For patients with NYHA class II–III obstructive HCM,

EXPLORER-HCM: A Pivotal Trial for the Efficacy and Safety of CAMZYOS vs Placebo

Explore this page:    |    Study Design    |    Primary Composite Functional Endpoint    |    Postexercise LVOT Peak Gradient    |   NYHA Class    |   Cardiac Biomarker: NT-proBNP

EXPLORER-HCM: Primary Composite Functional Endpoint

CAMZYOS® Demonstrated Significant Benefit in the Primary Composite Functional Endpoint vs Placebo1,2

Primary Endpoint of CAMZYOS® (mavacamten) vs Placebo, Chart

Patients achieving the primary composite functional endpoint at Week 301

Difference (95% CI): 19% (9, 30); P=0.0005

CI=confidence interval; HCM=hypertrophic cardiomyopathy; NYHA=New York Heart Association; pVO2=peak oxygen consumption.

EXPLORER-HCM: Postexercise LVOT Gradient (Secondary Endpoint)

CAMZYOS Significantly Reduced LVOT Obstruction vs Placebo1,2

Secondary Endpoint LVOT Mean Change CAMZYOS® (mavacamten) vs Placebo, Chart
  • Threshold for obstruction is a peak gradient ≥30 mmHg3

  • A resting or provoked LVOT gradient of ≥50 mmHg is the guideline-based obstructive threshold for SRT3

Secondary endpoint: mean change in postexercise LVOT peak gradient from baseline to Week 301‡

Difference (95% CI): -35 mmHg (-43, -28); P<0.0001

Prespecified exploratory endpoint: Valsalva LVOT gradient1

At Week 30, the mean (SD) changes from baseline in Valsalva LVOT gradient were -49 (34) mmHg for the CAMZYOS group and -12 (31) mmHg for the placebo group.

While this endpoint was prespecified, it was not powered for significance.

Data based on all randomized patients who received ≥1 dose of study treatment. LVOT gradient was analyzed with all available data without imputation. Given the secondary endpoints in EXPLORER-HCM are hierarchical in nature, the endpoint related to NYHA class presented on this page is subsequent to the significance achieved for the endpoint related to pVO2. The mean change (SD) of pVO2 from baseline to Week 30 was 1.4 (3.1) mL/kg/min in the CAMZYOS group vs -0.1 (3.0) mL/kg/min in the placebo group; difference (95% CI): 1.4 (0.6, 2.1); P=0.0006.2


LVOT=left ventricular outflow tract; SD=standard deviation.

EXPLORER-HCM: NYHA Class (Secondary Endpoint)

Significantly More Patients Improved by ≥1 NYHA Class With CAMZYOS vs Placebo1,2 

 CAMZYOS® (mavacamten) vs Placebo NYHA class improvement from baseline to week 30, Graphic

Secondary endpoint: proportion of patients with at least 1 NYHA class improvement from baseline to Week 301

Difference (95% CI): 34% (22, 45); P<0.0001

At baseline, approximately 73% of the patients were NYHA Class II and 27% were NYHA Class III.1

Data used to Calculate Secondary Endpoint  NYHA Class Changes CAMZYOS® (mavacamten) vs Placebo, Chart

At Week 30, 42% (n=52) of patients taking CAMZYOS were Class II and 7% (n=8) were Class III, vs 58% (n=74) and 20% (n=25) in the placebo arm, respectively.2

These data were used to calculate the secondary endpoint related to NYHA class but were exploratory in nature, and not evaluated for significance to compare between the treatment groups.2,5

EXPLORER-HCM: Cardiac Biomarker: NT-proBNP (Exploratory Endpoint)

80% greater reduction in NT-proBNP with CAMZYOS than with placebo1,2

NT-proBNP is a marker for negative cardiac outcomes in patients with symptomatic obstructive HCM2

Exploratory Endpoint NT-proBNP Mean Change CAMZYOS® (mavacamten) vs Placebo, Chart

While this endpoint was prespecified, it was not powered for significance. The clinical significance of this finding is unknown.

Exploratory endpoint: mean change in NT-proBNP over the 30-week treatment period

§Proportion of geometric mean ratio between the group is 0.20 (95% CI: 0.17, 0.24).1

NT-proBNP=N-terminal pro B-type natriuretic peptide.

The efficacy of CAMZYOS was evaluated in EXPLORER-HCM, a phase 3, double-blind, randomized, placebo-controlled trial that enrolled 251 adult patients with symptomatic (NYHA Class II and III) obstructive HCM, with LVOT peak gradient ≥50 mmHg, and LVEF ≥55% at rest or with provocation.1 Patients were randomized in a 1:1 ratio to receive CAMZYOS (n=123) or placebo (n=128) once daily for 30 weeks.1

All subjects were initiated on CAMZYOS 5 mg (or matching placebo) once daily, and the dose was periodically adjusted to optimize patient response (decrease in LVOT gradient with Valsalva maneuver), maintain LVEF ≥50%, and was further informed by plasma concentrations of CAMZYOS.1,2

References:

  1. CAMZYOS [package insert]. Princeton, NJ: Bristol-Myers Squibb Company; 2025.
  2. Olivotto I, Oręziak A, Barriales-Villa R, et al; EXPLORER-HCM study investigators. Mavacamten for treatment of symptomatic obstructive hypertrophic cardiomyopathy (EXPLORER-HCM): a randomised, double-blind, placebo-controlled, phase 3 trial. Lancet. 2020;396(10253):759-769. doi:10.1016/S0140-6736(20)31792-X
  3. 2024 AHA/ACC/AMSSM/HRS/PACES/SCMR Guideline for the Management of Hypertrophic Cardiomyopathy: A Report of the American Heart Association/American College of Cardiology Joint Committee on Clinical Practice Guidelines. Circulation. 2024;150(8):e198. doi:10.1161/CIR.0000000000001277
  4. Data on file. BMS-REF-MAVA-002. Princeton, NJ: Bristol-Myers Squibb Company; 2021.
  5. Olivotto I. Efficacy and safety of mavacamten in adults with symptomatic obstructive hypertrophic cardiomyopathy: results of the EXPLORER-HCM study. Presented at ESC Congress the Digital Experience; 2020.
  6. Argulian E, Sherrid MV, Messerli FH. Misconceptions and facts about hypertrophic cardiomyopathy. Am J Med. 2016;129(2):148-152. doi:10.1016/j.amjmed.2015.07.035

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