Telix’s Brain Cancer Imaging Agent Faces Approval Setback

The U.S. Food and Drug Administration (FDA) has issued a denial for Telix’s application for a new investigational imaging agent used to diagnose glioma, a rare form of brain cancer. The imaging agent, TLX101-CDx (Floretyrosine F18 or 18F-FET, Pixclara®) is an investigational agent for the imaging of glioma, a rare and life-threatening brain cancer.

According to the announcement made by Telix, the FDA was unable to approve the application in its current form and stated additional that additional clinical evidence is needed to progress the application.

Telix said this decision comes despite a “robust consultation process” with the FDA prior to submission. Authorities have not raised concerns about the product’s safety, and Telix plans to request a hearing to review the basis for the decision. 

This outcome is particularly disappointing for American glioma patients. FET-PET imaging is recognized as a recommended best practice in international oncology guidelines and is widely used in other regions. Notably, the FDA has granted TLX101-CDx both Orphan Drug and Fast Track designations — an acknowledgment of the candidate's potential to address a significant unmet medical need and to provide meaningful clinical benefit over existing treatment options.

Telix remains committed to commercializing Pixclara and improving care for glioma patients, with leaders assessing strategies to address the agency’s concerns. The FDA rejection does not impact the company’s financial forecasts for 2025, which excludes revenue predictions for unapproved products. 

Christian Behrenbruch, PhD, MBA, Telix’s managing director and group CEO, stated, “We have multiple go-forward pathways available to us, such as providing additional confirmatory data through several active clinical programs, including company-led studies. Our immediate focus is understanding the FDA’s feedback and augmenting our submission with additional data to satisfy the agency as soon as possible.”