11:57 AM EDT, 08/20/2025 (MT Newswires) -- EnVVeno Medical ( NVNO ) shares were down 70% in recent Wednesday trading after the company said it received a not-approvable letter from the US Food and Drug Administration in response to its premarket approval application for VenoValve, a surgical replacement venous valve to treat deep chronic venous insufficiency.

The FDA indicated it cannot approve the company's application in its current form, and that the favorable revised Venous Clinical Severity Score data from a study to show clinical improvement was not enough to determine favorability of the benefit-risk profile for the surgical valve, according to the company.

In the absence of a specific hemodynamic measurement that correlates with patient improvement, the FDA is concerned about bias and the possibility that clinical improvement occurred as a result of the patients being enrolled in a study, the company said.

The FDA also flagged safety concerns regarding the VenoValve open surgical procedure. The company said it is reviewing the feedback and assessing all options like a meeting to discuss requirements for a resubmission of the VenoValve application or appealing the decision.

The company said it also expects to apply the learnings from this FDA approval process as it advances enVVe, a non-surgical replacement venous valve for which it is preparing an investigational device exemption application.

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