The FDA has put a partial hold on Bright Minds Biosciences’ seizure study application over preclinical toxicity data and concerns about its preparations for enrolling children.
Bright Minds filed to run a randomized placebo-controlled phase 2 clinical trial of BMB-101 in patients with developmental and epileptic encephalopathies (DEEs). BMB-101 activates 5-HT2C, a serotonin receptor targeted by drugs including UCB’s Fintepla. Bright Minds designed the molecule to be more selective for 5-HT2C, relative to 5-HT2A and 5-HT2B receptors, to support chronic treatment.
But the FDA has just derailed part of Bright Minds' efforts to validate the drug candidate. Based on an email from the FDA, the biotech believes the partial clinical hold only applies to the planned phase 2 DEE trial in the U.S. Ongoing clinical trials are unaffected by the hold.
The biotech's stock took an immediate hit from the news, with Bright Minds' shares down 49% to $28 in pre-market trading Monday from a Friday closing price of $54.98.
Officials imposed the hold over toxicity in mice and the lack of adequate pharmacokinetic and juvenile toxicity data to support pediatric enrollment. Bright Minds believes the toxicity observation is limited to mice and that the findings were incidental and unrelated to the drug. The biotech’s position is based on its toxicity reports, peer reviewers and input from independent toxicology experts.
Bright Minds is awaiting the partial clinical hold letter from the FDA, which is due within 30 days. The biotech expects the letter to include additional details, non-hold recommendations and advice on study design. Bright Minds plans to immediately request further clarification from the FDA.
The letter will shape the next steps, with Bright Minds planning to refine its study in line with the FDA’s recommendations to address the issues and advance future clinical trials in the U.S. More data or studies may be needed, and the biotech cannot guarantee when or whether the FDA will lift the hold.
Bright Minds raised $175 million in January. The biotech secured the cash via a public offering days after presenting phase 2 data on BMB-101 in DEEs. The 11 patients with absence seizures who received BMB-101 orally twice daily for three months had an average of 73.1% fewer seizures.