A Deep Dive Into the Trials That Have Shaped the Evidence for CAMZYOS1-15
Explore this page: | Study Designs | Patient Characteristics
Studied in 1 Pediatric Trial (SCOUT-HCM) and 2 Adult Trials (EXPLORER-HCM & VALOR-HCM) in Patients With Symptomatic Obstructive HCM1,2,6,9
Study Design of the SCOUT-HCM Pivotal Phase 3 Trial1,6,12
Initial CAMZYOS once-daily dosing was based on weight:
91% of patients started on the 5 mg dose and 9% started on the 2.5 mg dose.
Study design1,6,7
- SCOUT-HCM is an ongoing global, Phase 3, double-blind, randomized, placebo-controlled trial in patients [N=44] aged 12-17 diagnosed with obstructive HCM with NYHA Class II–III symptoms
Select inclusion criteria1,6,7,12
- Ages 12-17 years
- Diagnosis of HCM with NYHA Class II–III symptoms
- Valsalva LVOT gradient ≥30 mmHg and maximal measured LVOT gradient ≥50 mmHg (resting, Valsalva, or postexercise)
- LVEF ≥60%
Select exclusion criteria1,6,7,12
- HCM phenocopies (Noonan's Syndrome, Fabry's Disease)
- Resting LVEF <50% in prior 6 months
- Planned escalation in HCM therapy or upcoming cardiac intervention
- Current treatment (within 14 days before screening) with moderate or strong CYP2C19 inhibitors or strong CYP3A4 inhibitors
Treatment1,6,7
- Starting dose: 5 mg of CAMZYOS once daily for patients weighing ≥45 kg or 2.5 mg once daily for those weighing ≥35 kg to <45 kg
- Dose could be down-titrated at Weeks 5 and 9 or up-titrated at Weeks 12 and 24 by one level based on Valsalva LVOT gradient and LVEF. Doses available for titration were 1 mg, 2.5 mg, 5 mg, 10 mg, and 15 mg
Primary endpoint1,6,7
- Change from baseline in Valsalva LVOT gradient at Week 28
Secondary endpoints (not powered; descriptive only)6,7
- Changes in (from Baseline to Week 28):
- Resting LVOT gradient
- Postexercise peak LVOT gradient
- Maximal LV wall thickness
- E/e'
- HCMSQ-SoB domain score
- Proportion of patients achieving (at Week 28):
- An increase in pVO₂
- An LVOT gradient (Resting or Valsalva) <30 mmHg
- ≥1 NYHA class improvement
- ≥1 mitral regurgitation grade improvement
- Select safety data:
- Incidence of adverse events
- Serious adverse events
- A decrease in LVEF to <50%
Concomitant beta blockers, calcium channel blockers, disopyramide, and combinations as background HCM therapies were allowed if the patient was on a stable dose for ≥14 days prior to screening, and there were no plans for dose changes or other HCM interventions during the study.6
Titration was based on echocardiographic assessment of the Valsalva LVOT gradient and LVEF.12
1 patient (Placebo group) requested unblinding prior to Week 28 and was removed from the primary endpoint analysis.6
CYP=cytochrome P450; E/e′=ratio between early mitral inflow velocity and mitral annular early diastolic velocity; HCM=hypertrophic cardiomyopathy; HCMSQ-SoB=Hypertrophic Cardiomyopathy Symptom Questionnaire‑Shortness-of-Breath domain score; LTE=long-term extension; LV=left ventricle; LVEF=left ventricular ejection fraction; LVOT=left ventricular outflow tract; NYHA=New York Heart Association; pVO2=peak oxygen consumption; QD=once daily; R=randomization.
