– ALN-CC5 Demonstrates Potent C5 Knockdown of up to 98.7% and Inhibition of Complement Activity of up to 96.8% in Non-Human Primates (NHP) –
– RNAi-Mediated Knockdown of C5 Shown to be as Effective as Anti-C5 Monoclonal Antibody in Reducing Clinical Disease Activity in Mouse Arthritis Model –
– Company On Track to File Investigational New Drug (IND) Application in Late 2014 and Now Guides to Report Initial Clinical Results in Mid-2015

CAMBRIDGE, MA, USA I June 9, 2014 I Alnylam Pharmaceuticals, Inc. (Nasdaq:ALNY), a leading RNAi therapeutics company, announced today new pre-clinical results with its Development Candidate (DC) for ALN-CC5, a subcutaneously administered investigational RNAi therapeutic targeting complement component C5 in development for the treatment of complement-mediated diseases. These results were presented at the 7th International Conference on Complement Therapeutics being held June 6 – 11, 2014, in Olympia, Greece. New data demonstrate that ALN-CC5 led to an up to 98.7% knockdown of serum C5 and an up to 96.8% inhibition of complement activity in non-human primates (NHP) with weekly subcutaneous dose administration. Alnylam believes that ALN-CC5 – part of the company’s “Alnylam 5×15” product strategy – could represent a novel approach for the treatment of complement-mediated diseases, with a potentially competitive profile compared with intravenously administered anti-C5 monoclonal antibody therapy. ALN-CC5 utilizes the company’s Enhanced Stabilization Chemistry (ESC)-GalNAc-conjugate technology, which enables subcutaneous dosing with increased potency and durability and a wide therapeutic index. ESC-GalNAc conjugates are a clinically validated platform based on recent preliminary Phase 1 study results from the company’s ALN-AT3 program in development for the treatment of hemophilia. The company is on track to file its ALN-CC5 IND or IND equivalent in late 2014, and is now guiding that it expects to present initial clinical results in mid-2015.

“These new pre-clinical data with our recently selected Development Candidate for ALN-CC5 demonstrate potent C5 knockdown and robust inhibition of complement activity in NHPs with weekly subcutaneous dosing. We believe that these are promising results since an over 80% inhibition of complement activity has been shown to be associated with clinical benefit. Further, comparative studies in a mouse arthritis model showed ALN-CC5 to be as effective as an anti-C5 antibody in reducing disease activity, demonstrating a necessary and sufficient role for liver-expressed C5 in localized complement-mediated disease,” said Akshay Vaishnaw, M.D., Ph.D., Executive Vice President and Chief Medical Officer of Alnylam. “ALN-CC5 employs our ESC-GalNAc-siRNA conjugate platform that has recently been validated in preliminary data from human studies and where we observe a further ten-fold increase in potency as compared with studies in NHPs. Accordingly, we believe we are seeing the emergence of a compelling therapeutic profile for ALN-CC5, which could make it competitive with anti-C5 monoclonal antibody therapy. We look forward to filing an IND or IND-equivalent by the end of this year, and are now guiding that we expect to present initial clinical results in mid-2015.”

