The U.S. Food and Drug Administration (FDA) has indicated deficiencies and has requested additional data from Telix Pharmaceuticals for its biologics license application (BLA) regarding its investigational PET agent for kidney cancer, TLX250-CDx (Zircaix).
Via a letter sent to the firm, the FDA communicated concerns about TLX250-CDx (zirconium-89 [Zr-89] DFO-girentuximab), the company said in an August 28 regulatory update. The FDA accepted Telix's BLA for TLX250-CDx in February and granted it priority review.
The agency requested more data 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, Telix explained. Additionally, the FDA documented notices of deficiency issued to two third-party manufacturing and supply chain partners that will require remediation prior to resubmission, the company noted.
TLX250-CDx is a PET agent developed to diagnose and characterize clear cell renal cell carcinoma (ccRCC), the most common and one of the most aggressive subtypes of kidney cancer. It works by binding to carbonic anhydrase IX (CA IX), a target protein expressed on 95% of ccRCC cells, to produce images with a high tumor-to-background ratio, according to the company.
The company said it intends to continue to provide patient access to TLX250-CDx through the FDA-approved expanded access program (EAP), subject to consultation with the FDA.