Study Design of the EXPLORER-HCM Pivotal Phase 3 Trial and Its Long-Term Extension1-4,11
The majority of patients (92%) were on background therapy with a BB or CCB at baseline in both trials.1-4,11
EXPLORER-HCM (Week 30)
Study design1,2
- EXPLORER-HCM was a randomized, double-blind, placebo‑controlled, 30-week, Phase 3 trial that evaluated the efficacy and safety of CAMZYOS in 251 adult patients1
Select inclusion criteria1,2
- Symptomatic NYHA Class ll–lll obstructive HCM
- LVOT peak gradient ≥50 mmHg and LVEF ≥55%
Select exclusion criteria1,2,13
- Underwent SRT within 6 months prior to screening, or planned during study
- Treatment (within 14 days of screening) or planned treatment with disopyramide, ranolazine, or a combination of BBs and CCBs
Primary composite endpoint1
- Increased exercise capacity (pVO2) and improvement or no worsening in symptoms (NYHA class)
Secondary endpoints (Baseline to Week 30)1,2
|
|
Treatment1,2
- In the active treatment arm: 5 mg of CAMZYOS with opportunities for dose titration at Weeks 8 and 14 (based on patient response with Valsalva LVOT gradient, LVEF, and plasma concentration)
- During the treatment period, patients were evaluated every 2 to 4 weeks
EXPLORER-LTE (Week 252)4,11
Study design4,11
- EXPLORER-LTE cohort of MAVA-LTE: a single-arm, open-label, ongoing extension of the Phase 3 EXPLORER-HCM study to evaluate the long-term safety and efficacy of CAMZYOS starting at 5 mg
- 231 of 251 eligible patients from the pivotal trial enrolled in the long-term extension after an 8-week washout period
- The EXPLORER-LTE cohort of the MAVA-LTE trial sought to evaluate the long-term safety and efficacy of CAMZYOS starting at 5 mg in eligible adults who completed the EXPLORER-HCM trial. The EXPLORER-LTE cohort (n=231) is a single-arm study without an active comparator
Study objectives4,11
- Primary: Safety and tolerability
- Secondary: Changes in NYHA class, LVOT gradients at rest and with Valsalva, and LVEF
- Exploratory: Changes in NT-proBNP and measures of left ventricular filling
Study limitations
- These LTE data are not included in the CAMZYOS U.S. Full Prescribing Information and caution should be used in interpreting the data; there are limitations with the data including decreased sample size and different continuation rates based on the continued involvement of responders and attrition of nonresponders
- MAVA-LTE, including the EXPLORER-LTE cohort (n=231), is a single-arm study without active comparator, and data were no statistically tested for significance but are only descriptive in nature
- Patients enrolled in EXPLORER-LTE were part of either the CAMZYOS or placebo arm in the EXPLORER-HCM study; therefore, baseline characteristics for EXPLORER-LTE changed due to time and the consolidation of both arms to one cohort
In EXPLORER-HCM, all assessments for secondary endpoints were performed and Type I error was controlled in hierarchical order (sequence as indicated above) upon achieving significance in the primary endpoint (with two‑tailed P<0.05 required to proceed). Data based on all randomized patients who received ≥1 dose of study treatment. Model-estimated least-square mean differences were reported for continuous variables. Missing NYHA class data at Week 30 were imputed with the Week 26 value, in the case of NYHA response. Patients with a nonevaluable primary endpoint and NYHA secondary endpoint were considered as nonresponders. LVOT gradient, pVO2, KCCQ-23–CSS, and HCMSQ-SoB were analyzed with all available data without imputation. NYHA class was analyzed using the Cochran-Mantel-Haenszel test; continuous data were analyzed by ANCOVA (LVOT gradient, pVO2) or mixed-effect model for repeated measurements (KCCQ-23–CSS, HCMSQ-SoB).2
| * | 5-mg starting dose was taken orally QD. The dose was periodically adjusted to optimize patient response.2 |
| † | Scheduled dose assessments of CAMZYOS in EXPLORER-LTE occurred at Weeks 4, 8, and 12 based on Valsalva LVOT gradient and LVEF, every 12 weeks through Week 156, and every 24 weeks through Week 252.4 |
| ANCOVA=analysis of covariance; BB=beta blocker; CCB=calcium channel blocker; HCM=hypertrophic cardiomyopathy; HCMSQ-SoB=Hypertrophic Cardiomyopathy Symptom Questionnaire‑Shortness-of-Breath domain score; KCCQ‑23‑CSS=Kansas City Cardiomyopathy Questionnaire (23-item version)‑Clinical Summary Score; LTE=long-term extension; LVEF=left ventricular ejection fraction; LVOT=left ventricular outflow tract; NT‑proBNP=N‑terminal pro–B‑type natriuretic peptide; NYHA=New York Heart Association; pVO2=peak oxygen consumption; QD=once daily; R=randomization; SRT=septal reduction therapy. |
