Preclinical Safety Evaluation of Etripamil Nasal Spray in Cynomolgus Macaques (Macaca fascicularis) to Assess for Safety in Patients With Paroxysmal Supraventricular Tachycardia.

Etripamil is a calcium channel blocker currently in Phase 3 trials for the treatment of paroxysmal supraventricular tachycardia (PSVT). Systemic and local toxicity following once-weekly intranasal administration of etripamil was evaluated in cynomolgus macaques to support clinical development. Groups of animals (N = 8, 4 males and 4 females) were administered etripamil into the left nostril weekly at dose levels of 0 (vehicle), 1.9, 3.8, or 5.7 mg/kg/dose for 26 doses. Persistence, reversibility, and progression of findings were examined following a 28-day recovery period. Clinical signs were transient and were related to the intranasal administration (e.g., nasal discharge, sneezing, etc.) of etripamil. There were no macroscopic or systemic microscopic findings at any dose. Etripamil-related adaptive and reactive local changes affecting the nasal cavity, larynx, and nasopharynx were observed at ≥1.9 mg/kg/dose. Minimal to severe dose-dependent nasal epithelial damage was observed, mainly affecting respiratory and transitional epithelium. Following the 28-day recovery period, microscopic changes were confined to the left nasal cavity and nasopharynx. These changes were significantly lower in incidence and severity, with noticeable reversal of the adaptive and reactive changes, indicating partial to complete recovery of the epithelial lining. Based on the lack of systemic toxicity and the minimal and transient nasal changes, the systemic, no observable adverse effect level (NOAEL) of etripamil in monkeys was the high dose, 5.7 mg/kg/dose. The NOAEL for local toxicity was 1.9 mg/kg/dose. Collectively, these data support further study of etripamil in human trials as a potential treatment for PSVT.

Rationale for and design of a multicenter, placebo-controlled, phase 3 study to assess efficacy and safety of intranasal etripamil for the conversion of paroxysmal supraventricular tachycardia.

Presently, acute pharmacological termination of paroxysmal supraventricular tachycardia (PSVT) unresponsive to patient-initiated vagal maneuvers requires in-hospital intervention. Etripamil, a fast-acting, nondihydropyridine, L-type calcium channel blocker, is formulated as an intranasal spray to rapidly terminate atrioventricular (AV) nodal-dependent PSVT in a medically unsupervised setting. The NODE-301 study did not meet its prespecified primary end point of PSVT conversion over 5 hours following a single dose of etripamil 70 mg. However, analysis at earlier time points demonstrated etripamil treatment effect during the first 30 minutes, consistent with its expected rapid onset and short duration of action. This led to the design of the RAPID study, which includes a new dosing regimen (up to 2 etripamil 70 mg doses separated by 10 minutes) to increase the exposure and pharmacodynamic effect of etripamil. The primary objective of RAPID (NCT03464019) is to determine if etripamil self-administered by patients is superior to placebo in terminating PSVT in an at-home setting. The secondary objective is to evaluate the safety of etripamil when self-administered by patients without medical supervision. Additional efficacy end points include the proportion of patients requiring additional medical intervention in an emergency department to terminate PSVT and patient-reported outcomes. After successfully completing a test dose to assess the safety of 2 70 mg doses of etripamil during sinus rhythm, approximately 500 patients will be randomized 1:1 to etripamil or placebo to accrue 180 positively adjudicated AV nodal-dependent PSVT events for treatment with the study drug. Etripamil may offer a new alternative to the current in-hospital treatment modality, providing for safe and effective at-home termination of PSVT.

Plain language summary of the safety and effectiveness of etripamil for atrioventricular-nodal-dependent supraventricular tachycardia: the RAPID study.

