TAK-861: Takeda Plans to Begin Late-Stage Testing for Experimental Narcolepsy Treatment

In February 2024, Jacob Bell reported in Biopharma Dive that pharmaceutical company Takeda Pharmaceuticals is planning on rapidly advancing late-stage testing of TAK-861 for people with type 1 narcolepsy (also known as narcolepsy with cataplexy). TAK-861 is an orally administered, highly selective orexin-type 2 receptor (OX2R) agonist. Orexin receptors have been shown to play a role in regulating wakefulness and arousal. By stimulating OX2R, Takeda looks to understand whether TAK-861 can improve wakefulness and reduce excessive daytime sleepiness.

While Takeda Pharmaceuticals has been evaluating the therapy for narcolepsy types 1 and 2; however, it seems like the company will focus on type 1 moving forward. It is unclear exactly what trial data prompted Takeda to focus on narcolepsy type 1. However, some analysts believe that promising efficacy data in type 1 could be the cause. A study in narcolepsy type 1 included 112 people. The study found that, within eight weeks of taking the drug, people experienced heightened wakefulness that was seen as both clinically relevant and statistically significant. Moving forward, Takeda plans to continue the therapy into Phase 3 studies.

What to Know About Narcolepsy

Narcolepsy is a chronic neurological disorder that affects the sleep-wake cycle. A typical sleep cycle includes early and deeper sleep stages before rapid eye movement (REM) sleep. In narcolepsy, people may enter REM sleep almost immediately. People with this disorder may fall instantly asleep for a few moments, a few minutes, or sometimes longer. When they wake up, they may experience hallucinations. Narcolepsy also causes excessive daytime sleepiness, which can interrupt daily life. Right now, this disorder is split into two subsets:

  • Narcolepsy with cataplexy: This is called type 1 narcolepsy. People with this condition may experience cataplexy, a sudden loss of muscle control characterized by uncontrollable muscle weakness or paralysis. Cataplexy is often triggered by strong emotions like anger or excitement. Laughter is often a common trigger. People with cataplexy are usually aware of what is happening but simply cannot move. Cataplectic episodes may last for up to a few minutes.
  • Narcolepsy without cataplexy: This is considered type 2 narcolepsy. These people do not experience cataplexy.

Many people with this condition are undiagnosed until years after symptoms manifest. Narcolepsy may be treated with Xyrem, while cataplexy may be treated with sodium oxybate and gamma-hydroxybutyrate.