The expanding field of personalized medicine has not left hypertrophic cardiomyopathy behind. In fact, two companies are currently developing targeted gene therapies for HCM patients. Each therapy targets a separate and distinct HCM gene mutation.
Yet another company is developing a new drug for hypertrophic cardiomyopathy, and this time, the drug is intended for non-obstructive HCM patients. The company is Imbria Pharmaceuticals, and this week they announced the randomizing of the first patient in their Phase 2 study of the drug IMB-101 in patients with non-obstructive HCM. The study, called IMPROVE-HCM, is a Phase 2 study that will look at the safety and tolerability of this drug in non-obstructed HCM patients. IMB-101 is designed to increase the efficiency of the heart’s use of energy which will be measured through cardiopulmonary exercise testing over a 12 week period.
HCM specialists at Tufts Medical Center and Toronto General Hospital have devised a formula which they hope will help predict which HCM patients may go on to develop atrial fibrillation (“AFib”) over time. This tool can assist doctors in determining which patients are at highest risk so that these patients can be closely monitored and treated appropriately. AFib can be extremely dangerous for HCM patients since it can precipitate a stroke if not appropriately treated.
The formula works as follows: Find your left atrial diameter on your most recent echocardiogram report. On the chart below, find the number of points (listed in the 2nd column) that corresponds with your left atrial measurement (measured in millimeters). Then, find the number in the 2nd column that corresponds to your current age range. Add these two numbers together. From that sum, subtract the number listed in the 2nd column that correlates with your age range when you were first diagnosed with HCM. Lastly, if you have heart failure symptoms, add in 3 points. The total is your score.
As always, discuss with your doctor. Everyone has individual factors which will influence their degree of risk. This tool is intended as a general guideline to facilitate discussion with your physician.
According to a recent retrospective study at Oregon Health & Sciences University, appropriately selected patients 65 or older who underwent septal myectomy for obstructive hypertrophic cardiomyopathy (HOCM) have surgical outcomes similar to younger patients. Therefore, older age should NOT be an automatic disqualifier for myectomy. All potential treatments for outflow tract obstruction should be considered, with age being only one of many factors influencing the decision.
More positive data about the Bristol Myers Squibb experimental drug mavacamten was revealed at last weekend’s American College of Cardiology meeting and simultaneously published in The Lancet.
The data showed improvement in how patients felt taking the drug, as reported and quantified by the patients themselves. The clinical trial participants filled out a questionnaire called the KCCQ, or Kansas City Cardiomyopathy Questionnaire, 6 different times over the 38 weeks that the trial was ongoing.
Analysis of these responses showed that just over a third of patients who took mavacamten reported a substantial improvement in symptoms, though not all participants responded to the drug. And, it is important to note that the improvements seen by patients returned to baseline once mavacamten was discontinued.
DISCLOSURES: CYNTHIA BURSTEIN WALDMAN OF HCMBEAT SERVED AS A PATIENT ADVISOR ON THE STEERING COMMITTEE OF MYOKARDIA’S EXPLORER TRIAL AND IS CREDITED AS AN AUTHOR OF THE EXPLORER STUDY. until recently CYNTHIA also SERVED ON MYOKARDIA’S PATIENT ADVISORY BOARD.
Children with HCM are more likely to have sarcomere mutations, have a higher risk of ventricular arrhythmias, and are twice as likely as adults to require advanced interventions like ventricular assist devices, heart transplant or other advanced heart failure therapies.
This week, Bristol Myers Squibb submitted its New Drug Application for mavacamten to the FDA. Mavacamten is the first drug specifically designed to treat obstructive hypertrophic cardiomyopathy. The application was based on the recent positive results of the Phase 3 EXPLORER-HCM trial.
The FDA has assigned a Prescription Drug User Fee Act goal date of January 28, 2022 to the drug, which means that the FDA is expected to complete its review of mavacamten by January 28, 2022.
DISCLOSURES: CYNTHIA BURSTEIN WALDMAN OF HCMBEAT SERVED AS A PATIENT ADVISOR ON THE STEERING COMMITTEE OF MYOKARDIA’S EXPLORER TRIAL AND IS AN AUTHOR OF THE STUDY AS PUBLISHED IN THE LANCET. CYNTHIA ALSO SERVES ON MYOKARDIA’S PATIENT ADVISORY BOARD.
This paper concludes that epigenetics (things which influence expression of DNA like behavioral and environmental factors) greatly influence the expression of HCM genetic mutations.
The researchers studied 11 pairs of twins with HCM. 9 of the twin pairs had known HCM sarcomere mutations while 2 of the pairs had HCM of unknown cause. The siblings were followed for a time frame of between 5 to 14 years.
Researchers compared left ventricular wall thickness, left atrial size and left ventricular ejection fraction. Differences were found in the left ventricular wall thickness of all 11 pairs of twins, while left atrial size was similar in 3 of the 9 twin pairs who carried HCM mutations. Left ventricular ejection fraction was different in 4 of 7 twin pairs.
The researchers theorize that similarities in left atrial size may be due to impaired ventricular relaxation directly tied to sarcomere dysfunction. In contrast, environmental factors yield more influence over ventricular function.
HCM epigenetics is a field ripe for research. As HCM patients, we hope that it will yield actionable data in the near future.