Juniper Biosciences

Juniper’s JBS-003 (F-MISO) Program Receives FDA Breakthrough Therapy Designation, Advancing a First-in-Class Hypoxia Tracer Enabling Radiation De-escalation in HPV-Positive Head and Neck Cancer

BEDMINSTER, N.J., Sept. 01, 2026 (GLOBE NEWSWIRE) -- Juniper Biosciences today announced that the U.S. Food and Drug Administration (FDA) has granted Breakthrough Therapy Designation to JBS-003 (18F-fluoromisonidazole, or FMISO), the first-in-class hypoxia tracer in the U.S., for the identification of tumor hypoxia to guide de-escalated radiation therapy in patients with HPV-positive Oropharyngeal Carcinoma (OPC). JBS-003, licensed from Memorial Sloan Kettering Cancer Center (MSK), is the cornerstone of a new precision oncology paradigm designed to spare patients from the devastating side effects of high-dose radiation therapy. As a leader in molecular imaging, MSK pioneered the use of hypoxia tracers to overcome the limitations of traditional imaging.

FDA Recognition of a Substantial Improvement Over the Current Standard of Care

Breakthrough Therapy Designation is reserved for programs intended to address a serious condition where preliminary clinical evidence indicates the potential for substantial improvement over available therapy on a clinically significant endpoint. The designation for JBS-003 was supported by the body of clinical evidence generated to date for FMISO-guided radiation de-escalation, spanning the foundational investigator-led hypoxia imaging experience at MSK and the ongoing clinical program now advancing under Juniper’s leadership. The designation provides for intensive FDA guidance on an efficient development program, organizational commitment involving senior agency leadership, and eligibility for rolling and priority review.

Redefining the Standard of Care: From 70 Gray to 30 Gray Radiation

In the current standard of care for HPV-positive OPC, patients are subjected to a “one-size-fits-all” aggressive radiation regimen regardless of their individual tumor biology, often resulting in severe, permanent morbidity—including the risk of jawbone removal (osteoradionecrosis), significant weight loss requiring feeding tubes, and long-term quality-of-life impairment. JBS-003 utilizes precision molecular imaging to identify tumor hypoxia, a known marker of radioresistance. By mapping these oxygen-starved regions, clinicians can, for the first time, accurately risk-stratify patients. Research indicates that approximately 80% of these patients have non-hypoxic tumors and may safely undergo a greater than 50% reduction in radiation, de-escalating from the standard 70 Gray to 30 Gray absorbed dose of ionizing radiation.

Accelerating the Precision Radiopharmaceutical Platform

JBS-003 is a vital component of Juniper Biosciences’ expanding multi-indication precision platform. The Breakthrough Therapy Designation reinforces the value of the Company’s partnership with MSK and its commitment to building a high-value pipeline that addresses the most complex challenges in nuclear medicine. Juniper Biosciences will work closely with the FDA to define the most efficient path to registration for JBS-003.

“This designation is a powerful validation of what precision imaging can do for these patients. Using F-MISO PET imaging, we can visualize the specific hypoxic signatures of a tumor to maintain aggressive control where it’s needed, while safely reducing radiation doses for patients with well-oxygenated tissue. The FDA has now recognized that this approach may represent a substantial improvement over the current standard of care. We are very excited to see future patients benefit from it.” said Alex Agnoletto, CEO.

About the JBS-003 Phase 3 Clinical Trial (NCT06563479)

The ongoing Phase 3 trial is a randomized, double-blind study evaluating FMISO-selected de-escalated radiation therapy. Patients in the personalized arm receive a FMISO scan at week two; those with non-hypoxic scans are eligible for a reduced 30 Gray radiation dose, while those with positive scans continue with the standard 70 Gray regimen. The trial is expected to reach primary completion in early 2028. “We are excited that the FDA has granted Breakthrough Therapy designation, and we look forward to completing this Phase 3 trial and generating the pivotal evidence needed to support potential FDA approval,” says Nancy Y. Lee, MD, FASTRO, Radiation Oncologist and Service Chief for Head & Neck Oncology, and Proton Therapy, at MSK.

About Juniper Biosciences

Juniper Biosciences is a cutting-edge radiopharmaceutical drug development company, with a mission to improve access to novel therapeutic and diagnostic radiopharmaceutical agents. The founding team is comprised of distinguished industry members with proven track records and deep expertise in radiochemistry and complex manufacturing.

MSK has financial interests in Juniper. Dr. Lee has financial interests in Juniper.

For further information please contact:

Alex Agnoletto, CEO

Alex.Agnoletto@juniperbiosci.com