Mechanism of Action (MOA)

To understand how tasimelteon works, let’s first briefly review what Non-24-Hour Sleep-Wake Disorder (Non-24) is. 

Non-24-Hour Sleep-Wake Disorder (Non-24) 

Non-24 is a serious, chronic condition that commonly affects people who are totally blind. Because they cannot perceive light, their brains do not receive the signals needed to synchronize the body’s internal clock with the normal 24-hour day. 

Generally, your body has an internal clock, also called the sleep-wake cycle or circadian rhythm. It functions as your body’s natural clock, helping regulate when you feel awake and when you feel sleepy over a roughly 24-hour cycle. In people who can see, sunlight helps reset this clock every day.

When light reaches the brain during the day, it helps keep you awake and alert. As it gets dark, your brain produces more melatonin, a hormone that helps regulate your sleep-wake cycle. The increase in melatonin signals to your body that it is time to sleep.

People who are totally blind (Non-24) do not receive these light signals. As a result, their internal clock slowly falls out of sync with the normal 24-hour day. Their bedtime keeps shifting later, which makes it hard to sleep at night and causes excessive daytime sleepiness.

Hetlioz helps synchronize the body’s internal clock with the 24-hour day, improving nighttime sleep and daytime alertness in people with Non-24. 

Hetlioz Working Mechanism

Tasimelteon is a melatonin receptor agonist, which is a class of medication designed to mimic the action of the melatonin hormone. Tasimelteon activates the MT1 and MT2 melatonin receptors in the brain, mimicking the effects of natural melatonin. By helping synchronize the body’s internal clock with the 24-hour day, it improves nighttime sleep and daytime alertness in people with Non-24-Hour Sleep-Wake Disorder and helps treat nighttime sleep disturbances associated with Smith-Magenis Syndrome.