Cytokinetics Announces Additional Data from ACACIA-HCM Presented at the HFSA Annual Scientific Meeting 2026

The additional analyses showed broader clinical responses versus placebo, alongside higher rates of serious heart failure events.

Rhea-AI Summary

Cytokinetics (CYTK) presented additional ACACIA-HCM analyses showing exercise improvements and safety findings for aficamten in patients with non-obstructive hypertrophic cardiomyopathy.

At 36 weeks, aficamten improved a composite exercise score versus placebo (p<0.001). A clinical response in at least three of five domains occurred in 53% versus 13% (p<0.001). A specified peak oxygen uptake improvement occurred in 45% versus 37%, but was not statistically significant (p=0.1). Left ventricular ejection fraction, the proportion of blood pumped out per beat, fell below 50% in 10.5% versus 0.8%. Serious heart failure events occurred in 4.7% versus 1.2%; all aficamten heart failure events occurred during dose titration or before Week 12 and responded to typical medical therapy. Cytokinetics plans to submit a supplemental FDA application in Q4 2026.

10 points · 0 major

MixediHow this balance works

How this balance works

Rhea-AI gives every point it takes from this document a weight. Minor counts 1, Moderate 3 and Major 9, so one Major point outweighs several Minor ones. The bar adds up the weights on each side, and when neither side holds more than 65% of the total the balance reads Mixed.

It reads the document as published, with the same rules for every company, and it does not look at what the market expected or at how the stock traded, so a point can be objectively good on a day the stock falls.

Rhea-AI Sentiment measures something else, the tone of the wording.

How the balance worksHow Sentiment works

0 major · 3 points

Hollow bars mark forward-looking points. How the balance works

Positive

• Moderate point. Forward-looking: it has not happened yet and may not happen.Cytokinetics plans a supplemental FDA application in Q4 2026.
• Minor pointComposite exercise performance improved versus placebo at 36 weeks (p<0.001), across all five exercise and recovery domains.
• Minor pointClinical responses in three or more domains reached 53% versus 13% on placebo at 36 weeks (p<0.001).
• Minor pointLimiting symptom relief improved significantly versus placebo at 36 weeks (p<0.05).
• Minor pointLeft atrial volume index, a heart chamber size measure, decreased versus placebo at 36 weeks (p<0.05).

5 minor points

• Minor pointSeptal e’ velocity, a heart relaxation measure, improved versus placebo at 36 weeks (p<0.05).
• Minor pointPatients achieving ≥50% reduction in NT-proBNP, a cardiac biomarker, were more frequent versus placebo at 36 weeks (p<0.05).
• Minor pointComposite exercise improvements correlated with health status improvements (p=0.001) and NT-proBNP improvements (p<0.001).
• Minor pointLeft ventricular ejection fraction remained stable from Week 8 through Week 36 after dose-related reductions.
• Minor pointAficamten heart failure events responded to typical medical therapy, including diuretics.

Negative

• Moderate pointSerious heart failure events affected 12 patients (4.7%) on aficamten versus three (1.2%) on placebo.
• Moderate pointLeft ventricular ejection fraction below 50% occurred in 27 patients (10.5%) versus two (0.8%) on placebo.
• Minor pointPeak oxygen uptake gains ≥0.5 mL/kg/min occurred in 45% versus 37% at 36 weeks; not statistically significant (p=0.1).

News Explained

The update broadens the clinical record with a cross-domain exercise measure and dose-titration observations.

The newly reported BEAP-RS analysis adds a composite view of exercise performance to ACACIA-HCM’s evidence on aficamten in non-obstructive HCM.

BEAP-RS combines five exercise domains, from submaximal exercise through recovery; at 36 weeks, the score improved versus placebo (p<0.001), and improvements correlated with health status, NYHA class and NT-proBNP.

At the end of dose titration, 80.7% of patients were taking 15 or 20 mg; the release reports that dose-related changes in LVEF then remained stable from Week 8 through Week 36.

