Cytokinetics Announces Four Presentations at the American College of Cardiology Annual Scientific Session & Expo

New Analyses from Three Trials in Obstructive HCM Support Findings from Previously Published Data on MYQORZO™ (aficamten)

SOUTH SAN FRANCISCO, Calif., March 16, 2026 (GLOBE NEWSWIRE) -- Cytokinetics, Incorporated (Nasdaq: CYTK) today announced four presentations related to MYQORZO™ (aficamten) at the American College of Cardiology (ACC) Annual Scientific Session & Expo taking place March 28–30, 2026 in New Orleans, LA. Recently approved for the treatment of adults with symptomatic obstructive hypertrophic cardiomyopathy (oHCM) by the U.S. Food and Drug Administration, European Commission, and the China National Medical Products Administration, MYQORZO is an allosteric and reversible inhibitor of cardiac myosin motor activity. In patients with oHCM, myosin inhibition with MYQORZO reduces cardiac contractility and consequently, left ventricular outflow tract (LVOT) obstruction.

“We are pleased to contribute further evidence that we believe will help physicians and patients with clinical decision making,” said Stephen Heitner, M.D., Senior Vice President, Clinical Research and Development. “The new data can help empower evidence-based choices of therapy for patients living with symptomatic oHCM, showing that aficamten improves exercise capacity, when compared to placebo or the beta blocker, metoprolol, while maintaining its safety profile.”

Scientific Presentations Include:

Evaluation of Aficamten or Beta-Blocker Monotherapy Versus Placebo in Patients with Obstructive Hypertrophic Cardiomyopathy: A Pooled Analysis of SEQUOIA-HCM and MAPLE-HCM (1186-09)Moderated Poster Presentation, March 30,2026, 11:00 AM-12:00 PM CT, E Hall P. Christian Schulze, M.D., Ph.D., Chair of the Department of Medicine and Division of Cardiology, Angiology and Intensive Medical Care at the University Hospital Jena

A new analysis based on combined data from SEQUOIA-HCM (Safety, Efficacy, and Quantitative Understanding of Obstruction Impact of Aficamten in HCM) and MAPLE-HCM (Metoprolol vs Aficamten in Patients with LVOT Obstruction on Exercise Capacity in HCM) evaluated aficamten or metoprolol monotherapy versus placebo. Patients (n=371) were pooled into three groups: aficamten as monotherapy, metoprolol as monotherapy, and placebo without background beta-blockers. For patients with symptomatic oHCM, treatment with beta-blocker monotherapy was no different compared to placebo across many clinically relevant outcomes (exercise capacity, symptoms, cardiac biomarkers and Valsalva gradient). Conversely, aficamten as monotherapy was superior to both metoprolol and placebo, consistent with previously published1 findings and supporting the emerging role of aficamten in the treatment of symptomatic oHCM.

Clinical Implications Associated with Temporary Treatment Interruption and Reinitiation of Aficamten Therapy in Obstructive Hypertrophic Cardiomyopathy (906-11)Oral Presentation, March 29, 2026, 9:30 AM-10:30 AM CT, Hall EMartin Maron, M.D., Director, Hypertrophic Cardiomyopathy Center, Lahey Hospital & Medical Center; and National Principal Investigator of SEQUOIA-HCM

This new analysis evaluated data from SEQUOIA-HCM and FOREST-HCM (Follow-up, Open-Label, Research Evaluation of Sustained Treatment with Aficamten in HCM) related to the safety of interrupting treatment with aficamten. The analysis, which included 182 participants, evaluated the impact of discontinuing treatment with aficamten for a four-week washout period after assessment of the primary endpoint at 24-weeks as occurred per protocol in SEQUOIA-HCM. Most of these patients subsequently reinitiated treatment in the open-label extension, FOREST-HCM. The analyses showed that washout of aficamten was not associated with increased risk of cardiac adverse events or rebound compared to placebo. One (0.7%) patient in the aficamten arm experienced an adverse event of mild worsening heart failure due to an acute drop in hemoglobin. Three patients experienced recurrence of HCM symptoms of moderate severity after discontinuing aficamten consistent with the loss of therapeutic drug effect during washout​. Importantly, reinitiation of aficamten yielded a favorable therapeutic response, suggesting aficamten can be safely discontinued if treatment interruptions are required for non-cardiac medical reasons, such as surgery or cancer treatment.

Aficamten Versus Metoprolol in Patients with Hypertension and Obstructive Hypertrophic Cardiomyopathy (1395-221)Poster Presentation, March 28, 2026, 2PM-3PM CT, Hall E Ahmad Masri, M.D., MS, Director of the Hypertrophic Cardiomyopathy Center at Oregon Health & Science University

A new analysis of MAPLE-HCM evaluated the efficacy and safety of treatment with aficamten vs. metoprolol in patients with hypertension at baseline, which is common in patients with oHCM. In this analysis of 175 patients, 50% had a history of hypertension, and 81% were treated with a beta-blocker and/or calcium channel blocker before randomization in MAPLE-HCM. While blood pressure increased slightly with aficamten (+3.6±14.0 mmHg) compared to a decrease with metoprolol, (−8.3±18.2 mmHg), the analysis showed there was no statistically significant difference in the rates of uncontrolled hypertension, defined as systolic blood pressure (SBP) > 140 mmHg or diastolic blood pressure (DBP) > 90 mmHg emergent during treatment (34% vs. 25% in the aficamten and metoprolol arms respectively; p=0.38). Aficamten was equally effective and displayed a similar safety profile irrespective of hypertension history. These findings suggest aficamten is suitable as therapy independent of hypertension history and given the decrease in LVOT gradient during treatment with aficamten, may allow for greater optionality in the choice of antihypertensive agents.

Electrocardiographic Changes and Associations with Echocardiographic Changes in Patients with Symptomatic Obstructive Hypertrophic Cardiomyopathy: Insights from the SEQUOIA-HCM Trial (1514-243)Poster Presentation, March 29, 2026, 2PM-3PM CT, Hall E Alberto Foà, M.D., Ph.D., Cardiologist, Brigham and Women's Hospital, Harvard Medical School; Heart Failure and Transplant Unit - IRCCS Azienda Ospedaliero-Universitaria di Bologna

A new analysis of SEQUOIA-HCM examined electrocardiographic (ECG) changes in patients with symptomatic oHCM following 24 weeks of treatment with aficamten or placebo. The results showed that, compared to placebo, aficamten decreased the presence of ST segment changes (adjusted odds ratio 0.23; 95% CI 0.11, 0.46; p