Alume Biosciences Receives FDA Breakthrough Therapy Designation for Bevonescein in Intraoperative Nerve Visualization
Alume Biosciences, Inc. announced that the U.S. Food and Drug Administration (FDA) has granted Breakthrough Therapy Designation (BTD) to bevonescein, an investigational fluorescent imaging agent being developed as an adjunct for the real-time intraoperative visualization of nerves during head and neck surgical procedures in adults.
Bevonescein is an investigational, intravenously administered fluorescent peptide-dye conjugate designed to bind to nerve tissue. Unlike imaging technologies that require a camera, specialized imaging interface, or display monitor, bevonescein generates a fluorescent signal within the visible spectrum. This enables surgeons to directly see highlighted nerves with the naked eye during an operation.
The FDA’s Breakthrough Therapy Designation represents a significant regulatory milestone for Alume as the company advances bevonescein toward potential use in surgical procedures where inadvertent nerve injury is a known risk. The designation follows the FDA’s Fast Track designation for bevonescein, which was granted in 2022.
Addressing Nerve Injury Risks in Head and Neck Surgery
Nerve identification and preservation are important considerations in many head and neck procedures. Surgical manipulation around delicate neural structures can create a risk of inadvertent nerve injury, which may result in significant complications for patients depending on the nerve involved and the type of procedure performed.
Bevonescein is being developed to provide surgeons with an additional means of identifying nerves during surgery. By highlighting nerve tissue through visible fluorescence, the technology is intended to supplement conventional visualization under standard white light.
“Iatrogenic nerve injury remains one of the most consequential complications for patients undergoing surgical procedures in the head and neck,” said Quyen T. Nguyen, M.D., Ph.D., Co-Founder and Chief Executive Officer of Alume Biosciences and Professor of Otolaryngology–Head and Neck Surgery and Pharmacology at UC San Diego Health.
The company’s approach is designed to provide information directly within the surgical field rather than requiring surgeons to look away from the operative site toward a separate monitor. Because the fluorescent signal can be observed directly, bevonescein could potentially be incorporated into existing surgical workflows without requiring an additional camera-based visualization system.
The FDA’s Breakthrough Therapy Designation reflects the agency’s assessment of the investigational therapy based on the regulatory criteria for the designation. The FDA grants BTD to investigational drugs intended to treat a serious or life-threatening condition when preliminary clinical evidence indicates that the drug may demonstrate substantial improvement over available therapies on at least one clinically significant endpoint.
Phase 3 Development Program Covers Multiple Head and Neck Procedures
Alume has completed three multicenter, prospective, randomized Phase 3 clinical trials evaluating bevonescein in head and neck surgical settings. The Phase 3 development program includes procedures involving thyroid, parathyroid, and parotid surgery, as well as neck dissection procedures.
The company identified the clinical trials as NCT05377554 and NCT06227585 in its announcement, with the Phase 3 program encompassing multiple surgical applications.
Across the studies, nerves were assessed under two visualization conditions: conventional white-light visualization alone and white-light visualization combined with bevonescein-enabled fluorescence. This design allowed investigators to evaluate whether the addition of fluorescence improved the ability of surgeons to identify and delineate nerves during surgery.
According to Alume, bevonescein-enabled fluorescence visualization resulted in a statistically significant improvement in the co-primary endpoint of Nerve Conspicuity in all three Phase 3 trials.
Nerve conspicuity refers to the ability to identify and distinguish nerves within the surgical field. Improving this characteristic could be particularly relevant in procedures where nerves may be located close to the intended surgical target or where anatomical structures make direct identification more challenging.
The company also reported statistically significant improvements in visible nerve length and branching delineation in pooled analyses of the Phase 3 data. Both measures achieved p-values of ≤0.0001.
The findings indicate that the fluorescence approach was associated not only with improved recognition of nerves but also with greater visualization of nerve structures and their branching patterns during the evaluated procedures.
Safety Findings Across Phase 3 Studies
Safety is another important component of the clinical development of an investigational imaging agent intended for use during surgery.
Across Alume’s Phase 3 program, the company reported that no serious drug-related adverse events were observed. The finding comes from three multicenter, prospective, randomized trials conducted across the targeted surgical settings.
While the absence of serious drug-related adverse events in these trials is an important reported finding, bevonescein remains investigational and has not been approved by the FDA for commercial use. Further regulatory review will determine whether the available clinical and manufacturing data support approval and, if applicable, the conditions under which the product could be used.
The Phase 3 results form an important part of the evidence package supporting Alume’s development program and the company’s efforts to advance bevonescein toward regulatory review.
