Adagio's vCLAS posts 59% VT-free rate at 6 months ahead of PMA decision
FULCRUM-VT's single-arm pivotal data show 84% freedom from ICD shock and a 2.4% adverse-event rate, setting the bar for the FDA's expected 2026 marketing decision.
Executive Summary
- Adagio's pivotal cryoablation trial for recurrent ventricular tachycardia has posted six-month results showing most patients free of VT recurrence, most free of defibrillator shocks, and a low rate of procedure-related adverse events.
- No other device has completed a VT-specific pivotal study in the United States, so a marketing decision would open a category that has run on catheters designed for atrial fibrillation.
- A Breakthrough Device Designation and a submitted marketing application put the decision squarely with the FDA, and the sponsor has held to a year-end 2026 timeline through two public guidance updates.
- The trial's own completion date has slipped by more than three years since first registered, a pattern the operational risk model flags as a high-delay signal even as enrollment and the six-month readout both landed on schedule for the pivotal cohort.
What the trial found
At the Heart Rhythm Society meeting on April 26, 2026, Adagio disclosed six-month pivotal results from FULCRUM-VT: 59% freedom from VT recurrence, 84% freedom from ICD shock, 98% non-inducibility of VT at the end of the ablation procedure, and a 2.4% rate of protocol-defined major adverse events within seven days of the procedure. The trial's primary efficacy endpoint is six-month freedom from recurrent monomorphic VT without a new or increased antiarrhythmic drug dose, and its primary safety endpoint is freedom from device- or procedure-related major adverse events within seven days. No p-values or comparator arm accompanied the disclosed results, consistent with the single-arm, open-label design. AdagioAdagio Medical, Inc. Announces Completion of Enrollment for FULCRUM-VT Pivotal Clinical Trial Evaluating Ultra-Low Temperature Cryoablation for Ventricular TachycardiaOct 1, 2025
Probability of SuccessBased on the AppliedXL Probability of Success model. For more information about the methodology, read the research here.
The design
FULCRUM-VT is a prospective, single-arm, multi-center, open-label IDE study run across 20 centers in the United States and Canada, enrolling patients with ischemic or non-ischemic structural heart disease and recurrent sustained monomorphic VT who had failed or could not tolerate at least one Class III antiarrhythmic drug. The trial completed enrollment of 208 patients in 11 months as of October 1, 2025, against a registered target of 206. Adagio filed the PMA application with the FULCRUM-VT data as its clinical support, and the FDA had already granted the device Breakthrough Device Designation in May 2025. Adagio+1Adagio Medical, Inc. Announces Completion of Enrollment for FULCRUM-VT Pivotal Clinical Trial Evaluating Ultra-Low Temperature Cryoablation for Ventricular TachycardiaOct 1, 2025Cryoablation for Monomorphic Ventricular TachycardiaNCT05675865
The regulatory stake
"Adagio's vCLAS System is the first VT-specific ablation technology to complete enrollment in a pivotal IDE study in the United States," said Dr. Atul Verma, FULCRUM-VT co-principal investigator, at the time enrollment closed. That statement frames the competitive setup: physicians treating monomorphic VT have relied on catheters and energy sources built for atrial fibrillation, according to co-principal investigator Dr. Rod Tung, who called VT ablation trials historically slow to enroll. No competing trial shares vCLAS's target or mechanism class in this indication, and the closest identified comparator, a needle-based radiofrequency ablation trial for refractory VT, uses a different energy modality and remains in earlier-stage testing. AdagioAdagio Medical, Inc. Announces Completion of Enrollment for FULCRUM-VT Pivotal Clinical Trial Evaluating Ultra-Low Temperature Cryoablation for Ventricular TachycardiaOct 1, 2025
Timing and the delay signal
The trial's primary completion date has moved twice since it was first registered: from November 30, 2023 to December 30, 2025 in January 2024, then to January 31, 2027 in April 2026. Enrollment count also grew from an initial 20 to the current 206, a registry update made in May 2024 that reflected the trial's full pivotal size rather than a late-stage change. Adagio has held to the same year-end 2026 PMA completion guidance across two public disclosures, in October 2025 and again in March 2026. The cumulative primary-completion slippage is flagged as a high-severity signal in the trial's own operational risk profile, a pattern to weigh against the sponsor's repeated year-end 2026 guidance for the marketing decision itself. NCT05675865+1Cryoablation for Monomorphic Ventricular TachycardiaNCT05675865Adagio Medical, Inc. Announces Completion of Enrollment for FULCRUM-VT Pivotal Clinical Trial Evaluating Ultra-Low Temperature Cryoablation for Ventricular TachycardiaOct 1, 2025
This analysis was produced using AI-assisted reporting systems, AppliedXL data, and official public records. These systems undergo editorial review, quality checks, and regular audits by human experts. Errors may still occur, as with any automated system. Always consult the linked primary sources. Read our AI Editorial Policy.