Washington – Treatment of symptomatic obstructive patients Hypertrophic cardiomyopathy Patients who continued treatment with the investigational drug Mavacamten for a median of 62 weeks continued to show the same level of safe response to the drug as seen after the first 30 weeks of treatment in the primary trial of this drug.
New discoveries from long-term treatment are good precursors for Mabakamten. This is because if the drug is used in routine practice to avoid the need for surgery or invasive intervention to reduce the obstruction of the patient’s left ventricular outflow tract, the duration of Mabacamten treatment is probably years, even even more. This is because it needs to continue for decades. Florian Radar, MDPresented the results at the American College of Cardiology’s annual science session.
“In practice, Mabacamten will probably be used for years, especially to replace septal reduction therapy, so long-term data is needed,” Dr. Raider said in a press conference on his report. I mentioned in. Follow-up “I’m very happy with the long-term data.”
The Food and Drug Administration is currently considering whether to approve Mabacamten for regular marketing to treat patients with symptomatic obstructive hypertrophic cardiomyopathy (oHCM). Expected to make a decision By the end of April 2022.
A study reported by Dr. Raider followed 231 patients with symptomatic oHCM who completed a 30-week major clinical trial of Mabacamten. EXPLORER-HCMAnd continued treatment initiated during the study, or continued open-label extended treatment with mabacamten, either by receiving placebo during the study followed by transfer to mabacamten.
Main findings from EXPLORER-LTE (Long-term extension) Median continuous treatment for about 62 weeks is blinded, randomized, First 30-week phaseDr. Raider, co-director of the Hypertrophic Cardiomyopathy and Aortology Clinic at Cedars-Sinai Medical Center in Los Angeles, said.
“Almost revolutionary”
Mavacamten commented that it represents a “nearly revolutionary change” for treating oHCM. Maya E. Gugulin, MDProfessor of clinical medicine and advanced heart failure Physician at Indiana University in Indianapolis. “Until now, there was no suitable treatment for symptomatic oHCM. This will change the situation and undoubtedly change the treatment guidelines for oHCM,” Dr. Guglin said at a press conference.
“All of us treating patients with oHCM were looking forward to receiving disease-specific treatment. It is encouraging to confirm that long-term follow-up remained safe and effective. That’s what Kyle W. Klarich, MD, commented. Professor and cardiologist specializing in the treatment of HCM patients at the Mayo Clinic in Rochester, Minnesota.
Mavacamten is a direct myosin inhibitor that reduces the excess number of myosin-actin crossbridges formed in patients with oHCM, thereby directly targeting the underlying pathophysiology of the disorder, Dr. Rader said. explained.
Patients with Mabacamten included in the long-term extension reported by Dr. Raider averaged 60 years and 61% were male. They had an average decrease of 35.6 mm Hg in the left ventricular outflow tract (LVOT) gradient at rest 48 weeks after treatment and 32.8 mm Hg 84 weeks later. When researchers measured the LVOT gradient during the Balsalva operation, the reduction from baseline averaged 45.3 mm Hg after 48 weeks and 46.4 mm Hg after 84 weeks.
The resting left ventricular ejection fraction also dropped an average of 7.0 percentage points from baseline after 48 weeks and an average of 9.0 percentage points after 84 weeks. After 48 weeks of treatment, 68% of patients had at least one class improvement from baseline in the New York Heart Association functional class.
Safety results showed that most treatment-related adverse events were mild or moderate, and approximately 2% of patients had serious drug-related adverse events. Ten of the 231 patients discontinued Mavacamten due to treatment-related adverse events.
EXPLORER-HCM and EXPLORER-LTE are developing mavacamten and are now sponsored by Myo Kardia, owned by Bristol-Myers Squibb. Dr. Rader is a consultant for MyoKardia, Medtronic and ReCor. There was no disclosure to Dr. Gugulin and Dr. Klarich.
This article was originally MDedge.comIs part of the Medscape Professional Network.
