Theranostic AGuIX nanoparticles as radiosensitizer: A phase I, dose-escalation study in patients with multiple brain metastases (NANO-RAD trial).

BACKGROUND AND PURPOSE: Brain metastasis impacts greatly on patients' quality of life and survival. The phase I NANO-RAD trial assessed the safety and maximum tolerated dose of systemic administration of a novel gadolinium-based nanoparticle, AGuIX, in combination with whole brain radiotherapy in patients with multiple brain metastases not suitable for stereotactic radiotherapy. MATERIALS AND METHODS: Patients with measurable brain metastases received escalating doses of AGuIX nanoparticles (15, 30, 50, 75, or 100 mg/kg intravenously) on the day of initiation of WBRT (30 Gy in 10 fractions) in 5 cohorts of 3 patients each. Toxicity was assessed using NCI Common Terminology Criteria for Adverse Events v4.03. RESULTS: Fifteen patients with 354 metastases were included. No dose-limiting toxic effects were observed up to AGuIX 100 mg/kg. Plasma elimination half-life of AGuIX was similar for all groups (mean 1.3 h; range 0.8-3 h). Efficient targeting of metastases (T1 MRI enhancement, tumor selectivity) and persistence of AGuIX contrast enhancement were observed in metastases from patients with primary melanoma, lung, breast, and colon cancers. The concentration of AGuIX in metastases after administration was proportional to the injected dose. Thirteen of 14 evaluable patients had a clinical benefit, with either stabilization or reduction of tumor volume. MRI analysis showed significant correlation between contrast enhancement and tumor response, thus supporting a radiosensitizing effect. CONCLUSION: Combining AGuIX with radiotherapy for patients with brain metastases is safe and feasible. AGuIX specifically targets brain metastases and is retained within tumors for up to 1 week; ongoing phase II studies will more definitively assess efficacy.

Transferability of health cost evaluation across locations in oncology: cluster and principal component analysis as an explorative tool.

BACKGROUND: The transferability of economic evaluation in health care is of increasing interest in today's globalized environment. Here, we propose a methodology for assessing the variability of data elements in cost evaluations in oncology. This method was tested in the context of the European Network of Excellence "Connective Tissues Cancers Network". METHODS: Using a database that was previously aimed at exploring sarcoma management practices in Rhône-Alpes (France) and Veneto (Italy), we developed a model to assess the transferability of health cost evaluation across different locations. A nested data structure with 60 final factors of variability (e.g., unit cost of chest radiograph) within 16 variability areas (e.g., unit cost of imaging) within 12 objects (e.g., diagnoses) was produced in Italy and France, separately. Distances between objects were measured by Euclidean distance, Mahalanobis distance, and city-block metric. A hierarchical structure using cluster analysis (CA) was constructed. The objects were also represented by their projections and area of variability through correlation studies using principal component analysis (PCA). Finally, a hierarchical clustering based on principal components was performed. RESULTS: CA suggested four clusters of objects: chemotherapy in France; follow-up with relapse in Italy; diagnosis, surgery, radiotherapy, chemotherapy, and follow-up without relapse in Italy; and diagnosis, surgery, and follow-up with or without relapse in France. The variability between clusters was high, suggesting a lower transferability of results. Also, PCA showed a high variability (i.e. lower transferability) for diagnosis between both countries with regard to the quantities and unit costs of biopsies. CONCLUSION: CA and PCA were found to be useful for assessing the variability of cost evaluations across countries. In future studies, regression methods could be applied after these methods to elucidate the determinants of the differences found in these analyses.

7th cancer scientific forum of theCancéropôle Lyon Auvergne Rhône-Alpes: March 20-21, 2012, Lyon, France.