Key Figures

BEAP-RS treatment effect: p<0.001 Statistically significant domains: 4 of 5 domains; all p<0.05 Response in 3 or more domains: 53% vs. 13% +4 more

BEAP-RS treatment effect

p<0.001

Aficamten vs. placebo at 36 weeks

Statistically significant domains

4 of 5 domains; all p<0.05

Global efficacy responder analysis at 36 weeks

Response in 3 or more domains

53% vs. 13%

Aficamten vs. placebo; p<0.001

Peak VO2 response

45% vs. 37%

Increase of at least 0.5 mL/kg/min; p=0.1

Patients at 15 or 20 mg

80.7%

At the end of the titration period

LVEF below 50%

10.5% vs. 0.8%

Aficamten vs. placebo

Serious heart failure adverse events

4.7% vs. 1.2%

Aficamten vs. placebo

Key Terms

new drug application, lvef, nt-probnp, dose titration, +2 more

6 terms

new drug application regulatory

"submit a supplemental New Drug Application to the FDA"

A new drug application is a formal request submitted to government regulators seeking approval to market a new medicine. It is like a detailed proposal that shows the drug has been tested for safety and effectiveness. For investors, receiving approval signals that the drug may soon become available for sale, potentially leading to revenue growth and impacting the company's value.

lvef medical

"reductions in left ventricular ejection fraction (LVEF)"

Left ventricular ejection fraction (LVEF) is a percentage that measures how much blood the heart’s main pumping chamber pushes out with each beat, like the share of water a pump empties from a bucket each cycle. Investors watch LVEF because it’s a key medical yardstick used to diagnose and track heart function, shaping demand for drugs, devices, clinical trials, insurance costs and the financial outlook of healthcare-related businesses.

nt-probnp medical

"as well as the cardiac biomarker NT-proBNP"

A blood test marker released when the heart is under strain; higher NT‑proBNP levels indicate the heart is working harder or may be failing, similar to a dashboard warning light that signals engine stress. Investors watch NT‑proBNP because changes in the marker can drive clinical trial results, treatment approvals, hospital use, and insurance decisions for heart drugs and devices, all of which affect revenue, adoption and valuation in healthcare companies.

dose titration medical

"Data related to dose titration and the safety profile"

A planned, gradual adjustment of a drug's dose to reach and maintain the level that produces the desired therapeutic effect while limiting side effects; adjustments can increase or decrease the amount and are guided by the patient's symptoms, tolerability, vital signs, laboratory results, or predefined schedules. Titration is a dosing strategy used in clinical care and clinical trials and is different from a one-time fixed dose—its pace and end point are individualized and determined by clinical response or safety thresholds.

serious adverse event medical

"experienced a serious adverse event (SAE) of heart failure"

A serious adverse event is an unexpected medical problem tied to a treatment or trial that leads to death, is life‑threatening, requires (or prolongs) hospitalization, causes lasting disability, or results in a birth defect. Investors care because such events can prompt regulatory investigations, clinical holds, added safety studies, or product withdrawals—like a major car recall that halts sales, adds costs and damages trust, potentially affecting a company’s value and timelines.

rems regulatory

"under a restricted program under a Risk Evaluation and Mitigation Strategy (REMS)"

Risk Evaluation and Mitigation Strategies (REMS) are safety programs required by regulators for certain medications to make sure their benefits outweigh known dangers; they can include extra training, special certifications for prescribers, restricted distribution channels, patient monitoring, or paperwork. For investors, REMS act like a safety checkpoint that can slow or limit a drug’s sales, raise costs, complicate manufacturing and distribution, and affect revenue forecasts and legal risk, so they matter for a product’s market potential and timeline.

AI-generated analysis. How Rhea-AI works. Not financial advice.

See more from StockTitan in Google Search and AI answers. Adds StockTitan as a preferred source · opens Google

Add on Google Not now

Additional Analyses from ACACIA-HCM Further Characterize Exercise Performance, Treatment Effect, Dose Titration and Safety of Aficamten in Non-Obstructive HCM

SOUTH SAN FRANCISCO, Calif., Oct. 12, 2026 (GLOBE NEWSWIRE) -- Cytokinetics, Incorporated (Nasdaq: CYTK) today announced that additional data from ACACIA-HCM (Assessment Comparing Aficamten to Placebo on Cardiac Endpoints In Adults with Non-Obstructive HCM) were presented at the Heart Failure Society of America (HFSA) Annual Scientific Meeting 2026 in Phoenix, AZ.

