure was comparable between monotherapy and combination therapy. No MTD was identified. Across all treatment groups, the most common adverse event was diarrhea (43%, 1 patient grade ≥3); discontinuation due to adverse events was uncommon (13%). Objective response rates were 83%, 93%, and 100%, and complete responses were 7%, 7%, and 10% in patients receiving tirabrutinib, tirabrutinib/idelalisib, and tirabrutinib/entospletinib, respectively. As of February 21, 2019, 46 of 53 patients continue to receive treatment on study.Conclusions:Tirabrutinib in combination with idelalisib or entospletinib was well tolerated in patients with CLL, establishing an acceptable safety profile for concurrent selective inhibition of BTK with either PI3Kδ or SYK. This small study did not establish a superior efficacy of the combinations over tirabrutinib alone. This trial is registered at www.clinicaltrials.gov (NCT02457598).

Introduction: Non-small cell lung cancer (NSCLC) is a major cause of cancer-related deaths globally with high unmet need. A variety of novel therapeutic strategies are being explored to improve patient outcomes including the use of antibody drug conjugates (ADCs) to deliver highly potent, cytotoxic payloads to tumors. Trophoblast cell-surface antigen 2 (TROP2), also known as tumor-associated calcium signal transducer 2 (TACSTD2), has emerged as an attractive target for ADCs. Sacituzumab govitecan-hziy is a novel ADC composed of a TROP2 antibody coupled to SN-38 and is being evaluated in NSCLC. High TROP2 mRNA expression is observed in many tumor types, however, TROP2 protein expression in NSCLC is not well-established. Here we characterized TROP2 expression across three independent datasets to explore the TROP2 relationship to baseline characteristics, molecular features of interest, and its prognostic value in NSCLC. Methods: We analyzed three independent datasets: (1) The Cancer Genome Atlas (TCGA) NSCLC adenocarcinoma (LUAD, N=660) and squamous cell carcinoma (LUSC, N=484) mRNA expression data, (2) a NSCLC adenocarcinoma FFPE tumor sample set (“Translational data set”; N=107), (3) an independent clinical NSCLC adenocarcinoma (N=103) and squamous cell carcinoma (N=37) data set. TROP2 IHC was performed on tumor sample sets (2) and (3) using the SP295 antibody (Robust Prototype Assay, Ventana) with H-Score and assessment of the percentage of membrane-positive tumor cells as readouts. Wilcoxon rank-sum and Kruskal-Wallis tests (continuous variables), Kaplan-Meier method (survival probability curves) and log-rank test (time to event outcome) were used (GraphPad Prism 8.1.2 and R version 4.0.5). Results: TROP2 mRNA was highly expressed in NSCLC and expression was similar in adenocarcinoma and squamous cell carcinoma in the TCGA data set. TROP2 expression did not vary with patient’s age, gender, race or tumor stage. Furthermore, TROP2 expression was not associated with TP53, KRAS or driver mutation status (including EGFR, ALK, ROS, RET, MET). TROP2 expression in the Translational sample set was consistent with the findings from the TCGA data analysis: TROP2 mRNA and protein expression were high and independent of patient baseline demographics, tumor stage and TP53 and KRAS mutation status. Finally, in an independent clinical NSCLC dataset, TROP2 protein was highly expressed and there was no relationship between TROP2 and baseline demographics including gender and age. TROP2 membrane H-scores and percentage of membrane-positive tumor cells also highly correlated in the two independent datasets. Conclusions: Three large independent datasets confirmed high expression of TROP2 in NSCLC both, as mRNA and protein. TROP2 expression in tumors did not differ between histological subtypes, baseline characteristics or clinically relevant driver alterations. Based on the TCGA data set, TROP2 expression was not prognostic for survival. Citation Format: Peiwen Kuo, Emon Elboudwarej, Lauri Diehl, Jilpa Patel, Sabeen Mekan, Juliane M. Jürgensmeier. TROP2 expression in non-small cell lung cancer. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4396.

B-cell receptor (BCR) signaling pathway inhibitors (including Bruton’s tyrosine kinase [BTK] inhibitors, and phosphatidylinositol-3 kinase inhibitors [PI3Ki]) have shown clinical efficacy in non-Hodgkin lymphoma (NHL). However, responses to these agents have been limited in depth and duration. This may be due to resistance to PI3Kδ and BTK inhibitors as monotherapy [1,2,3,4,5]. The emergence of resistant clones may be addressed by combining these 2 classes of drugs. Furthermore, tolerability of these drug classes has been a concern. Combination therapy using lower doses of one or more classes of inhibitors may address some limitations.

Tirabrutinib is an irreversible, small-molecule Bruton's tyrosine kinase (BTK) inhibitor, which was approved in Japan (VELEXBRU) to treat B-cell malignancies and is in clinical development for inflammatory diseases. As an application of model-informed drug development, a semimechanistic pharmacokinetic/pharmacodynamic (PK/PD) model for irreversible BTK inhibition of tirabrutinib was developed to support dose selection in clinical development, based on clinical PK and BTK occupancy data from two phase I studies with a wide range of PK exposures in healthy volunteers and in subjects with rheumatoid arthritis. The developed model adequately described and predicted the PK and PD data. Overall, the model-based simulation supported a total daily dose of at least 40 mg, either q.d. or b.i.d., with adequate BTK occupancy (> 90%) for further development in inflammatory diseases. Following the PK/PD modeling and simulation, the relationship between model-predicted BTK occupancy and preliminary clinical efficacy data was also explored and a positive trend was identified between the increasing time above adequate BTK occupancy and better efficacy in treatment for RA by linear regression.

Background Inhibitors of tyrosine kinases downstream of the B-cell receptor, such as Bruton's tyrosine kinase (Btk) or Spleen tyrosine kinase (Syk), used alone or in combination are new therapeutic options in the treatment of B-cell malignancies. A challenge in the development of second-generation Btk inhibitors is to limit their side effects such as the increased bleeding risk. Considering the pivotal role of Syk in immunoreceptor tyrosine-based activation motif mediated platelet signaling, the impact of inhibiting this kinase on platelet functions is also worth analyzing. Objectives We investigated the effect of a novel Btk inhibitor, tirabrutinib, and a Syk inhibitor, entospletinib, alone and in combination on platelet signaling and functions in vitro and ex vivo. Methods Platelet aggregation, secretion, and signaling responses as well as thrombus growth under flow were analyzed in the presence of the inhibitors alone or in combination in vitro, at clinically relevant doses, and ex vivo in patients treated with these inhibitors in the context of a phase I trial. Results Although tirabrutinib alone had modest effects on platelet activation in vitro and ex vivo, entospletinib alone efficiently inhibited washed platelet aggregation in response to collagen. However, entospletinib weakly affected platelet activation in platelet-rich plasma, in whole blood and ex vivo. Importantly, the combination of tirabrutinib and entospletinib induced a significant decrease in platelet response to collagen in vitro and ex vivo correlating with mild bleedings reported in some of the treated patients. Conclusion These new results should contribute to improve the safety of these targeted therapies.