Study Design of the VALOR-HCM Pivotal Phase 3 Trial and Its Long-Term Extension1,8-10
After 16 weeks, 93% of patients originally randomized to placebo were crossed over to CAMZYOS 5 mg once daily.9
VALOR-HCM (Week 16)
Study design1,9
- Randomized, double-blind, placebo-controlled, 16-week Phase 3 trial
- 112 adults with symptomatic obstructive HCM who were SRT-eligible
- Evaluated CAMZYOS vs placebo
Select inclusion criteria1,9
- Age ≥18 years
- Severely symptomatic, drug-refractory obstructive HCM
- NYHA Class III/IV or Class II with exertional syncope or near syncope
- SRT-eligible and actively considering the procedure
- LVEF ≥60%
- LVOT peak gradient ≥50 mmHg at rest or with provocation
Select exclusion criteria9,14
- Known infiltrative or storage disorder mimicking obstructive HCM
- Background obstructive HCM medication adjustment within 14 days before screening or anticipated within the first 16 weeks
- Planned invasive procedure during the first 32 weeks
- Prior invasive SRT or cardiotoxic agents
Primary composite functional endpoint9
- Proportion of patients who remained guideline-eligible for SRT or decided to proceed with SRT by Week 16‡
Select secondary endpoints (from Baseline to Week 16)9
- Change in postexercise LVOT peak gradient
- Proportion of patients with ≥1 NYHA class improvement
- Change in NT-proBNP
Select exploratory endpoints9
- Change from baseline in Valsalva LVOT gradient
- Change from baseline in LVEF
Treatment1,9
- CAMZYOS 2.5 mg, 5 mg, 10 mg, or 15 mg once daily, or placebo
- Dose adjustment based on core-lab LVEF and LVOT gradient
- Temporary treatment interruption for LVEF <50%
- Permanent treatment discontinuation for LVEF ≤30%
VALOR-LTE (Week 128)
Study design10
- Open-label, long-term extension of VALOR-HCM
- Followed patients receiving CAMZYOS through Week 128
Study objectives10
- Assess long-term safety and efficacy of CAMZYOS
- Evaluate patients continuing CAMZYOS or crossing over from placebo after Week 16
Study limitations10
- The following LTE data are not included in the CAMZYOS US Full Prescribing Information and caution should be used in interpreting LTE data; it is descriptive, and no statistical comparisons have been made
- The LTE data are from analyses without active placebo comparator and are descriptive in nature with respect to the VALOR-HCM Week 16 primary analysis
- With the crossover during the active-control treatment period, the LTE data is presented separately for the original CAMZYOS and placebo-to-CAMZYOS crossover groups
| * | Patients were evaluated for possible down-titration at Week 4 and up-titration at Weeks 8 and 12.1,9 |
| † | Patients who received placebo during the first 16 weeks began CAMZYOS 5 mg at Week 16 and were evaluated for possible down-titration at Week 20 and up-titration at Weeks 24 and 28.9,15 |
| ‡ | A subject with NYHA Class III or IV at baseline with improvement to NYHA Class II no longer remained SRT-eligible unless they had exertional syncope or presyncope. Early dropouts or patients whose response status could not be assessed at the end of the dosing period were classified as SRT-eligible.9 |
| EOS=end of study; EOT=end of treatment; HCM=hypertrophic cardiomyopathy; LTE=long-term extension; LVEF=left ventricular ejection fraction; LVOT=left ventricular outflow tract; NT-proBNP=N-terminal pro-B-type natriuretic peptide; NYHA=New York Heart Association; R=randomization; SRT=septal reduction therapy. |
Select Patient Baseline Characteristics in the 4 Studies1,2,4,6,9-11
Select Patient Baseline Characteristics in SCOUT-HCM1,6
| * | Race and ethnic group were reported by the patient.6 |
| † | Concomitant treatment with a combination of background hypertrophic cardiomyopathy therapies was permitted.6 |
| ‡ | Data were missing for two patients on CAMZYOS group and for one patient on placebo.6 |
| § | Data were missing for 6 patients in the CAMZYOS group and 4 patients in the placebo group.6 |
| || | Data were missing for one patient in the CAMZYOS group.6 |
| E/e′=ratio between early mitral inflow velocity and mitral annular early diastolic velocity; HCM=hypertrophic cardiomyopathy; IQR=interquartile range; LVEF=left ventricular ejection fraction; LVOT=left ventricular outflow tract; NT‑proBNP=N‑terminal pro–B‑type natriuretic peptide; NYHA=New York Heart Association; SD=standard deviation. |
References:
- CAMZYOS [package insert]. Princeton, NJ: Bristol-Myers Squibb Company; 2026.
