Alnylam Files Clinical Trial Application to Initiate a Phase I Study for ALN-AT3, a Subcutaneously Administered RNAi Therapeutic Targeting Antithrombin (AT) for the Treatment of Hemophilia A and B

Alnylam Files Clinical Trial Application to Initiate a Phase I Study for ALN-AT3, a Subcutaneously Administered RNAi Therapeutic Targeting Antithrombin (AT) for the Treatment of Hemophilia A and B
– Company Expects to Initiate Phase I Study in Early 2014 with Interim Data from Hemophilia Subjects by Year-End 2014 –
CAMBRIDGE, Mass.--(BUSINESS WIRE)--Oct. 29, 2013-- Alnylam Pharmaceuticals, Inc. (Nasdaq: ALNY), a leading RNAi therapeutics company, announced today that it has filed a Clinical Trial Application (CTA) with the U.K. Medicines and Healthcare products Regulatory Agency (MHRA) to initiate a Phase I clinical trial with ALN-AT3, a subcutaneously administered RNAi therapeutic targeting antithrombin (AT) for the treatment of hemophilia, including people with "inhibitors." Hemophilia is a hereditary disorder caused by genetic deficiencies in various blood clotting factors, resulting in recurrent bleeds into joints, muscles, and other major internal organs. By knocking down AT, ALN-AT3 administration is expected to increase thrombin generation and reduce disease burden, including annualized bleeding rate, severity of bleeding, and requirement for replacement factor or bypass agent, and to potentially improve quality of life. ALN-AT3 is a key program in the company's "Alnylam 5x15" product development and commercialization strategy, in which the company aims to advance five RNAi therapeutic programs toward genetically validated disease targets into clinical development, including programs in advanced stages, by the end of 2015.
"Hemophilia is characterized by a genetic deficiency in clotting factors that ultimately leads to inadequate thrombin generation and a bleeding disorder. ALN-AT3 aims to correct the hemostatic imbalance in hemophilia by knocking down AT – an endogenous anticoagulant – thus increasing thrombin generation and improving hemostasis, and reducing disease burden. This innovative approach is strongly supported by clinical cases in people with hemophilia who have co-inherited prothrombotic traits, including AT deficiency, and are characterized by a milder bleeding phenotype," said Akshay Vaishnaw, M.D., Ph.D., Executive Vice President and Chief Medical Officer at Alnylam. "This CTA for ALN-AT3 marks our second for an RNAi therapeutic that utilizes our proprietary GalNAc conjugate delivery platform, which we have now shown to be clinically validated. Our pre-clinical data with ALN-AT3 have demonstrated normalization of thrombin generation and improvement of hemostasis in hemophilia models. We have also demonstrated that ALN-AT3 has a wide therapeutic index in the context of hemophilia. We very much look forward to the continued advancement of ALN-AT3, including the start of our Phase I clinical trial in early 2014 with data from hemophilia subjects expected by the end of that year."
ALN-AT3 is a subcutaneously administered RNAi therapeutic that comprises an siRNA conjugated to a triantennary N-acetylgalactosamine (GalNAc) ligand. GalNAc-siRNA conjugates are a proprietary, clinically validated delivery platform and are designed to achieve targeted delivery of RNAi therapeutics to hepatocytes through uptake by the asialoglycoprotein receptor. Pre-clinical studies have shown that subcutaneous administration of ALN-AT3 can normalize thrombin generation and improve hemostasis in hemophilia mice and fully correct thrombin generation in a non-human primate (NHP) hemophilia "inhibitor" model. A single subcutaneous dose of ALN-AT3 that resulted in plasma AT reduction of approximately 90% led to normalization of thrombin generation and improvement in hemostasis in hemophilia mice. In wild type NHPs, repeat dosing with ALN-AT3 resulted in potent, titratable, and reversible silencing of plasma AT. Weekly subcutaneous doses of 0.50 mg/kg resulted in 90% AT knockdown, while an ED50 knockdown was achieved at a dose as low as 0.125 mg/kg. Furthermore, in an NHP "inhibitor" model, in which a hemophilia A (HA) phenotype was induced via administration of a polyclonal anti-factor VIII antibody, ALN-AT3-treated animals showed the expected level of AT knockdown but also showed a statistically significant (p<0.01) dose-dependent increase in thrombin generation, fully restoring this hemostatic parameter back to normal levels. We believe these results demonstrate that ALN-AT3 can normalize thrombin generation in the absence of functional levels of factor VIII and/or in the presence of anti-factor VIII antibodies in a large animal model, providing key proof of concept for the program. In addition, single doses of ALN-AT3 as high as 500 mg/kg – over 100-fold greater than doses that result in essentially complete ablation of AT – were well tolerated in HA mice: 100% of animals survived, and there were no toxicologically significant findings in clinical or pathology exams.