Purpose: Bruton tyrosine kinase (BTK) inhibition alone leads to incomplete responses in chronic lymphocytic leukemia (CLL). Combination therapy may reduce activation of escape pathways and deepen responses. This open-label, phase Ib, sequential dose-escalation and dose-expansion study evaluated the safety, tolerability, pharmacokinetics, and preliminary efficacy of the selective BTK inhibitor tirabrutinib alone, in combination with the PI3K delta (PI3Kδ) inhibitor idelalisib, or with the spleen tyrosine kinase (SYK) inhibitor entospletinib in patients with relapsed/refractory CLL. Patients and Methods: Patients received either tirabrutinib monotherapy (80 mg every day) or tirabrutinib 20–150 mg every day in combination with either idelalisib (50 mg twice a day or 100 mg every day) or entospletinib (200 mg or 400 mg every day). Results: Fifty-three patients were included. Systemic tirabrutinib exposure was comparable between monotherapy and combination therapy. No MTD was identified. Across all treatment groups, the most common adverse event was diarrhea (43%, 1 patient grade ≥3); discontinuation due to adverse events was uncommon (13%). Objective response rates were 83%, 93%, and 100%, and complete responses were 7%, 7%, and 10% in patients receiving tirabrutinib, tirabrutinib/idelalisib, and tirabrutinib/entospletinib, respectively. As of February 21, 2019, 46 of 53 patients continue to receive treatment on study. Conclusions: Tirabrutinib in combination with idelalisib or entospletinib was well tolerated in patients with CLL, establishing an acceptable safety profile for concurrent selective inhibition of BTK with either PI3Kδ or SYK. This small study did not establish a superior efficacy of the combinations over tirabrutinib alone. This trial is registered at www.clinicaltrials.gov (NCT02457598).

Tirabrutinib is a second-generation, potent, selective irreversible Bruton tyrosine kinase (BTK) inhibitor in clinical development for relapsed/refractory chronic lymphocytic leukemia (CLL) in combination with entospletinib and obinutuzumab. To study the modulation or inhibition of different signaling pathways in response to drug treatment, we developed a phospho-flow cytometric assay that can measure up to 110 intracellular signaling proteins. This method was validated in an in vitro setting to develop the pre-analytical sample handling, assay setup and analysis parameters. The optimized procedure was implemented in a phase II clinical study (NCT02983617). For the in vitro experiments, whole blood was collected from healthy volunteers and CLL patients. Following a stimulation with anti-IgD/anti-IgM, the blood was processed and stained with a panel of 110 phospho-specific antibodies and evaluated by flow cytometry. A panel of 43 phosphoproteins was selected based on their relevance to the inhibited pathways and/or their responsiveness to B cell receptor cross-linking. In the clinical study, whole blood was collected at baseline, week 2 and 25 post-treatment from 23 patients treated with tirabrutinib in combination with entospletinib and obinutuzumab. The samples were stimulated with anti-IgM/anti-IgD and stained with surface markers to identify the cancer cells and their signaling fingerprint was evaluated with the selected panel of phosphoprotein markers. The data from the in vitro experiments showed, at baseline, both CLL and healthy B cells had no or minimal constitutive activation of downstream BCR signaling proteins. In normal B cells, of the phospho-proteins analyzed, most showed great increase after activation of BCR. However, BCR-induced phosphorylation of most signaling proteins was significantly lower in the CLL cells from the patients. In addition, the fraction of cells responding to the in vitro stimulation was highly variable among the CLL patient samples compared to normal donors. Down-regulation of phosphoproteins, including pBTK (Y223)/pITK (Y180), pSyk (Y348), pSyk (Y525/Y526) was observed in most of the patients both in stimulated or un-stimulated conditions at week 2 and 25. The level of the phosphorylation of pBTK (Y223)/pITK (Y180), pSyk (Y348), pSyk (Y525/Y526) from stimulated blood was highly correlated with the blast counts in the periphery at week 1 and 2. These findings support the utility of this multi-parameter flow assay to detect and monitor immune signaling inside different immune cells. Evaluating the effects of targeted therapeutics following clinical administration can inform on disease and drug mechanisms, combination strategies, and identify potential biomarkers for pharmacodynamic or patient stratification that are otherwise inaccessible using less sensitive or non-functional analyses. Citation Format: Xiaoyun Yang, Tom Wehrman, Justin Laboriante, Biao Li, Nadine Kutsch, Christian Pallasch, Barbara Eichhorst, Juliane M. Jürgensmeier. Intracellular phospho-flow reveals novel insights to pathway modulation by tirabrutinib in combination with entospletinib and obinutuzumab [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 3036.

Bruton's tyrosine kinase (BTK) is a clinically validated target for B-cell leukemias and lymphomas with FDA-approved small-molecule inhibitors ibrutinib and acalabrutinib. Tirabrutinib (GS-4059/ONO-4059, Gilead Sciences, Inc., Foster City, CA) is a second-generation, potent, selective, irreversible BTK inhibitor in clinical development for lymphoid malignancies, including chronic lymphocytic leukemia (CLL) and diffuse large B-cell lymphoma (DLBCL). An accurate pharmacodynamic assay to assess tirabrutinib target coverage in phase 1/2 clinical studies will inform dose and schedule selection for advanced clinical evaluation. We developed a novel duplex homogeneous BTK occupancy assay based on time-resolved fluorescence resonance energy transfer (TR-FRET) to measure free and total BTK levels in a multiplexed format. The dual-wavelength emission property of terbium-conjugated anti-BTK antibody served as the energy donor for two fluorescent energy acceptors with distinct excitation and emission spectra. The assay was characterized and qualified using full-length purified recombinant human BTK protein and peripheral blood mononuclear cells derived from healthy volunteers and patients with CLL. We demonstrated assay utility using cells derived from lymph node and bone marrow samples from patients with CLL and DLBCL. Our TR-FRET-based BTK occupancy assay provides accurate, quantitative assessment of BTK occupancy in the clinical trial program for tirabrutinib and is in use in ongoing clinical studies.

Background: This study evaluated soluble serum proteins as biomarkers to subset patients with metastatic colorectal cancer (mCRC) treated with chemotherapy±cediranib, a vascular endothelial growth factor (VEGF) signalling inhibitor (VEGFi). Exploring biomarkers at pre- and on-treatment may identify patient subgroups showing clinical benefit on cediranib combination. Methods: Two hundred and seven serum proteins were analysed in 588 mCRC patients at pre- and on-treatment with chemotherapy (FOLFOX/CAPOX)±cediranib 20 mg. Patients were enrolled in the phase III trial HORIZON II. We correlated baseline biomarker signatures and pharmacodynamic (PD) biomarkers with PFS and OS. Results: We identified a baseline signature (BS) of 47 biomarkers that included VEGFA, VEGFD, VEGFR2, VEGFR3 and TIE-2, which defined two distinct subgroups of patients. Patients treated with chemotherapy plus cediranib who had ‘high' BS had shorter PFS (HR=1.82, P=0.003) than patients with ‘low' BS. This BS did not correlate with PFS of the patients treated with chemotherapy plus placebo. In addition, we identified a profile of 16 PD proteins on treatment associated with PFS (HR=0.58, P

Purpose: Cediranib is a potent VEGF signaling inhibitor with activity against all three VEGF receptors and KIT. This phase II study evaluated the antitumor activity of cediranib in patients with metastatic gastrointestinal stromal tumor (GIST) resistant/intolerant to imatinib, or metastatic soft-tissue sarcomas (STS; ClinicalTrials.gov, NCT00385203). Experimental Design: Patients received cediranib 45 mg/day. Primary objective was to determine the antitumor activity of cediranib according to changes in 2[18F]fluoro-2-deoxy-D-glucose positron emission tomography (18FDG-PET) tumor uptake in patients with GIST using maximum standardized uptake values (SUVmax). Secondary objectives included objective tumor response and tolerability in patients with GIST/STS. Results: Thirty-four of 36 enrolled patients were treated (GIST n = 24; STS n = 10). At day 29, five patients had confirmed decreases in SUVmax (≥10% from day 8) and two had confirmed partial metabolic responses (≥25% decrease), but arithmetic mean percentage changes in SUVmax, averaged across the cohort, were not significant at day 8 [6.8%; 95% confidence interval (CI), 19.95–33.54) or day 29 (4.6%; 95% CI, 8.05–17.34). Eleven patients with GIST achieved a best objective tumor response of stable disease; eight achieved stable disease ≥16 weeks. In patients with STS, four of six with alveolar soft-part sarcoma (ASPS) achieved confirmed and durable partial responses. The commonest adverse events were diarrhea (85%), fatigue (74%), and hypertension (68%). Conclusions: In patients progressing on imatinib/sunitinib, cediranib 45 mg/day demonstrated evidence of activity by 18FDG-PET, but did not reduce average SUVmax. Evidence of antitumor activity was seen in ASPS. Clin Cancer Res; 20(13); 3603–12. ©2014 AACR.

