Vanda Announces Positive Pivotal Study Results for HETLIOZ® (tasimelteon) in Patients with Smith-Magenis Syndrome


Vanda Pharmaceuticals Inc. (Vanda) (Nasdaq: VNDA) today announced that HETLIOZ® (tasimelteon) improved sleep quality and increased sleep duration in patients with Smith-Magenis Syndrome (SMS) in a pivotal placebo controlled clinical study. 
We are extremely pleased with the results of this study of tasimelteon in patients with Smith-Magenis Syndrome. Tasimelteon was shown to meaningfully improve sleep in SMS patients, addressing an unmet medical need for the most severe symptom constellation of this rare disorder, said Mihael H. Polymeropoulos MD, Vandas President and Chief Executive Officer. VEC-162-2401 was a double masked 4 week cross-over pivotal clinical trial that studied the effects of tasimelteon versus placebo in 25 patients with SMS. Patients were evaluated for daily diary sleep quality (DDSQ) and for daily diary total nighttime sleep duration (DDTST) via a parental post sleep questionnaire (PSQ). Total nighttime sleep duration was also measured via daily actigraphy. The study had two predefined primary endpoints: DDSQ and DDTST. 

Tasimelteon met the primary endpoint of improvement in the 50% worst sleep quality (DDSQ) (p=0.0139) and also showed improvement on the primary endpoint of 50% worst total nighttime sleep duration (DDTST) (p=0.0556) (Table 1). Tasimelteon demonstrated significant improvement in overall sleep quality (DDSQ) (p=0.0155) and overall total nighttime sleep duration (DDTST) (p=0.0134). Tasimelteon improved the overall total nighttime sleep duration (DDTST) by an average of approximately 41 minutes per night, a highly clinically meaningful effect. Given that most of the baseline nights were of shortened sleep duration, tasimelteon also improved sleep duration for the best half of the baseline nights versus placebo (50% best DDTST, 46.6 min, p=0.0052). Tasimelteon also showed significant improvement in subjective measures of total nighttime sleep duration via actigraphy, for 50% worst TST (p=0.0309) and overall TST (p=0.0218) (Table 1). In this study, aberrant behaviors improved from baseline on both tasimelteon and placebo but likely due to the relative short duration of the study the differences were not significant between the two groups. In a longer open label study of tasimelteon in SMS, patients were treated for a period of approximately 27 weeks following a 6 week baseline evaluation. In that study, significant improvements from baseline were observed in sleep quality …

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Source: US SEC
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