Exploratory window-of-opportunity trial to investigate the tumor pharmacokinetics/pharmacodynamics of the IAP antagonist Debio 1143 in patients with head and neck cancer.

Inhibitor of apoptosis proteins (IAPs) regulate apoptosis and modulate NF-κB signaling thereby driving expression of genes involved in immune/inflammatory responses. The orally available IAP antagonist Debio 1143 has potential to enhance tumor response to chemoradiotherapy and/or immunotherapy. Patients with pre-operative squamous cell carcinomas of the head and neck (SCCHN) received: Debio 1143 monotherapy (200 mg/day [D]1-15 +/- 2); Debio 1143 (200 mg/day D1-15 +/- 2) plus cisplatin (40 mg/m2 D 1 and 8); cisplatin alone (40 mg/m2 D 1 and 8; EudraCT: 2014-004655-31). Pharmacokinetic/pharmacodynamic effects were assessed in plasma and resected tumors. Primary end point; effect of Debio 1143 on cellular IAP-1 (cIAP-1). Levels of cIAP-1/-2, X-linked inhibitor of apoptosis protein (XIAP), tumor infiltrating lymphocytes (TILs), including CD8+ T cells, programmed cell death protein 1 (PD-1), PD-ligand 1 (PD-L1), and gene expression were also analyzed. Twenty-three of 26 patients completed treatment. In the Debio 1143 monotherapy cohort (n = 13), mean tumor concentrations of Debio 1143 were 18-fold (maximum 55.2-fold) greater than in plasma, exceeding the half-maximal inhibitory concentration for cIAPs and XIAP by 100 to 1000-fold, with significant engagement/degradation of cIAP-1 (p < 0.05). Overall, levels of CD8+ TILs, PD-1, and PD-L1 positive immune cells increased significantly (p < 0.05) following Debio 1143 treatment. Changes were observed in the expression of genes related to NF-κB signaling. Treatments were well-tolerated. Debio 1143 penetrated SCCHN tumors, engaged cIAP-1, and induced immune inflammatory changes in the tumor microenvironment. Based on the mode of action demonstrated here and in previous studies, these data support future combinations of Debio 1143 with immune-checkpoint agents.

Novel Survivin-Targeted Small Interfering RNA Delivered by Nanoparticles.

BACKGROUND: The aim of the present study was to investigate the antitumor effect of our novel survivin-targeted small interfering RNA (siRNA) nanoliposomes on xenograft mouse models with human cervical carcinoma HeLa cells, and to evaluate pharmacokinetics. MATERIALS AND METHODS: siRNA nanoliposome was prepared and transfected into xenograft mouse models. Tumor growth in mice was determined and survivin expression was analyzed by using histologic and immunohischemical staining. Furthermore, low, moderate and high doses of survivin siRNA nanoliposomes were injected in 3 groups, and plasma concentrations were detected at various time points by reverse transcription quantitative polymerase chain reaction. Biodistribution of siRNA in tumor and other important organs were also determined. RESULTS: Survivin expression was significantly downregulated by survivin siRNA delivery mediated by nanoliposome, along with significant suppression of cell growth. Peak concentrations were obtained at 15 minutes after injection in each group, with 1,042,538.00, 6,837,099.54 and 14,631,333.15pg/mL, respectively, and the plasma concentration decreased significantly after 24 hours. The half-time life of survivin siRNA nanoliposomes in each group was 3.60, 2.64 and 2.80 hours, respectively. The area under curve values were 952,190.88, 6,800,687.79 and 13,803,680.96h/pg/mL, and the total drug clearance were 1,050.12, 441.13 and 434.67mL/h/kg. A significant accumulation of Cy5-labeled siRNA was found in the tumor, and a nonspecific accumulation was reduced significantly in lung. CONCLUSIONS: Our findings revealed that survivin suppression by siRNA may contribute to tumor inhibition through both proliferation inhibition and apoptosis promotion effect, and the pharmacokinetic characteristics serve as a fundamental role for further studies on its applicability for cancer therapy.

High Sensitivity RT-qPCR Assay of Nonlabeled siRNA in Small Blood Volume for Pharmacokinetic Studies: Application to Survivin siRNA.