Introduction Bevacizumab improves outcome for patients with advanced colorectal cancer (CRC) when added to chemotherapy. The HORIZON I trial resulted in similar outcome with bevacizumab or cediranib, a small-molecule tyrosine kinase inhibitor of vascular endothelial growth factor (VEGF) receptor, as treatment of advanced CRC. The spectrum of lactate dehydrogenase (LDH) isoenzyme expression was examined in serum samples of HORIZON I participants to identify biomarkers predictive of efficacy of VEGF pathway inhibitors. Materials and Methods Total LDH levels, as well as LDH isoenzyme levels in frozen baseline serum samples, were retrospectively evaluated. Total LDH serum levels measured during the study, progression-free survival (PFS), and overall survival (OS) were available from the HORIZON I study data. Results Total LDH levels measured in the frozen serum samples correlated with those measured in fresh samples. The expected reciprocal correlation was found between hypoxic and oxic LDH isoenzymes. High total LDH correlated with shorter PFS, and high hypoxia-related LDH isoenzymes correlated with shorter PFS and OS. The difference in outcome of the cediranib-treated patients vs. those treated with bevacizumab was not substantially different in the various LDH isoform expression subgroups. In patients with a hypoxic LDH pattern of expression, there was a nonsignificant trend of better outcome in cediranib-treated patients. Conclusion Evaluation of total LDH and its isoforms in frozen serum samples is feasible. High total LDH and high hypoxic LDH isoenzymes were associated with poor prognosis. Further studies are needed to evaluate the predictive value of LDH isoenzyme expression pattern for VEGF-pathway inhibition efficacy.

Introduction: In CLL, numerous new therapeutic options have been introduced recently, without establishing a definitive standard therapy or cure for most patients (pts). An advantage of targeted therapies is the avoidance of toxicities associated with chemotherapy. However, all new kinase inhibitors used for treatment of CLL have low rates of complete remission (CR). Combinations of targeted agents have the potential to improve outcomes, shorten treatment duration, and reduce toxicity. Tirabrutinib (a BTK inhibitor), and entospletinib (a SYK inhibitor), both show significant single-agent clinical activity in pts with CLL. In this study, we evaluated tirabrutinib and entospletinib as dual therapy (TE), and as triple therapy in combination with obinutuzumab (TEO). Methods: This is a prospective, open-label, phase 2 protocol (NCT02983617) at 15 clinical centers in Germany that recruited pts with relapsed or refractory CLL between April 2017 and September 2018. As of amendment 3, pts who did not progress while on an inhibitor of BTK, SYK, PI3K, BCL-2 or on obinutuzumab were also included. Pts received the TE regimen with tirabrutinib 80 mg once daily (QD) + entospletinib 400 mg QD for up to 104 weeks, or the TEO regimen adding obinutuzumab at standard dosing for a total of 8 doses of 1000 mg over 21 weeks. After the implementation of protocol amendment 3, randomization was discontinued and all subsequently enrolled pts received the TEO regimen. Response was measured by modified iwCLL 2008 criteria. The primary endpoint was the CR rate at week 25. Results: Thirty-six pts were treated, 6 with TE and 30 with TEO. Median (range) age was 68 (45-82) years, with a median of 1 (1-2) and 2 (1-8) prior anticancer therapies in those assigned to TE and TEO, respectively. As of 16 May 2019, 29 of all 36 pts (81%) continue to receive tirabrutinib and entospletinib on study; 2 (6%) pts completed study drug dosing as specified per protocol at week 104. Twenty-eight of 30 pts (93%) in the TEO arm completed obinutuzumab dosing as specified per protocol. Of the 36 pts, 34 (94%) continued the study and 2 (6%) discontinued the study due to adverse events (AEs) or death, both were in the TEO group. Median duration (range) of exposure to tirabrutinib and entospletinib was 99 (90-105) weeks on TE and 50 (4-104) weeks on TEO, including 20 (2-35) weeks for obinutuzumab. At week 25, CR rate was 0% (90% confidence interval [CI] 0-39.3) with TE and 7% (90% CI 1.2-19.5) with TEO (Table 1). Overall response rates at week 25 were 100% (90% CI 60.7-100) and 90% (90% CI 76.1-97.2) for TE and TEO.One pt on the TEO regimen experienced disease progression (per clinical response assessment) after 3.75 months of therapy. Three (10%) pts on TEO were minimal residual disease (MRD) negative in peripheral blood (PB MRD-) at week 25; one (3%) pt was also MRD negative in bone marrow (BM MRD-).No pts showed MRD negativity with TE therapy. Best rate of CR/PB MRD- was 7% (90% CI 1.2-19.5) and for CR/BM MRD- was 3% (90% CI 0.2-14.9) with TEO. Median time to first PB MRD- was 32 weeks on TEO. Median progression-free survival (PFS) and overall survival have not been reached yet, and 24-month PFS rates were not yet estimable in either treatment group. Treatment-emergent AEs (TEAEs) are listed in Table 2. No pt in the TE and 3 pts (10%) in the TEO group discontinued tirabrutinib and entospletinib due to TEAEs, and no pt discontinued obinutuzumab due to TEAEs. Two (7%) pts in the TEO arm died following a TEAE: an 82-year-old male from subdural hematoma (onset within 30 days of last dosing, and death within 68 days) and a 77-year-old male from syncope (onset on the last dosing date, and death at day 35 after last dosing); both deaths were considered unrelated to study treatment by investigators. Conclusion: A triple combination with tirabrutinib, entospletinib, and obinutuzumab (TEO regimen) was tolerable and demonstrated excellent therapeutic activity in pts with relapsed or refractory CLL, but with limited CR rate. Disclosures Kutsch: Gilead Sciences, Inc.: Research Funding; Mundipharma, AbbVie, Janssen: Other: Travel, accomodation, expenses. Pallasch:Gilead Sciences, Inc.: Honoraria, Research Funding. Tausch:AbbVie: Consultancy, Honoraria, Other: travel support, Speakers Bureau; Roche: Consultancy, Honoraria, Speakers Bureau. Boehme:Abbvie: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel Grant; Servier: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel Grant; Glenmark Pharmaceutical: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel Grant; Mundipharma: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel Grant; Roche: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel Grant; Janssen-Cilag: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel Grant; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel Grant; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel Grant; Merck: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel Grant; Sanofi: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel Grant; Helsinn: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel Grant; VioPharm: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel Grant; InCyte: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel Grant; Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel Grant. Ritgen:AbbVie: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; BMS: Membership on an entity's Board of Directors or advisory committees; Roche: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: travel support, Research Funding. Wacker:Celgene: Consultancy; Roche: Consultancy; BMS: Consultancy; Incyte: Consultancy; Amgen: Consultancy. Trappe:Celgene, Janssen, Takeda, TEVA: Other: Congress related travel support ; Atara: Consultancy, Membership on an entity's Board of Directors or advisory committees; Roche Pharma: Consultancy, Honoraria, Other: Congress related travel support , Research Funding; AbbVie: Consultancy, Other: Congress related travel support . Dreger:AbbVie, Gilead, Novartis, Riemser, Roche: Speakers Bureau; AbbVie, AstraZeneca, Gilead, Janssen, Novartis, Riemser, Roche: Consultancy; Neovii, Riemser: Research Funding; MSD: Membership on an entity's Board of Directors or advisory committees, Other: Sponsoring of Symposia. Stilgenbauer:AbbVie, AstraZeneca, Celgene, Gilead Sciences, Inc., GSK, Hoffmann La-Roche, Janssen, Novartis: Consultancy, Honoraria, Research Funding, Speakers Bureau. Zhang:Gilead Sciences, Inc.: Employment, Other: Shareholder. Jürgensmeier:Gilead Sciences, Inc.: Employment, Other: Shareholder. Bhargava:Gilead Sciences, Inc.: Employment, Other: Shareholder; Tioma Therapeutics: Membership on an entity's Board of Directors or advisory committees; Dicerna Pharmaceuticals: Consultancy; Sanofi, Aveo Pharma: Patents & Royalties. Hallek:Roche, Gilead Sciences, Inc., Mundipharma, Janssen, Celgene, Pharmacyclics, AbbVie: Honoraria, Research Funding, Speakers Bureau. Eichhorst:ArQule: Membership on an entity's Board of Directors or advisory committees; BeiGene: Research Funding; Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Roche: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Gilead Sciences, Inc.: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; AbbVie: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. OffLabel Disclosure: GAZYVA (obinutuzumab) is a CD20-directed cytolytic antibody and is indicated in combination with chlorambucil, for the treatment of patients with previously untreated chronic lymphocytic leukemia.