Expert Perspective on Potential Surgical Impact
Gregory W. Randolph, M.D., Professor of Otolaryngology Head and Neck Surgery, Director of the Thyroid/Parathyroid Endocrine Surgical Division at Massachusetts Eye and Ear Infirmary, Bertucci Endowed Chair in Thyroid Surgical Oncology, and a faculty member at Harvard Medical School, was one of the principal investigators involved in the clinical trials.
Commenting on the FDA designation, Randolph said that the work led by Nguyen and Alume has influenced modern head and neck cranial nerve surgery. He added that the Breakthrough Therapy Designation recognizes the potential impact of bevonescein, if ultimately approved by the FDA, in procedures where inadvertent nerve injury represents a known risk.
According to Randolph, the technology could provide improved nerve detection and visualization beyond what is available through the surgical eye alone.
The comments highlight the intended role of bevonescein as an adjunct rather than a replacement for established surgical techniques. Surgeons currently rely on anatomical knowledge, direct visualization, surgical dissection techniques, and other tools to identify and preserve nerves. A fluorescence-based approach could potentially add another layer of visual information during an operation.
Presentations of Phase 3 Data
Alume’s Phase 3 findings have also been presented to the head and neck surgical community.
The company reported that Phase 3 data were presented at the 2026 American Head and Neck Society (AHNS) meeting in Boston. Additional data were presented at the 2026 Collegium Otorhinolaryngology Amitiae Sacrum (CORLAS) meeting in Groningen, the Netherlands.
Presentation of the clinical results at specialty meetings provides an opportunity for investigators and surgical specialists to review the study findings, methodology, efficacy endpoints, and safety observations associated with bevonescein.
The reported results across the three Phase 3 studies, including improvements in Nerve Conspicuity, visible nerve length, and branching delineation, represent the principal clinical evidence cited by Alume in connection with the program.
FDA Breakthrough Therapy Designation
The FDA’s Breakthrough Therapy Designation is intended to accelerate the development and regulatory review of certain investigational drugs. To qualify, an investigational drug must be intended to treat a serious or life-threatening disease or condition and have preliminary clinical evidence indicating that it may demonstrate substantial improvement over available therapy on at least one clinically significant endpoint.
The designation can facilitate more frequent interactions between the FDA and the sponsor during development. It is designed to help address potential development challenges and support an efficient review process when the available evidence meets the agency’s criteria.
For Alume, the BTD follows the Fast Track designation previously granted to bevonescein in 2022. Fast Track and Breakthrough Therapy Designation are regulatory programs intended to facilitate development of therapies addressing significant unmet medical needs, although neither designation constitutes FDA approval.
The Breakthrough Therapy Designation therefore represents a regulatory development rather than a marketing authorization. Bevonescein remains an investigational product, and its ultimate availability for clinical use will depend on the outcome of the FDA’s future regulatory review.
Advancing Fluorescence-Guided Surgery
Alume’s development program is centered on the potential use of visible fluorescence to help surgeons identify nerves in real time during head and neck procedures. The company’s Phase 3 program has evaluated the technology across thyroid, parathyroid, parotid, and neck dissection surgery, providing clinical data from several settings in which nerve identification is an important component of surgical care.
The reported statistically significant improvements in nerve conspicuity across all three Phase 3 trials, together with improvements in visible nerve length and branching delineation in pooled analyses, provide the clinical basis cited by Alume for the FDA’s Breakthrough Therapy Designation.
If bevonescein ultimately receives FDA approval, its proposed role would be to complement existing surgical visualization and nerve-preservation practices. The ability to directly observe fluorescence without relying on a camera or external display could also distinguish the approach from image-guided technologies that require dedicated visualization hardware.
For now, Alume continues to advance bevonescein as an investigational technology. The FDA’s Breakthrough Therapy Designation marks the latest regulatory milestone following the 2022 Fast Track designation and comes after completion of the company’s three Phase 3 studies in head and neck surgery.
About Bevonescein
Bevonescein is a first-in-class, investigational fluorescent peptide-dye conjugate. It is administered intravenously before surgery and selectively highlights nerve tissue when viewed with fluorescence-capable equipment such as analog surgical microscopes or filter-modified surgical loupes. Bevonescein has not been approved by FDA or any other regulatory authority, and its safety and efficacy have not been established.
About Iatrogenic Nerve Injury in Head and Neck Surgery
More than 250,000 head and neck procedures that place critical nerves at risk are performed each year in the United States. Injury to the facial, recurrent laryngeal, or spinal accessory nerves can cause facial paralysis, voice and airway impairment, or shoulder dysfunction. Current intraoperative nerve monitoring with electromyography can signal nerve electrical activity, but it does not allow surgeons to directly see highlighted nerves during active dissection.
About Alume Biosciences
Alume Biosciences is a clinical-stage company developing molecularly targeted fluorescent drugs that help surgeons see critical anatomy in real time.