The Innovative Approaches in Anti-Cancer Monoclonal Antibodies meeting, held on March 20, 2012 in Lyon, was organized by Cancéropôle Lyon Auvergne-Rhône-Alps in partnership with the French competitiveness cluster Lyonbiopôle. CLARA is one of the seven cancer research clusters within France in charge of facilitating Translational Oncology Research by taking into account the objectives of the French National Cancer Plans I and II and, in coordination with the French National Cancer Institute and local authorities (mainly Grand Lyon, Rhône County and Rhône-Alpes Region), to perform economic development of research findings. The contribution of lectures by outstanding speakers as described in this report, the organization of two-round tables: "Antibody treatment in cancer: Unmet needs in solid tumors and hematological malignancies," and "From chimeric to more than human antibodies," together with face-to-face meetings, was shared by over 230 participants. The lectures provided an overview of the commercial pipeline of monoclonal antibody (mAb) therapeutics for cancer; discussion of the distinction between biosimilar, biobetter and next generation therapeutic antibodies for cancer; updates on obinutuzumab and the use of mAbs in lymphoma; and discussion of antibody-drug conjugates.

Whole spectrum analysis of ligand efficacy at constitutively active human wild-type and S267K 5-HT6 receptors in HEK-293F cells.

INTRODUCTION: Modulation of constitutive activity by the recombinant wild-type human 5-HT6 receptor was investigated with a series of 5-HT6 receptor ligands by monitoring the cAMP signalling pathway. The impact of the mutation S267K near the B(261)BXXB(265) CIII-loop motif was analyzed on the magnitude of constitutive receptor activity as previously conflicting results have been reported. METHODS: The wild-type 5-HT6 receptor plasmid was obtained by PCR and the mutant S267K5-HT6 receptor was constructed by site-directed mutagenesis and stably transfected in HEK-293F cells by electroporation. The cAMP signalling pathway was monitored as a functional read-out to investigate ligands' responses using homogeneous time resolved fluorescence. RESULTS: Constitutive activity was present both at wild-type and mutant S267K 5-HT6 receptors. Negative efficacy (E(max), % versus basal) as observed at nanomolar concentrations with SB-271046 was larger for mutant (-92+/-1%) than wild-type 5-HT6 receptor (-45+/-1%). Ro 04-6790 also demonstrated negative efficacy at the wild-type 5-HT6 receptor with a magnitude similar to SB-271046 but with a 36-fold lower potency. MS-245 demonstrated at nanomolar concentrations intermediate negative efficacy; -48+/-3% and -16+/-2% at mutant and wild-type 5-HT6 receptor, respectively. The 5-HT-mediated cAMP response was blocked by SB-271046, MS-245 and Ro 04-6790 to their respective level of negative efficacy with pKB values fitting with their binding pK(i) values. E-6801 was a highly potent (pEC50: 10.17 to 10.19) and efficacious agonist (+98 to +102% versus 5-HT) at both wild-type and mutant 5-HT6 receptors. DISCUSSION: The recombinant wild-type human 5-HT6 receptor is constitutively active in HEK-293F cells and displays a high resolution to monitor efficacy properties of 5-HT6 receptor ligands. The resolution capacity to differentiate between efficacy properties of 5-HT6 receptor ligands, in particular for negative efficacy, can be further enhanced by monitoring the mutant S267K 5-HT6 receptor.

Reanalysis of constitutively active rat and human 5-HT7(a) receptors in HEK-293F cells demonstrates lack of silent properties for reported neutral antagonists.

