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.
A small study of 29 patients conducted recently in the U.K. found that the use of a biventricular pacing in patients with non-obstructive hypertrophic cardiomyopathy improved symptoms of breathlessness and improved exercise capacity as demonstrated during oxygen consumption testing.
Medications are the only treatments currently available to non-obstructed patients. The authors of this study hypothesized that biventricular pacing could be a viable way to address exercise limitations in non-obstructed patients if medications have been ineffective.
Larger trials may establish biventricular pacing as a viable treatment for non-obstructed patients in the future.
A recent study conducted in the U.K. evaluated whether the anti-anginal drug trimetazidine would improve symptoms and exercise capacity for those patients with non-obstructive hypertrophic cardiomyopathy.
Unfortunately, this study which was conducted by Dr. Perry Elliott and his colleagues at University College London, found that trimetatazidine did not improve exercise capacity in these patients. Following the results of this study, trimetazidine will now join ranolazine and spironolactone in the compost heap of drugs which tried and failed to improve HCM symptoms. While a third drug, perhexiline, was found to improve symptoms for non-obstructive HCM, its limitations, including potentially serious side effects, stand in the way of its common usage.
In a companion editorial to this study entitled “Non-Obstructive Hypertrophic Cardiomyopathy-the High Hanging Fruit,” Dr. Sharlene Day of the University of Michigan’s HCM Center discusses the difficulties seen in drug trials related to non-obstructive HCM.