Introduction: Several targeted therapies have been added to the treatment landscape of CLL. These agents have more favorable toxicity profiles compared with chemotherapy, but achieve only low complete remission (CR) rates. However, combination regimens with targeted drugs have the potential for improved duration and depth of response while exhibiting an acceptable safety profile. Tirabrutinib is a selective, irreversible, second generation, small-molecule BTK inhibitor. Tirabrutinib and idelalisib individually have shown promising results as single-agent therapy in patients (pts) with CLL. This study evaluated tirabrutinib and idelalisib together as dual therapy (TI), and as triple therapy adding obinutuzumab (TIO). Methods: This is a prospective, open-label, phase 2 protocol (NCT02968563) at 15 clinical centers in Germany that recruited between April 2017 and September 2018. Pts with relapsed or refractory CLL were eligible, including those who did not progress while treated with any inhibitor of BTK, SYK, PI3K, BCL-2, or with obinutuzumab. Pts received the TI regimen with tirabrutinib 80 mg once daily (QD) + idelalisib 100 mg QD, or TIO adding obinutuzumab at standard dosing, for a total of 8 doses of 1000 mg over 21 weeks. After the implementation of protocol amendment 3, randomization was discontinued and all subsequently enrolled pts received the TIO regimen. The primary endpoint was CR rate at week 25. Results: Thirty-five pts were enrolled, of which 5 were treated with TI and 30 with TIO. Median (range) age was 66 (47-82) years, with a median of 1 (1-1) and 1 (1-4) prior anticancer therapies in those assigned to TI and TIO, respectively. As of 7 June 2019, 1 of 5 pts (20%) on TI and 21 of 30 pts (70%) on TIO continue to receive tirabrutinib on study, while 1 pt (20%) in the TI and 19 pts (63%) in the TIO arm continued with idelalisib. Tirabrutinib dosing as specified per protocol at week 104 was completed by 1 pt (20%) in the TI and 4 pts (13%) in the TIO arm, respectively. No pts receiving TI and 4 pts (13%) on TIO completed idelalisib as specified per protocol. Altogether 3 pts out of 35 (9%) discontinued tirabrutinib and 7 pts (20%) discontinued idelalisib prematurely due to adverse events (AEs). Twenty-eight of 30 (93%) pts completed obinutuzumab dosing as specified per protocol. Four pts (80%) treated with TI and 29 pts (97%) treated with TIO were ongoing in the study. Median duration (range) of exposures to tirabrutinib and idelalisib were 67 (4.3-104.0) and 61 (1.6-95.4) weeks on TI therapy, 49 (0.1-105.4) and 37 (0.1-105.4) weeks on TIO, and 20 (0.1-22.4) weeks for obinutuzumab. CR rate at week 25 was 0% (90% confidence interval [CI] 0-45.1) with TI and 7% (90% CI 1.2-20.2) with the TIO regimen (Table 1).Overall response rates at week 25 were 40% (90% CI 7.6-81.1) and 86% (90% CI 71.2-95.1) with TI and TIO.No pts on TI and 1 pt (3%) on TIO was MRD negative in peripheral blood (PB MRD-) at week 25; no pts were MRD- in bone marrow (BM MRD-) at week 25. Best rates of CR/PB MRD- were 0% (90% CI 0-45.1) and 7% (90% CI 1.2-20.2) for TI and TIO. Median time to first PB MRD- was 42 weeks on TIO. Median progression-free survival (PFS) and overall survival have not yet been reached. Three pts on TI and 1 pt on TIO experienced disease progression (per clinical response assessment) after the end of treatment. Twenty-four month PFS rates were 60% (90% CI 19.0-85.0) and 77% (90% CI 34.0-94.0) in pts receiving the TI and TIO regimens, respectively. Treatment-emergent AEs (TEAEs) grade 3-4 occurred in 3 of 5 (60%) pts with TI and 24 of 30 (80%) pts with TIO (Table 2). Two out of 35 pts had a TEAE leading to death: a 63-year-old male in the TI arm had grade 5 acute cardiac failure (related to tirabrutinib and idelalisib) when on treatment for 45 days, and died on the same date as the AE onset date/last dosing date; a 68-year-old female on TIO had grade 5 cerebral infarction (not related to any study drug as judged by the investigator) when on treatment for only 1 day, and died 27 days after the AE onset date/last dosing date. Conclusion: Combination therapy with tirabrutinib, idelalisib, and obinutuzumab (TIO regimen) had good efficacy with some relevant toxicity in relapsed/refractory CLL. Disclosures Kutsch: Mundipharma, AbbVie, Janssen: Other: Travel, accomodation, expenses; Gilead Sciences, Inc.: Research Funding. Pallasch:Gilead Sciences, Inc.: Honoraria, Research Funding. Decker:Novartis: Consultancy. Graeven:Servier: Honoraria; Amgen: Consultancy; Merck KGaA: Consultancy; Novartis: Consultancy; Hexal: Consultancy; Boehringer Ingelheim: Honoraria; Daiichi Sankyo: Honoraria; Bristol-Myers Squibb: Consultancy; Sirtex Medical: Honoraria; Merck KGaA: Other: Travel, Accommodations; Amgen: Other: Travel, Accommodations. Kroeber:Celgene: Honoraria; Janssen-Cilag: Honoraria; Amgen: Honoraria; Roche: Honoraria. Tausch:Roche: Consultancy, Honoraria, Speakers Bureau; AbbVie: Consultancy, Honoraria, Other: travel support, Speakers Bureau. Wendtner:MorphoSys: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; AbbVie: Consultancy, Honoraria, Research Funding, Speakers Bureau; Gilead Sciences, Inc.: Consultancy, Honoraria, Research Funding, Speakers Bureau; Janssen-Cilag: Consultancy, Honoraria, Research Funding, Speakers Bureau; Hoffman-La Roche: Consultancy, Honoraria, Research Funding, Speakers Bureau. Stilgenbauer:AbbVie, AstraZeneca, Celgene, Gilead Sciences, Inc., GSK, Hoffmann La-Roche, Janssen, Novartis: Consultancy, Honoraria, Research Funding, Speakers Bureau. Huang:Gilead Sciences, Inc.: Employment, Other: Shareholder. Jürgensmeier:Gilead Sciences, Inc.: Employment, Other: Shareholder. Bhargava:Gilead Sciences, Inc.: Employment, Other: Shareholder; Tioma Therapeutics: Membership on an entity's Board of Directors or advisory committees; Dicerna Pharmaceuticals: Consultancy; Sanofi, Aveo Pharma: Patents & Royalties. Hallek:Roche, Gilead Sciences, Inc., Mundipharma, Janssen, Celgene, Pharmacyclics, AbbVie: Honoraria, Research Funding, Speakers Bureau. Eichhorst:Gilead Sciences, Inc.: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Roche: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; AbbVie: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; ArQule: Membership on an entity's Board of Directors or advisory committees; BeiGene: Research Funding. OffLabel Disclosure: GAZYVA (obinutuzumab) is a CD20-directed cytolytic antibody and is indicated in combination with chlorambucil, for the treatment of patients with previously untreated chronic lymphocytic leukemia.

