The U.S. Food and Drug Administration has identified a possible safety concern after four deaths were reported among patients with treatment-resistant schizophrenia who received the investigational agent evenamide in clinical studies. The agency’s review follows a prior action in April when it halted enrollment in a Phase 3 trial at U.S. sites after a participant experienced sudden death.
According to the source, the enrollment hold at U.S. study centers remains in place, although enrollment is continuing at trial sites in other countries and additional international sites are being added. The FDA’s concern links to the pharmacologic class properties of some sodium channel blockers, which — the agency warns — may precipitate arrhythmias that could result in serious cardiovascular events or seizures. The specific details about the deaths, patient characteristics, doses, or causal determinations were not reported in the source article.
The reporting on this development was based on coverage from MedPage Today and summarized in the Pharmalittle column. The source indicates the regulatory scrutiny is focused on whether evenamide’s mechanism as a sodium channel blocker could meaningfully increase risk for life‑threatening cardiac or neurologic events.
Argenx announced that its marketed biologic Vyvgart did not demonstrate superiority to placebo in a Phase 3 study enrolling patients with Sjögren’s disease, a chronic autoimmune condition. The outcome represents an uncommon setback for Argenx, a company that the source notes has accumulated a series of clinical successes in autoimmune disorders and grown into one of the largest biotechs by market capitalization.
Per the report, the Phase 3 trial was stopped early after an independent data monitoring committee concluded the study was unlikely to meet its primary endpoint. The source emphasizes that patient populations with Sjögren’s disease frequently show high placebo response rates, a factor that contributed to analysts characterizing the program as high risk.
William Blair analysts had been cited in the source as projecting potential peak sales of $1.4 billion for Vyvgart in Sjögren’s disease, but they had also described the trial as carrying significant risk because of the disorder’s typical placebo responses. The article does not provide additional details about the trial design, the number of participants, specific endpoints assessed, or timing for any further analyses; those details were not reported in the source.
Both items covered in the source reflect different facets of regulatory risk in drug development. Argenx’s early stoppage in a Phase 3 program illustrates how high placebo rates and interim data reviews can lead to halting a study when a primary endpoint is judged unlikely to be met. The source highlights that such trial outcomes can counter recent company momentum built on earlier wins in autoimmune indications.
Separately, the FDA’s action on evenamide underscores how safety signals emerging during clinical development — including deaths — prompt targeted regulatory interventions such as enrollment holds, at least at domestic sites. The source notes that the agency’s concern about sodium channel blockers is rooted in the class’ potential to provoke arrhythmias that manifest as severe cardiovascular events or seizures.
The Pharmalittle column aggregates these developments and links to original reporting: STAT’s coverage of Argenx’s Sjögren’s study and MedPage Today’s reporting on the FDA’s review of evenamide. The article was authored by Ed Silverman and published Oct. 9, 2026. Portions of the full story are designated as STAT+ exclusive; the source indicates subscription is required to read the remainder of the article.
Author and source notes
This summary reflects the facts presented in the Pharmalittle column and the referenced news reports. Specific granular data — including patient counts, doses, detailed trial protocols, case histories for the reported deaths, and any investigational sponsor statements beyond the headlines — were not reported in the source material and therefore are not included here.