– Expected Top-line Data Readout Remains Unchanged in Mid-2017 –

CAMBRIDGE, MA, USA I October 10, 2016 I Alnylam Pharmaceuticals, Inc. (NASDAQ:ALNY), the leading RNAi therapeutics company, announced today that the Data Monitoring Committee (DMC) for the Phase 3 APOLLO study of patisiran in patients with hereditary ATTR amyloidosis with polyneuropathy (hATTR-PN) met on October 7, 2016 and recommended continuation of the trial without modification. The APOLLO DMC met at the request of the Company following the decision – announced on October 5, 2016 – to discontinue development of revusiran for the treatment of hereditary ATTR amyloidosis with cardiomyopathy (hATTR-CM). The DMC will continue to meet periodically per their remit to monitor the overall safety of patisiran in the APOLLO study through its completion.

The APOLLO study has completed enrollment of 225 patients at 44 sites in 19 countries, between December 2013 and January 2016.

“As part of our vigilance around patient safety, we felt it was important to take immediate action and requested that the APOLLO DMC convene to evaluate accumulated safety data from the randomized, placebo-controlled Phase 3 study of patisiran,” said Akshay Vaishnaw, M.D., Ph.D., Executive Vice President of R&D and Chief Medical Officer at Alnylam. “We’re pleased to learn of the DMC’s recommendation that dosing can continue in APOLLO, and we look forward to the top-line data readout from that study expected in mid-2017. There is substantial unmet need in hATTR-PN and we are committed to advancing patisiran through development in hopes of bringing a new and needed treatment option to patients.”

About ATTR Amyloidosis

ATTR amyloidosis is a progressively debilitating and often fatal disease caused by deposition of transthyretin (TTR) in peripheral tissues. TTR protein is produced primarily in the liver and is normally a carrier of vitamin A. In hereditary ATTR amyloidosis (hATTR), mutations in TTR cause abnormal amyloid proteins to accumulate and damage body organs and tissue, such as the peripheral nerves and heart, resulting in intractable peripheral sensory neuropathy, autonomic neuropathy, and/or cardiomyopathy. Hereditary ATTR amyloidosis represents a major unmet medical need with significant morbidity and mortality; hATTR amyloidosis with polyneuropathy (hATTR-PN) – also known as familial amyloidotic polyneuropathy (FAP) – affects approximately 10,000 people worldwide. hATTR-PN patients have a life expectancy of 5 to 15 years from symptom onset, and the only approved treatment options for early stage disease are liver transplantation and tafamidis (approved in Europe, certain countries in Latin America and Japan, where it is approved for all stages of disease). There is a significant need for novel therapeutics to treat patients with ATTR amyloidosis.

Sanofi Genzyme Alliance

In January 2014, Alnylam and Sanofi Genzyme, the specialty care global business unit of Sanofi, formed an alliance to accelerate and expand the development and commercialization of RNAi therapeutics across the world. The alliance is structured as a multi-product geographic alliance in the field of rare diseases. Alnylam retains product rights in North America and Western Europe, while Sanofi Genzyme obtained the right to access certain programs in Alnylam’s current and future Genetic Medicines pipeline in the rest of the world (ROW) through the end of 2019, together with certain broader co-development/co-commercialization rights and global rights for certain products. In the case of patisiran, Alnylam will advance the product in North America and Western Europe, while Sanofi Genzyme will advance the product in the ROW.

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 LNP Technology

Alnylam has licenses to Arbutus Biopharma LNP intellectual property for use in RNAi therapeutic products using LNP technology.

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. Alnylam’s pipeline of investigational RNAi therapeutics is focused in 3 Strategic Therapeutic Areas (STArs): Genetic Medicines, with a broad pipeline of RNAi therapeutics for the treatment of rare diseases; Cardio-Metabolic Disease, with a pipeline of RNAi therapeutics toward genetically validated, liver-expressed disease targets for unmet needs in cardiovascular and metabolic diseases; and Hepatic Infectious Disease, with a pipeline of RNAi therapeutics that address the major global health challenges of hepatic infectious diseases. In early 2015, Alnylam launched its “Alnylam 2020” guidance for the advancement and commercialization of RNAi therapeutics as a whole new class of innovative medicines. Specifically, by the end of 2020, Alnylam expects to achieve a company profile with 3 marketed products, 10 RNAi therapeutic clinical programs – including 4 in late stages of development – across its 3 STArs. The company’s demonstrated commitment to RNAi therapeutics has enabled it to form major alliances with leading companies including Ionis, Novartis, Roche, Takeda, Merck, Monsanto, The Medicines Company, and Sanofi Genzyme. 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, New England Journal of Medicine, and The Lancet. Founded in 2002, Alnylam maintains headquarters in Cambridge, Massachusetts. For more information about Alnylam’s pipeline of investigational RNAi therapeutics, please visit www.alnylam.com.

SOURCE: Alnylam Pharmaceuticals