In a presentation titled “RNAi-Mediated C5 Silencing for Complement Inhibition,” Alnylam scientists presented new pre-clinical data with ALN-CC5. In NHP studies, weekly subcutaneous doses of ALN-CC5 at 5 mg/kg led to serum C5 knockdown of up to 98.7% (mean of 97.9 +/- 0.7%), as well as inhibition of complement activity of up to 91.3% (mean of 84.9 +/- 7.1%) by serum hemolytic activity assay and up to 96.8% (mean of 94.6. +/- 1.8%) by complement alternative pathway (CAP) ELISA. Based on early human translational data for ESC-GalNAc conjugates, weekly dosing at less than 1 mg/kg is expected to result in similar effects in humans. The observed inhibitory effect toward complement activity is notable since an over 80% level of complement inhibition has been shown to yield clinical benefit in paroxysmal nocturnal hemoglobinuria (PNH) based on published data with eculizumab, an intravenously administered monoclonal antibody that binds to serum C5 (Hillmen et al., N Engl J Med 2004,350:552-559). The company is continuing dosing in the primate study to explore twice-monthly and once-monthly subcutaneous dosing regimens, and expects to report additional pre-clinical data later this year. In addition, in vitro reconstitution studies in human serum were performed to evaluate the potential anti-C5 monoclonal antibody (anti-C5 mAb) dose sparing effects of ALN-CC5. Specifically, in serum in which C5 was reduced to 5% of normal (i.e., a level corresponding to 95% C5 knockdown with RNAi), the concentration of anti-C5 mAb required to achieve 80% inhibition of hemolytic activity was found to be reduced approximately 20-fold. This lower concentration requirement could reduce frequent dose requirements and the high costs of anti-C5 antibody therapy. Finally, results were presented from a study comparing subcutaneous doses of ALN-CC5 to a high, intravenously administered dose of an anti-C5 mAb in a mouse anti-collagen antibody induced arthritis (CAIA) model. Results showed that C5 knockdown with ALN-CC5 was as effective as the anti-C5 antibody in reducing clinical disease activity, with both treatments resulting in an approximately 80% reduction in clinical disease activity score. Moreover, ALN-CC5 maintained its knockdown effect toward C5 following lipopolysaccharide (LPS) treatment, showing the ability of RNAi to blunt induction of C5 as part of an inflammatory response. These results demonstrate that knockdown of liver-derived C5 should be fully sufficient to achieve a therapeutic effect, and show the absence of a significant role for local complement production in this disease model.

“The complement system evolved as part of the innate immune system and plays a key role in host defenses. Dysregulation of the complement system can lead to serious complications in a wide range of human diseases including paroxysmal nocturnal hemoglobinuria, atypical hemolytic uremic syndrome, and neuromyelitis optica,” said Anita Hill, MBChB (Hons), MRCP, FRCPath, Ph.D., Consultant Haematologist for Leeds Teaching Hospitals NHS Trust, UK, and Honorary Senior Lecturer at the University of Leeds. “I am very encouraged by these pre-clinical data showing potent and durable knockdown of serum C5 with robust inhibition of complement activity using a subcutaneously administered RNAi therapeutic. If these results can be extended to the clinical setting, I believe that they could represent an attractive therapeutic strategy and potential new treatment option for patients with complement-mediated diseases.”

About ALN-CC5

ALN-CC5 is an RNAi therapeutic targeting the C5 component of the complement pathway for the treatment of complement-mediated diseases. The complement system plays a central role in immunity as a protective mechanism for host defense, but its dysregulation results in life-threatening complications in a broad range of human diseases including paroxysmal nocturnal hemoglobinuria (PNH), atypical hemolytic-uremic syndrome (aHUS), myasthenia gravis, neuromyelitis optica, amongst others. Complement component C5, which is predominantly expressed in liver cells, is a genetically and clinically validated target; loss of function human mutations are associated with an attenuated immune response against certain infections and intravenous anti-C5 monoclonal antibody therapy has demonstrated clinical activity and tolerability in a number of complement-mediated diseases. A subcutaneously administered RNAi therapeutic that silences C5 represents a novel approach to the treatment of complement-mediated diseases. ALN-CC5 utilizes Alnylam’s ESC-GalNAc conjugate technology, which enables subcutaneous dosing with increased potency and durability and a wide therapeutic index.

About GalNAc Conjugates and Enhanced Stabilization Chemistry (ESC)-GalNAc Conjugates

GalNAc-siRNA conjugates are a proprietary Alnylam delivery platform and are designed to achieve targeted delivery of RNAi therapeutics to hepatocytes through uptake by the asialoglycoprotein receptor. Alnylam’s Enhanced Stabilization Chemistry (ESC)-GalNAc-conjugate technology enables subcutaneous dosing with increased potency and durability, and a wide therapeutic index. This delivery platform is being employed in several of Alnylam’s genetic medicine programs, including programs in clinical development.