The present study reinvestigated a series of 5-HT receptor antagonists at both constitutively active rat and human 5-HT7(a) receptors in HEK-293F cells using the cAMP signalling pathway as a functional read-out. Both rat and human 5-HT7(a) receptors were expressed in similar amounts ([3H]-LSD binding: 1.0 to 1.1 pmol/mg protein). Attenuation of basal cAMP formation by the inverse agonist SB-691673 (1 microM) was slightly larger by the human 5-HT7(a) (-73+/-3 %) than rat 5-HT7(a) receptor (-62+/-3 %). The 5-HT receptor antagonists investigated here displayed systematically inverse agonism. While methiothepin and SB-269970 displayed similar negative intrinsic activity to SB-691673 at the rat 5-HT7(a) receptor, the compounds SB-258719, mesulergine and metergoline displayed some lower negative intrinsic activity (between -38 and -49%). Inverse agonist properties were observed with potencies fitting with their respective binding pIC50 values and pKB values as estimated from antagonist studies with 5-HT. With the exception of SB-258719 and mesulergine, which remained a partial inverse agonist at the human 5-HT7(a) receptor, the other compounds behaved with a similar Emax value to the full inverse agonist SB-691673. In conclusion, none of the 5-HT receptor antagonists investigated displayed silent properties at the rat or human 5-HT7(a) receptor, when these are expressed in a system allowing detection of constitutive activity. They appear to be partial to full inverse agonists, further illustrating that an antagonist is preferentially an inverse agonist when investigated under constitutively active receptor conditions.

Efficacy of selective 5-HT6 receptor ligands determined by monitoring 5-HT6 receptor-mediated cAMP signaling pathways.

1. Two novel selective 5-HT6 receptor ligands E-6801 (6-chloro-N-(3-(2-(dimethylamino)ethyl)-1H-indol-5-yl)imidazo[2,1-b]thiazole-5-sulfonamide) and E-6837 (5-chloro-N-(3-(2-(dimethylamino)ethyl)-1H-indol-5-yl)naphthalene-2-sulfonamide) were investigated and compared to the putative 5-HT6 receptor antagonists SB-271046 (5-chloro-N-(4-methoxy-3-(piperazin-1-yl)phenyl)-3-methylbenzo[b]thiophene-2-sulfonamide) and Ro 04-06790 (N-(2,6-bis(methylamino)pyrimidin-4-yl)-4-aminobenzenesulfonamide) using a cAMP-mediated pathway. 2. Forskolin stimulation, to increase the magnitude of agonist cAMP responses, and site-directed mutagenesis of the 5-HT6 receptor, in order to yield constitutively active receptor, were applied. 3. 5-HT (E(max), % over basal: 200), E-6801 (120) and E-6837 (23) induced cAMP formation at the rat 5-HT6 receptor. In the copresence of forskolin, cAMP responses were more potent and enhanced to 294 (5-HT, % over forskolin), 250 (E-6801) and 207 (E-6837), respectively. 5-HT-mediated cAMP formation was dose-dependently blocked by SB-271046 (pA(2): 8.76+/-0.22) and Ro 04-6790 (pA(2): 7.89+/-0.10) and not affected by the copresence of forskolin. Both E-6801 and E-6837 yielded partial antagonism of the 5-HT response in the absence of forskolin, whereas antagonism was either completely absent (E-6801) or attenuated (E-6837) in the copresence of forskolin. Intrinsic activity of these 5-HT6 receptor ligands at a constitutively active human S267K 5-HT6 receptor in Cos-7 cells indicated similar efficacy (E(max), % over basal) for 5-HT (97), E-6801 (91) and E-6837 (100), while Ro 04-6790 (-33) and SB-271046 (-39) were equi-efficacious inverse agonists. 4. The use of either forskolin or a constitutively active S267K 5-HT6 receptor enhances the resolution for monitoring the efficacy of 5-HT6 receptor ligands. E-6801 and E-6837 are potent partial agonists at the 5-HT6 receptor. Ro 04-6790 and SB-271046 appear to act as inverse agonists/antagonists.

A recombinant humanized anti-insulin-like growth factor receptor type I antibody (h7C10) enhances the antitumor activity of vinorelbine and anti-epidermal growth factor receptor therapy against human cancer xenografts.

