Bright Minds's Spike Wasn't Random- It was Serotonin

On October 14, 2024 Lundbeck announced a $2B acquisition of Longboard Pharmaceuticals, and the price of Bright Minds Biosciences spiked from around $3 to over $50. Bright Minds Biosciences had no press release or study results to justify the move. What they had was a low price and a 5-HT2c agonist about to start Phase 2 trials.

Rare Developmental Epilepsy Treatments

Why are Longboard and Bright Minds similar?

Both Longboard (with LP-352 aka Bexicaserin) and Bright Minds (with BPB-101) are developing a new generation of selective serotonin agonists targeting a rare group of seizures known as developmental and epileptic encephalopathies (DEE), including Dravet Syndrome.

DEEs are rare, and there aren’t a lot of studies or drugs targeting them. The plot below shows the number of interventional clinical trials launched since 2018 for various DEEs.

Plot of the number of rare epilepsy interventional studies started per year from 2018 through June 2025.
The number of rare epilepsy interventional studies started per year from 2018 through June 2025.

As a point of comparison, there are roughly 3x as many interventional studies initiated for Alzheimer’s disease every year.

Why Selectivity Matters

Serotonin is one of the most widely studied chemical messengers in biology. In humans, it is involved in everything from emotion and sleep regulation to digestion, acting through 14 receptor subtypes throughout the body, making it a popular drug target.

Due to its broad distribution in the body and many different downstream targets, untargeted serotonin modulators often cause debilitating side effects. For example, fenfluramine, used to treat DEEs like Dravet syndrome can cause heart valve disease, which is attributed to stimulation of the serotonin 2B receptor subtype (5-HT2B) in heart valves.

Longboard and Bright Minds drugs are similar and novel with their selectivity for the 2C receptor subtype (5-HT2C), which should have anti-seizure effect but reduce the risk of off-target effects.

Targeted serotonin treatments are promising for a number of disorders, and industry has taken notice. For example, since 2018 over 14 companies have initiated serotonin-targeting or modulating trials, including:

Promising New Opportunities

The sudden interest in Bright Minds wasn’t random. Longboard had just shown that a selective 5-HT2C agonist could attract significant strategic interest. That’s good news for DEE treatments and for any biotech working on other targeted serotonin modulators.

The serotonin system is broad, with many receptor subtypes and therapeutic angles that remain underexplored. It’s an accessible target-rich field with real potential for scientific teams who know where to look. We’ll be tracking this space closely, with a focus on companies quietly advancing programs without much fanfare.

RxDataLab focuses on scientific analysis of the biotech industry. While most industry coverage focuses on what companies say, we focus on what they do. This was a short report on Bright Minds and the interest in 5-HT2C agonists for rare epilepsy. We’ll be publishing similar reports each week. Have a tip or a request? Send an email or subscribe to follow along.