Long-Term Safety and Efficacy of Mavacamten in Symptomatic Obstructive Hypertrophic Cardiomyopathy : Interim Results of the PIONEER-OLE Study

BACKGROUND: The phase 2 PIONEER-HCM (Phase 2 Open-label Pilot Study Evaluating Mavacamten in Subjects With Symptomatic Hypertrophic Cardiomyopathy and Left Ventricular Outflow Tract Obstruction) study showed that mavacamten improved left ventricular outflow tract gradients, exercise capacity, and symptoms in patients with obstructive hypertrophic cardiomyopathy (HCM), but the results of longer-term treatment are less well described. We report interim results from the PIONEER-OLE (PIONEER Open-Label Extension) study, the longest-term study of mavacamten in patients with symptomatic obstructive HCM.

METHODS AND RESULTS: Patients who previously completed PIONEER-HCM (n=20) were eligible to enroll in PIONEER-OLE. Patients received oral mavacamten, 5 mg once daily (starting dose), with individualized dose titration at week 6. Evaluations included serial monitoring of safety, echocardiography, Kansas City Cardiomyopathy Questionnaire-Overall Summary Score, and serum NT-proBNP (N-terminal pro-B-type natriuretic peptide) levels. Thirteen patients enrolled and received mavacamten (median study duration at data cutoff, 201 weeks). Most patients (92.3%) received β-blockers concomitantly. Treatment-emergent adverse events were predominantly mild/moderate. One patient had an isolated reduction in left ventricular ejection fraction to 47%, which recovered and remained normal with continued treatment at a reduced dose. At week 180, mavacamten was associated with New York Heart Association class improvements from baseline (class II to I, n=9; class III to II, n=1; and unchanged, n=2), sustained reductions in left ventricular outflow tract gradients (mean [SD] change from baseline: resting, -50 [55] mm Hg; Valsalva, -70 [41] mm Hg), and serum NT-proBNP levels (median [interquartile range] change from baseline: -498 [-2184 to -76] ng/L), and improved Kansas City Cardiomyopathy Questionnaire-Overall Summary Score (mean [SD] change from baseline: +17 [16]).

CONCLUSIONS: This long-term analysis supports the continued safety and effectiveness of mavacamten for >3 years in obstructive HCM.

REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT03496168.

Medienart:

E-Artikel

Erscheinungsjahr:

2024

Erschienen:

2024

Enthalten in:

Zur Gesamtaufnahme - volume:13

Enthalten in:

Journal of the American Heart Association - 13(2024), 8 vom: 16. Apr., Seite e030607

Sprache:

Englisch

Beteiligte Personen:

Masri, Ahmad [VerfasserIn]
Lester, Steven J [VerfasserIn]
Stendahl, John C [VerfasserIn]
Hegde, Sheila M [VerfasserIn]
Sehnert, Amy J [VerfasserIn]
Balaratnam, Ganesh [VerfasserIn]
Shah, Ashish [VerfasserIn]
Fox, Shawna [VerfasserIn]
Wang, Andrew [VerfasserIn]

Links:

Volltext

Themen:

56HH86ZVCT
Benzylamines
Clinical Trial
Echocardiography
Health status
Journal Article
Long‐term follow‐up
MYK-461
Safety
Symptoms
Uracil

Anmerkungen:

Date Completed 17.04.2024

Date Revised 22.04.2024

published: Print-Electronic

ClinicalTrials.gov: NCT03496168

Citation Status MEDLINE

doi:

10.1161/JAHA.123.030607

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM37080614X