Background: The prognostic and predictive value of multiple serum biomarkers was evaluated using samples from a randomised phase III study (HORIZON II) investigating chemotherapy with or without cediranib in metastatic colorectal cancer (mCRC). Methods: Baseline levels of 207 protein markers were measured in serum samples from 582 HORIZON II (FOLFOX/XELOX plus cediranib 20 mg (n=330) or placebo (n=252)) patients. Median baseline values of each biomarker were used to categorise patients as high or low. Markers were then assessed for their association with efficacy, defined by progression-free survival (PFS) and overall survival (OS). A generalised boosted regression model identified markers of particular interest. Results: Correlation of protein levels with PFS and OS suggested that multiple factors had a prognostic value, independent of treatment arm, including IL-6, IL-8, C-reactive protein (CRP), ICAM-1 and carcinoembryonic antigen (CEA). Among the angiogenesis regulators, low levels of vascular endothelial growth factor (VEGF), VEGF-D, VEGFR-1, VEGFR-3, NRP1 and Tie-2 correlated with better outcome. Conclusion: This large data set generated using serum samples from mCRC patients treated with chemotherapy and VEGF inhibitors, defines baseline characteristics for 207 serum proteins. Multiple prognostic factors were identified that could be disease related or predict which patients derive most benefit from 5-fluorouracil (5-FU)-based chemotherapy, meriting further exploration in prospective studies.

Purpose The prognostic potential of KRAS mutations in advanced colorectal cancer (CRC) patients and the impact of KRAS mutation status on the effectiveness of chemotherapy or vascular endothelial growth factor (VEGF) signalling inhibitor therapy remain unclear. KRAS mutation status was evaluated retrospectively as a potential prognostic/predictive marker of clinical outcomes using tumour samples from patients with metastatic CRC receiving cediranib or placebo plus FOLFOX/XELOX in a Phase III trial (HORIZON II; NCT00399035). Methods KRAS codon 12 and 13 mutation analyses were performed using a commercially available, allele-specific, amplification refractory mutation system (ARMS)-based polymerase chain reaction (PCR) assay. Retrospective analyses of progression-free survival (PFS) and overall survival (OS) according to KRAS mutation status were performed for patients randomised to cediranib 20mg or placebo. Results KRAS status was determined in 599/1076 patients (cediranib 20mg, n =285/502; cediranib 30mg, n =110/216; placebo, n =204/358). Baseline characteristics were similar across KRAS mutant ( n =258; 24.0%), wild-type ( n =341; 31.7%) and status unknown ( n =477; 44.3%) groups. There was a trend towards improved PFS and OS in the wild-type versus mutant subgroups independent of treatment (cediranib 20mg and placebo: PFS hazard ratio (HR)=0.85 [median PFS: wild-type=8.5months; mutant=8.3months]; OS HR=0.71 [median OS: wild-type=20.9months; mutant=16.9months]). Treatment effects were similar between KRAS subgroups for cediranib 20mg versus placebo (PFS: wild-type HR=0.78, mutant HR=0.82; OS: wild-type HR=0.92, mutant HR=1.01). Conclusion Data from this large randomised Phase III study show that KRAS codon 12/13 mutations have negative prognostic value in metastatic CRC patients receiving treatment with FOLFOX/XELOX, but KRAS mutation status is not predictive of treatment benefit with cediranib, using PFS or OS.

Background: The prognostic/predictive value of potential vascular endothelial growth factor (VEGF) signalling biomarkers was evaluated retrospectively using samples from two randomized Phase III studies (HORIZON II and III) investigating cediranib in metastatic colorectal cancer (mCRC). Methods: Baseline levels of VEGF, soluble VEGF receptor-2 (sVEGFR-2) and carcinoembryonic antigen (CEA) were measured in plasma/serum samples collected from patients participating in HORIZON II (n=860; FOLFOX/XELOX plus cediranib 20 mg (n=502) or placebo (n=358)) and HORIZON III (n=1422; mFOLFOX6 plus cediranib 20 mg (n=709) or bevacizumab (n=713)). Median biomarker baseline levels determined cutoff values for the patient subgroups. Results: Baseline data were available for 88–97% of patients/study (>2000 patients). In both the studies, high baseline VEGF and CEA were associated with worse outcomes for progression-free survival (PFS) and overall survival (OS) independent of treatment (HORIZON II OS: VEGF, hazard ratio (HR)=1.35 (95% confidence interval (CI): 1.12–1.63); CEA, HR=1.63 (1.36–1.96); HORIZON III OS: VEGF, HR=1.32 (1.12–1.54); CEA, HR=1.50 (1.29–1.76)). sVEGFR-2 was not prognostic for PFS/OS. Baseline VEGF and CEA were not predictive for PFS/OS outcome to cediranib treatment; low sVEGFR-2 was associated with a trend towards improved cediranib effect in HORIZON II. Conclusion: Baseline VEGF and CEA levels were treatment-independent prognostic biomarkers for PFS and OS in both the studies.

Cediranib (AZD2171) is a highly potent inhibitor of all three vascular endothelial growth factor receptors. The aim of this preclinical study was to examine the effect of combining cediranib with mechanistically distinct anti-tumour therapies.Cediranib (1.5 or 3 mg/kg/day) was evaluated alone and in combination with either gefitinib, imatinib, ZD6126, saracatinib, selumetinib, bevacizumab, 5-fluorouracil (5-FU), docetaxel, oxaliplatin, gemcitabine, pemetrexed, irinotecan or cisplatin in human tumour xenograft models. Anti-tumour activity was measured by assessing the change in tumour volume following treatment compared with vehicle-treated time-matched controls.In all cases, the combination regimens, at tolerated doses and schedules, inhibited tumour growth to a greater extent than the corresponding monotherapy treatments. Compared with cediranib alone, statistically significant enhancements in anti-tumour activity were observed with all combination regimens. Notably, after 14 days of treatment, the combination of cediranib with ZD6126 induced substantial tumour regression (60 % compared with pre-treatment volume), whilst treatment with each agent alone led only to partial growth inhibition. A combination of cediranib with gefitinib also induced tumour regressions, and cediranib combined with either gemcitabine or irinotecan was found to inhibit tumour growth profoundly (by 99 and 98 %, respectively).Combining cediranib with selected cytotoxic or targeted agents proved efficacious in a range of human tumour xenograft models.