WHAT IS THIS SUMMARY ABOUT?: This is a plain language summary of a clinical research study called RAPID. The study looked at the potential for how safe and effective etripamil was at stopping an episode of rapid heartbeats in people with atrioventricularnodal-dependent supraventricular tachycardia (AV-node-dependent SVT). An episode is used to describe the period of time when a person experiences an abnormally very fast heartbeat. This was done by comparing an investigational drug called etripamil with a placebo, each administered via a rapidly acting nasal spray. AV-node-dependent SVT affects the rhythm of the heart, causing it to suddenly beat rapidly. The condition often requires medical treatment to help return the heart to its normal, healthy heartbeat pattern and speed, called 'sinus rhythm'. Researchers are looking at ways of improving the management of supraventricular tachycardias (SVT) by reducing the need for patients to attend an urgent care clinic, emergency ward or hospital for treatment. In the RAPID study, participants used a nasal spray containing either 70 mg etripamil or a placebo solution when they experienced an episode of SVT. The researchers wanted to know how long it took for each participant's rapid heartbeat to return to sinus rhythm after administering the etripamil or placebo nasal spray. Participants in the study were considered successfully treated if their heartbeats returned to sinus rhythm for at least 30 seconds within 30 minutes of using the nasal spray. Although 30 seconds may seem brief, it's medically important because it shows that a person's heartbeat has been temporarily stabilized and returned to normal functioning. WHAT WERE THE RESULTS?: Out of 99 people who used etripamil during an SVT episode, 63 participants (64%) experienced a return to sinus rhythm for at least 30 seconds within 30 minutes after using the nasal spray. In contrast, 26 out of 85 participants (31%) who used the placebo nasal spray experienced a return to sinus rhythm for at least 30 seconds within 30 minutes after use. Furthermore, the average time taken for the return to sinus rhythm was 17 minutes for the etripamil group which was 3-times faster than the placebo group at 53 minutes. Also, in the study no serious side effects occurred that were related to etripamil. WHAT DO THE RESULTS OF THE STUDY MEAN?: The RAPID study supports the potential that etripamil may be safe and well tolerated by participants as a treatment for episodes of rapid heartbeat in people with AV-node-dependent SVT. The results also showed a significant improvement in symptoms following treatment with etripamil.

Intranasal etripamil for rapid treatment of paroxysmal supraventricular tachycardia.

Paroxysmal supraventricular tachycardia (PSVT) is a common arrhythmia that, although usually benign, can occur unpredictably, cause disabling symptoms and significantly impair quality of life. If spontaneous resolution does not occur, the only current self-treatment is for the patient to attempt vagal maneuvers, however, these are frequently unsuccessful. Hospital attendance is then required for intravenous therapy. Etripamil, an intranasal calcium channel blocker similar to verapamil, may be able to fill this therapeutic gap, allowing rapid self-treatment of PSVT at home. This narrative review discusses the latest evidence for etripamil and its potential role in future clinical practice.

Paroxysmal supraventricular tachycardia (PSVT) is an abnormal heart rhythm, causing the heart to beat rapidly. There are several ways to treat PSVT. This article discusses a new therapy, etripamil. One treatment involves breathing techniques called 'vagal maneuvers'. These avoid medication and sometimes stop the abnormal rhythm, however, in many cases, this does not work. An alternative is a tablet taken when symptoms occur. Unfortunately, tablets take time to absorb, meaning symptoms may continue until the medication takes effect, and this approach does not work for everyone. If these approaches fail, patients suffering from PSVT may need to seek treatment at a hospital. This may involve intravenous therapy, with certain drugs causing unpleasant sensations of chest discomfort. Some patients may also be kept in the hospital for monitoring. Although PSVT can often be cured via a catheter ablation procedure, this is invasive (involving wires inserted via veins in the groin), so not everyone wishes to pursue this, and in some cases, it cannot be performed safely. There is a need for a rapid, safe, and effective treatment that patients can administer at home when PSVT occurs. Etripamil shows promise. Because it is a nasal spray, etripamil allows rapid absorption into the body ­ much faster than a tablet. Etripamil is not yet available on the market; however, several studies have demonstrated its effectiveness and safety, so it may be available in the near future. Promising evidence for etripamil in certain groups, such as elderly patients, is still lacking.

Pharmacokinetics and Pharmacodynamics of Etripamil, an Intranasally Administered, Fast-Acting, Nondihydropyridine Calcium Channel Blocker.

