Associations of TACSTD2/TROP2 and NECTIN-4/NECTIN-4 with molecular subtypes, PD-L1 expression, and FGFR3 mutational status in two advanced urothelial bladder cancer cohorts.

AIMS: Treatment options for advanced urothelial carcinoma (aUC) rapidly evolved: besides immunomodulative therapeutic options and inhibitors targeting Fibroblast growth factor receptor (FGFR) alterations, two new antibody-drug conjugates (ADC), sacituzumab govitecan (SG) and enfortumab vedotin (EV), have been approved. However, little is known about the associations of specific aUC properties and the surface target expression of TROP2 and NECTIN-4. Our aim was to characterize associations of TACSTD2/TROP2 and NECTIN-4/NECTIN-4 protein and gene expression with morphomolecular and clinicopathological characteristics of aUC in two large independent cohorts. METHODS AND RESULTS: The TCGA BLCA (n = 405) and the CCC-EMN (n = 247) cohorts were retrospectively analysed. TROP2/TACSTD2 and NECTIN-4/NECTIN-4 are highly expressed at the protein and transcript level in aUC, and their expression status did not correlate with patient survival in both cohorts. NECTIN-4/NECTIN-4 expression was higher in luminal tumours and reduced in squamous aUCs. NECTIN-4 was negative in 10.6% of samples, and 18.4% of samples had low expression (H-score <15). The TROP2 negativity rate amounted to 6.5%. TACSTD2 and NECTIN-4 expression was reduced in neuroendocrine-like and/or protein-based double-negative tumours. TROP2- and NECTIN-4-negative tumours included one sarcomatoid and four neuroendocrine aUC. FGFR3 alterations and PD-L1 expression on tumour and immune cells did not associate with TROP2 or NECTIN-4 expression. CONCLUSIONS: TACSTD2/TROP2 and NECTIN-4/NECTIN-4 are widely expressed in aUC, independent of FGFR3 alterations or PD-L1 expression, thus representing a suitable target for ADC treatment in the majority of aUC. The expression loss was associated with aggressive morphomolecular aUC subtypes, i.e. neuroendocrine(-like) and sarcomatoid aUC.

Vascular endothelial growth factor c promotes ovarian carcinoma progression through paracrine and autocrine mechanisms.

Vascular endothelial growth factor C (VEGFC) has been reported to promote tumor progression in several tumor types, mainly through the stimulation of lymphangiogenesis and lymphatic metastasis. However, the expression and biological significance of the VEGFC/VEGF receptor (VEGFR)-3 pathway in ovarian cancer growth and dissemination are unclear, and have been investigated in this study. Soluble VEGFC was detected in the plasma and ascites of patients with ovarian carcinoma, and VEGFR3 expression was found in their tumor tissues. In human ovarian carcinoma xenograft models, high levels of soluble VEGFC in ascites and serum were detected, in association with disease progression, tumor burden, and volume of ascites. Peak VEGFC expression preceded para-aortic lymph node infiltration by HOC8 neoplastic cells. Histological detection of tumor cells in blood and lymphatic vessels indicated both hematogenous and lymphatic dissemination. Overexpression of VEGFC in the VEGFR3-positive and luciferase-expressing IGROV1 cells promoted carcinoma dissemination after orthotopic transplantation in the ovary of immunodeficient mice. In vitro, VEGFC released by the tumor cells stimulated tumor cell migration in an autocrine manner. Cediranib, an inhibitor of VEGFR1-3 and c-kit, inhibited in vivo metastasis of VEGFC-overexpressing IGROV1 and in vitro autocrine effects. These findings suggest that the VEGFC/VEGFR3 pathway acts as an enhancer of ovarian cancer progression through autocrine and paracrine mechanisms, hence offering a potential target for therapy.

Phase 1 first-in-human study of dalutrafusp alfa, an anti-CD73-TGF-ß-trap bifunctional antibody, in patients with advanced solid tumors.