Purpose A randomized, phase III, placebo-controlled, partially blinded clinical trial (REGAL [Recentin in Glioblastoma Alone and With Lomustine]) was conducted to determine the efficacy of cediranib, an oral pan–vascular endothelial growth factor (VEGF) receptor tyrosine kinase inhibitor, either as monotherapy or in combination with lomustine versus lomustine in patients with recurrent glioblastoma. Patients and Methods Patients (N = 325) with recurrent glioblastoma who previously received radiation and temozolomide were randomly assigned 2:2:1 to receive (1) cediranib (30 mg) monotherapy; (2) cediranib (20 mg) plus lomustine (110 mg/m2); (3) lomustine (110 mg/m2) plus a placebo. The primary end point was progression-free survival based on blinded, independent radiographic assessment of postcontrast T1-weighted and noncontrast T2-weighted magnetic resonance imaging (MRI) brain scans. Results The primary end point of progression-free survival (PFS) was not significantly different for either cediranib alone (hazard ratio [HR] = 1.05; 95% CI, 0.74 to 1.50; two-sided P = .90) or cediranib in combination with lomustine (HR = 0.76; 95% CI, 0.53 to 1.08; two-sided P = .16) versus lomustine based on independent or local review of postcontrast T1-weighted MRI. Conclusion This study did not meet its primary end point of PFS prolongation with cediranib either as monotherapy or in combination with lomustine versus lomustine in patients with recurrent glioblastoma, although cediranib showed evidence of clinical activity on some secondary end points including time to deterioration in neurologic status and corticosteroid-sparing effects.

The effect of vascular endothelial growth factor (VEGF) ligands and cediranib on tumor cell proliferation, migration, and invasion was determined. It has recently been suggested that autocrine signaling through the VEGF receptor (VEGFR) pathway may play a role in tumor cell survival, invasion, and migration. The purpose of the present study was to determine the expression of VEGFRs and VEGFR ligands in a panel of gastrointestinal carcinoma cells. Additionally, we evaluated the effects of VEGF autocrine signaling on tumor cell proliferation, migration, and invasion utilizing cediranib (AZD2171), a pan-VEGFR inhibitor. Five colorectal, three pancreatic, and two hepatocellular carcinoma cell lines were screened for VEGFR and VEGF expression by several methods. Expression of VEGFR-1 and VEGFR-3 was cell line–dependent, whereas VEGFR-2 was not detected. Secretion of VEGF-A was detected in the supernatants of all cell lines whereas VEGF-C secretion was detected in the Panc-1, MiaPaca2, and Hep1 cells only. Tumor cells showed increased migratory activity, but not proliferation, when stimulated with VEGFs. The pan-VEGFR inhibitor cediranib (100 nmol/L) inhibited tumor cell migration and invasion, with no effects on proliferation. Cediranib decreased VEGFR-1 and VEGFR-3 phosphorylation as well as activation of downstream effectors. VEGFR-1 and VEGFR-3 expression was detected in all the gastrointestinal carcinoma cells evaluated. Although activation of the VEGF pathway did not affect cell proliferation, our data indicate that this pathway seems to play a role in tumor cell migration and invasion in these cell lines. Therefore, inhibition of VEGFR by cediranib may represent a clinically relevant treatment option for gastrointestinal tumors. [Mol Cancer Ther 2009;8(9):2546–58]

Intratumoral heterogeneity in human solid tumors represents a major barrier for the development of effective molecular treatment strategies, as treatment efficacies will reflect the molecular variegation in individual tumors. In glioblastoma, the generation of composite genomic profiles from bulk tumor samples has allowed one to map the genomic amplifications of putative genetic drivers and to prioritize therapeutic targeting strategies aimed at eradicating the tumor burden. Notably, amplification of multiple receptor tyrosine kinases (RTK) within a single tumor specimen obtained from patients is frequently observed. In this study, use of a detailed multicolor FISH mapping procedure in pathologic specimens revealed a mutual exclusivity of gene amplification in the majority of glioblastoma tumors examined. In particular, the two most commonly amplified RTK genes, EGFR and PDGFRA, were found to be present in variable proportions across the tumors, with one or the other gene predominating in certain areas of the same specimen. Our findings have profound implications for designing efficacious therapeutic regimens, as it remains unclear that how the cells with different gene amplification events contribute to disease propagation or the response to molecular targeted therapies. Cancer Res; 72(7); 1614–20. ©2012 AACR.

Purpose: Ras/Raf/mitogen-activated protein–extracellular signal-regulated kinase (ERK) kinase (MEK)/ERK signaling is critical for tumor cell proliferation and survival. Selumetinib is a potent, selective, and orally available MEK1/2 inhibitor. In this study, we evaluated the therapeutic efficacy of selumetinib alone or with cediranib, an orally available potent inhibitor of all three VEGF receptor (VEGFR) tyrosine kinases, in murine orthotopic non–small cell lung carcinoma (NSCLC) models. Experimental Design: NCI-H441 or NCI-H460 KRAS-mutant human NSCLC cells were injected into the lungs of mice. Mice were randomly assigned to treatment with selumetinib, cediranib, paclitaxel, selumetinib plus cediranib, or control. When controls became moribund, all animals were sacrificed and assessed for lung tumor burden and locoregional metastasis. Lung tumors and adjacent normal tissues were subjected to immunohistochemical analyses. Results: Selumetinib inhibited lung tumor growth and, particularly at higher dose, reduced locoregional metastasis, as did cediranib. Combining selumetinib and cediranib markedly enhanced their antitumor effects, with near complete suppression of metastasis. Immunohistochemistry of tumor tissues revealed that selumetinib alone or with cediranib reduced ERK phosphorylation, angiogenesis, and tumor cell proliferation and increased apoptosis. The antiangiogenic and apoptotic effects were substantially enhanced when the agents were combined. Selumetinib also inhibited lung tumor VEGF production and VEGFR signaling. Conclusions: In this study, we evaluated therapy directed against MEK combined with antiangiogenic therapy in distinct orthotopic NSCLC models. MEK inhibition resulted in potent antiangiogenic effects with decreased VEGF expression and signaling. Combining selumetinib with cediranib enhanced their antitumor and antiangiogenic effects. We conclude that combining selumetinib and cediranib represents a promising strategy for the treatment of NSCLC. Clin Cancer Res; 18(6); 1641–54. ©2012 AACR.

Cediranib is a potent inhibitor of the VEGF receptor (VEGFR)-2 and VEGFR-3 tyrosine kinases. This study assessed the activity of cediranib against the VEGFR-1 tyrosine kinase and the platelet-derived growth factor receptor (PDGFR)-associated kinases c-Kit, PDGFR-α, and PDGFR-β. Cediranib inhibited VEGF-A–stimulated VEGFR-1 activation in AG1-G1-Flt1 cells (IC50 = 1.2 nmol/L). VEGF-A induced greatest phosphorylation of VEGFR-1 at tyrosine residues Y1048 and Y1053; this was reversed by cediranib. Potency against VEGFR-1 was comparable with that previously observed versus VEGFR-2 and VEGFR-3. Cediranib also showed significant activity against wild-type c-Kit in cellular phosphorylation assays (IC50 = 1–3 nmol/L) and in a stem cell factor–induced proliferation assay (IC50 = 13 nmol/L). Furthermore, phosphorylation of wild-type c-Kit in NCI-H526 tumor xenografts was reduced markedly following oral administration of cediranib (≥1.5 mg/kg/d) to tumor-bearing nude mice. The activity of cediranib against PDGFR-β and PDGFR-α was studied in tumor cell lines, vascular smooth muscle cells (VSMC), and a fibroblast line using PDGF-AA and PDGF-BB ligands. Both receptor phosphorylation (IC50 = 12–32 nmol/L) and PDGF-BB–stimulated cellular proliferation (IC50 = 32 nmol/L in human VSMCs; 64 nmol/L in osteosarcoma cells) were inhibited. In vivo, ligand-induced PDGFR-β phosphorylation in murine lung tissue was inhibited by 55% following treatment with cediranib at 6 mg/kg but not at 3 mg/kg or less. In contrast, in C6 rat glial tumor xenografts in mice, ligand-induced phosphorylation of both PDGFR-α and PDGFR-β was reduced by 46% to 61% with 0.75 mg/kg cediranib. Additional selectivity was showed versus Flt-3, CSF-1R, EGFR, FGFR1, and FGFR4. Collectively, these data indicate that cediranib is a potent pan-VEGFR kinase inhibitor with similar activity against c-Kit but is significantly less potent than PDGFR-α and PDGFR-β. Mol Cancer Ther; 10(5); 861–73. ©2011 AACR.

