Zenflow raises $52m Series D and signs Cook Medical distribution deal
Zenflow has closed a $52 million Series D financing round and announced an exclusive US distribution agreement with Cook Medical, pairing fresh capital with one of urology's most established commercial networks for the commercial rollout of its Zenflow Spring System.
The round was led by Cook Medical, which is now both a financial backer and the company's primary route to market. New investor ClavystBio joined alongside returning investors Invus Opportunities, F-Prime, and Medtech Venture Partners. Venture debt from HSBC Bank USA and Trinity Capital further expanded the total package. The oversubscribed close follows the Zenflow Spring System receiving US Food and Drug Administration premarket approval (PMA) in December 2025 for the treatment of benign prostatic hyperplasia (BPH).
The deal
Under the distribution agreement, Cook Medical's established urology salesforce will carry the Zenflow Spring System to urologists across the United States. Zenflow retains its operational and clinical infrastructure, while Cook provides the commercial reach. DJ Sirota, Senior Vice President of Cook's MedSurg Division, cited the device's flexible cystoscope, multiple implant sizes, and integrated positioning balloon as features that give it a competitive foothold in what the company describes as the "first-line interventional therapy" (FIT) category for BPH.
Chief executive Shreya Mehta said Cook's relationships within urology made them the natural partner to accelerate patient access. The proceeds from the Series D will fund that commercial launch.
The Zenflow Spring is designed to be placed in-office, without general anaesthesia, and Zenflow says it is fully reversible if the patient or physician chooses. The company claims it avoids common complications associated with surgical BPH procedures, including post-procedure catheterisation and sexual dysfunction, though independent long-term comparative data have not been summarised in the announcement.
Market context
BPH affects an estimated 32 million men in the United States and approximately 79 million worldwide, with prevalence rising steeply with age. The condition is treated along a spectrum ranging from watchful waiting and drug therapy to minimally invasive procedures and surgery. Zenflow is positioning its Spring System as a device-based alternative that can be offered before or instead of pharmaceutical options, a category that has attracted growing interest as evidence has mounted on the side-effect profiles of alpha-blockers and 5-alpha-reductase inhibitors.
The BPH device space is competitive. Established players include Boston Scientific, whose Rezum water vapour therapy and UroLift systems are widely adopted, as well as Olympus and various laser-based surgical platforms. Zenflow's reversibility claim is a differentiator worth watching, as physician preference increasingly favours procedures that preserve future treatment pathways. Cook Medical's existing urology footprint should reduce the friction of clinical adoption, though reimbursement coverage breadth and physician training capacity will be key commercial variables in the near term.
The Cook Medical investment-cum-distribution structure is an increasingly common model in medtech, allowing a larger strategic to secure preferential commercial access without a full acquisition. For Zenflow, it provides non-dilutive commercial infrastructure while keeping the company independent at a stage when post-approval valuation could grow substantially. Investors will be watching revenue ramp metrics closely through 2027 as the first indicator of whether the FIT category gains durable traction with US urologists.