BACKGROUND: Cluster of differentiation (CD)73-adenosine and transforming growth factor (TGF)-ß pathways are involved in abrogated antitumor immune responses and can lead to protumor conditions. This Phase 1 study (NCT03954704) evaluated the safety, pharmacokinetics, pharmacodynamics, and efficacy of dalutrafusp alfa (also known as GS-1423 and AGEN1423), a bifunctional, humanized, aglycosylated immunoglobulin G1 kappa antibody that selectively inhibits CD73-adenosine production and neutralizes active TGF-ß signaling in patients with advanced solid tumors. METHODS: Dose escalation started with an accelerated titration followed by a 3+3 design. Patients received dalutrafusp alfa (0.3, 1, 3, 10, 20, 30, or 45 mg/kg) intravenously every 2 weeks (Q2W) up to 1 year or until progressive disease (PD) or unacceptable toxicity. RESULTS: In total, 21/22 patients received at least one dose of dalutrafusp alfa. The median number of dalutrafusp alfa doses administered was 3 (range 1-14). All patients had at least one adverse event (AE), most commonly fatigue (47.6%), nausea (33.3%), diarrhea (28.6%), and vomiting (28.6%). Nine (42.9%) patients had a Grade 3 or 4 AE; two had Grade 5 AEs of pulmonary embolism and PD, both unrelated to dalutrafusp alfa. Target-mediated drug disposition appears to be saturated at dalutrafusp alfa doses above 20 mg/kg. Complete CD73 target occupancy on B cells and CD8+ T cells was observed, and TGF-ß 1/2/3 levels were undetectable at dalutrafusp alfa doses of 20 mg/kg and higher. Free soluble (s)CD73 levels and sCD73 activity increased with dalutrafusp alfa treatment. Seventeen patients reached the first response assessment, with complete response, partial response, stable disease, and PD in 0, 1 (4.8%), 7 (33.3%), and 9 (42.9%) patients, respectively. CONCLUSIONS: Dalutrafusp alfa doses up to 45 mg/kg Q2W were well tolerated in patients with advanced solid tumors. Additional evaluation of dalutrafusp alfa could further elucidate the clinical utility of targeting CD73-adenosine and TGF-ß pathways in oncology.

Semi-Mechanistic PK/PD Modeling and Simulation of Irreversible BTK Inhibition to Support Dose Selection of Tirabrutinib in Subjects with RA.

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.

XIAP-mediated caspase inhibition in Hodgkin's lymphoma-derived B cells.

The malignant Hodgkin and Reed-Sternberg cells of Hodgkin's lymphoma (HL) and HL-derived B cell lines were previously shown to be resistant to different apoptotic stimuli. We show here that cytochrome c fails to stimulate caspases-9 and -3 activation in cytosolic extracts of HL-derived B cells, which is due to high level expression of X-linked inhibitor of apoptosis (XIAP). Coimmunoprecipitation studies revealed that XIAP, apoptosis protease-activating factor-1, and caspase-3 are complexed in HL-derived B cell lysates. Even after stimulation with exogenous cytochrome c and dATP, XIAP impairs the proteolytic processing and activation of caspase-3. In cytosolic extracts, inhibition of XIAP by the second mitochondria-derived activator of caspases (Smac)/DIABLO, or immunodepletion of XIAP restores cytochrome c-triggered processing and activation of caspase-3. Smac or a Smac-derived agonistic peptide also sensitized intact HL-derived B cells for the apoptotic action of staurosporine. Finally, Hodgkin and Reed-Sternberg cells of primary tumor HL tissues also constitutively and abundantly express XIAP. The results of this paper suggest that high level XIAP expression is a hallmark of HL, which may play a crucial role in resistance to apoptosis.

Effects of novel Btk and Syk inhibitors on platelet functions alone and in combination in vitro and in vivo.

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.

Phase Ib Study of Tirabrutinib in Combination with Idelalisib or Entospletinib in Previously Treated Chronic Lymphocytic Leukemia.

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).

Acute pharmacodynamic and antivascular effects of the vascular endothelial growth factor signaling inhibitor AZD2171 in Calu-6 human lung tumor xenografts.

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 (>or=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.