Interaction of insulin-like growth factor receptor I (IGF-IR) with its ligands has been reported to induce cell proliferation, transformation and blockade of cell apoptotic functions. IGF-IR is overexpressed on numerous tumor cell types and its blockade could be of importance for anti-cancer therapy. We have generated a humanized anti-IGF-IR antibody h7C10 that blocks in vitro IGF-I and IGF-II-induced cell proliferation of MCF-7 breast cancer cells. Analysis of the IGF-I transduction cascade demonstrated that the humanized anti-IGF-IR antibody and its murine parental form block IGF-I-induced tyrosine phosphorylation, both its beta-chain and IRS-1 tyrosine phosphorylation. This presumably leads to cell cycle arrest and, consequently, growth inhibition. Treatment of nude mice bearing either human breast cancer cells (MCF-7) or non small lung cancer cells (A549) with h7C10, or its murine parental form 7C10, inhibited significantly tumor growth. An almost complete inhibition of A549 tumor growth was observed when mice were treated with the anti-IGF-IR antibody combined with either a chemotherapeutic agent, Vinorelbine or an anti-epidermal growth factor receptor (EGFR) antibody, 225. Combined therapy prolonged significantly the life span of mice in an orthotopic in vivo model of A549; the combination of the anti-IGF-IR antibody with an anti-EGFR antibody was superior to the Vinorelbine combination. The present results indicate that the humanized anti-IGF-IR antibody h7C10 has a great potential for cancer therapy when combined with either a chemotherapeutic agent or an antibody that targets other growth factor receptors, such as the epidermal growth factor receptor.

Dissimilar pharmacological responses by a new series of imidazoline derivatives at precoupled and ligand-activated alpha 2A-adrenoceptor states: evidence for effector pathway-dependent differential antagonism.

Whereas agonist-directed differential signaling at a single receptor subtype has become an accepted pharmacological concept, distinct behaviors by ligands that are assumed to be antagonists is less documented. The intrinsic activity and capacity of antagonism for a new series of imidazoline-derived adrenergic ligands analogous to dexefaroxan were investigated by measuring two distinct signaling pathways at the recombinant human alpha 2A-adrenoceptor (alpha 2A AR): 1) pertussis toxin-resistant guanosine 5'-O-(3-[35S]thio)triphosphate ([35S]GTP gamma S) binding responses mediated by either a recombinant G alpha oCys351Ile or G alpha i2Cys352Ile protein in CHO-K1 cells, and 2) inhibition of cAMP formation in a stably transfected C6-glial cell line. Ligands could be differentiated as inverse agonists [i.e., 2-(4-methoxy-2-ethyl-2,3-dihydrobenzofuran-2-yl)-4,5-dihydro-1H-imidazole; RX 851062], neutral antagonists [i.e., 2-(4-hydroxy-2-ethyl-2,3-dihydrobenzofuran-2-yl)-4,5-dihydro-1H-imidazole; RX 851057], partial [i.e., 2-(4-chloro-2,3-dihydrobenzofuran-2-yl)-4,5-dihydro-1H-imidazole; RX 821008], and high-efficacy [i.e., 2-(6,7-dichloro-2,3-dihydrobenzofuran-2-yl)-4,5-dihydro-1H-imidazole; RX 821010] agonists at a precoupled alpha 2A AR state in the copresence of a G alpha oCys351Ile protein but not G alpha i2Cys352Ile protein by monitoring [35S]GTP gamma S binding responses. Neither positive nor negative efficacy was observed for these compounds by monitoring the adenylate cyclase pathway at a presumably low-affinity alpha 2A AR state. The capacity of the dexefaroxan analogs to antagonize the (-)-epinephrine-mediated [35S]GTP gamma S binding response at a G alpha oCys351Ile protein was inversely correlated with their magnitude of intrinsic activity and unrelated to their ligand binding affinity for the alpha 2A AR. On the other hand, their capacity to antagonize either (-)-epinephrine or 5-bromo-6-(2-imidazolin-2-ylamino)quinoxaline tartrate (UK 14304)-mediated inhibition of forskolin-stimulated cAMP formation was not related with the rank order of antagonist capacity for the (-)-epinephrine-mediated [35S]GTP gamma S binding response. In conclusion, these data demonstrate that certain alpha2 AR ligands that are assumed to be antagonists, may yield dissimilar pharmacological responses, dependent on the investigated agonist-stimulated effector pathway.