New (Positive) Clinical Trial Results for Totally Blind Persons with Sleep Disorders

Photo of a clock face at 2:00 AM

On December 18, 2012, Vanda Pharmaceuticals, Inc. announced positive Phase III clinical trial results from the recently completed Safety and Efficacy of Tasimelteon (SET) study. Tasimelton is an experimental drug treatment for totally blind individuals with no light perception who experience a sleep problem called “Non-24-Hour Sleep-Wake Disorder.” In the United States, this disorder affects approximately 65,000 totally blind individuals who lack the light sensitivity necessary to reset their internal “body clocks.”

About Vanda Pharmaceuticals, Inc.

Vanda Pharmaceuticals, Inc. is a biopharmaceutical company in Rockville, MD that is working to advance the science of developing new medicines and to use novel approaches to deliver these new medicines to individuals who can benefit from them. Primarily, Vanda is focused on the development and commercialization of products for the treatment of central nervous system disorders.

Non-24 Hour Sleep-Wake Disorder

Non-24 Hour Sleep-Wake Disorder (Non-24) is a serious, rare circadian rhythm disorder that affects a majority of totally blind individuals who lack light perception and cannot reset their master body clocks to the 24-hour day. At the present time, there is no FDA-approved treatment for Non-24. You can find more information about Non-24-Hour Sleep-Wake Disorder, including frequently-asked questions, news, and research updates at the 24SleepWake website.

Recent Clinical Trial Results

The SET study was an 84-patient randomized, double-masked, placebo-controlled study in subjects with Non-24, and the first of four clinical studies that comprise Vanda’s Phase III development program for tasimelteon.

Results from the SET study indicated that tasimelteon was safe, well-tolerated, and successfully reset the master body clock. In addition, tasimelteon significantly improved clinical symptoms across a number of sleep and wake measures, including total sleep time, nap duration, and the timing of sleep.

Data from the RESET study (the second Phase III clinical trial), which is evaluating the maintenance of the “resetting” effect of tasimelteon, is expected to be announced in early 2013. In addition, Vanda plans to submit a New Drug Application (NDA) for tasimeleton to the U.S. Food and Drug Administration (FDA) in mid-2013.

Tasimelteon and Non-24

From the Vanda Pharmaceuticals website:

Graphic of a tasimelteon molecule

Tasimelteon is an oral compound in development for sleep and mood disorders, including Circadian Rhythm Sleep Disorders (CRSD). Examples of CRSD include transient disorders, such as jet lag, and chronic disorders such as shift work sleep disorder and Non-24-Hour Sleep-Wake Disorder.

Tasimelteon has been shown to improve sleep parameters in prior clinical studies that simulated a [disruption] of the circadian clock. In two such studies, tasimelteon caused significant improvement in sleep onset and sleep maintenance without evidence of next-day residual effects.

On January 19, 2010, the FDA granted orphan drug designation status for tasimelteon in Non-24-Hour Sleep-Wake Disorder in blind individuals without light perception. The FDA’s Orphan Drug Designation program provides “orphan” status to drugs defined as those intended for the safe and effective treatment, diagnosis, or prevention of rare diseases/disorders that affect fewer than 200,000 people in the United States, or that affect more than 200,000 persons but are not expected to recover the costs of developing and marketing a treatment drug.

More About the Study

Here is additional clinical trial information from the Vanda Pharmaceuticals website:

Individuals who are totally blind with recurring sleeping or napping problems are needed to answer a survey and/or take part in a clinical research study. For each completed survey, $25 will be donated to organizations that support people with blindness.

Eligible persons who take part in the clinical research study will be compensated for their time and will receive all study-related investigational medication, medical evaluation, and transportation at no cost.

Sleep problems and napping occur in some individuals who are totally blind. This may be caused by the lack of light needed to reset the “body clock.” The result is recurrent sleep problems similar to jet lag.

Individuals may qualify who:

  • are between 18 and 75 years of age
  • are totally blind with no light perception
  • have recurrent trouble sleeping at night
  • or experience daytime sleepiness or napping.

Interim Study Results Thus Far

From the 24SleepWake website:

  • Vanda has completed over 1,000 surveys of totally blind individuals with no light perception. Over 75% of participants taking the survey report one or more of the following: trouble falling asleep, staying asleep, staying awake, and/or difficulty with napping.
  • During the screening and diagnosis part of the trial, sleep diary information highlighted some of the sleep problems caused by Non-24. Over 50% of individuals with a Non-24 diagnosis have the equivalent of one night per month with almost no sleep, and almost 10% have the equivalent of one night per week with almost no sleep.
  • In addition to the severe sleep problems, Non-24 patients report daytime napping that comes and goes, depending upon where the body clock is set relative to the normal day. This napping is increased only when the body clock is out of alignment with the normal day/night cycle; those with Non-24 do not show increased napping at times when the body clock is aligned.

Additional Non-24-Hour Sleep-Wake Information

For more information, you can visit the project website at; call 1-888-389-7033 (toll free) Monday-Friday, 9:00 AM to 5:00 PM EST; or send an email to

Matilda Ziegler magazine has published an informative five-part series on Non-24-Hour Sleep-Wake Disorder by Lynne Lamberg, a science writer with expertise in the area of circadian rhythm biology.

VisionAware will provide additional updates of this important research as they become available.