- Olivotto I, Oreziak A, Barriales-Villa R, et al. 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.
- Ho CY, Olivotto I, Jacoby D, et al. Study design and rationale of EXPLORER-HCM: evaluation of mavacamten in adults with symptomatic obstructive hypertrophic cardiomyopathy. Circ Heart Fail. 2020;13(6):e006853.
- Garcia-Pavia P, Oreziak A, Masri A, et al. Long-term effect of mavacamten in obstructive hypertrophic cardiomyopathy. Eur Heart J. 2024;45(47):5071-5083.
- Garcia-Pavia P, Oręziak A, Masri A, et al. Long-term effect of mavacamten in obstructive hypertrophic cardiomyopathy. Eur Heart J. 2024;45(47):5071-5083 [supplementary appendix].
- Rossano JW, Canter C, Wolf CM, et al. Mavacamten in adolescents with obstructive hypertrophic cardiomyopathy. N Engl J Med. 2026;395(4):362-373.
- Rossano JW, Canter C, Wolf CM, et al. Mavacamten in adolescents with obstructive hypertrophic cardiomyopathy. N Engl J Med. 2026;395(4):362-373 [supplementary appendix].
- Desai MY, Wolski K, Owens A, et al. Study design and rationale of VALOR-HCM: evaluation of mavacamten in adults with symptomatic obstructive hypertrophic cardiomyopathy who are eligible for septal reduction therapy. Am Heart J. 2021;239:80-89.
- Desai MY, Owens A, Geske JB, et al. Myosin inhibition in patients with obstructive hypertrophic cardiomyopathy referred for septal reduction therapy. J Am Coll Cardiol. 2022;80(2):95-108.
- Desai MY, Wolski K, Owens A, et al. Mavacamten in patients with hypertrophic cardiomyopathy referred for septal reduction: Week 128 results From VALOR-HCM. Circulation. 2025;151(19):1378-1390.
- Owens AT, Oręziak A, Masri A, et al. Safety and efficacy of treatment with mavacamten for up to 5 years in patients with obstructive hypertrophic cardiomyopathy: final results from MAVA-LTE. Oral presentation at ESC 2026; August 28-31, 2026; Munich, Germany.
- Rossano J, Canter C, Wolf C, et al. Mavacamten in symptomatic adolescent patients with obstructive hypertrophic cardiomyopathy: design of the phase 3 SCOUT-HCM trial. Am Heart J. 2026;292:107283.
- Ho CY, Olivotto I, Jacoby D, et al. Study design and rationale of EXPLORER-HCM: evaluation of mavacamten in adults with symptomatic obstructive hypertrophic cardiomyopathy. Circ Heart Fail. 2020;13(6):e006853 [supplementary appendix].
- Desai MY, Owens A, Geske JB, et al. Myosin inhibition in patients with obstructive hypertrophic cardiomyopathy referred for septal reduction therapy. J Am Coll Cardiol. 2022;80(2):95-108 [supplementary appendix].
- Desai MY, Wolski K, Owens A, et al. Mavacamten in patients with hypertrophic cardiomyopathy referred for septal reduction: Week 128 results from VALOR-HCM. Circulation. 2025;151(19):1378-1390 [supplementary appendix].