Purpose: Vascular endothelial growth factor (VEGF) signaling is key to tumor angiogenesis and is an important target in the development of anticancer drugs. However, VEGF receptor (VEGFR) expression in human cancers, particularly the relative expression of VEGFR-2 and VEGFR-3 in tumor vasculature versus tumor cells, is poorly defined. Experimental Design: VEGFR-2– and VEGFR-3–specific antibodies were identified and used in the immunohistochemical analysis of human primary cancers and normal tissue. The relative vascular localization of both receptors in colorectal and breast cancers was determined by coimmunofluorescence with vascular markers. Results: VEGFR-2 and VEGFR-3 were expressed on vascular endothelium but not on malignant cells in 13 common human solid tumor types (n > 400, bladder, breast, colorectal, head and neck, liver, lung, skin, ovarian, pancreatic, prostate, renal, stomach, and thyroid). The signal intensity of both receptors was significantly greater in vessels associated with malignant colorectal, lung, and breast than adjacent nontumor tissue. In colorectal cancers, VEGFR-2 was expressed on both intratumoral blood and lymphatic vessels, whereas VEGFR-3 was found predominantly on lymphatic vessels. In breast cancers, both receptors were localized to and upregulated on blood vessels. Conclusions: VEGFR-2 and VEGFR-3 are primarily localized to, and significantly upregulated on, tumor vasculature (blood and/or lymphatic) supporting the majority of solid cancers. The primary clinical mechanism of action of VEGF signaling inhibitors is likely to be through the targeting of tumor vessels rather than tumor cells. The upregulation of VEGFR-3 on tumor blood vessels indicates a potential additional antiangiogenic effect for dual VEGFR-2/VEGFR-3–targeted therapy. Clin Cancer Res; 16(14); 3548–61. ©2010 AACR.

VEGFR and c-Kit signaling pathways may contribute to the pathophysiology of acute myeloid leukemia (AML). Thirty-five patients with AML received cediranib (RECENTIN), an oral, highly potent VEGF signaling inhibitor with c-Kit activity, at doses of < or =30 mg/day. The most common adverse events were diarrhea, hypertension and fatigue. Six patients experienced an objective response (3 each at 20 and 30 mg). Dose- and time-dependent reductions in sVEGFR-2 were observed, and there was a positive correlation between cediranib exposure and the change in plasma VEGF levels from baseline. Cediranib was generally well tolerated and showed preliminary evidence of activity as a monotherapy.

Contains fulltext : 89775.pdf (Publisher’s version ) (Closed access) AIM: Cediranib is a highly potent inhibitor of vascular endothelial growth factor receptor (VEGFR) signalling. Preclinical and clinical data suggest that inhibition of the VEGFR and epidermal growth factor receptor (EGFR) pathways may be synergistic. Combination treatment with cediranib and gefitinib, an EGFR signalling inhibitor, was evaluated in patients with advanced solid tumours. PATIENTS AND METHODS: Ninety patients received treatment in this four-part, open-label study (NCT00502060). The patients received once-daily oral doses of cediranib (20-45mg) and gefitinib 250mg (part A1; n=16) or 500mg (part B1; n=44). A cohort expansion phase investigated the potential pharmacokinetic interaction of cediranib 30mg with gefitinib 250mg (part A2; n=15) or 500mg (part B2; n=15). The primary objective was to assess the safety and tolerability of cediranib with gefitinib. Secondary assessments included pharmacokinetics, efficacy and pharmacodynamics. RESULTS: Combination treatment was generally well tolerated; the protocol-defined maximum-tolerated dose of cediranib was 30mg/day with gefitinib 250mg/day (part A1) and cediranib 45mg/day was the maximum dose investigated with gefitinib 500mg/day (part B1). The most common adverse events were diarrhoea (84 [93%]), anorexia (63 [70%]) and fatigue (60 [67%]). Cediranib pharmacokinetic parameters were not substantially different when given alone or in combination with gefitinib. Gefitinib pharmacokinetic parameters were similar to those seen previously with gefitinib monotherapy. Efficacy results included eight (9%) confirmed partial responses (6 renal; 1 lung; 1 osteosarcoma) and 38 (42%) patients with stable disease. Pharmacodynamic assessments demonstrated changes in levels of VEGF and soluble VEGFR-2 following treatment. CONCLUSIONS: Combination treatment was generally well tolerated and showed encouraging antitumour activity in patients with advanced solid tumours. These results merit further exploration. 01 maart 2010

Purpose: The goal of this study was to examine the therapeutic potential of the vascular endothelial growth factor (VEGF) signaling inhibitor cediranib in a human model of renal cell carcinoma (Caki-1). Methods and Materials: The effects of cediranib treatment on in vitro endothelial cell function (proliferation, migration, and tube formation), as well as in vivo angiogenesis and tumor growth, were determined. Results: In vitro, cediranib significantly impaired the proliferation and migration of endothelial cells and their ability to form tubes, but had no effect on the proliferation of Caki-1 tumor cells. In vivo, cediranib significantly reduced Caki-1 tumor cell-induced angiogenesis, reduced tumor perfusion, and inhibited the growth of Caki-1 tumor xenografts. Conclusions: The present results are consistent with the notion that inhibition of VEGF signaling leads to an indirect (i.e., antiangiogenic) antitumor effect, rather than a direct effect on tumor cells. These results further suggest that inhibition of VEGF signaling with cediranib may impair the growth of renal cell carcinoma.

