Updates On a Clinical Trial for Totally Blind Individuals with Sleep Disorders

Photo of a clock face at 2:00 AM

Vanda Pharmaceuticals, Inc., a biotechnology company in Rockville, MD, is continuing to recruit study participants for a Phase III clinical trial of 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 the Study

According to Vanda, “We are close to completing enrollment, but need several more people at each of our 23 research sites across the US to complete the study.” Here is the study announcement, along with 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.

About Non-24 Hour Sleep-Wake Disorder and Tasimelteon

You can find information about Non-24-Hour Sleep-Wake Disorder, including frequently-asked questions, news, and research updates at the 24SleepWake website. The drug that is being studied in the clinical trial is Tasimelteon:

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 and biologics which are 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.

Interim Study Results Thus Far

From the 24SleepWake website:

  • Tasimelteon was shown for the first time to reset the body clock and to align it to a constant 24-hour day in patients suffering from Non-24-Hour Disorder (Non-24).
  • 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.
  • For the 143 patients analyzed to date in the Non-24 diagnosis stage of the study, 70% received a confirmed diagnosis of Non-24. The median amount of time patients’ body clocks moved was over three hours per week, with some people moving more than one hour every day.
  • 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.

More Non-24-Hour Sleep-Wake Information

For more information about the clinical trial, visit the project website at www.non24registry.com; call 1-888-389-7033 (toll free) Monday-Friday, 9:00 AM to 5:00 PM EST; or send an email to info@non24registry.com.

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 research as they become available.