11 October 2023

Cytokinetics Presents Baseline Characteristics From SEQUOIA-HCM at the HCM Society Scientific Sessions

Topline Results from SEQUOIA-HCM Expected by End of Year

Cytokinetics, Incorporated (Nasdaq: CYTK) recently announced that the baseline characteristics of patients randomized in SEQUOIA-HCM (Safety, Efficacy, and Quantitative Understanding of Obstruction Impact of Aficamten in HCM), the pivotal Phase 3 clinical trial of aficamten in patients with symptomatic obstructive hypertrophic cardiomyopathy (HCM), were presented at the HCM Society Scientific Sessions in Cleveland, Ohio by Martin S. Maron, M.D., Director of the Hypertrophic Cardiomyopathy Center at Lahey Hospital and Medical Center.

“The baseline characteristics of SEQUOIA-HCM show that the patients enrolled into this pivotal trial align with our objectives for aficamten, which include assessing our next-in-class cardiac myosin inhibitor in a population with substantial deficit in exercise capacity and significant symptom burden despite background treatment with guideline directed medical therapies,” said Fady I. Malik, M.D., Ph.D., Cytokinetics’ Executive Vice President of Research & Development. “We look forward to announcing topline results from SEQUOIA-HCM by the end of the year and our hopefully elaborating on clinical effects to the benefit of patients.”

SEQUOIA-HCM: Baseline Characteristics

SEQUOIA-HCM was designed to evaluate aficamten in patients with symptomatic obstructive HCM on background medical therapy over a 24-week period. Patients enrolled in SEQUOIA-HCM were required to have severe left ventricular outflow tract (LVOT) obstruction as evidenced by a resting LVOT-G ≥30 mmHg, a post-Valsalva peak LVOT-G ≥50 mmHg, NYHA functional class II or III, and a peak VO2 ≤90% predicted.

SEQUOIA-HCM enrolled a total of 282 patients, with one third from the United States, one half from Europe and Israel, and the remainder from China. Patients were on average 59.1 years of age, 40.4% female, and 21% were non-white. Background medical therapy consisted of beta-blockers (61%), calcium channel blockers (26.6%), and disopyramide (12.8%); combination background therapy was permitted. At baseline, 75.9% of patients were NYHA functional class II, 23.8% were functional class III, and 0.4% were functional class IV. One quarter of patients were guideline-eligible for septal reduction therapy at the time of enrollment. The pooled mean (SD) for baseline peak VO2 was 18.5 (4.5) mL/kg/min or 56.9% (11.8) of age- and sex-predicted peak VO2, and for the Kansas City Cardiomyopathy Questionnaire Clinical Summary Score (KCCQ-CSS) was 74.7 (18.0). The geometric mean (Q1, Q3) high-sensitivity cardiac troponin I was 12.1 (7.7, 27.3) ng/L. (Table 1). Key baseline characteristics that remain blinded include left ventricular ejection fraction (LVEF), resting and Valsalva LVOT-G, and NT-proBNP.

Additional information

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 hypertrophic cardiomyopathy (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 and relieves symptoms in patients with HCM as well as its potential long-term effects on cardiac structure and function. Aficamten is currently the subject of SEQUOIA-HCM (Safety, Efficacy, and Quantitative Understanding of Obstruction Impact of Aficamten in HCM), a pivotal Phase 3 clinical trial in patients with symptomatic obstructive hypertrophic cardiomyopathy (HCM), MAPLE-HCM (Metoprolol vs Aficamten in Patients with LVOT Obstruction on Exercise Capacity in HCM), a Phase 3 clinical trial evaluating aficamten as monotherapy compared to metoprolol as monotherapy in patients with obstructive HCM, and ACACIA-HCM (Assessment Comparing Aficamten to Placebo on Cardiac Endpoints In Adults with Non-Obstructive HCM), a pivotal Phase 3 clinical trial in patients with symptomatic non-obstructive HCM. Results from SEQUOIA-HCM are expected by the end of 2023. Aficamten received Breakthrough Therapy Designation for the treatment of symptomatic obstructive HCM from the U.S. Food & Drug Administration (FDA) as well as the National Medical Products Administration (NMPA) in China.

Cytokinetics is a late-stage, specialty cardiovascular biopharmaceutical company focused on discovering, developing and commercializing first-in-class muscle activators and next-in-class muscle inhibitors as potential treatments for debilitating diseases in which cardiac muscle performance is compromised. As a leader in muscle biology and the mechanics of muscle performance, the company is developing small molecule drug candidates specifically engineered to impact myocardial muscle function and contractility. Aficamten is a next-in-class cardiac myosin inhibitor, currently the subject of three Phase 3 clinical trials: SEQUOIA-HCM, evaluating aficamten in patients with obstructive hypertrophic cardiomyopathy (HCM), MAPLE-HCM, evaluating aficamten as monotherapy compared to metoprolol as monotherapy in patients with obstructive HCM and ACACIA-HCM, evaluating aficamten in patients with non-obstructive HCM. Cytokinetics is also developing omecamtiv mecarbil, a cardiac muscle activator, in patients with heart failure. Additionally, Cytokinetics is developing CK-136, a cardiac troponin activator for the potential treatment HFrEF and other types of heart failure, such as right ventricular failure, resulting from impaired cardiac contractility, and CK-586, a cardiac myosin inhibitor with a mechanism of action distinct from aficamten for the potential treatment of HFpEF. In 2023, Cytokinetics is celebrating its 25-year history of pioneering innovation in muscle biology and related pharmacology focused to diseases of muscle dysfunction and conditions of muscle weakness. For additional information about Cytokinetics, visit www.cytokinetics.com


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