RNAi therapeutics provide an opportunity to correct faulty genes, and several RNAi have entered clinical evaluation. The existing quantification methods typically use radioactivity- or fluorescence-labeled RNAi, require large blood volumes, and/or have a limited dynamic detection range. We established a quantitative reverse transcriptase real-time polymerase chain reaction (RT-qPCR) assay to measure RNAi; the model analyte was survivin siRNA (siSurvivin). A second siRNA was used as the internal standard. The three major steps were (a) extraction of the two siRNAs from blood or water, (b) synthesis of their cDNA by poly-A extension, and (c) qPCR of cDNA. Standard curves were established. Utility of the assay was demonstrated in a pharmacokinetic study where all 12 samples for the blood concentration-time profile were obtained from a single mouse given an intravenous dose of 1 nmole siSurvivin (prepared as lipoplex with pegylated cationic liposomes). The RT-qPCR assay was sensitive (lower detection limit of 100 fM) and had a 5 × 107-fold dynamic range and low sample volume requirement (10 µL). The 16-point standard curves constructed using whole blood samples were linear (R (2) > 0.98). The intraday and interday variations for the slopes were ≤6%, although the variations for accuracy and precision at individual concentrations were substantially higher (58-145%). Standard curves prepared with water in place of blood showed similar results (<6% difference), indicating water may be used when blood is not available. The current RT-qPCR assay enabled the measurement of nonlabeled siRNA in small volume of blood samples.

Phase I dose-escalation study of LCL161, an oral inhibitor of apoptosis proteins inhibitor, in patients with advanced solid tumors.

PURPOSE: LCL161 antagonizes the function of inhibitor of apoptosis proteins (IAPs), thereby promoting cancer cell death. This first-in-human dose-escalation study assessed the maximum-tolerated dose (MTD), safety, pharmacokinetics, and pharmacodynamics of LCL161 in patients with advanced solid tumors. A second part of the study assessed the relative bioavailability of a tablet versus solution formulation. PATIENTS AND METHODS: LCL161 was administered orally, once weekly, on a 21-day cycle to adult patients with advanced solid tumors by using an adaptive Bayesian logistic regression model with overdose control-guided dose escalation. RESULTS: Fifty-three patients received at least one dose of LCL161 (dose range, 10 to 3,000 mg). LCL161 was well tolerated at doses up to 1,800 mg. Cytokine release syndrome (CRS) was the only dose-limiting toxicity (in three [6%] of 53 patients) and was the most common grades 3 to 4 event (in five [9%] of 53 patients). Vomiting, nausea, asthenia/fatigue, and anorexia were common but not severe. Although the MTD was not formally determined, an 1,800-mg dose was selected in compliance with the protocol for additional study, given the dose-limiting CRS at higher doses and pharmacodynamic activity at lower doses. LCL161 was rapidly absorbed, and exposure was generally increased with dose. The tablet formulation of LCL161 was better tolerated than the solution; tablet and solution formulations had similar exposures, and the solution was discontinued. No patient had an objective response. LCL161 induced degradation of cellular IAP1 protein in the blood, skin, and tumor and increased circulating cytokine levels. CONCLUSION: The 1,800-mg dose of LCL161, administered as a single agent once weekly, in tablet formulation is the recommended dose for additional study. This combined dose and formulation was well tolerated and had significant pharmacodynamic activity, which warrants additional investigation.

Survivin mutant protects differentiated dopaminergic SK-N-SH cells against oxidative stress.

Oxidative stress is due to an imbalance of antioxidant/pro-oxidant homeostasis and is associated with the progression of several neurological diseases, including Parkinson's and Alzheimer's disease and amyotrophic lateral sclerosis. Furthermore, oxidative stress is responsible for the neuronal loss and dysfunction associated with disease pathogenesis. Survivin is a member of the inhibitors of the apoptosis (IAP) family of proteins, but its neuroprotective effects have not been studied. Here, we demonstrate that SurR9-C84A, a survivin mutant, has neuroprotective effects against H2O2-induced neurotoxicity. Our results show that H2O2 toxicity is associated with an increase in cell death, mitochondrial membrane depolarisation, and the expression of cyclin D1 and caspases 9 and 3. In addition, pre-treatment with SurR9-C84A reduces cell death by decreasing both the level of mitochondrial depolarisation and the expression of cyclin D1 and caspases 9 and 3. We further show that SurR9-C84A increases the antioxidant activity of GSH-peroxidase and catalase, and effectively counteracts oxidant activity following exposure to H2O2. These results suggest for the first time that SurR9-C84A is a promising treatment to protect neuronal cells against H2O2-induced neurotoxicity.