HCM Patients at Greater Risks of Atrial Fibrillation, Heart Failure and Increased Mortality
Younger Age of Diagnosis and Genetic Status Associated with Higher Rates of Long-term Complications and Early
Death
SOUTH SAN FRANCISCO, Calif., Aug. 23, 2018 (GLOBE NEWSWIRE) -- The Sarcomeric Human Cardiomyopathy Registry (SHaRe) and
MyoKardia, Inc. (Nasdaq: MYOK) announced today the publication of results from a multicenter, international, longitudinal study of
data from nearly 4,600 patients with hypertrophic cardiomyopathy (HCM), the largest comprehensive HCM cohort assembled to date.
Hypertrophic cardiomyopathy is a chronic and progressive disease characterized by increased thickening of the heart muscle.
Analyses of SHaRe data revealed that HCM patients are at substantially elevated risks of long-term complications and
comorbidities, such as atrial fibrillation and heart failure. HCM patients also have significantly higher mortality rates
compared to that of the general U.S. population. Further, patients with genetic HCM exhibited clinical disease at younger
ages and were more likely to experience HCM-related complications and early death than patients with non-genetic HCM. The
article, “Genotype and Lifetime Burden of Disease in Hypertrophic Cardiomyopathy: Insights from the Sarcomeric Human Cardiomyopathy
Registry (SHaRe)” will be published in an upcoming print edition of Circulation, the peer-reviewed journal of the American
Heart Association. A copy of the manuscript is now available via the following link: https://www.ahajournals.org/doi/10.1161/CIRCULATIONAHA.117.033200.
“These data provide a comprehensive and far-reaching look at the impact of HCM on patients’ lives and
importantly change our understanding of their risks over time,” said Carolyn Ho, M.D., Associate Professor of Medicine at Harvard
Medical School, Medical Director of the Cardiovascular Genetics Center at Brigham and Women’s Hospital and lead author of the SHaRe
paper. “The cumulative burden and progressive nature of HCM emphasizes that patients require careful long-term follow-up and
underscores the need to develop disease-modifying therapies that may avert the onset of serious comorbidities.”
Researchers from eight high-volume HCM centers associated with SHaRe analyzed clinical information collected
from 4,591 patients diagnosed with HCM to understand the cumulative burden of disease over a lifetime. The data set reflects
more than 24,000 patient-years. Data from SHaRe demonstrate that:
- The burden of disease and complications increased progressively over time for HCM patients, with most HCM-related
complications occurring later in life between the ages of 50-70 years.
- The late onset of severe comorbidities implies that adverse remodeling of the HCM heart is occurring throughout life.
- The most frequently reported comorbidities were heart failure and atrial fibrillation.
- Mortality among HCM patients was shown to be approximately three-fold higher than the United States general population at
similar ages (per the Centers for Disease Control database). Compared to the U.S. general population, mortality was four
times higher among young HCM patients (ages 20-29 years).
Additional analyses were performed examining the impact of sarcomeric mutations and age of diagnosis on disease
experience. Genetic information was available for 2,763 HCM patients in the registry and 46 percent of these patients
possessed a sarcomeric mutation presumed to cause their disease.
- In patients with sarcomere mutations, the median age of diagnosis was 37.5 years, compared to 51.1 years for
patients without a sarcomere mutation.
- Patients with sarcomeric mutations experienced earlier onset of HCM-related complications and the cumulative
burden of disease was shown to be substantial.
- Younger age at the time of HCM diagnosis was associated with increased cumulative incidence of adverse
events: HCM patients under 40 years old at the time of diagnosis had a 77 percent cumulative incidence of cardiac arrest,
defibrillator or left-ventricular assist device (LVAD) implantation, Class III or IV heart failure symptoms, heart
transplantation, atrial fibrillation, stroke or death by age 60. In contrast, patients diagnosed with HCM after the age of
60 years had a 32 percent cumulative incidence of such complications by age 70 years.
“We are greatly indebted to the SHaRe researchers who continue to contribute to this remarkable collective
effort to transform our understanding of the HCM patient journey. The data published in Circulation provide seminal
insights into the burden of disease on HCM patients, underscoring the profound risks associated with HCM over time and the urgent
need for therapies that can potentially alter the course of disease,” said Marc Semigran, M.D., Chief Medical Officer of
MyoKardia. “MyoKardia’s goal supporting SHaRe is to obtain meaningful longitudinal and centralized data to better understand
the risks associated with cardiomyopathy and the course of disease progression. As we gain a greater understanding of the
factors driving HCM, we will be able to develop better treatments to potentially alter the progression of the disease to prevent
late-stage manifestations of HCM’s progression, such as heart failure and atrial fibrillation.”
The SHaRe centers contributing data to this study include Brigham and Women’s Hospital, Boston; University of
Michigan Medical Center; Stanford University Medical Center; Boston Children’s Hospital; Yale-New Haven Hospital; Florence Centre
for Cardiomyopathies, Italy; Erasmus University Medical Center, Netherlands; and InCOR, Sao Paulo, Brazil.
About SHaRe
The Sarcomeric Human Cardiomyopathy Registry (SHaRe) was formed in 2014 by MyoKardia, Inc. in collaboration with several
world-leading cardiovascular centers with the goal of advancing the understanding of hypertrophic cardiomyopathy (HCM). The
registry collects and serves as a repository of clinical and laboratory data on individuals and families with genetic heart
disease. Since its formation, SHaRe has grown into the largest international database of clinical information on HCM patients
with de-identified data on more than 8,000 subjects worldwide.
About MyoKardia, Inc.
MyoKardia is a clinical-stage biopharmaceutical company pioneering a precision medicine approach to discover, develop and
commercialize targeted therapies for the treatment of serious and rare cardiovascular diseases. MyoKardia’s initial focus is
on the treatment of heritable cardiomyopathies, a group of rare, genetically driven forms of heart failure that result from
biomechanical defects in cardiac muscle contraction. MyoKardia has used its precision medicine platform to generate a
pipeline of therapeutic programs for the chronic treatment of two of the most prevalent forms of heritable cardiomyopathy –
hypertrophic cardiomyopathy (HCM), and dilated cardiomyopathy (DCM). MyoKardia’s most advanced product candidate is mavacamten
(formerly MYK-461), a novel, oral, allosteric modulator of cardiac myosin intended to reduce hypercontractility. Mavacamten
is being studied in a pivotal Phase 3 clinical trial, known as EXPLORER-HCM, in patients with symptomatic, obstructive HCM.
MyoKardia is also developing mavacamten in a second indication, non-obstructive HCM, in the Phase 2 MAVERICK-HCM clinical
trial. MYK-491, MyoKardia’s second product candidate, is designed to increase the overall extent of the heart’s contraction
in DCM patients by increasing cardiac contractility. MyoKardia is currently evaluating MYK-491 in a Phase 1b study in DCM
patients. A cornerstone of the MyoKardia platform is the Sarcomeric Human Cardiomyopathy Registry (SHaRe), a multi-center,
international repository of clinical and laboratory data on individuals and families with genetic heart disease, which MyoKardia
helped form in 2014. MyoKardia’s mission is to change the world for patients with serious cardiovascular disease through bold
and innovative science.
Contacts: Michelle Corral Corporate Communications & Investor Relations MyoKardia, Inc. 650-351-4690 mcorral@myokardia.com Hannah Deresiewicz (Investors) Stern Investor Relations, Inc. 212-362-1200 hannahd@sternir.com Steven Cooper (Media) Edelman 415-486-3264 steven.cooper@edelman.com
