The FDA has accepted the new drug application (NDA) for TLX101-CDx (Pixclara; 18F-floretyrosine) and granted it priority review for glioma treatment, potentially bringing advanced brain cancer imaging to the U.S. The Prescription Drug User Fee Act (PDUFA) goal date is set for April 26, 2025. If approved, this agent could become commercially available in the U.S. in 2025, addressing a critical unmet need in brain tumor imaging.
Kevin Richardson, chief executive officer, Telix Precision Medicine, stated, “Telix believes that the FDA approval of Pixclara will drive a step-change for brain cancer imaging in the US and bring it into line with a more advanced standard of care currently used in other markets. There is currently a critical need for better imaging in brain cancer, and Telix is dedicated to delivering precision medicine solutions that address patient needs and enhance both cancer imaging and treatment outcomes.”
Mechanism of Action and Clinical Development
TLX101-CDx is a PET imaging agent targeting the membrane transport proteins LAT1 and LAT2. It is being developed as a companion diagnostic to TLX101, an investigational small molecule therapy for glioblastoma that crosses the blood-brain barrier. TLX101-CDx aims to differentiate progressive or recurrent glioma from post-treatment changes in both adult and pediatric patients. The FDA previously granted orphan drug and fast track designations to the agent in 2020 and 2024, respectively.
Current Clinical Trials
TLX101 is currently under investigation in the phase 1 IPAX-2 trial (NCT05450744), where it is being administered with the best standard of care for newly diagnosed glioblastoma. It is also being evaluated in combination with concomitant external radiation therapy in the phase 2 IPAX-Linz-01 trial (EudraCT2021-006426-43) for patients with recurrent IDH1/2-mutated high-grade glioma.
Potential Clinical Impact
If TLX101 receives FDA approval, it can potentially provide clearer differentiation between tumor recurrence and treatment effects. This enhanced diagnostic capability could lead to more accurate treatment planning and decision-making, improving patient outcomes. The potential of TLX101 as a companion diagnostic for TLX101-Tx, an investigational neuro-oncology drug, is also being explored. Like TLX101, TLX101-Tx targets the same amino acid transporter mechanism but uses therapeutic radiation for treatment.
While FET PET imaging is included in international clinical practice guidelines for glioma, there is currently no FDA-approved amino acid PET agent for brain cancer imaging in the U.S.
