Surgeons may soon have a glowing ally in the operating room.
A first-of-its-kind fluorescent drug is showing promise in helping doctors see and avoid nerves during surgery, reducing the risk of accidental nerve damage during procedures.
Named Bevonescein, the drug developed by a University of New Mexico surgeon lights up nerve tissue under special imaging equipment, giving surgeons a visual edge that could transform how delicate procedures are performed.
“The way that I explain this drug to patients is that I think if we can help surgeons see things better, they can do faster, more efficient, safer surgery,” said Dr. Ryan Orosco, a head and neck surgeon at the University of New Mexico who co-authored the study.
Making nerves glow green
The experimental compound was tested in a small Phase 1–2 clinical trial involving 27 cancer patients undergoing neck, thyroid, or parotid gland surgeries. These procedures often put critical cranial nerves at risk, making precise navigation essential.
Administered intravenously before surgery, Bevonescein binds selectively to nerve tissue and emits a greenish-yellow glow when exposed to a specific light frequency, allowing surgeons to identify and avoid nerves that would otherwise be nearly invisible.
“We can image them (patients) five, six, seven, eight hours later, and it still stays bound to the nerves, but it flushes out of the body within 12 hours,” said Orosco.
The drug’s safety and imaging effectiveness were confirmed in the initial trial, setting the stage for a larger Phase 3 study now underway across 10 sites in the U.S., including UNM Hospital.
In the operating room, surgeons typically use high-powered microscopes fitted with specialized filters to detect the fluorescent signal. The third trial of the research will also test specially modified headband-mounted magnifying loupes—the kind surgeons already wear—as a more practical alternative to bulky microscopes.
The technology traces its roots to the lab of Dr. Quyen Nguyen at the University of California, San Diego, who collaborated with the late Nobel laureate Roger Tsien, famous for his discovery of green fluorescent protein.
Sharper sight, simpler gear
Their work laid the foundation for Bevonescein, which fuses a fluorescent molecule to a short chain of amino acids that selectively attaches to nerve tissue.
If the ongoing Phase 3 trials show significant improvements in surgical outcomes, Bevonescein could be approved by the FDA, initially for use in head and neck surgeries.
The trials, expected to be completed by this summer, will assess whether use of the imaging agent meaningfully improves overall surgical outcomes, something the initial trial was not designed to determine.
If successful, Bevonescein could receive FDA approval for use in head and neck surgeries, with potential applications far beyond.
“Once the FDA has approved it for a certain indication, then it’ll be on the shelves,” Orosco said.
“Surgeons can also use it off-label for whatever they want. Then the big question is, how does that go? Who starts using it and in which types of surgeries?”
The study has been published in the journal Nature Communications.