“These additional analyses from ACACIA-HCM add to the body of evidence supporting the overall benefit-risk profile of aficamten in patients with nHCM,” said Stephen Heitner, M.D., Cytokinetics’ Chief Medical Officer. “The current CPET analysis demonstrates significant improvement in a clinically relevant and novel metric of global exercise performance, while additional data provide insights into dose titration and reinforce our confidence in the safety and treatment effect of aficamten in nHCM. We plan to submit a supplemental New Drug Application to the FDA this quarter.”

ACACIA-HCM: Effect of Aficamten on Comprehensive Exercise Performance

Data from a prespecified analysis of comprehensive exercise performance from ACACIA-HCM were presented in a Late Breaking Clinical Trial Presentation. This analysis examined the effect of aficamten on multiple exercise parameters using the novel 2026 Boston Exercise Aggregate Physiologic Response Score (BEAP-RS). The score captures outputs from five individual domains, ranging from submaximal exercise through to recovery, and generates a composite of global exercise performance. At 36 weeks, treatment with aficamten significantly improved BEAP-RS compared to placebo (p<0.001), with improvements in individual exercise and recovery measures across all five domains. Improvement in BEAP-RS correlated significantly with improvements in health status measured by both Kansas City Cardiomyopathy Questionnaire Clinical Summary Score (KCCQ-CSS) (p = 0.001) and New York Heart Association (NYHA) Functional Class (p = 0.001), as well as the cardiac biomarker NT-proBNP (p<0.001). This analysis provides a greater understanding of the complete impact of aficamten on exercise capacity in patients with non-obstructive HCM (nHCM).

ACACIA-HCM: Global Efficacy Responder Analysis

Data from a responder analysis of ACACIA-HCM evaluating the global efficacy of aficamten in patients with symptomatic nHCM were presented in a Late Breaking Clinical Trial Presentation. The results were published in Circulation in August 2026.¹ The analysis assessed clinical improvements across five key domains. At 36 weeks, a greater proportion of patients treated with aficamten demonstrated a clinically meaningful response compared to placebo in all five domains, with statistically significant improvements in four domains: relief of limiting symptoms, decrease in left atrial volume index (LAVI), increase in septal e’ velocity and ≥50% reduction in NT-proBNP (all p<0.05). An increase in peak VO₂ of at least 0.5 mL/kg/min was observed in 45% of patients on aficamten compared to 37% on placebo (p=0.1). Overall, 53% of patients on aficamten demonstrated a clinical response in three or more domains compared to only 13% of patients on placebo (p<0.001). These data place the primary results into clinical context and underscore the opportunity to impact several aspects of disease burden by addressing the underlying pathobiology in patients living with symptomatic nHCM.

ACACIA-HCM: Dose Titration and Safety

Data related to dose titration and the safety profile of aficamten in ACACIA-HCM were also presented. At the end of the titration period, 80.7% of patients were on 15 or 20 mg. Dose titration led to predictable, dose-proportional changes in plasma concentration of aficamten and reductions in left ventricular ejection fraction (LVEF), which then remained stable from Week 8 through Week 36. LVEF <50% occurred in 27 (10.5%) patients taking aficamten and in two (0.8%) patients taking placebo. The only patient characteristics associated with LVEF <50% were lower baseline LVEF and permanent atrial fibrillation. As previously reported, two participants on aficamten experienced a serious adverse event (SAE) of heart failure associated with LVEF <50%. Ten additional patients on aficamten had SAEs of heart failure not associated with LVEF <50%, for a total of 12 patients (4.7%) compared to three patients (1.2%) on placebo. All heart failure events in patients treated with aficamten occurred during dose titration or prior to Week 12, often following a precipitating event such as rapid atrial fibrillation or infection, and responded to typical medical therapy such as diuretics. Overall, these data suggest that, in ACACIA-HCM, titration of aficamten to the maximum tolerated dose based on LVEF alone was generally well tolerated in the great majority of patients with nHCM.