Select Patient Baseline Characteristics in EXPLORER-HCM and EXPLORER-LTE1,2,4,11
| * | BB use at baseline derived from concomitant medication data in EXPLORER-LTE.4 |
| † | Nondihydropyridine CCBs.2 |
| ‡ | Data missing for one patient in the CAMZYOS group and one patient in the placebo group.2 |
| BB=beta blocker; CCB=calcium channel blocker; HCM=hypertrophic cardiomyopathy; LVEF=left ventricular ejection fraction; LVOT=left ventricular outflow tract; NYHA=New York Heart Association; SD=standard deviation; SRT=septal reduction therapy. |
References:
- CAMZYOS [package insert]. Princeton, NJ: Bristol-Myers Squibb Company; 2026.
- Olivotto I, Oreziak A, Barriales-Villa R, et al. 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.
- Ho CY, Olivotto I, Jacoby D, et al. Study design and rationale of EXPLORER-HCM: evaluation of mavacamten in adults with symptomatic obstructive hypertrophic cardiomyopathy. Circ Heart Fail. 2020;13(6):e006853.
- Garcia-Pavia P, Oreziak A, Masri A, et al. Long-term effect of mavacamten in obstructive hypertrophic cardiomyopathy. Eur Heart J. 2024;45(47):5071-5083.
- Garcia-Pavia P, Oręziak A, Masri A, et al. Long-term effect of mavacamten in obstructive hypertrophic cardiomyopathy. Eur Heart J. 2024;45(47):5071-5083 [supplementary appendix].
- Rossano JW, Canter C, Wolf CM, et al. Mavacamten in adolescents with obstructive hypertrophic cardiomyopathy. N Engl J Med. 2026;395(4):362-373.
- Rossano JW, Canter C, Wolf CM, et al. Mavacamten in adolescents with obstructive hypertrophic cardiomyopathy. N Engl J Med. 2026;395(4):362-373 [supplementary appendix].
- Desai MY, Wolski K, Owens A, et al. Study design and rationale of VALOR-HCM: evaluation of mavacamten in adults with symptomatic obstructive hypertrophic cardiomyopathy who are eligible for septal reduction therapy. Am Heart J. 2021;239:80-89.
- Desai MY, Owens A, Geske JB, et al. Myosin inhibition in patients with obstructive hypertrophic cardiomyopathy referred for septal reduction therapy. J Am Coll Cardiol. 2022;80(2):95-108.
- Desai MY, Wolski K, Owens A, et al. Mavacamten in patients with hypertrophic cardiomyopathy referred for septal reduction: Week 128 results From VALOR-HCM. Circulation. 2025;151(19):1378-1390.
- Owens AT, Oręziak A, Masri A, et al. Safety and efficacy of treatment with mavacamten for up to 5 years in patients with obstructive hypertrophic cardiomyopathy: final results from MAVA-LTE. Oral presentation at ESC 2026; August 28-31, 2026; Munich, Germany.
- Rossano J, Canter C, Wolf C, et al. Mavacamten in symptomatic adolescent patients with obstructive hypertrophic cardiomyopathy: design of the phase 3 SCOUT-HCM trial. Am Heart J. 2026;292:107283.
- Ho CY, Olivotto I, Jacoby D, et al. Study design and rationale of EXPLORER-HCM: evaluation of mavacamten in adults with symptomatic obstructive hypertrophic cardiomyopathy. Circ Heart Fail. 2020;13(6):e006853 [supplementary appendix].
- Desai MY, Owens A, Geske JB, et al. Myosin inhibition in patients with obstructive hypertrophic cardiomyopathy referred for septal reduction therapy. J Am Coll Cardiol. 2022;80(2):95-108 [supplementary appendix].
- Desai MY, Wolski K, Owens A, et al. Mavacamten in patients with hypertrophic cardiomyopathy referred for septal reduction: Week 128 results from VALOR-HCM. Circulation. 2025;151(19):1378-1390 [supplementary appendix].