As per the filed CTA, the Phase I trial of ALN-AT3 will be conducted in the U.K. as a single- and multi-dose, dose-escalation study consisting of two parts. The first part will be a randomized, single-blind, placebo-controlled, single-dose, dose-escalation study, enrolling up to 24 healthy volunteer subjects. The primary objective of the first part of the study is to evaluate the safety and tolerability of a single dose of subcutaneously administered ALN-AT3. Secondary objectives include assessment of clinical activity as determined by knockdown of circulating AT levels. The second part of the study will be an open-label, multi-dose, dose-escalation study enrolling up to 18 people with moderate to severe hemophilia A or B. The primary objective of this part of the study is to evaluate the safety and tolerability of multiple doses of subcutaneously administered ALN-AT3 in hemophilia subjects. Secondary objectives include assessment of clinical activity as determined by knockdown of circulating AT levels and increase in ex vivo thrombin generation.
About Hemophilia and Rare Bleeding Disorders (RBD)
Hemophilias are hereditary disorders caused by genetic deficiencies of various blood clotting factors, resulting in recurrent bleeds into joints, muscles, and other major internal organs. Hemophilia A is defined by loss-of-function mutations in factor VIII, and there are greater than 40,000 people in the U.S. and E.U. Hemophilia B, defined by loss-of-function mutations in factor IX, affects greater than 9,500 people in the U.S. and E.U. Other Rare Bleeding Disorders (RBD) are defined by congenital deficiencies of other blood coagulation factors, including Factors II, V, VII, X, and XI, and there are about 1,000 people worldwide with a severe bleeding phenotype. Standard treatment for people with hemophilia involves replacement of the missing clotting factor either as prophylaxis or on-demand therapy. However, as many as one third of people with hemophilia A will develop an antibody to their replacement factor – a very serious complication; these "inhibitor" subjects become refractory to standard replacement therapy. There exists a small subset of people with hemophilia who have co-inherited a prothrombotic mutation, such as factor V Leiden, antithrombin deficiency, protein C deficiency, and prothrombin G20210A. People with hemophilia that have co-inherited these prothrombotic mutations are characterized as having a later onset of disease, lower risk of bleeding, and reduced requirements for factor VIII or factor IX treatment as part of their disease management. There exists a significant need for novel therapeutics to treat hemophilia and RBD.
About Antithrombin (AT)
Antithrombin (AT, also known as "antithrombin III" and "SERPINC1") is a liver expressed plasma protein and member of the "serpin" family of proteins that acts as an important endogenous anticoagulant by inactivating factor Xa and thrombin. AT plays a key role in normal hemostasis, which has evolved to balance the need to control blood loss through clotting with the need to prevent pathologic thrombosis through anticoagulation. In hemophilia, the loss of certain procoagulant factors (factor VIII and factor IX, in the case of hemophilia A and B, respectively) results in an imbalance of the hemostatic system toward a bleeding phenotype. In contrast, in thrombophilia (e.g., factor V Leiden, protein C deficiency, antithrombin deficiency, amongst others), certain mutations result in an imbalance in the hemostatic system toward a thrombotic phenotype. Since co-inheritance of prothrombotic mutations may reduce disease burden in people with hemophilia, inhibition of AT defines a novel strategy for improving hemostasis.
About 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. Research findings demonstrate potent and durable target gene silencing, as well as a wide therapeutic index, with subcutaneously administered GalNAc-siRNAs from multiple "Alnylam 5x15" programs.
About RNA Interference (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 toward genetically defined targets for the treatment of serious, life-threatening diseases with limited treatment options for patients and their caregivers. These include: 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 familial amyloidotic cardiomyopathy (FAC); ALN-AT3, an RNAi therapeutic targeting antithrombin (AT) for the treatment of hemophilia and rare bleeding disorders (RBD); ALN-AS1, an RNAi therapeutic targeting aminolevulinate synthase-1 (ALAS-1) for the treatment of porphyria including acute intermittent porphyria (AIP); ALN-PCS, an RNAi therapeutic targeting PCSK9 for the treatment of hypercholesterolemia; ALN-TMP, an RNAi therapeutic targeting TMPRSS6 for the treatment of beta-thalassemia and iron-overload disorders; ALN-AAT, an RNAi therapeutic targeting alpha-1-antitrypsin (AAT) for the treatment of AAT deficiency liver disease; and ALN-CC5, an RNAi therapeutic targeting complement component C5 for the treatment of complement-mediated diseases, amongst other programs. As part of its "Alnylam 5x15TM" strategy, the company expects to have five RNAi therapeutic products for genetically defined diseases in clinical development, including programs in advanced stages, on its own or with a partner by the end of 2015. Alnylam has additional partnered programs in clinical or development stages, including ALN-RSV01 for the treatment of respiratory syncytial virus (RSV) infection and ALN-VSP for the treatment of liver cancers. The company's leadership position on RNAi therapeutics and intellectual property have enabled it to form major alliances with leading companies including Merck, Medtronic, Novartis, Biogen Idec, Roche, Takeda, Kyowa Hakko Kirin, Cubist, Ascletis, Monsanto, Genzyme, and The Medicines Company. In addition, Alnylam holds an equity position in Regulus Therapeutics Inc., a company focused on discovery, development, and commercialization of microRNA therapeutics. Alnylam has also formed Alnylam Biotherapeutics, a division of the company focused on the development of RNAi technologies for applications in biologics manufacturing, including recombinant proteins and monoclonal antibodies. Alnylam's VaxiRNA™ platform applies RNAi technology to improve the manufacturing processes for vaccines; GlaxoSmithKline is a collaborator in this effort. Alnylam scientists and collaborators have published their research on RNAi therapeutics in over 100 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 visitwww.alnylam.com.