Homogeneous BTK Occupancy Assay for Pharmacodynamic Assessment of Tirabrutinib (GS-4059/ONO-4059) Target Engagement.

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.

Targeted therapy against VEGFR and EGFR with ZD6474 enhances the therapeutic efficacy of irradiation in an orthotopic model of human non-small-cell lung cancer.

PURPOSE: Conventional therapies for patients with lung cancer have reached a therapeutic plateau. We therefore evaluated the feasibility of combined vascular endothelial growth factor (VEGF) receptor 2 (VEGFR2) and epidermal growth factor (EGF) receptor (EGFR) targeting with radiation therapy in an orthotopic model that closely recapitulates the clinical presentation of human lung cancer. METHODS AND MATERIALS: Effects of irradiation and/or ZD6474, a small-molecule inhibitor of VEGFR2 and EGFR tyrosine kinases, were studied in vitro for human lung adenocarcinoma cells by using proliferation and clonogenic assays. The feasibility of combining ZD6474 with radiation therapy was then evaluated in an orthotopic model of human lung adenocarcinoma. Lung tumor burden and spread within the thorax were assessed, and tumor and adjacent tissues were analyzed by means of immunohistochemical staining for multiple parameters, including CD31, VEGF, VEGFR2, EGF, EGFR, matrix metalloproteinase-2 and -9, and basic fibroblast growth factor. RESULTS: ZD6474 enhanced the radioresponse of NCI-H441 human lung adenocarcinoma cells by a factor of 1.37 and markedly inhibited sublethal damage repair. In vivo, the combined blockade of VEGFR2 and EGFR by ZD6474 blocked pleural effusion formation and angiogenesis and enhanced the antivascular and antitumor effects of radiation therapy in the orthotopic human lung cancer model and was superior to chemoradiotherapy. CONCLUSIONS: When radiation therapy is combined with VEGFR2 and EGFR blockade, significant enhancement of antiangiogenic, antivascular, and antitumor effects are seen in an orthotopic model of lung cancer. These data provide support for clinical trials of biologically targeted and conventional therapies for human lung cancer.

AZD2171: a highly potent, orally bioavailable, vascular endothelial growth factor receptor-2 tyrosine kinase inhibitor for the treatment of cancer.

Inhibition of vascular endothelial growth factor-A (VEGF) signaling is a promising therapeutic approach that aims to stabilize the progression of solid malignancies by abrogating tumor-induced angiogenesis. This may be accomplished by inhibiting the kinase activity of VEGF receptor-2 (KDR), which has a key role in mediating VEGF-induced responses. The novel indole-ether quinazoline AZD2171 is a highly potent (IC50 < 1 nmol/L) ATP-competitive inhibitor of recombinant KDR tyrosine kinase in vitro. Concordant with this activity, in human umbilical vein endothelial cells, AZD2171 inhibited VEGF-stimulated proliferation and KDR phosphorylation with IC50 values of 0.4 and 0.5 nmol/L, respectively. In a fibroblast/endothelial cell coculture model of vessel sprouting, AZD2171 also reduced vessel area, length, and branching at subnanomolar concentrations. Once-daily oral administration of AZD2171 ablated experimental (VEGF-induced) angiogenesis in vivo and inhibited endochondral ossification in bone or corpora luteal development in ovary; physiologic processes that are highly dependent upon neovascularization. The growth of established human tumor xenografts (colon, lung, prostate, breast, and ovary) in athymic mice was inhibited dose-dependently by AZD2171, with chronic administration of 1.5 mg per kg per day producing statistically significant inhibition in all models. A histologic analysis of Calu-6 lung tumors treated with AZD2171 revealed a reduction in microvessel density within 52 hours that became progressively greater with the duration of treatment. These changes are indicative of vascular regression within tumors. Collectively, the data obtained with AZD2171 are consistent with potent inhibition of VEGF signaling, angiogenesis, neovascular survival, and tumor growth. AZD2171 is being developed clinically as a once-daily oral therapy for the treatment of cancer.

Bax-induced cytochrome c release from mitochondria depends on alpha-helices-5 and -6.

