Newron prepares response to U.S. hold after 4 deaths among evenamide recipients
Key Facts
Newron Pharmaceuticals said it had received written comments from the U.S. Food and Drug Administration on the hold on participant enrollment at U.S. sites in its second evenamide study and was reviewing them to prepare its response. In an update on its clinical program, the company said the agency had cited 4 deaths among patients who had received the drug across all its clinical studies to date. In the comparison presented by Newron, one death was recorded among placebo recipients. The agency described the deaths as a "potential safety signal," according to the company's disclosure, with a possible fatal mechanism linked to cardiac arrhythmia. The response is being prepared to address the regulator's concerns about the drug, which the program is testing as an add-on treatment for patients with treatment-resistant schizophrenia alongside existing antipsychotics, including clozapine.
The regulatory concerns relate to a known risk with some sodium channel blockers: the potential to trigger cardiac arrhythmia, according to Newron's account of the U.S. agency's comments. Such arrhythmia could lead to serious cardiovascular events or seizures, according to the disclosure. The company said the subsequent review of the deaths did not allow the possible fatal mechanism linked to arrhythmia to be definitively ruled out. In the study investigators' assessment of a potential relationship to treatment, 3 deaths were considered unrelated to evenamide. The other death was classified by investigators as "possibly related" to the drug, according to the company.
Newron announced the U.S. enrollment hold on 29 April 2026 after notifying the FDA of a participant's sudden death. That death occurred at a clinical site outside the United States, according to the company's announcement at the time. The independent international safety monitoring committee reviewed the initial incident and recommended that "the studies continue as designed." Newron subsequently met with the U.S. agency to discuss potential measures to address the reasons for the hold. The discussions included changes the company intends to propose as part of its efforts to resolve the regulatory issues surrounding continuation of the study.
The hold is limited to new patient enrollment at U.S. sites in the program's second study, while enrollment continues at sites outside the United States, according to Newron's update. The study aims to enroll at least 400 patients under its announced design. About 80 patients had entered screening at the September update preceding the news, according to the company. Screening included U.S. patients, but none had received evenamide in the study subject to the hold. The first global study aims to enroll at least 600 patients, and the company had expected to reach that target by mid-October.
On the financial front, Newron's research and development expenses rose to 14.6 million euros in the first half of 2026, according to its financial results. Comparable expenses were 6.1 million euros in the same period of 2025. The company expected to receive an additional financing tranche of 5.5 million euros from investors. It set a deadline of 30 November 2026 for receipt of that tranche, according to its financial and operational update. It also expected additional financing of 12 million euros after the program's results are announced, conditional on positive results.
FDA procedures provide for a review of a complete response addressing all clinical hold deficiencies within 30 calendar days of receipt. The review aims to determine whether the response addresses the problems that led to the hold, according to the agency's published rules. A suspended study may not resume until the sponsor receives notification from the agency allowing it to proceed. Newron had previously expected, in guidance published in July, to announce primary endpoint results in the fourth quarter of 2026. The announced timing for top-line results from the program's first study is now the first quarter of 2027.