Etripamil, a fast-acting nondihydropyridine L-type calcium channel blocker, is under investigation for potential self-administration for the acute treatment of supraventricular tachyarrhythmias in a medically unsupervised setting. We report detailed pharmacokinetics and pharmacodynamics of intranasally administered etripamil in healthy adults from 2 Phase 1, randomized, double-blind studies: Study MSP-2017-1096 (sequential dose-escalation, crossover study design, n = 64) and NODE-102 (single dose, 4-way crossover study, n = 24). Validated bioanalytical assays determined plasma concentrations of etripamil and its inactive metabolite. Noncompartmental pharmacokinetic parameters were calculated. Pharmacodynamic parameters were determined for PR interval, blood pressure, and heart rate. Etripamil was rapidly absorbed intranasally, with time to maximal plasma concentration of 5-8.5 minutes, corresponding to a rapid greater than 10% increase in mean maximum PR interval from baseline within 4-7 minutes of doses of 60 mg or greater. Following peak plasma concentrations, systemic etripamil levels declined rapidly within the first 15 minutes following dosing and decreased more gradually thereafter. PR interval prolongation greater than 10% from baseline was generally sustained for about 45 minutes at doses of 60 mg or greater. The mean terminal half-life ranged from about 1.5 hours with 60 mg to about 2.5-3 hours for the 70- and 105-mg doses. Etripamil was generally well tolerated without symptomatic hypotension. Adverse events were primarily mild to moderate and related to the administration site; no serious adverse events or episodes of atrioventricular block occurred. Intranasal etripamil administration, at doses of 60 mg or greater, produced rapidly occurring slowing of atrioventricular nodal conduction with a limited duration of effect without hemodynamic or electrocardiographic safety signals in healthy volunteers.

Etripamil Nasal Spray for Conversion of Repeated Spontaneous Episodes of Paroxysmal Supraventricular Tachycardia During Long-Term Follow-Up: Results From the NODE-302 Study.

Background Self-administration of investigational intranasal L-type calcium channel blocker etripamil during paroxysmal supraventricular tachycardia (PSVT) appeared safe and well-tolerated in the phase 3 NODE-301 (Multi-Centre, Randomized, Double-Blind, Placebo-Controlled, Efficacy, and Safety Study of Etripamil Nasal Spray for the Termination of Spontaneous Episodes of Paroxysmal Supraventricular Tachycardia) trial of adults with sustained atrioventricular nodal-dependent PSVT. The NODE-302 open-label extension further characterized etripamil safety and efficacy. Methods and Results Eligible patients were monitored via self-applied cardiac monitoring system for 5 hours after etripamil self-administration. The primary end point was time-to-conversion of positively adjudicated PSVT to sinus rhythm after etripamil treatment. Probability of conversion to sinus rhythm was reported via Kaplan-Meier plot. Adverse events were based on self-reported symptoms and clinical evaluations. Among 169 patients enrolled, 105 self-administered etripamil ≥1 time for perceived PSVT (median [range], 232 [8-584] days' follow-up). Probability of conversion within 30 minutes of etripamil was 60.2% (median time to conversion, 15.5 minutes) among 188 PSVT episodes (92 patients) positively adjudicated as atrioventricular nodal dependent by independent ECG analysis. Among 40 patients who self-treated 2 episodes, 75% had a significantly consistent response by 30 minutes; 9 did not convert on either episode, and 21 converted on both episodes (χ2=8.09; P=0.0045). Forty-five of 105 patients (42.9%) had ≥1 treatment-emergent adverse event, generally transient and mild-to-moderate, including nasal congestion (14.3%), nasal discomfort (14.3%), or rhinorrhea (12.4%). No serious cardiac safety events were observed within 24 hours of etripamil. Conclusions In this extension study, investigational etripamil nasal spray was well tolerated for self-treating recurrent episodes of PSVT without medical supervision. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT03635996.

Multicenter, Phase 2, Randomized Controlled Study of the Efficacy and Safety of Etripamil Nasal Spray for the Acute Reduction of Rapid Ventricular Rate in Patients With Symptomatic Atrial Fibrillation (ReVeRA-201).