About RNAi

RNAi (RNA interference) is a revolution in biology, representing a breakthrough in understanding how genes are turned on and off in cells, and a completely new approach to drug discovery and development. Its discovery has been heralded as “a major scientific breakthrough that happens once every decade or so,” and represents one of the most promising and rapidly advancing frontiers in biology and drug discovery today which was awarded the 2006 Nobel Prize for Physiology or Medicine. RNAi is a natural process of gene silencing that occurs in organisms ranging from plants to mammals. By harnessing the natural biological process of RNAi occurring in our cells, the creation of a major new class of medicines, known as RNAi therapeutics, is on the horizon. Small interfering RNA (siRNA), the molecules that mediate RNAi and comprise Alnylam’s RNAi therapeutic platform, target the cause of diseases by potently silencing specific mRNAs, thereby preventing disease-causing proteins from being made. RNAi therapeutics have the potential to treat disease and help patients in a fundamentally new way.

About Alnylam Pharmaceuticals

Alnylam is a biopharmaceutical company developing novel therapeutics based on RNA interference, or RNAi. The company is leading the translation of RNAi as a new class of innovative medicines with a core focus on RNAi therapeutics as genetic medicines, including programs as part of the company’s “Alnylam 5×15TM” product strategy. Alnylam’s genetic medicine programs are RNAi therapeutics directed toward genetically defined targets for the treatment of serious, life-threatening diseases with limited treatment options for patients and their caregivers. These include: patisiran (ALN-TTR02), an intravenously delivered RNAi therapeutic targeting transthyretin (TTR) for the treatment of TTR-mediated amyloidosis (ATTR) in patients with familial amyloidotic polyneuropathy (FAP); ALN-TTRsc, a subcutaneously delivered RNAi therapeutic targeting TTR for the treatment of ATTR in patients with TTR cardiac amyloidosis, including familial amyloidotic cardiomyopathy (FAC) and senile systemic amyloidosis (SSA); ALN-AT3, an RNAi therapeutic targeting antithrombin (AT) for the treatment of hemophilia and rare bleeding disorders (RBD); ALN-CC5, an RNAi therapeutic targeting complement component C5 for the treatment of complement-mediated diseases; ALN-AS1, an RNAi therapeutic targeting aminolevulinic acid synthase-1 (ALAS-1) for the treatment of hepatic porphyrias including acute intermittent porphyria (AIP); ALN-PCS, an RNAi therapeutic targeting PCSK9 for the treatment of hypercholesterolemia; ALN-AAT, an RNAi therapeutic targeting alpha-1 antitrypsin (AAT) for the treatment of AAT deficiency-associated liver disease; ALN-TMP, an RNAi therapeutic targeting TMPRSS6 for the treatment of beta-thalassemia and iron-overload disorders; ALN-ANG, an RNAi therapeutic targeting angiopoietin-like 3 (ANGPTL3) for the treatment of genetic forms of mixed hyperlipidemia and severe hypertriglyceridemia; ALN-AC3, an RNAi therapeutic targeting apolipoprotein C-III (apoCIII) for the treatment of hypertriglyceridemia; and other programs yet to be disclosed. As part of its “Alnylam 5×15” strategy, as updated in early 2014, the company expects to have six to seven genetic medicine product candidates in clinical development – including at least two programs in Phase 3 and five to six programs with human proof of concept – by the end of 2015. Alnylam is also developing ALN-HBV, an RNAi therapeutic targeting the hepatitis B virus (HBV) genome for the treatment of HBV infection. The company’s demonstrated commitment to RNAi therapeutics has enabled it to form major alliances with leading companies including Merck, Medtronic, Novartis, Biogen Idec, Roche, Takeda, Kyowa Hakko Kirin, Cubist, GlaxoSmithKline, Ascletis, Monsanto, The Medicines Company, and Genzyme, a Sanofi company. In March 2014, Alnylam acquired Sirna Therapeutics, a wholly owned subsidiary of Merck. In addition, Alnylam holds an equity position in Regulus Therapeutics Inc., a company focused on discovery, development, and commercialization of microRNA therapeutics. Alnylam scientists and collaborators have published their research on RNAi therapeutics in over 200 peer-reviewed papers, including many in the world’s top scientific journals such as Nature, Nature Medicine, Nature Biotechnology, Cell, the New England Journal of Medicine, and The Lancet. Founded in 2002, Alnylam maintains headquarters in Cambridge, Massachusetts. For more information, please visit www.alnylam.com.

SOURCE: Alnylam Pharmaceuticals