Takeda Pharmaceutical plans to quickly begin late-stage testing of an experimental drug for narcolepsy, which, if successful, could help the company enter what Wall Street analysts see as a multibillion-dollar market.
There are two kinds of narcolepsy, with a key difference being that “Type 1” can involve a sudden loss of muscle control. Takeda has been testing its drug, known as TAK-861, as a potential treatment for both, and on Friday disclosed high-level results from a pair of studies that each focused on one type.
Takeda said the Type 1 trial, which evaluated 112 patients, found those given its drug as opposed to a placebo experienced statistically significant and “clinically meaningful” improvements in wakefulness at the eight-week mark. The company now intends to begin Phase 3 trials in the first half of its fiscal year, which begins April 1.
Conversely, results from the Type 2 trial convinced Takeda not to advance that program further. The company said those data are still being analyzed to “determine next steps.”
For years, Takeda has been trying to develop a narcolepsy medicine that works by stimulating proteins called orexin receptors. Research indicates these proteins have powerful effects on the brain, regulating wakefulness, arousal and food satiation. While orexins have a direct tie to narcolepsy Type 1, companies like Takeda, Alkermes and Jazz Pharmaceuticals think they also may be useful targets for treating Type 2 or other sleep disorders, such as idiopathic hypersomnia.
But creating a therapy that’s both effective and not weighed down by side effects has been challenging. Takeda scrapped an earlier orexin-targeting agent because of liver toxicity. More recently, Alkermes disclosed results from a small study that found some patients on its drug experienced blurred or distorted vision. Jazz not long after halted an early-stage trial of its drug due to reports of visual disturbances and cardiovascular effects.
With TAK-861, Takeda aimed for a drug that was more tolerable but still taken as a convenient tablet.
“As a reminder, TAK-861 is a more potent agent that may provide efficacy at a much lower dose than our previously tested oral orexin agonist, significantly reducing the potential for adverse effects, including liver toxicity, which tends to be dose-related,” said Andy Plump, Takeda’s research and development head, on a recent company earnings call.
In a note to clients, Evercore ISI analyst Umer Raffat guessed that efficacy data — rather than safety — were what made Takeda decide to push forward in Type 1 narcolepsy and not Type 2.
He highlighted how the company was “very focused” on keeping the maximum daily dose of its drug under a certain threshold because of safety concerns. “It's possible that such a dose was sufficient” in Type 1, he wrote, though previous research suggests a dose three- to four-times higher may be needed for Type 2 patients.
Takeda’s strategy could still pan out, though. Raffat estimates the market for narcolepsy Type 1 drugs is worth more than $3 billion, whereas the markets for Type 2 and idiopathic hypersomnia are around $1 billion to $2 billion combined.
Takeda is already developing a successor drug with an “entirely novel structure” relative to TAK-861, according to Plump. The company hopes to get that medicine, dubbed TAK-360, into human testing this year.
“How we position that to a large extent will depend on the data sets that we’ll see in the near future on TAK-861. But there are lots of possibilities,” Plump said on that February earnings call.