Federal Administration denies Telix's Biologics License Application for investigational PET agent in the treatment of kidney cancer

The U.S. Food and Drug Administration (FDA) has requested additional data from Telix Pharmaceuticals for its biologics license application (BLA) regarding its investigational PET agent for kidney cancer, TLX250-CDx (Zircaix).

The BLA for TLX250-CDx, also known as zirconium-89 [Zr-89] DFO-girentuximab, was granted priority review by the FDA in February. However, the FDA has communicated concerns about the PET agent and has identified certain deficiencies that require remediation before the resubmission of the application.

The FDA's note about these deficiencies was authored by the regulatory body itself. The concerns stem from the need to establish comparability between the drug product used in the ZIRCON phase III clinical trial and the scaled-up manufacturing process intended for commercial use.

TLX250-CDx is a PET agent developed for diagnosing and characterizing clear cell renal cell carcinoma (ccRCC), the most common and aggressive subtype of kidney cancer. The PET agent produces images with a high tumor-to-background ratio, making it a potentially valuable tool in the early detection and treatment of ccRCC.

Despite the current review and the need for additional data, Telix Pharmaceuticals plans to maintain patient access to TLX250-CDx through the FDA-approved expanded access program (EAP), pending consultation with the FDA. The company has also received notices of deficiency from the FDA regarding two third-party manufacturing and supply chain partners.

The FDA's review of the BLA for TLX250-CDx is ongoing, and the agency has not yet made a decision on the approval of the PET agent. Telix Pharmaceuticals will work closely with the FDA to address the concerns and provide the necessary data to support the approval of TLX250-CDx for the diagnosis and characterization of ccRCC.