About MYQORZO® (aficamten)

MYQORZO^® (aficamten) is a cardiac myosin inhibitor approved in the U.S., China, European Union and United Kingdom for the treatment of symptomatic obstructive hypertrophic cardiomyopathy (oHCM). In patients with oHCM, myosin inhibition with MYQORZO reduces cardiac contractility and consequently, left ventricular outflow tract (LVOT) obstruction. MYQORZO was engineered to achieve a predictable exposure response, rapid onset of action and reversibility.²

Aficamten was also evaluated in a pivotal Phase 3 clinical trial, ACACIA-HCM, in patients with non-obstructive HCM (nHCM), which met both dual primary endpoints, demonstrating statistically significant improvements in both dual primary endpoints of Kansas City Cardiomyopathy Questionnaire Clinical Summary Score (KCCQ-CSS) and maximal exercise performance (pVO₂). Statistically significant improvements compared to placebo were also observed in key secondary endpoints. There were no new safety signals identified. Left ventricular ejection fraction (LVEF) <50% occurred in 10% of participants taking aficamten and in 1% of participants taking placebo. Overall, 12 (4.7 %) patients on aficamten had serious adverse events of heart failure compared to three patients (1.2%) on placebo.

Aficamten is also under clinical investigation in CEDAR-HCM in a pediatric population with oHCM. Safety and efficacy of aficamten have not been established in a pediatric patient population. In addition, aficamten is being studied in FOREST-HCM, an open-label extension clinical study.

INDICATION

MYQORZO is indicated for the treatment of adults with symptomatic obstructive hypertrophic cardiomyopathy (oHCM) to improve functional capacity and symptoms.

IMPORTANT SAFETY INFORMATION

WARNING: RISK OF HEART FAILURE

MYQORZO reduces left ventricular ejection fraction (LVEF) and can cause heart failure due to systolic dysfunction. Echocardiogram assessments are required prior to and during treatment with MYQORZO to monitor for systolic dysfunction. Initiation of MYQORZO in patients with LVEF <55% is not recommended. Decrease the dose of MYQORZO if LVEF is <50% and ≥40%. Interrupt the dose of MYQORZO if LVEF <40% or if the patient experiences heart failure symptoms or worsening clinical status due to systolic dysfunction. Because of the risk of heart failure due to systolic dysfunction, MYQORZO is available only through a restricted program under a Risk Evaluation and Mitigation Strategy (REMS) called the MYQORZO REMS Program.

CONTRAINDICATIONS 

MYQORZO is contraindicated with concomitant use of rifampin.

WARNINGS AND PRECAUTIONS

Heart Failure

MYQORZO reduces cardiac contractility, which can reduce LVEF and cause heart failure.
Patients who experience a serious intercurrent illness (eg, serious infection) or arrhythmia (eg, new or uncontrolled atrial fibrillation) may be at greater risk of developing systolic dysfunction and heart failure.

Assess patients’ clinical status and LVEF prior to and during treatment and adjust the MYQORZO dose accordingly. New or worsening arrhythmia, dyspnea, chest pain, fatigue, leg edema, or elevations in N-terminal pro-B-type natriuretic peptide may be signs and symptoms of heart failure.

Initiation of MYQORZO in patients with LVEF <55% is not recommended.

MYQORZO REMS Program

MYQORZO is available only through a restricted program called the MYQORZO REMS Program, because of the risk of heart failure due to systolic dysfunction.

Notable requirements of the MYQORZO REMS Program include:

• Prescribers must be certified by enrolling in the MYQORZO REMS Program
• Patients must enroll in the MYQORZO REMS Program and comply with ongoing monitoring requirements
• Pharmacies must be certified by enrolling in the MYQORZO REMS Program and must only dispense to patients who are authorized to receive MYQORZO
• Wholesalers and distributors must only distribute to certified pharmacies
  
  

Further information is available at www.MYQORZOREMS.com, or at 1-844-285-7367.

