Phase I/II Study of EP-guided Noninvasive Cardiac Radioablation (ENCORE) for Treatment of Ventricular Tachycardia
Patients with Ventricular Tachycardia (VT) who have failed standard therapy (medicines, invasive catheter ablation) have limited options, with one-year survival below 20%. Preclinical data demonstrate that single fraction stereotactic body radiotherapy (SBRT) to discrete portions of the heart is feasible and may result in a reduction or elimination of VT. The efficacy may be further improved when guided by cardiac electrophysiologic (EP) testing. In total, the mapping and ablation proposed for this EP-guided Noninvasive Cardiac Radioablation (ENCORE) is a rapid and totally non-invasive method. Overall safety and early efficacy of ENCORE have not been rigorously studied in a prospective trial to-date. The purpose of this phase I/II study is to demonstrate the short-term safety and preliminary efficacy of ENCORE for patients with life-threatening, treatment-refractory VT.
Study Type
INTERVENTIONAL
Allocation
NA
Purpose
TREATMENT
Masking
NONE
Enrollment
19
(Cardiac ablative radiotherapy)
Washington University School of Medicine
St Louis, Missouri, United States
Number of Serious Adverse Events
Demonstrate acute (≤ 90 days) safety of noninvasive stereotactic cardiac ablation radiotherapy (ENCORE). The primary safety endpoint is defined by a ≤ 20% rate of serious adverse events (SAEs) using CTCAE v4.0 criteria that are possibly/probably/definitely related to study treatment, based on previously published data for expected invasive catheter-based VT-ablation procedures.
Time frame: < or = 90 days
Number of Participants With Reduction in Ventricular Tachycardia (VT) Burden
Primary efficacy endpoint is defined by the number of subjects with a reduction in VT burden comparing the period six months before ENCORE treatment to the six months after ENCORE treatment as adjudicated by continuous ICD monitoring (number of ATP and ICD shocks and sustained (\>30 second) nontreated slow VT). There will be a six-week "blanking period" after therapy to allow for ablation effect. For patients with PVC-induced cardiomyopathy, the primary efficacy will be any reduction in PVC burden based on ambulatory heart monitors.
Time frame: 12 months (6mo prior to and 6mo post SBRT)
Overall Survival
Determine six-month and twelve-month survival (overall mortality endpoint) after treatment with ENCORE.
Time frame: 12 months
Number of Adverse Events That Are Possibly/Probably/Definitely Related to Study Treatment
Toxicities that occur after treatment, but are not acutely ascribed to treatment that are possibly/probably/definitely related to study treatment, based on previously published data for expected invasive catheter-based VT-ablation procedures, using the CTCAE v4.0 criteria.
Time frame: 90 days to 12 months
Health Related Quality of Life (HRQOL)
The 36-Item Short Form Survey (SF-36) is a set of generic, coherent, and easily administered quality of life measures that rely on patient self-reporting. The SF-36 evaluates 8 domains: physical functioning, bodily pain, role limitations due to physical health problems, role limitations due to personal or emotional problems, emotional well-being, social functioning, energy/fatigue, and general health perceptions. Scale values for each domain range from 0 to 100 where the higher score defines a more favorable health state.
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Time frame: 6 week, 6 month, 12 month
Number of Participants With a 50% Reduction in Ventricular Tachycardia (VT) Burden
Evaluate stricter efficacy endpoint of ENCORE treatment, as defined by number of patients who have had 50% reduction in any VT therapies (ATP or ICD shocks or sustained (\>30sec) nontreated slow VT) after ENCORE treatment (6 months before vs. 6 months after treatment, with a 6 week blanking period immediately after treatment). For patients with PVC-induced cardiomyopathy, the stricter efficacy will be \>50% reduction in PVC burden based on ambulatory heart monitors.
Time frame: 6 months
Number of Participants With a 95% Reduction in Ventricular Tachycardia (VT) Burden
Evaluate strictest efficacy endpoint of ENCORE treatment, as defined by number of patients who have had 95% reduction in any VT (ATP or ICD shocks or sustained (\>30 sec) slow VT) after ENCORE treatment (6 months before vs. 6 months after treatment, with a 6 week blanking period immediately after treatment). For patients with PVC-induced cardiomyopathy, the strictest efficacy will be abolition of PVC burden (\<1%) based on ambulatory heart monitors.
Time frame: 6 months
Number of Participants With Reduction in ICD Shocks and LVEF Improvement
Evaluate the most clinically useful efficacy endpoint of ENCORE treatment, namely, number of patients with reduction specifically in ICD shocks (6 months before vs. 6 months after treatment, with a 6 week blanking period immediately after treatment). For patients with PVC-induced cardiomyopathy, the most clinically useful efficacy will be improvement in cardiac function in the setting of any improvement in PVC burden.
Time frame: 6 months
Number of Participants With Reduction in Ventricular Tachycardia (VT) Therapies Between 6 and 12 Months
Evaluate longer-term durability endpoint of ENCORE treatment, as defined by number of patients with reduction in VT therapies (ATP or ICD shock or sustained (\>30 sec) slow VT and ICD shock alone) during the early phase (treatment to 6 months, with 6 week blanking period) vs. the late phase (6 months to 1 year). For patients with PVC-induced cardiomyopathy, the longer-term durability efficacy will be persistence of any reduction in PVC burden based on ambulatory heart monitors during early phase vs. late phase.
Time frame: 12 months