An artery is an awkward place to leave a souvenir. A stent can hold it open, but the metal stays after the procedure ends. Advanced NanoTherapies is developing a different arrangement: a balloon that visits the narrowed vessel, delivers two drugs, and departs. Its wager is that the useful part of treatment can linger without the hardware. The problem sounds almost domestic. How do you make something stay when the thing that brought it has gone?
- SirPlux Duo combines sirolimus and paclitaxel in biodegradable nanoparticles.
- Its intended job is to prevent renewed narrowing without adding a permanent implant.
- Human studies are under way. Commercial approval remains ahead.
The company operates in the small, consequential world of catheter-based vascular intervention. Its intended users are interventional cardiologists and vascular specialists; its eventual buyers would be the hospitals and laboratories where they work. Today, the relationship is principally with investigators and selected trial participants. A patient cannot simply order SirPlux Duo. It is an investigational device, and that word carries more weight than any adjective in the brochure.
A short visit, a long assignment
A drug-coated balloon has two jobs. The balloon helps open the artery. The coating delivers medicine intended to restrain the cellular growth that can narrow it again, a process called restenosis. That second assignment extends beyond the device’s brief visit. Opening a passage and keeping it open are different engineering problems, though the patient experiences them as one.
ANT’s proposed answer is a coating made with functionalized nanoparticles: tiny, biodegradable carriers designed to improve drug uptake and retention in the vessel wall. The company exclusively licensed the underlying technology from Cleveland Clinic in 2019. The distinction matters. Its expertise includes the journey between drug and tissue, rather than merely the choice of drug.
SirPlux Duo carries sirolimus and paclitaxel together. Both are established antiproliferative drugs, meaning they inhibit cell growth. ANT is investigating whether their combination, delivered through its nanoparticle system, can provide sustained treatment at lower doses. The company calls the platform drug-agnostic, suggesting a carrier that could accommodate other medicines. That is a development possibility; the product readers should watch is the balloon actually being studied.
Two familiar drugs, an unfamiliar arrangement
“Sirolimus and paclitaxel are both proven drugs in the vascular space, each with unique benefits, limitations, and mechanisms of action,” said co-founder Mehdi Shishehbor in the company’s 2022 financing announcement. The attraction is combination rather than novelty for novelty’s sake. Two known agents might do a more useful job together if the delivery system puts them where they belong.
The competitive distinction requires care. Drug-coated balloons already offer treatment without a new permanent implant. Boston Scientific’s AGENT paclitaxel-coated balloon received FDA approval in February 2024 for coronary in-stent restenosis, where a previously stented artery narrows again. ANT does not own the idea of leaving no new metal. Its proposed distinction is simultaneous dual-drug delivery with biodegradable nanoparticles.
Nor does the choice reduce to a fashionable balloon versus an unfashionable stent. A stent provides mechanical support. A drug coating addresses biology. ANT’s goal of stent-like patency, or continued openness, without a permanent scaffold is an ambitious substitution that needs clinical evidence. A compelling mechanism cannot settle every question about how a vessel behaves after treatment.
The product changed before the market could
The early company story contains a revealing turn. In October 2020, its $5.3 million seed announcement emphasized sirolimus-coated angioplasty balloons for peripheral artery disease. By the June 2022 Series A announcement, the focus was SirPlux Duo and first-in-human testing in newly occurring coronary lesions. The public record shows an evolution in product emphasis, from a single-drug peripheral starting point toward a dual-drug coronary program.
What makes that useful to another device builder is the sequence. ANT paired a licensed delivery platform with a specific clinical problem, then raised money for the next layer of evidence. Its $7.2 million Series A supported first-in-human work. In August 2023, a $4 million strategic extension accompanied news that ten patients had been treated. Financing milestones and clinical milestones travelled together.
Opening a passage and keeping it open are different engineering problems.
The company’s published team reflects the work required: nanoparticle research, device engineering, regulatory affairs and quality assurance. Scientific advisor Vinod Labhasetwar, the Cleveland Clinic inventor associated with the platform, sits alongside specialists in the practical disciplines of making a medical device. There is a useful lesson here: a clever coating still needs a catheter, a manufacturing process and a defensible testing plan.
The next answer costs money
In June 2026, ANT announced more than $31 million in Series B financing, co-led by S3 Ventures and an undisclosed strategic investor. Manufacturing scale-up and U.S. clinical and regulatory work were explicit priorities. The figure is capital raised, not the price of a treatment or an itemized development bill. The company says it aims for lower costs than stent-based treatment; that remains an economic proposition to demonstrate.
Capital for manufacturing and the next clinical steps. The device is still investigational.
The evidence is advancing in stages. ANT’s 2024 announcement described positive first-in-human findings. Its 2026 update described 28 patients in that initial study, with two-year follow-up reporting no new treatment failures. Encouraging follow-up in a small study is a reason to investigate further. It cannot establish that the device outperforms alternatives across a broad patient population.
Thirty patients, a carefully bounded question
The registered Spanish ADVANCE-DUO study makes the boundaries visible. It lists an estimated 30 participants, a single-group, open-label design, and target lesion failure at 12 months as its primary outcome. There is no randomized comparison group. Its protocol excludes severely calcified lesions and patients with significant sensitivity to either drug, among other conditions. Those limits describe the study population, rather than a universal rulebook for eventual use.
Biodegradable carriers and two antiproliferative drugs.
Safety and performance in selected patients.
The next work needed to support commercial use.
ANT has reported FDA Breakthrough Device designations for three vascular indications. The FDA program provides prioritized review and closer interaction; devices must still meet safety and effectiveness standards for marketing authorization. For clinicians, the practical interest is a possible future option. For founders, the copyable discipline is funding specific questions in succession. The balloon’s departure is easy to picture. Whether the benefit lasts is the question the trials must answer.