Cytochrome P450 Interactions Leading to Heart Failure or Loss of Effectiveness

MYQORZO is metabolized primarily by CYP2C9, and to a lesser extent by CYP3A, CYP2D6, and CYP2C19 enzymes. Initiation of medications that inhibit multiple P450 pathways of MYQORZO elimination (eg, fluconazole, voriconazole, or fluvoxamine) or strong CYP2C9 inhibitors, and discontinuation of moderate-to-strong CYP3A inducers may lead to increased blood concentrations of aficamten and increase the risk of heart failure due to systolic dysfunction. Conversely, initiation of medications that induce P450 pathways of MYQORZO (eg, rifampin, moderate-to-strong CYP3A inducers) may lead to decreased blood concentrations of aficamten and potential loss of effectiveness. Assess LVEF 2 to 8 weeks after initiation of such inhibitors or after discontinuation of such inducers and adjust the dose of MYQORZO accordingly.

Advise patients of the potential for drug interactions. Advise patients to inform their healthcare provider of all concomitant medications prior to and during MYQORZO treatment.

ADVERSE REACTIONS

Hypertension (8% vs 2%) was the only adverse reaction occurring in >5% of patients and more commonly on MYQORZO than on placebo in the pivotal trial.

INDICATIONS AND USAGE

MYQORZO is indicated for the treatment of adults with symptomatic obstructive hypertrophic cardiomyopathy (oHCM) to improve functional capacity and symptoms.

Please see full Prescribing Information approved in the U.S., including Boxed WARNING.

Please see full Summary of Product Characteristics approved in the European Union.

About Hypertrophic Cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is a disease in which the heart muscle becomes abnormally thick. HCM can be obstructive, when thickened muscle blocks blood flow, or non-obstructive, when blood flow is not blocked but heart function is still affected. In obstructive HCM, the thickening of cardiac muscle leads to the inside of the left ventricle becoming smaller, stiffer and less able to relax and fill with blood. Ultimately, HCM limits the heart’s pumping function, leading to reduced exercise capacity and a variety of symptoms.

HCM is the most common monogenic inherited cardiovascular disorder, affecting approximately 1 out of 350 individuals worldwide.³

Approximately half of patients with HCM have obstructive HCM (oHCM) and half have non-obstructive HCM (nHCM).⁴

People with HCM are at high risk of also developing cardiovascular complications including atrial fibrillation, stroke and mitral valve disease.⁵ People with HCM are at risk for potentially fatal ventricular arrhythmias and it is one of the leading causes of sudden cardiac death in younger people or athletes.⁶ A subset of patients with HCM are at high risk of progressive disease leading to dilated cardiomyopathy and heart failure necessitating cardiac transplantation.

About Cytokinetics

Cytokinetics is a specialty cardiovascular biopharmaceutical company, building on its over 25 years of pioneering scientific innovations in muscle biology, and advancing a pipeline of potential new medicines for patients suffering from diseases of cardiac muscle dysfunction. Cytokinetics’ MYQORZO^® (aficamten) is a cardiac myosin inhibitor approved in the U.S., China, European Union and United Kingdom for the treatment of adults with symptomatic obstructive hypertrophic cardiomyopathy (oHCM). Following positive results in ACACIA-HCM, a Phase 3 clinical trial of aficamten in patients with non-obstructive HCM (nHCM), the company plans to submit a Supplemental New Drug Application in Q4 2026. Cytokinetics is also developing omecamtiv mecarbil, an investigational cardiac myosin activator for the potential treatment of patients with heart failure with severely reduced ejection fraction and ulacamten, an investigational cardiac myosin inhibitor for the potential treatment of heart failure with preserved ejection fraction, while continuing pre-clinical research and development in muscle biology.

For additional information about Cytokinetics, visit www.cytokinetics.com and follow us on X, LinkedIn, Facebook and YouTube.

