Eisai halts Phase 3 Dravet drug trial due to recruitment issues

Eisai has discontinued the Phase 3 clinical development of its adjunctive treatment for Dravet syndrome, as confirmed by a company spokesperson to Endpoints News on Friday afternoon. The Tokyo-based pharmaceutical company has terminated the late-stage trial of lorcaserin this week, in accordance with an update on the federal clinical trials database. Although the medication, which has orphan drug designation from the FDA, was still listed on Eisai's public pipeline as of November 8, the decision to halt the trial was not linked to safety concerns.

Dravet syndrome, a rare and severe disorder that typically begins in infancy, leads to epilepsy. According to an Eisai spokesperson, the emergence of other FDA-approved therapies for this complex condition has made it exceedingly difficult to recruit patients for their investigational therapy.

Originally, the oral drug lorcaserin was acquired from Arena Pharmaceuticals and marketed by Eisai under the brand name Belviq for obesity management. However, in 2020, the FDA requested that Eisai withdraw Belviq from the market due to concerns that the cancer risks surpassed the benefits.

Lorcaserin is a 5-HT2C agonist, which means it selectively stimulates serotonin 2C receptors in the brain, with an aim to suppress seizures in Dravet syndrome patients.

In related developments, Longboard Pharmaceuticals, another company working on a 5-HT2C superagonist, initiated its Phase 3 trial for Dravet syndrome patients this fall. Lundbeck announced its plans to acquire Longboard Pharmaceuticals for $2.6 billion in cash. Another notable player in this field, Bright Minds Biosciences, is developing a related drug that is currently in mid-stage testing for rare epilepsies and is also conducting preclinical research on obesity treatments.

Several other pharmaceutical companies are actively engaged in the development of treatments for Dravet syndrome. Stoke Therapeutics and Jazz Pharmaceuticals are among those pursuing new therapies. This summer, Takeda's own drug candidate for Dravet syndrome failed to meet the primary endpoints in its Phase 3 trial.

Eisai's decision to halt the late-stage trial of lorcaserin underscores the challenges faced by pharmaceutical companies in developing effective treatments for rare and complex disorders like Dravet syndrome. As the landscape of available therapies evolves, patient recruitment for clinical trials remains a significant hurdle.