The New England Journal of Medicine (NEJM) has published the results from a pivotal study of the Exablate Neuro system (InSightec) in the noninvasive treatment of patients with essential tremor (ET). The study met its primary endpoint, with patients in the Exablate Neuro cohort demonstrating a clinically significant 47% improvement in a composite tremor score at three months compared with no change in the sham-treatment cohort.
The NEJM article presented findings from a study designed to evaluate the safety and efficacy of Exablate Neuro for the treatment of essential tremor in subjects for whom medications were not effective. The results of this randomized, double-blind, multicenter trial supported the FDA approval of Exablate Neuro as the first focused ultrasound device to treat essential tremor.
Seventy-six patients were enrolled in the study and were randomly assigned to receive either the Exablate treatment (56 patients) or a sham procedure (20 patients), which consisted of the Exeblate procedure but without the transmission of ultrasound energy. Patients in the placebo treatment arm were later allowed to undergo an Exablate Neuro treatment.
The study’s primary endpoint combined parts A and B of the Clinical Rating Scale for Tremor (CRST)––an eight-element measure of tremor and hand function. For the Exablate Neuro treatment group, a mean score of 18.1 at baseline was reduced to 9.6 at three months (a 47% reduction), whereas the sham group showed no change. The between-group difference was highly significant (P < 0.001).
Patients in the treatment group showed a 63% reduction in tremor amplitude alone (CRST, part A), which was maintained at one year of follow up. In addition, the total disability score (CRST, part C) improved by 68%, and the patients’ quality of life (QUEST) improved by 51% at 12 months for treated patients.
The Exablate Neuro system uses high-intensity focused ultrasound waves to ablate targeted tissue through an intact skull with no incisions. During planning and treatment, the patient is fully conscious, lying on the treatment bed in a magnetic resonance imaging (MRI) scanner. MRI allows high-resolution visualization, patient-specific treatment planning, and continuous real-time monitoring of the procedure. Focused ultrasound technology has also been used to treat other clinical indications, including uterine fibroids and painful bone metastases.
Source: InSightec; August 25, 2016.