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 alpha-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 alpha-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.

A Novel Small-Molecule Inhibitor Targeting CREB-CBP Complex Possesses Anti-Cancer Effects along with Cell Cycle Regulation, Autophagy Suppression and Endoplasmic Reticulum Stress.

Lung adenocarcinoma, the most common subtype of lung cancer, is the leading cause of cancer death worldwide. Despite attempts for the treatment of lung cancer which have been accumulating, promising new therapies are still needed. Here, we found that cyclic-AMP response element-binding protein (CREB)-CREB binding protein (CBP) transcription factors complex inhibitor, Naphthol AS-TR phosphate (NASTRp), is a potential therapeutic agent for lung cancer. We show that NASTRp inhibited oncogenic cell properties through cell cycle arrest with concomitant suppression of tumor-promoting autophagy with down-regulations of Atg5-12 and Atg7, and accumulation of p62 in human lung cancer cell lines. In addition, NASTRp induced expression of endoplasmic reticulum stress markers such as DDIT3/CHOP, and led to apoptosis along with Bim induction. These findings suggest that transcription factor/co-activator complex, CREB-CBP, can be a potential therapeutic target and its inhibition could be a novel therapeutic strategy for lung cancer.

c-Myc is able to sensitize human melanoma cells to diverse apoptotic triggers.

Compared with other types of tumours, malignant melanomas are highly refractory to radio- or chemotherapy. To support the search for possible sensitizers, we explored the effects of the cellular oncoproteins c-Myc and N-Ras, which can decrease the clonogenic potential of irradiated p53-negative IGR39D melanoma cells. Using stable transfectants of this cell line, we showed that mutant N-Ras decreased the proliferation rate by inducing a prolonged cell cycle arrest. In contrast, c-Myc made these melanoma cells more prone to radiation-induced cell death. Membrane blebbing, the formation of apoptotic bodies and caspase activation, as measured by cleavage of Asp-Glu-Val-Asp (DEVD) substrate and poly(ADP-ribose) polymerase (PARP), indicate that these cells die by an apoptotic process. c-Myc also sensitized these p53-deficient melanoma cells to treatment with various cytotoxic drugs and heat shock. Similar results were obtained in inducible c-Myc models of IGR39D and in another melanoma cell line, 9007, which expresses functional p53. Together, these findings indicate that c-Myc is capable of sensitizing typically resistant tumour cells and that this occurs irrespective of the functional status of the p53 protein. Our results should facilitate the identification of factors that can be exploited for the treatment of aggressive cancers.

New strategies in personalized medicine for solid tumors: molecular markers and clinical trial designs.

The delineation of signaling pathways to understand tumor biology combined with the rapid development of technologies that allow broad molecular profiling and data analysis has led to a new era of personalized medicine in oncology. Many academic institutions now routinely profile patients and discuss their cases in meetings of personalized medicine tumor boards before making treatment recommendations. Clinical trials initiated by pharmaceutical companies often require specific markers for enrollment or at least explore multiple options for future markers. In addition to the still small number of targeted agents that are approved for the therapy of patients with histological and molecularly defined tumors, a broad range of novel targeted agents in development are undergoing clinical studies with companion profiling to determine the best-responding patient population. Although the present focus of profiling lies in genetic analyses, additional tests of RNA, protein, and immune parameters are being developed and incorporated in clinical research, and these methods are likely to contribute significantly to future patient selection and treatment approaches. As the advances in tumor biology and human genetics have identified promising tumor targets, the ongoing clinical evaluation of novel agents will now need to show if the promise can be translated into benefit for patients.

Correlation of lactate dehydrogenase isoenzyme profile with outcome in patients with advanced colorectal cancer treated with chemotherapy and bevacizumab or cediranib: Retrospective analysis of the HORIZON I study.

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.

Phase II study of cediranib in patients with advanced gastrointestinal stromal tumors or soft-tissue sarcoma.

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 ((18)FDG-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 (18)FDG-PET, but did not reduce average SUVmax. Evidence of antitumor activity was seen in ASPS.