ALN-TTR01 uses the identical siRNA as ALN-TTR02 our lead RNAi therapeutic for the treatment of ATTR, but ALN-TTR02 employs a proprietary second-generation LNP formulation that has demonstrated improved potency and tolerability based on pre-clinical and clinical studies.  ALN-TTR02 is currently being tested in a Phase I clinical study in normal healthy volunteers with results expected in the third quarter of 2012.  Further, the we expects to start a Phase II study of ALN-TTR02 in ATTR patients in the second half of 2012 and start pivotal studies in 2013.

 The new data also highlight continued improved efficacy and tolerability for Alnylam’s second-generation lipid nanoparticle (LNP) delivery technology.

 View John’s Testimony (234KB PDF)

Based on analysis of serum samples, mRNAs appear to circulate in blood via exosomes, a newly discovered class of cell-derived particles.  The cERD method allows analysis of all circulating RNA, whether or not it is associated with exosomes.

New pre-clinical results demonstrate that tissue-specific mRNAs can be detected in blood and CSF in a non-invasive manner.

• Administration of RNAi therapeutics targeting two tissue mRNA, TTR and Tmprss6, resulted in dose-dependent silencing — measured in tissue samples, and blood-derived mRNA–measured by the cERD method.  Both onset and duration of mRNA silencing were found to be closely matched between tissue and blood-derived mRNA.  Pre-clinical results were confirmed in a variety of animal models.
• Administration of RNAi therapeutics targeting alpha-synuclein in the CNS resulted in silencing the target gene in both tissue and CSF-derived mRNA– measured by the cERD method.

The cERD method was also successfully applied to monitor activity of microRNA therapeutics and gene therapy vectors.

Research on the new cERD method was done in collaboration with Derrick Gibbings at the Swiss Federal Institute of Technology, Zurich.

Summary

Insulin resistance leads to hypertriglyceridemia and hepatic steatosis and is associated with increased SREBP-1c, a transcription factor that activates fatty acid synthesis. Here, we show that steatosis in insulin-resistant ob/ob mice was abolished by deletion of Scap, an escort protein necessary for generating nuclear isoforms of all three SREBPs. Scap deletion reduced lipid synthesis and prevented fatty livers despite persistent obesity, hyperinsulinemia, and hyperglycemia. Scap deficiency also prevented steatosis in mice fed high-fat diets. Steatosis was also prevented when siRNAs were used to silence Scap in livers of sucrose-fed hamsters, a model of diet-induced steatosis and hypertriglyceridemia. This silencing reduced all three nuclear SREBPs, decreasing lipid biosynthesis and abolishing sucrose-induced hypertriglyceridemia. These results demonstrate that SREBP activation is essential for development of diabetic hepatic steatosis and carbohydrate-induced hypertriglyceridemia, but not insulin resistance. Inhibition of SREBP activation has therapeutic potential for treatment of hypertriglyceridemia and fatty liver disease.

Abstract

Primary mouse hepatocytes are an important tool in the biomedical research field for the assessment of hepatocyte function. Several methods for hepatocyte isolation have been published; however, many of these methods require extensive handling and can therefore compromise the viability and function of the isolated cells. Since one advantage of utilizing freshly isolated cells is to maintain an environment in which the cells are more comparable to their in vivo state, it is important to have robust methods that produce cells with high viability, good purity and that function in a similar manner to that in their in vivo state. Here we describe a modified two-step method for the rapid isolation and characterization of mouse primary hepatocytes that results in high yields of viable cells. The asialoglycoprotein receptor (ASGPR), which is one of the most abundant cell surface receptors on hepatocytes, was used to monitor the function of the isolated hepatocytes by demonstrating specific binding of its ligand using a newly developed flow cytometry based ligand-receptor binding assay. Also, an in vitro screening method for siRNA drug candidates was successfully developed utilizing freshly isolated hepatocytes with minimum culture time.

Abstract

Since the discovery of RNA interference (RNAi), researchers have identified a variety of small interfering RNA (siRNA) structures that demonstrate the ability to silence gene expression through the classical RISC-mediated mechanism. One such structure, termed “Dicer-substrate siRNA” (dsiRNA), was proposed to have enhanced potency via RISC-mediated gene silencing, although a comprehensive comparison of canonical siRNAs and dsiRNAs remains to be described. The present study evaluates the in vitro and in vivo activities of siRNAs and dsiRNAs targeting Phosphatase and Tensin Homolog (PTEN) and Factor VII (FVII). More than 250 compounds representing both siRNA and dsiRNA structures were evaluated for silencing efficacy. Lead compounds were assessed for duration of silencing and other key parameters such as cytokine induction. We identified highly active compounds from both canonical siRNAs and 25/27 dsiRNAs. Lead compounds were comparable in potency both in vitro and in vivo as well as duration of silencing in vivo. Duplexes from both structural classes tolerated 2′-OMe chemical modifications well with respect to target silencing, although some modified dsiRNAs demonstrated reduced activity. On the other hand, dsiRNAs were more immunostimulatory as compared with the shorter siRNAs, both in vitro and in vivo. Because the dsiRNA structure does not confer any appreciable benefits in vitro or in vivo while demonstrating specific liabilities, further studies are required to support their applications in RNAi therapeutics.

Abstract

The mammalian stress sensor IRE1α plays a central role in the unfolded protein, or endoplasmic reticulum (ER), stress response by activating its downstream transcription factor XBP1 via an unconventional splicing mechanism. IRE1α can also induce the degradation of a subset of mRNAs in a process termed regulated IRE1-dependent decay (RIDD). Although diverse mRNA species can be degraded by IRE1α in vitro, the pathophysiological functions of RIDD are only beginning to be explored. Acetaminophen (APAP) overdose is the most frequent cause of acute liver failure in young adults in the United States and is primarily caused by CYP1A2-, CYP2E1-, and CYP3A4-driven conversion of APAP into hepatotoxic metabolites. We demonstrate here that genetic ablation of XBP1 results in constitutive IRE1α activation in the liver, leading to RIDD of Cyp1a2 and Cyp2e1 mRNAs, reduced JNK activation, and protection of mice from APAP-induced hepatotoxicity. A pharmacological ER stress inducer that activated IRE1α suppressed the expression of Cyp1a2 and Cyp2e1 in WT, but not IRE1α-deficient mouse liver, indicating the essential role of IRE1α in the down-regulation of these mRNAs upon ER stress. Our study reveals an unexpected function of RIDD in drug metabolism