BACKGROUND: Despite chronic therapies, atrial fibrillation (AF) leads to rapid ventricular rates (RVR) often requiring intravenous treatments. Etripamil is a fast-acting, calcium-channel blocker administered intranasally affecting the atrioventricular node within minutes. METHODS: Reduction of Ventricular Rate in Patients with Atrial Fibrillation evaluated the efficacy and safety of etripamil for the reduction of ventricular rate (VR) in patients presenting urgently with AF-RVR (VR ≥110 beats per minute [bpm]), was randomized, double-blind, placebo-controlled, and conducted in Canada and the Netherlands. Patients presenting urgently with AF-RVR were randomized (1:1, etripamil nasal spray 70 mg: placebo nasal spray). The primary objective was to demonstrate the effectiveness of etripamil in reducing VR in AF-RVR within 60 minutes of treatment. Secondary objectives assessed achievement of VR <100 bpm, reduction by ≥10% and ≥20%, relief of symptoms and treatment effectiveness; adverse events; and additional measures to 360 minutes. RESULTS: Sixty-nine patients were randomized, 56 dosed with etripamil (n=27) or placebo (n=29). The median age was 65 years; 39% were female patients; proportions of AF types were similar between groups. The difference of mean maximum reductions in VR over 60 minutes, etripamil versus placebo, adjusting for baseline VR, was -29.91 bpm (95% CI, -40.31 to -19.52; P<0.0001). VR reductions persisted up to 150 minutes. Significantly greater proportions of patients receiving etripamil achieved VR reductions <100 bpm (with longer median duration <100 bpm), or VR reduction by ≥10% or ≥20%, versus placebo. VR reduction ≥20% occurred in 66.7% of patients in the etripamil arm and no patients in placebo. Using the Treatment Satisfaction Questionnaire for Medication-9, there was significant improvement in satisfaction on symptom relief and treatment effectiveness with etripamil versus placebo. Serious adverse events were rare; 1 patient in the etripamil arm experienced transient severe bradycardia and syncope, assessed as due to hypervagotonia. CONCLUSIONS: Intranasal etripamil 70 mg reduced VR and improved symptom relief and treatment satisfaction. These data support further development of self-administered etripamil for the treatment of AF-RVR. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique Identifier: NCT04467905.

Podcast on Self-administered Intranasal Etripamil for Symptomatic Paroxysmal Supraventricular Tachycardia: The RAPID Trial.

Paroxysmal supraventricular tachycardia (PSVT) is commonly seen in clinical practice and represents a significant burden to the healthcare system and to patients. First-line treatments include calcium channel blockers (CCB), although they are intravenous and require medical supervision. Etripamil is an investigational self-administered intranasal L-type CCB for unsupervised treatment of PSVT. In this podcast, we discuss the RAPID trial (NCT03464019), which was a phase 3 study that evaluated the safety and efficacy of etripamil in terminating PSVT episodes using a repeat-dosing regimen. RAPID was a multicenter, randomized trial that enrolled adults with electrocardiograph (ECG)-documented PSVT episodes lasting ≥ 20 min. Patients who tolerated test doses of etripamil were randomized 1:1 to receive either etripamil or placebo. Upon perceiving PSVT symptoms, patients began ECG monitoring and performed a vagal maneuver. If arrhythmia termination was unsuccessful, they self-administered 70 mg of etripamil or placebo, followed by an optional second dose after 10 min. The primary endpoint was time to conversion of PSVT to sinus rhythm within 30 min of the initial dose and sustained for ≥ 30 s. The safety group included all patients who self-administered the study treatment. Of 692 enrollees, 184 self-administered the study drug (99 etripamil, 85 placebo) for ECG-confirmed PSVT. Conversion of PSVT to sinus rhythm within 30 min was achieved in 64.3% of etripamil-treated subjects versus 31.2% of placebo-treated subjects. A significant threefold reduction in the median time to conversion of 17.2 min was observed in the etripamil group versus 53.5 min in the placebo group. Treatment-emergent adverse events were mild or moderate and primarily included transient nasal discomfort, nasal congestion, and rhinorrhea. If etripamil is approved by the US FDA, it can potentially address a significant unmet need for PSVT treatment outside a clinical setting, reducing the need for intravenous treatments that require medical supervision.Podcast available for this article.

First Randomized, Multicenter, Placebo-Controlled Study of Self-Administered Intranasal Etripamil for Acute Conversion of Spontaneous Paroxysmal Supraventricular Tachycardia (NODE-301).

