Rating Swallowing Function in Patients with Huntington Disease Enrolled in the First-HD Study (S25.006)

Objective: The Swallowing Disturbance Questionnaire (SDQ) was administered to patients with Huntington’s disease (HD) as part of the First-HD study. Here, we describe the impact of deutetrabenazine on swallowing. Background: Swallowing function is an important clinical problem in patients with HD, but dysphagia severity is not surveyed or quantified in the Unified Huntington Disease Rating Scale (UHDRS). The SDQ is a 15-item survey, developed and validated to assess swallowing dysfunction in Parkinson’s disease (PD). It is recommended in the parkinsonism NINDS Common Data Elements. This is the first time the SDQ was used as a screening tool and swallowing assessment, in HD. Materials and Methods: HD participants (N=90) were randomized 1:1 to receive deutetrabenazine or placebo in a 12-week multicenter Phase III trial that included an eight-week titration. A normal SDQ score (< 11) was required at Screening. SDQ and patient weight data were collected at baseline (Week 0) and Weeks 2, 4, 6, 9, and 12. Reports of dysphagia as an adverse event were monitored up to Week 12. Results: Despite a number of screen failures attributed to high SDQ scores (n=8), the SDQ was an effective tool estimating swallowing ability in an HD population. Deutetrabenazine significantly reduced SDQ score versus placebo at Week 9 (P=.014), which was maintained up to Week 12 (P=.016). No deutetrabenazine-treated patients and one placebo patient reported dysphagia as an adverse event. There was a 2.1 kg treatment effect for weight gain in deutetrabenazine-treated patients at Week 12. Conclusions: The SDQ may be used as a brief bedside measure of swallowing proficiency in a non-PD population. Deutetrabenazine significantly improved swallowing function, as measured by SDQ, which may have contributed to the observed weight gain in HD patients. Given the improved swallow function in the deutetrabenazine arm, further study of chorea-associated dysphagia is warranted. Disclosure: Dr. Claassen has received research support from Auspex Pharmaceuticals. Dr. Frank has received research support through the Huntington Study Group, funded by Auspex Pharmaceuticals. Dr. Stamler has received personal compensation for activities with Auspex Pharma as an employee. Dr. Sung has received personal compensation for activities with Auspex Pharmaceuticals and Lundbeck, Inc. as a consultant. Dr. Janicki has nothing to disclose. Dr. Oakes has received personal compensation in an editorial capacity for Springer. Dr. Vaughan has nothing to disclose. Dr. Testa has received research support from the Huntington Study Group Ltd.