Cytokinetics Announces Positive Topline Results From MAPLE-HCM

Trial Demonstrates Superiority of Aficamten to Standard of Care Beta Blocker in Improving Peak Exercise Capacity in Patients with Obstructive Hypertrophic Cardiomyopathy

SOUTH SAN FRANCISCO, Calif., May 13, 2025 (GLOBE NEWSWIRE) -- Cytokinetics, Incorporated (NASDAQ:CYTK) today announced positive topline results from MAPLE-HCM (Metoprolol vs Aficamten in Patients with LVOT Obstruction on Exercise Capacity in HCM), a Phase 3 clinical trial comparing aficamten as monotherapy to the standard of care beta blocker metoprolol as monotherapy in patients with symptomatic obstructive hypertrophic cardiomyopathy (HCM).

MAPLE-HCM met its primary endpoint, demonstrating a statistically significant improvement in peak oxygen uptake (pVO₂) from baseline to Week 24 for aficamten compared to metoprolol. The safety and tolerability profile of aficamten was favorable in comparison to metoprolol in MAPLE-HCM.

The full results from MAPLE-HCM will be presented at an upcoming medical conference.

"These results represent the first evidence that aficamten may be used as monotherapy to deliver clinically meaningful improvements in people living with obstructive hypertrophic cardiomyopathy," said Fady I. Malik, M.D., Ph.D., Cytokinetics' Executive Vice President of Research & Development. "Importantly, the results from MAPLE-HCM provide important context to the benefit of this potential new medicine compared to the current standard of care. We are grateful to the investigators, site personnel and patients who participated in MAPLE-HCM, and look forward to presenting the full results at an upcoming medical meeting."

MAPLE-HCM: Clinical Trial Design

MAPLE-HCM was a Phase 3, multi-center, randomized, double-blind active-comparator clinical trial of aficamten compared to metoprolol in patients with symptomatic obstructive HCM. The primary endpoint was the change in peak oxygen uptake (pVO₂) from baseline to Week 24 measured by cardiopulmonary exercise testing (CPET). Secondary endpoints include the change from baseline to Week 24 in Kansas City Cardiomyopathy Questionnaire (KCCQ) score, the proportion of patients with ≥1 class improvement in New York Heart Association (NYHA) functional class, and changes in left ventricular mass index (LVMI), left atrial volume index (LAVI), post-Valsalva left ventricular outflow tract gradient (LVOT-G) and NT-proBNP.

MAPLE-HCM enrolled 175 patients, randomized on a 1:1 basis to receive aficamten or metoprolol as monotherapy in a double-blind, double dummy fashion. Randomization was stratified by CPET exercise modality (treadmill or bicycle) and recently diagnosed versus chronic obstructive HCM. At screening, patients enrolled in MAPLE-HCM had a resting LVOT-G ≥30 mmHg and/or post-Valsalva LVOT-G ≥50 mmHg in addition to left ventricular ejection fraction (LVEF) ≥ 60%, respiratory exchange ratio (RER) ≥ 1.05 and pVO2 <100% predicted, NYHA functional class II or III and a KCCQ Clinical Summary Score (KCCQ-CSS) score ≥ 35 and ≤ 90. Following the initial screening visit, all participants on standard of care (SOC) therapy underwent a washout period of up to 14 days to wean from SOC therapy, followed by an additional 7 days with no SOC therapy prior to the second screening visit. Each patient received up to four escalating doses of aficamten or metoprolol based on echocardiographic guidance as well as a matching placebo for the alternate therapy.

About Aficamten

Aficamten is an investigational selective, small molecule cardiac myosin inhibitor discovered following an extensive chemical optimization program that was conducted with careful attention to therapeutic index and pharmacokinetic properties and as may translate into next-in-class potential in clinical development. Aficamten was designed to reduce the number of active actin-myosin cross bridges during each cardiac cycle and consequently suppress the myocardial hypercontractility that is associated with HCM. In preclinical models, aficamten reduced myocardial contractility by binding directly to cardiac myosin at a distinct and selective allosteric binding site, thereby preventing myosin from entering a force producing state.

The development program for aficamten is assessing its potential as a treatment that improves exercise capacity as measured by peak oxygen uptake (pVO₂) and relieves symptoms in patients with HCM. Aficamten was compared to placebo in SEQUOIA-HCM, a positive pivotal Phase 3 clinical trial demonstrating improvements in functional capacity, LVOT gradients, and heart failure symptoms in patients with symptomatic obstructive hypertrophic cardiomyopathy (HCM). Aficamten received Breakthrough Therapy Designation for the treatment of symptomatic obstructive HCM from the U.S. Food & Drug Administration (FDA) and from the National Medical Products Administration (NMPA) in China.

Aficamten is currently under regulatory review in the U.S by the FDA with a Prescription Drug User Fee Act (PDUFA) target action date of December 26, 2025. Additionally, the European Medicines Agency (EMA) is reviewing a Marketing Authorization Application (MAA) for aficamten, and The Center for Drug Evaluation (CDE) of the China National Medical Products Administration (NMPA) is reviewing an NDA for aficamten with Priority Review.

Aficamten is also currently being evaluated in ACACIA-HCM, a Phase 3 clinical trial of aficamten in patients with non-obstructive HCM; CEDAR-HCM, a clinical trial of aficamten in a pediatric population with obstructive HCM; and FOREST-HCM, an open-label extension clinical study of aficamten in patients with HCM.

About Cytokinetics

Cytokinetics is a specialty cardiovascular biopharmaceutical company, building on its over 25 years of pioneering scientific innovations in muscle biology to advance a pipeline of potential new medicines for patients suffering from diseases of cardiac muscle dysfunction. Cytokinetics is readying for potential regulatory approvals and commercialization of aficamten, a cardiac myosin inhibitor following positive results from SEQUOIA-HCM, the pivotal Phase 3 clinical trial in patients with obstructive hypertrophic cardiomyopathy (HCM). Aficamten is also being evaluated in additional clinical trials enrolling patients with obstructive and non-obstructive HCM. Cytokinetics is also developing omecamtiv mecarbil, a cardiac myosin activator, in patients with heart failure with severely reduced ejection fraction (HFrEF), CK-586, a cardiac myosin inhibitor with a mechanism of action distinct from aficamten, for the potential treatment of heart failure with preserved ejection fraction (HFpEF) and CK-089, a fast skeletal muscle troponin activator with potential therapeutic application to a specific type of muscular dystrophy and other conditions of impaired skeletal muscle function.

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 express or implied relating to the properties, treatment effect or potential benefits of aficamten or any of our other drug candidates or our ability to obtain regulatory approval for aficamten for the treatment of obstructive hypertrophic cardiomyopathy or any other indication from FDA or any other regulatory body in the United States or abroad. 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 the risks related to Cytokinetics' business outlines in Cytokinetics' filings with the Securities and Exchange Commission. Forward-looking statements are not guarantees of future performance, and Cytokinetics' actual results of operations, financial condition and liquidity, and the development of the industry in which it operates, may differ materially from the forward-looking statements contained in this press release. Any forward-looking statements that Cytokinetics makes in this press release speak only as of the date of this press release. Cytokinetics assumes no obligation to update its forward-looking statements whether as a result of new information, future events or otherwise, after the date of this press release.

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Contact:

Cytokinetics

Diane Weiser

Senior Vice President, Corporate Affairs

(415) 290-7757

References:

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