BACKGROUND: Pharmacologic termination of paroxysmal supraventricular tachycardia (PSVT) often requires medically supervised intervention. Intranasal etripamil, is an investigational fast-acting, nondihydropyridine, L-type calcium channel blocker, designed for unsupervised self-administration to terminate atrioventricular nodal-dependent PSVT. Phase 2 results showed potential safety and efficacy of etripamil in 104 patients with PSVT. METHODS: NODE-301, a phase 3, multicenter, double-blind, placebo-controlled study evaluated the efficacy and safety of etripamil nasal spray administered, unsupervised in patients with symptomatic sustained PSVT. After a medically supervised etripamil test dose while in sinus rhythm, patients were randomized 2:1 to receive etripamil 70 mg or placebo. When PSVT symptoms developed, patients applied a cardiac monitor and attempted a vagal maneuver; if symptoms persisted, they self-administered blinded treatment. An independent Adjudication Committee reviewed continuous electrocardiogram recordings. The primary efficacy endpoint was termination of adjudicated PSVT within 5 hours after study drug administration. RESULTS: NODE-301 accrued 156 positively adjudicated PSVT events treated with etripamil (n=107) or placebo (n=49). The hazard ratio for the primary endpoint, time-to-conversion to sinus rhythm during the 5-hour observation period, was 1.086 (95% CI, 0.726-1.623; P=0.12). In predefined sensitivity analyses, etripamil effects (compared with placebo) occurred at 3, 5, 10, 20, and 30 minutes (P<0.05). For example, at 30 minutes, there was a 53.7% of SVT conversion in the treatment arm compared to 34.7% in the placebo arm (hazard ratio, 1.87 [95% CI, 1.09-3.22]; P=0.02). Etripamil was well tolerated; adverse events were mainly related to transient nasal discomfort and congestion (19.6% and 8.0%, respectively, of randomized treatment-emergent adverse events. CONCLUSIONS: Although the primary 5-hour efficacy endpoint was not met, analyses at earlier time points indicated an etripamil treatment effect in terminating PSVT. Etripamil self-administration during PSVT was safe and well tolerated. These results support continued clinical development of etripamil nasal spray for self-administration during PSVT in a medically unsupervised setting. REGISTRATION: URL: https://www. CLINICALTRIALS: gov; Unique identifier: NCT03464019.

Update on Etripamil Nasal Spray for the At-home Treatment of Acute Paroxysmal Supraventricular Tachycardia.

The current treatment of sustained paroxysmal supraventricular tachycardia (PSVT) often requires attendance at a medical facility. This burden is driven by the lack of an effective self-administered treatment for PSVT. Etripamil (Milestone Pharmaceuticals, Saint-Laurent, QC, Canada) is a novel intra-nasal preparation of a rapidly effective but short-acting calcium-channel blocker, which shows promise in offering out-of-hospital treatment for patients with PSVT. Studies, to date, have demonstrated good tolerability and potential efficacy, with a safety profile that is acceptable for unsupervised self-administration. This article reviews the current epidemiology and international guidelines for the treatment of acute PSVT, the pharmacology and clinical trial evidence behind the novel agent etripamil, and considers its potential role in the management of patients with PSVT.

Etripamil nasal spray: an investigational agent for the rapid termination of paroxysmal supraventricular tachycardia (SVT).

Introduction: Paroxysmal supraventricular tachycardia (SVT) can be very bothersome and may potentially lead to considerable health-care utilization. Non-parenteral medication is currently unavailable for the rapid termination of paroxysmal SVT. However, an intranasal spray formulation of etripamil, a short-acting calcium-channel blocker, is under investigation as a convenient, safe, and rapidly efficacious means to terminate paroxysmal SVT.Areas covered: This review summarizes the clinical rationale, potential benefit, and clinical trials safety and efficacy data for the use of etripamil nasal spray to terminate paroxysmal SVT.Expert opinion: Based on the efficacy and tolerability demonstrated in phase 1 and 2 clinical trials, etripamil nasal spray is a potential convenient, safe, and effective means for patients to terminate paroxysmal SVT. It has the potential to improve quality of life, reduce health-care burden, and alter the current management paradigm for many patients with SVT. Further ongoing evaluation in ambulatory patients will help to determine its real-life practicality, safety, and effectiveness.