Select Patient Baseline Characteristics in VALOR-HCM1,9
In VALOR-LTE, the baseline characteristics remained similar to the original phase 3 study (VALOR-HCM)1,9,10
- Mean age: 60 years in VALOR-HCM and 60 years in VALOR-LTE
- 49% of patients in VALOR-HCM and 50% in VALOR-LTE were female, respectively
- 95% of all patients in VALOR-HCM and 96% of patients in VALOR-LTE were on background therapy with a BB, CCB, or disopyramide, administered as monotherapy or combination therapy
| * | Nondihydropyridine CCB.2 |
| BB=beta blocker; CCB=calcium channel blocker; HCM=hypertrophic cardiomyopathy; LVOT=left ventricular outflow tract; NYHA=New York Heart Association; SD=standard deviation. |
References:
- CAMZYOS [package insert]. Princeton, NJ: Bristol-Myers Squibb Company; 2026.
- Olivotto I, Oreziak A, Barriales-Villa R, et al. 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.
- Ho CY, Olivotto I, Jacoby D, et al. Study design and rationale of EXPLORER-HCM: evaluation of mavacamten in adults with symptomatic obstructive hypertrophic cardiomyopathy. Circ Heart Fail. 2020;13(6):e006853.
- Garcia-Pavia P, Oreziak A, Masri A, et al. Long-term effect of mavacamten in obstructive hypertrophic cardiomyopathy. Eur Heart J. 2024;45(47):5071-5083.
- Garcia-Pavia P, Oręziak A, Masri A, et al. Long-term effect of mavacamten in obstructive hypertrophic cardiomyopathy. Eur Heart J. 2024;45(47):5071-5083 [supplementary appendix].
- Rossano JW, Canter C, Wolf CM, et al. Mavacamten in adolescents with obstructive hypertrophic cardiomyopathy. N Engl J Med. 2026;395(4):362-373.
- Rossano JW, Canter C, Wolf CM, et al. Mavacamten in adolescents with obstructive hypertrophic cardiomyopathy. N Engl J Med. 2026;395(4):362-373 [supplementary appendix].
- Desai MY, Wolski K, Owens A, et al. Study design and rationale of VALOR-HCM: evaluation of mavacamten in adults with symptomatic obstructive hypertrophic cardiomyopathy who are eligible for septal reduction therapy. Am Heart J. 2021;239:80-89.
- Desai MY, Owens A, Geske JB, et al. Myosin inhibition in patients with obstructive hypertrophic cardiomyopathy referred for septal reduction therapy. J Am Coll Cardiol. 2022;80(2):95-108.
- Desai MY, Wolski K, Owens A, et al. Mavacamten in patients with hypertrophic cardiomyopathy referred for septal reduction: Week 128 results From VALOR-HCM. Circulation. 2025;151(19):1378-1390.
- Owens AT, Oręziak A, Masri A, et al. Safety and efficacy of treatment with mavacamten for up to 5 years in patients with obstructive hypertrophic cardiomyopathy: final results from MAVA-LTE. Oral presentation at ESC 2026; August 28-31, 2026; Munich, Germany.
- Rossano J, Canter C, Wolf C, et al. Mavacamten in symptomatic adolescent patients with obstructive hypertrophic cardiomyopathy: design of the phase 3 SCOUT-HCM trial. Am Heart J. 2026;292:107283.
- Ho CY, Olivotto I, Jacoby D, et al. Study design and rationale of EXPLORER-HCM: evaluation of mavacamten in adults with symptomatic obstructive hypertrophic cardiomyopathy. Circ Heart Fail. 2020;13(6):e006853 [supplementary appendix].
- Desai MY, Owens A, Geske JB, et al. Myosin inhibition in patients with obstructive hypertrophic cardiomyopathy referred for septal reduction therapy. J Am Coll Cardiol. 2022;80(2):95-108 [supplementary appendix].
- Desai MY, Wolski K, Owens A, et al. Mavacamten in patients with hypertrophic cardiomyopathy referred for septal reduction: Week 128 results from VALOR-HCM. Circulation. 2025;151(19):1378-1390 [supplementary appendix].