Third Rock Ventures, LLC today announced the formation of MyoKardia, Inc. with a $38 million Series A financing of the company. MyoKardia is developing a pipeline of novel small molecule therapeutics that address key clinical needs for patients with genetic heart disease. The company's first programs include hypertrophic and dilated cardiomyopathy, which together afflict approximately 1 million people in the United States, and for which no novel therapeutics have been brought to market in over a decade. MyoKardia's proprietary drug discovery platform brings together advances from the fields of cardiovascular genomics and heart muscle biology to enable its scientists to target certain heart disease 'at its source.' This genetically targeted approach has the potential to revolutionize the treatment of cardiomyopathies, and ultimately a broader spectrum of cardiovascular disease, including heart failure. The company is founded by world leaders in the fields of muscle biology and cardiovascular genetics: James Spudich, Ph.D., Professor of Biochemistry, Stanford University, Leslie Leinwand, Ph.D., Professor of Molecular, Cellular and Developmental Biology, University of Colorado, Christine Seidman, M.D., Professor of Medicine and Genetics, Harvard Medical School and Director of the Cardiovascular Genetics Center at Brigham and Women's Hospital, and Jonathan Seidman, Ph.D., Professor of Genetics, Harvard Medical School.

"The last decade has been challenging for those pursuing novel therapeutics in the cardiovascular space, in part because most treatments target symptoms far downstream of the root cause," said Dr. Leinwand. "MyoKardia's approach addresses this challenge head on by employing genetics to more precisely define the disease and 'who we want to treat,' and by employing cutting-edge muscle biochemistry and a novel platform to determine 'how we want to treat.' Our initial targets are genetic cardiomyopathies, but this could very well be a novel and tractable therapeutic discovery approach to even larger diseases like heart failure."

Abnormalities in the basic unit of heart muscle, called the sarcomere, have been identified as the driving cause for a variety of heart disease, and the most common cause of hypertrophic and dilated cardiomyopathy. Mutations in the proteins of the sarcomere cause disease by rendering the muscle either 'hyper' or 'hypo' contractile. MyoKardia's platform brings together recent assay and protein expression advances pioneered by its founders with genetic insights to enable a personalized medicine approach. This allows for the rapid development of mutation-specific sarcomeric allosteric modulators that rebalance contractility, therefore stopping and potentially reversing the course of disease. MyoKardia's approach will leverage resident expertise in sarcomere genetics, in-vivo and in-vitro disease models, next-generation biochemical and biophysical assay development, and medicinal chemistry. Together, these capabilities will provide for the efficient progression of multiple programs in DCM, HCM, and other genetic cardiomyopathies and heart disease related to sarcomere dysfunction.

"With MyoKardia's platform, we have the ability to exquisitely characterize the biochemistry and biophysics of the human mutated sarcomere," said Dr. Spudich. "This not only allows us to better understand what drives pathophysiology, it also points us toward potential mutant specific solutions."

"Our goal is to provide treatments for patients with genetic diseases for whom the options to date have been profoundly limited," said Charles Homcy, M.D., interim chief executive officer of MyoKardia and venture partner at Third Rock Ventures. "With this Series A financing, we can meet our goals. We now have the resources and capabilities to effectively translate the insights of our founders and employees into multiple clinical products that positively impact patient lives."

Hypertrophic and dilated cardiomyopathies, MyoKardia's first two focus disease areas, are the most common forms of heart muscle disease and the most common diagnosis leading to cardiac transplantation. More than 60 million people worldwide have cardiomyopathy or carry a cardiomyopathy gene mutation, including approximately 1 million patients in the United States. Despite this large patient population and the persisting unmet clinical need, there is a lack of novel therapeutics being developed that directly target these diseases.

About Genetic Cardiomyopathy

Genetic cardiomyopathies are conditions that arise from mutation in a critical heart muscle protein. Hypertrophic cardiomyopathy (HCM) produces thickening of the heart walls and is best known as a leading cause of sudden cardiac death in young athletes. Dilated cardiomyopathy (DCM) produces weakening of the heart walls and enlargement of the heart chambers. Cardiomyopathy can occur at any age, and more than 30,000 children, from newborns to 18-year-olds, suffer from some form of cardiomyopathy in the United States - a patient population comparable to the number of people living with cystic fibrosis.

About MyoKardia, Inc.

MyoKardia is dedicated to revolutionizing the treatment of genetic cardiovascular disease. The company's proprietary platform combines recent breakthroughs in muscle biology with leading-edge cardiovascular disease genetics. This personalized, genetically targeted approach focuses on the underlying cause of disease and has the potential to drastically improve the treatment of cardiomyopathies, and ultimately a broader spectrum of cardiovascular disease, including heart failure. Founded by world leaders in muscle biology and cardiovascular disease genetics, MyoKardia was launched in 2012 with funding from leading life sciences investor, Third Rock Ventures. For more information, please visit www.myokardia.com.

About Third Rock Ventures

Third Rock Ventures is a venture capital firm founded in 2007 with the mission to launch transformative life sciences companies. With more than $800 million and two funds under management, the firm is focused on working with passionate entrepreneurs to build exceptional companies working in areas of disruptive science that will make a difference in the lives of patients. The firm has assembled a team with deep expertise and a proven track record of building respected and successful life sciences companies. With decades of complementary, cross-functional operational and leadership experience, the Third Rock team actively engages with its portfolio companies to provide hands-on strategy and experience to successfully launch companies with the best vision, science, operations, people and culture. With offices in Boston, MA and San Francisco, CA, Third Rock is well positioned geographically to closely collaborate with its portfolio companies to achieve their goals. To learn more about Third Rock and its portfolio companies, please visit www.thirdrockventures.com.