About "Alnylam 5x15™"
The "Alnylam 5x15" strategy, launched in January 2011, establishes a path for development and commercialization of novel RNAi therapeutics toward genetically defined targets for the treatment of diseases with high unmet medical need. Products arising from this initiative share several key characteristics including: a genetically defined target and disease; the potential to have a major impact in a high unmet need population; the ability to leverage the existing Alnylam RNAi delivery platform; the opportunity to monitor an early biomarker in Phase I clinical trials for human proof of concept; and the existence of clinically relevant endpoints for the filing of a new drug application (NDA) with a focused patient database and possible accelerated paths for commercialization. By the end of 2015, the company expects to have five such RNAi therapeutic programs in clinical development, including programs in advanced stages, on its own or with a partner. The "Alnylam 5x15" programs include: 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 familial amyloidotic cardiomyopathy (FAC); ALN-AT3, an RNAi therapeutic targeting antithrombin (AT) for the treatment of hemophilia and rare bleeding disorders (RBD); ALN-AS1, an RNAi therapeutic targeting aminolevulinate synthase-1 (ALAS-1) for the treatment of porphyria including acute intermittent porphyria (AIP); ALN-PCS, an RNAi therapeutic targeting PCSK9 for the treatment of hypercholesterolemia; ALN-TMP, an RNAi therapeutic targeting TMPRSS6 for the treatment of beta-thalassemia and iron-overload disorders; ALN-AAT, an RNAi therapeutic targeting alpha-1-antitrypsin (AAT) for the treatment of AAT deficiency liver disease; and ALN-CC5, an RNAi therapeutic targeting complement component C5 for the treatment of complement-mediated diseases, amongst other programs. Alnylam intends to focus on developing and commercializing certain programs from this product strategy itself in North and South America, Europe, and other parts of the world; these include ALN-TTR, ALN-AT3, ALN-AS1, and ALN-CC5, amongst other programs.
Alnylam Forward-Looking Statements
Various statements in this press release concerning Alnylam's future expectations, plans and prospects, including without limitation, Alnylam's expectations regarding its "Alnylam 5x15" product strategy, Alnylam's views with respect to the potential for RNAi therapeutics, including ALN-AT3, its expectations with respect to the timing and success of clinical trials for ALN-AT3, and its plans with respect to the commercial opportunity for the ALN-AT3 program, constitute forward-looking statements for the purposes of the safe harbor provisions under The Private Securities Litigation Reform Act of 1995. Actual results may differ materially from those indicated by these forward-looking statements as a result of various important factors, including, without limitation, Alnylam's ability to discover and develop novel drug candidates and delivery approaches, successfully demonstrate the efficacy and safety of its drug candidates, including ALN-AT3, the pre-clinical and clinical results for its product candidates, which may not support further development of product candidates, actions of regulatory agencies, which may affect the initiation, timing and progress of clinical trials, obtaining, maintaining and protecting intellectual property, Alnylam's ability to enforce its patents against infringers and defend its patent portfolio against challenges from third parties, obtaining regulatory approval for products, competition from others using technology similar to Alnylam's and others developing products for similar uses, Alnylam's ability to obtain additional funding to support its business activities and establish and maintain strategic business alliances and new business initiatives, Alnylam's dependence on third parties for development, manufacture, marketing, sales and distribution of products, the outcome of litigation, and unexpected expenditures, as well as those risks more fully discussed in the "Risk Factors" filed with Alnylam's Quarterly Report on Form 10-Q filed with the Securities and Exchange Commission (SEC) on August 9, 2013 and in other filings that Alnylam makes with the SEC. In addition, any forward-looking statements represent Alnylam's views only as of today and should not be relied upon as representing its views as of any subsequent date. Alnylam explicitly disclaims any obligation to update any forward-looking statements.