Serenity Medical, a NeuroTechnology Investors (NTI) portfolio company, has today announced a “landmark” US Food and Drug Administration (FDA) humanitarian device exemption (HDE) approval for its novel River stent—making it the “first” US FDA-approved, purpose-built cerebral venous stent, according to the company.
The River stent has been specifically developed for the treatment of severe idiopathic intracranial hypertension (IIH) in adult patients who have failed medical therapy.
Serenity notes in a press release that severe IIH can lead to debilitating chronic headaches, vision loss, and cognitive impairment, and disproportionately affects obese women aged 20–50 years. Certain patients with severe IIH symptoms have historically struggled to find appropriate surgical therapies that are US FDA-approved and indicated to safely relieve their symptoms, the release adds.
“Delivering the first venous stent approved for severe, refractory IIH is incredibly meaningful to our dedicated team and to people living with IIH who have had limited options for relief until now,” said Serenity founder Y Pierre Gobin (Weill Cornell Medicine, New York, USA). “Our company was founded with the goal of addressing a problem that has long perplexed the medical community and caused debilitating symptoms in the women suffering with it. Reaching this moment reflects years of persistence, partnership with investigators, and a shared commitment to bring new possibilities to this underserved patient community.”
The US FDA’s review and HDE approval of the River stent was based on the findings of the River study—a prospective, multicentre, open-label, single-arm trial from which results were published in the Journal of NeuroInterventional Surgery in February 2025. The study enrolled 39 patients at five US centres with the aim of demonstrating the safety and probable benefit of the River stent in patients refractory or intolerant to medications.
The River study met its primary safety endpoint at one year with an observed major adverse event rate of 5.4%. Additionally, Serenity states, improvements were observed in opening cerebrospinal fluid (CSF) pressure, headaches, papilloedema, pulsatile tinnitus, visual symptoms, and quality-of-life scores.
“The River study was groundbreaking as the first-of-its-kind study to evaluate a stent specifically designed for intracranial venous sinuses,” commented Adnan Siddiqui (Jacobs School of Medicine and Biomedical Sciences, Buffalo, USA), senior author on the paper. “There is no other stent that is optimised or approved for this indication. The US FDA’s review and acceptance of these data will now enable access to this important tool to the broader medical community to treat these patients.”
Serenity goes on to detail in today’s press release that it has formed a strategic partnership with Radical Catheter Technologies to commercialise the River stent.
“Radical has built a world-class commercialisation team with a proven track record of launching breakthrough neurovascular technologies through strategic physician engagement, rigorous clinical education, and hands-on procedural support,” said Martin Dieck, who is the chairman of Serenity, managing director of NTI, and chairman of Radical Catheter Technologies.