Forward-Looking Statements

This press release contains forward-looking statements for purposes of the Private Securities Litigation Reform Act of 1995 (the “Act”). Cytokinetics disclaims any intent or obligation to update these forward-looking statements and claims the protection of the Act’s Safe Harbor for forward-looking statements. Examples of such statements include, but are not limited to, statements relating to our ability to obtain regulatory approval for aficamten in nonobstructive hypertrophic cardiomyopathy in any jurisdiction by any particular date, if ever, the number of patients comprising the eligible treatment population for aficamten, or market acceptance of aficamten for the treatment of nonobstructive hypertrophic cardiomyopathy. Such statements are based on management’s current expectations, but actual results may differ materially due to various risks and uncertainties, including, but not limited to, potential difficulties or delays in the development, testing, regulatory approvals for trial commencement, progression or product sale or manufacturing of Cytokinetics’ drug candidates that could slow or prevent clinical development or product approval; Cytokinetics’ drug candidates may have adverse side effects or inadequate therapeutic efficacy; the FDA or foreign regulatory agencies may delay or limit Cytokinetics’ ability to conduct clinical trials; Cytokinetics may be unable to obtain or maintain patent or trade secret protection for its intellectual property; standards of care may change, rendering Cytokinetics’ drug candidates obsolete; and competitive products or alternative therapies may be developed by others for the treatment of indications Cytokinetics’ drug candidates and potential drug candidates may target. For further information regarding these and other risks related to Cytokinetics’ business, investors should consult Cytokinetics’ filings with the Securities and Exchange Commission.

CYTOKINETICS® and the CYTOKINETICS C-shaped logo are registered trademarks of Cytokinetics in the U.S. and certain other countries.

MYQORZO® is a registered trademark of Cytokinetics in the U.S., the European Union and the United Kingdom.

References

1. Maron MS, et al. Global Efficacy of Aficamten in Nonobstructive Hypertrophic Cardiomyopathy: Results From ACACIA-HCM. Circ. 2026
2. Maron, MS, et al. Aficamten for Symptomatic Obstructive Hypertrophic Cardiomyopathy. N Engl J Med. doi:10.1056/NEJMoa2401424
3. Tsenov et al. Healthcare access, symptom burden, and psychological impact in hypertrophic cardiomyopathy: a multinational patient-driven survey. Int J Cardiol Cardiovasc Risk Prev2025 Aug 4;27:200485. doi: 10.1016/j.ijcrp.2025.200485
4. Butzner M, et al. Epidemiology of Hypertrophic Cardiomyopathy in the United States From 2016 to 2023. JACC Adv. 2026;5(2):102552. doi:10.1016/j.jacadv.2025.102552
5. Gersh, B.J., Maron, B.J., Bonow, R.O., Dearani, J.A., Fifer, M.A., Link, M.S., et al. 2011 ACCF/AHA guidelines for the diagnosis and treatment of hypertrophic cardiomyopathy. A report of the American College of Cardiology Foundation/American Heart Association Task Force on practice guidelines. Journal of the American College of Cardiology and Circulation, 58, e212-260.
6. Hong Y, Su WW, Li X. Risk factors of sudden cardiac death in hypertrophic
   
   

Contact:
Cytokinetics
Diane Weiser
Senior Vice President, Corporate Affairs
(415) 290-7757

FAQ

AI-generated questions and answers. How Rhea-AI works. Not financial advice.

What did Cytokinetics report about aficamten exercise performance in ACACIA-HCM?

Aficamten significantly improved the BEAP-RS composite exercise score versus placebo at 36 weeks (p<0.001). The score combines five domains covering submaximal exercise through recovery, with improvements reported across all five domains.

When does Cytokinetics plan to submit aficamten for non-obstructive HCM to the FDA?

Cytokinetics plans to submit a supplemental New Drug Application in Q4 2026 following the ACACIA-HCM results.

How was aficamten dosing adjusted in Cytokinetics’ ACACIA-HCM trial?

Aficamten was titrated to the maximum tolerated dose based on left ventricular ejection fraction alone. At the end of titration, 80.7% of patients were on 15 or 20 mg. Dose adjustments produced predictable, dose-proportional changes in aficamten plasma concentrations and reductions in ejection fraction.

Which patient characteristics were linked to reduced ejection fraction in Cytokinetics’ ACACIA-HCM trial?

Lower baseline left ventricular ejection fraction and permanent atrial fibrillation were the only patient characteristics associated with ejection fraction below 50%. Two aficamten participants experienced serious heart failure events associated with ejection fraction below 50%; ten additional patients had serious heart failure events without that association.