The vascular endothelial growth factor-A (VEGF-A) signaling pathway, a key stimulant of solid tumor vascularization, is primarily dependent on the activation of the endothelial cell surface receptor VEGF receptor-2 (VEGFR-2). AZD2171 is an oral, highly potent small-molecule inhibitor of VEGFR tyrosine kinase activity that inhibits angiogenesis and the growth of human tumor xenografts in vivo. Here, we show pharmacodynamic changes in VEGFR-2 phosphorylation induced by AZD2171. In mouse lung tissue, a single dose of AZD2171 at 6 mg/kg inhibited VEGF-A–stimulated VEGFR-2 phosphorylation by 87% at 2 h with significant inhibition (≥60%) maintained to 24 h. To examine inhibition of VEGFR-2 phosphorylation in tumor vasculature by immunohistochemistry, a comprehensive assessment of antibodies to various phosphorylation sites on the receptor was undertaken. Antibodies to the phosphotyrosine epitopes pY1175/1173 and pY1214/1212 were found suitable for this application. Calu-6 human lung tumor xenografts, from mice receiving AZD2171 or vehicle treatment (p.o., once daily), were examined by immunohistochemistry. A significant reduction in tumor vessel staining of phosphorylated VEGFR-2 (pVEGFR-2) was evident within 28 h of AZD2171 treatment (6 mg/kg). This effect preceded a significant reduction in tumor microvessel density, which was detectable following 52 h of AZD2171 treatment. These data show that AZD2171 is a potent inhibitor of VEGFR-2 activation in vivo and suggest that AZD2171 delivers therapeutic benefit in Calu-6 tumors by targeting vessels dependent on VEGFR-2 signaling for survival. In addition, this work highlights the utility of measuring either pY1175/1173 or pY1214/1212 on VEGFR-2 as a pharmacodynamic marker of VEGFR-2 activation. [Mol Cancer Ther 2007;6(8):2198–208]

Purpose AZD2171 is a highly potent oral selective inhibitor of vascular endothelial growth factor (VEGF) signaling. This phase I study was designed to evaluate the safety and tolerability of increasing doses of AZD2171, with additional assessments of pharmacokinetics, pharmacodynamics, and efficacy. Patients and Methods In part A, 36 patients with solid tumors and liver metastases refractory to standard therapies received once-daily oral AZD2171 (0.5 to 60 mg). Doses were escalated in successive cohorts until the maximum-tolerated dose was identified. In part B, patients with (n = 36) or without (n = 11) liver metastases were randomly assigned to receive once-daily AZD2171 (20, 30, or 45 mg). In both parts, treatment continued until tumor progression or dose-limiting toxicity (DLT) was observed. Results Eighty-three patients received AZD2171, which was generally well tolerated at doses of 45 mg/d or less; the most frequently reported dose-related adverse events were diarrhea, dysphonia, and hypertension. The most common DLT was hypertension (n = 7), which occurred at AZD2171 doses of 20 mg and higher. After a single dose, maximum plasma (peak) drug concentration after single-dose administration (Cmax) was achieved 1 to 8 hours postdosing with an arithmetic mean half-life associated with terminal slope of a semilogarithmic concentration-time curve (t1/2λz) of 22 hours. Pharmacodynamic assessments demonstrated time-, dose-, and exposure-related decreases in initial area under the curve, defined over 60 seconds post-contrast arrival in the tissue (iAUC60) using dynamic contrast-enhanced magnetic resonance imaging, as well as dose- and time-dependent reductions in soluble VEGF receptor 2 levels. Preliminary evidence of efficacy included two confirmed partial responses and 22 patients with stable disease; effects on tumor size appeared to be dose related. Conclusion Once-daily oral AZD2171 at doses of 45 mg or less was generally well tolerated and was associated with encouraging antitumor activity in patients with a broad range of advanced solid tumors.

Bcl-2 family members have long been known to control permeabilization of the mitochondrial membrane during apoptosis, but involvement of these proteins in lysosomal membrane permeabilization (LMP) was not considered until recently. The aim of this study was to investigate the mechanism underlying the release of lysosomal proteases to the cytosol seen during apoptosis, with special emphasis on the role of Bax. In human fibroblasts, exposed to the apoptosis-inducing drug staurosporine (STS), the release of the lysosomal protease cathepsin D to the cytosol was observed by immunocytochemistry. In response to STS treatment, there was a shift in Bax immunostaining from a diffuse to a punctate pattern. Confocal microscopy showed co-localization of Bax with both lysosomes and mitochondria in dying cells. Presence of Bax at the lysosomal membrane was confirmed by immuno-electron microscopy. Furthermore, when recombinant Bax was incubated with pure lysosomal fractions, Bax inserted into the lysosomal membrane and induced the release of lysosomal enzymes. Thus, we suggest that Bax is a mediator of LMP, possibly promoting the release of lysosomal enzymes to the cytosol during apoptosis.

The pro-apoptotic protein Bax plays a key role in the mitochondrial signalling pathway. Upon induction of apoptosis, Bax undergoes a conformational change and translocates to mitochondrial membranes, where it inserts and mediates the release of cytochrome c from the intermembrane space into the cytosol. However, the domains of Bax that are essential for the induction of cytochrome c release are still elusive. Therefore various Bax deletion mutants were generated and expressed in Escherichia coli. The proteins were then purified in order to delineate the function of the transmembrane domain, the BH3 (Bcl-2 homology 3) domain and the putative pore-forming α-helices-5 and -6. These proteins were used to analyse the mechanism of Bax-induced cytochrome c release from mitochondria. None of the Bax proteins caused cytochrome c release merely through physical perturbation of the mitochondrial outer membrane. The α-helices-5 and -6 of Bax were shown to mediate the insertion of the protein into mitochondrial membranes and to be essential for the cytochrome c-releasing activity of Bax. In contrast, neither the transmembrane domain nor a functional BH3 domain is required for the Bax-mediated release of cytochrome c from mitochondria.

The mechanism of Bax-dependent cytochrome c release is still controversial and may also depend on the actual localisation of cytochrome C: (i) we studied the distribution of cytochrome c in sub-fractions of rat kidney mitochondria and found that 10-20% of the total cytochrome c was associated at the peripheral inner membrane and to some extent organised in the contact sites. (ii) Cytochrome c concentrations in the contact site fractions varied related to surface bound hexokinase activity. It decreased upon reduction of contact sites by glycerol or specific dissociation of the VDAC-ANT complexes by bongkrekate, whereas it increased upon induction of contacts by dextran or association of VDAC-ANT complexes by atractyloside. (iii) The outer membrane pore (VDAC) acquires high capacity for hexokinase binding by interacting with the ANT. Thus, surface-attached hexokinase protein indicated the frequency of VDAC-ANT complexes and the correlation between hexokinase activity and cytochrome c suggested association of the latter to the complexes. (iv) Substances affecting exclusively the structure of either hexokinase (glucose-6P) or cytochrome c (borate) led to a decrease only of the effected protein without changing the concentration of other contact site constituents. (v) Hexokinase was furthermore used as a tool to isolate the contact site forming complex of outer membrane VDAC and inner membrane ANT from Triton-dissolved membranes. Cytochrome c remained attached to the hexokinase VDAC-ANT complexes that were reconstituted in phospholipid vesicles. (vi) The vesicles were loaded with malate and BaxDeltaC released the endogenous cytochrome c from the reconstituted complexes without forming unspecific pores for malate. BaxDeltaC targeted a cytochrome c fraction associated at the VDAC-ANT complex. The cytochrome c organisation was dependent on the actual structure of VDAC and ANT. Thus, the BaxDeltaC effect was suppressed either by hexokinase utilising glucose and ATP or by bongkrekic acid both influencing the pore and ANT structure.

The mechanism by which external Bax releases cytochrome c is still controversial and may also depend on the type of mitochondria and the actual localisation of cytochrome c. Outer membrane porin acquires high binding affinity for hexokinase by interacting with the adenine nucleotide translocator (ANT) in the contact sites. (I) The hexokinase protein was thus used as a tool to isolate the contact site forming complex between outer membrane porin and inner membrane ANT from a TritonX100 extract of brain membranes. (II) A significant amount of cytochrome c was co-purified with the isolated hexokinase porin ANT complexes that were reconstituted in phospholipid vesicles. Bax-δC released the endogenous cytochrome c from the vesicles without forming unspecific pores. This was shown by loading the vesicles with malate that was not liberated by Bax-δC. (III) The Bax-δC effect was dependent on a specific association of cytochrome c with the porin ANT complex, as dissociation of the complex by bongkrekate abolished the Bax dependent cytochrome c liberation. (IV) The Bax-δC effect was as well suppressed by hexokinase phosphorylating glucose.