The MET Inhibitor AZD6094 (Savolitinib, HMPL-504) Induces Regression in Papillary Renal Cell Carcinoma Patient-Derived Xenograft Models.

PURPOSE: Papillary renal cell carcinoma (PRCC) is the second most common cancer of the kidney and carries a poor prognosis for patients with nonlocalized disease. The HGF receptor MET plays a central role in PRCC and aberrations, either through mutation, copy number gain, or trisomy of chromosome 7 occurring in the majority of cases. The development of effective therapies in PRCC has been hampered in part by a lack of available preclinical models. We determined the pharmacodynamic and antitumor response of the selective MET inhibitor AZD6094 in two PRCC patient-derived xenograft (PDX) models. EXPERIMENTAL DESIGN: Two PRCC PDX models were identified and MET mutation status and copy number determined. Pharmacodynamic and antitumor activity of AZD6094 was tested using a dose response up to 25 mg/kg daily, representing clinically achievable exposures, and compared with the activity of the RCC standard-of-care sunitinib (in RCC43b) or the multikinase inhibitor crizotinib (in RCC47). RESULTS: AZD6094 treatment resulted in tumor regressions, whereas sunitinib or crizotinib resulted in unsustained growth inhibition. Pharmacodynamic analysis of tumors revealed that AZD6094 could robustly suppress pMET and the duration of target inhibition was dose related. AZD6094 inhibited multiple signaling nodes, including MAPK, PI3K, and EGFR. Finally, at doses that induced tumor regression, AZD6094 resulted in a dose- and time-dependent induction of cleaved PARP, a marker of cell death. CONCLUSIONS: Data presented provide the first report testing therapeutics in preclinical in vivo models of PRCC and support the clinical development of AZD6094 in this indication.

Opioid interactions in rhesus monkeys: effects of delta + mu and delta + kappa agonists on schedule-controlled responding and thermal nociception.

Agonists at delta, mu, and kappa opioid receptors produce interacting effects in rodents and nonhuman primates. To further evaluate the determinants of these interactions, this study examined the effects of mixtures of delta + mu and delta + kappa agonists in rhesus monkeys (n = 4-5) using two behavioral procedures, an assay of schedule-controlled responding for food reinforcement and an assay of thermal nociception. Results were analyzed using dose-addition analysis. In the assay of schedule-controlled responding, the delta agonist (+)-4-[(alphaR)-alpha-((2S,5R)-4-allyl-2,5-dimethyl-1-piperazinyl)-3-methoxy-benzyl]-N,N-diethyl-benzamide (SNC80); the mu agonists methadone, fentanyl, morphine, and nalbuphine; and the kappa agonists (5alpha,7alpha,8beta)-(-)-N-methyl-N-(7-(1-pyrrolidinyl)-1-oxaspiro(4,5)dec-8-yl) benzeneacetamide (U69,593) and bremazocine all dose dependently decreased rates of food-maintained responding when administered alone. Fixed ratio mixtures of SNC80 + mu agonists produced additive or subadditive effects, whereas SNC80 + kappa agonist mixtures produced only additive effects. In the assay of thermal nociception, SNC80 produced no measurable effects when administered alone, whereas mu and kappa agonists produced dose-dependent antinociception. SNC80 + mu agonist mixtures produced superadditive effects manifested as leftward shifts in mu agonist dose-effect curves. This synergism was antagonized by the delta-selective antagonist naltrindole, suggesting that SNC80-induced enhancement of mu agonist antinociception was delta receptor-mediated. SNC80 did not enhance the antinociceptive effects of the highly selective kappa agonist U69,593, and it produced only a marginal enhancement of antinociception produced by the less selective kappa agonist bremazocine. These results suggest that delta agonists may selectively enhance the antinociceptive effects of mu agonists in rhesus monkeys. These results also confirm that opioid agonist interactions may depend on the receptor selectivity and relative doses of the agonists and on the experimental endpoint.

Kappa opioid antagonist effects of the novel kappa antagonist 5'-guanidinonaltrindole (GNTI) in an assay of schedule-controlled behavior in rhesus monkeys.

RATIONALE: Opioid receptors are divided into three types: kappa, mu, and delta receptors. Receptor-selective antagonists are useful experimental tools for evaluation of opioid receptor-mediated processes. 5'-Guanidinonaltrindole (GNTI) was recently developed as a novel kappa-selective antagonist. OBJECTIVES: To evaluate the potency, time course, and selectivity of GNTI's opioid antagonist effects in rhesus monkeys in an assay of schedule-controlled responding. METHODS: Five rhesus monkeys were trained to respond under a fixed ratio 30 schedule of food reinforcement. The rate-decreasing effects of the kappa agonists U50,488 and U69,593, the mu agonist morphine, and the delta agonist SNC80 were examined alone and after pretreatment with GNTI (0.1 and 1.0 mg/kg i.m.; 1 h to 14 days). RESULTS: U50,488, U69,593, morphine, and SNC80 dose-dependently decreased response rates in this procedure. GNTI produced a dose- and time-dependent antagonism of the rate-decreasing effects of U50,488. The kappa antagonist effects of GNTI had a slow onset and a long duration of action, and peak antagonist effects were observed after 24 h. A higher dose of 3.2 mg/kg GNTI eliminated responding in one monkey and was not studied further. The antagonist effects of GNTI were kappa selective, because 1.0 mg/kg GNTI also antagonized the effects of U69,593, but not those of morphine or SNC80. CONCLUSIONS: These results suggest that GNTI is a potent and selective kappa antagonist with a slow onset and long duration of action in rhesus monkeys. Relative to the prototype kappa antagonist nor-binaltorphimine, GNTI may have some advantages as a tool for the study of kappa receptor-mediated processes.