Terminated due to business decision

This was a randomized, placebo-controlled, investigator- and participant-blinded study to evaluate the efficacy, safety, tolerability, and pharmacokinetics (PK) of HSY244 in participants with atrial fibrillation (AF), with and without heart failure (HF).

A screening period of up to 3 days (72 hours) was used to assess eligibility. After eligibility was confirmed, patients were randomized to either HSY244 or placebo. Prior to study drug administration, pre-dose assessments were completed. After the start of study drug administration, the participant was monitored for cardioversion to sinus rhythm. If a participant was still in AF at 90 minutes after the start of study drug administration, direct current cardioversion was planned to be applied at a time deemed appropriate by the investigator.

Key Inclusion Criteria:

• At screening, written informed consent were required to be obtained before any assessment was performed and only participants able to provide written informed consent themselves were included in this study.

• Hemodynamically stable men and women (either of non-child-bearing potential or child bearing potential with highly effective contraception) between 18 and 80 years of age (inclusive) at screening with a clinical indication for direct current cardioversion of AF.

• At screening, current episode of AF had been ongoing for ≥6 hours and ≤60 days

• Successful initiation and achievement of therapeutic levels of national guideline and institution-specific anticoagulation therapy as appropriate for the duration of the AF episode and risk for the participant.

• Completion of national guideline and institution-specific imaging evaluation for left atrial thrombi as appropriate for the duration of AF episode and risk for the participant.

• At screening, participants were required to weigh at least 60 kg to participate in the study and were required to have a body mass index (BMI) within the range of 18 - 45 kg/m^2. BMI = Body weight (kg) / [Height (m)]^2

• At screening, vital signs (systolic blood pressure and pulse rate) were assessed in the sitting position. Sitting vital signs were required to be within the following ranges (exclusive):

  • systolic blood pressure between 100-160 mmHg and diastolic blood pressure 60-100 mmHg
  • pulse rate (ventricular rate) between 60-120 bpm.

Key Exclusion Criteria:

• Women of child-bearing potential, defined as all women physiologically capable of becoming pregnant, unless they were using highly effective methods of contraception during dosing and for 4 days after stopping of investigational drug.

• Sexually active males unwilling to use a condom during intercourse while taking investigational drug and for 96 hours after study drug administration. A condom was required for all sexually active male participants to prevent them from fathering a child AND to prevent delivery of the investigational drug via seminal fluid to their partner. In addition, male participants could not donate sperm for the time period specified above.

• Use of any anti-arrhythmic class I or III drug (including Ranolazine [Ranexa]) within 5 half lives before randomization; including use of amiodarone within 3 months before randomization.

• At screening, history of current diagnosis of ECG abnormalities or cardiac rhythm disorders as determined by the Investigator's interpretation of the ECG findings indicating a significant risk for participating in the study, such as:

  • History of Torsades de Pointes (TdP), any other polymorphic ventricular tachycardia, sustained monomorphic ventricular tachycardia, long QT syndrome, or Brugada syndrome.
  • Wolfe-Parkinson-White (WPW) syndrome
  • In the absence of a complete bundle branch block a resting QTcF >460 msec for men and >470 msec for women (mean of ≥ 5 consecutive QT intervals)
  • In the presence of a complete bundle branch block, a prolonged QTcF or JTc that, in the opinion of the investigator, may pose a risk to patient safety
  • Third-degree (complete) heart block, or second-degree Mobitz type II heart block

• Attempted or unsuccessful cardioversion within 2 weeks prior to randomization.

• Presence of known severe mitral regurgitation and/or known severely dilated left atrium.

• Pre-existing or tachycardia-induced moderate to severe cardiac dysfunction (New York Heart Association Class III and IV).

• History within the preceding 3 months prior to randomization of: myocardial infarction, unstable angina, cardiac surgery, or a percutaneous coronary intervention.

• History of a confirmed stroke or transient ischemic attack (TIA).

• History or current diagnosis of any seizure disorder, epilepsy, significant head trauma, or other disorders increasing the risk for seizures.

• History or current diagnosis of a major neurologic or psychiatric disorder that, in the opinion of the investigator, poses a risk to patient safety to participate.

Novartis is committed to sharing with qualified external researchers, access to patient-level data and supporting clinical documents from eligible studies. These requests are reviewed and approved by an independent review panel on the basis of scientific merit. All data provided is anonymized to respect the privacy of patients who have participated in the trial in line with applicable laws and regulations.

This trial data availability is according to the criteria and process described on www.clinicalstudydatarequest.com.

Adverse events were reported from first dose of study treatment until end of study treatment plus 30 days post treatment, up to a maximum duration of 31 days.

Any sign or symptom that occurs during the conduct of the trial and safety follow-up