FDA Grants Fast Track Designation to RAD101 in Brain Metastases

June 13, 2025
Spencer Feldman

Spencer, Assistant Editor of CURE®, has been with MJH Life Sciences since 2024. A graduate of Rowan University with a bachelor's degree in health communication, Spencer enjoys spending time with family and friends, hiking, playing guitar and rock climbing.

The FDA granted fast track designation to RAD101, an experimental imaging agent, to improve detection of recurrent brain metastases.

The U.S. Food and Drug Administration (FDA) has granted fast track designation to RAD101 to help differentiate between recurrent disease and treatment effect in brain metastases from solid tumors, including leptomeningeal disease, according to a news release from Radiopharm Theranostics.

RAD101 is an experimental imaging agent that targets fatty acid synthase, an enzyme that helps produce fatty acids in the body. Many solid tumors, including brain metastases, make too much of this enzyme. By binding to fatty acid synthase, RAD101 may help doctors better visualize tumors on scans.

The FDA’s fast track designation is meant to speed up the development and review of drugs that treat serious or life-threatening conditions, according to the release. It is granted to treatments that show potential to meet needs not addressed by current therapies. This designation allows for closer communication with the FDA, faster feedback during development and the ability to submit parts of a marketing application as they’re ready. If certain requirements are met, drugs with fast track status may also qualify for priority review, which can shorten the time it takes for the FDA to decide on approval.

“The FDA’s fast track designation for RAD101 highlights the seriousness of recurrent brain
metastases as a condition and the unmet medical need for innovative products that can differentiate between tumor recurrence and radiation necrosis or pseudprogression,” Riccardo Canevari, CEO and managing director of Radiopharm Theranostics, said in the news release. “RAD101 represents a promising advancement in improving diagnostic precision for brain metastases, offering hope for more effective clinical decision-making in the over 300,000 patients diagnosed annually in the U.S. We are excited to advance our phase 2 clinical trial and anticipate sharing topline results in the second half of 2025.”

A U.S. multicenter, open-label, single-arm phase 2b clinical trial is studying how well the imaging agent 18F-RAD101 can detect recurrent brain metastases in 30 patients with solid tumors that have spread to the brain. Brain metastases are cancer growths that return after initial treatment.

The main goal is to compare how closely lesions detected by 18F-RAD101 match those seen on standard MRI scans enhanced with a contrast dye called gadolinium. Accurate imaging is important because it helps doctors decide if brain lesions represent active cancer returning or if they are caused by treatment-related changes such as radiation necrosis, which is tissue damage from prior radiation therapy.

The study also measures how accurately 18F-RAD101 can tell the difference between tumor recurrence and radiation necrosis in brain lesions previously treated with precise radiation called stereotactic radiosurgery. These results will help determine whether 18F-RAD101 can improve diagnosis and guide better treatment decisions, supporting its fast-track designation by the FDA to speed development for use.

What is RAD101 and How Does it Work?

RAD101 is a new imaging molecule that targets fatty acid synthase, an enzyme involved in fat production that is overexpressed in many solid tumors including brain metastases, according to the news release. By focusing on this enzyme, RAD101 may improve the accuracy of detecting cancer cells in the brain. Early results from a phase 2a trial at Imperial College London showed strong uptake of RAD101 in brain tumors regardless of their origin.

The study also suggested that PET-MRI imaging with RAD101 could potentially predict overall survival noninvasively, supporting the need for larger studies to confirm these findings, the release concluded.

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