FDA Grants Fast Track Designation for TLX101-CDx, an Investigational Glioma Imaging Product

The FDA has granted a fast track designation for an investigational glioma imaging product, TLX101-CDx (Pixclara; Telix Pharmaceuticals), also known as F-floretyrosine. The product had previously received an orphan drug designation for as an imaging agent for the management of glioma, infiltrative tumors that also affect the neighboring brain tissue.¹

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TLX101-CDx uses positron emission tomography (PET) to determine whether glioma is progressive or recurrent. It targets the membrane transport proteins—LAT1 and LAT2—which enables TLX101-CDx to be potentially used as a companion diagnostic agent to TLX101, also known as 4-L-iodo-phenylalanine, an investigational glioblastoma therapy (GBM). Currently, there is no targeted PET agent for brain cancer imaging that has been approved by the FDA.¹

TLX101-CDx is being investigated alongside the GBM therapy TLX101 in the IPAX-2 (NCT05450744) and IPAX-Linz trials. The 2 trials are running concurrently, with IPAX-2 evaluating TLX101 in combination with post-surgical standard of care (eg, EBRT and temozolomide) in newly diagnosed GBM patients, and IPAX-Linz evaluates the benefit of TLX101 in patients in the refractory setting.^2,3

“Based on promising safety and early efficacy data for TLX101 in the IPAX-1 study, I am pleased to continue to explore this therapeutic modality in a larger patient cohort, where there are currently few effective treatment options,” said Josef Pichler, professor at Kepler University Hospital, Austria, and principal study investigator in the IPAX-Linz study, in a press release.³

The IPAX-Linz trial is a follow-up of the IPAX-1 trial, which demonstrated a favorable safety profile and an encouraging preliminary therapeutic effect for TLX101. Additionally, the IPAX-2 trial’s primary endpoints are the incidence rate and severity of DLTs and the safety, tolerability, and recommended phase 2 dose for TLX101. During these trials, TLX-101CDx is being used to identify patients with LAT1 over-expression who may be candidates for TLX101, in addition to generating a baseline for patients and follow-up data on tumor response and progression.^2,3

“We are pleased to have commenced the IPAX-Linz study, which alongside IPAX-2 supports Telix's goal to expedite the development of a potential new therapy in an aggressive cancer with poor prognosis,” said Colin Hayward, CMO of Telix Pharmaceuticals, in the press release.³

The product is also in its final stages and is likely to receive a United States new drug application for glioma imaging in both pediatric and adult patients. GBM is a high-grade glioma and is the most common aggressive form of the cancer, with treatment consisting of surgical resection that is followed by a combination of radiotherapy and chemotherapy; however, recurrence occurs in almost all patients with gliomas, emphasizing a need for wide patient access to imaging agents such as TLX101-CDx.¹

"There is critical unmet need to improve the diagnosis and management of glioma, particularly in the post-treatment setting, and we are excited to leverage the clinical experience at UCSF to help make this investigational agent more widely available,” said Thomas A. Hope, MD, professor of radiology at UC San Francisco, in a press release. “[TLX101-CDx] has the potential to help determine if a glioma is truly progressing or undergoing a treatment-induced change, known as pseudo-progression, where MRI—the standard of care—can often be inconclusive."¹

References

1. PR Newswire. TLX101-CDx (Pixclara™) Granted FDA Fast Track Designation. News release. April 15, 2024. Accessed April 17, 2024. https://prnmedia.prnewswire.com/news-releases/tlx101-cdx-pixclara-granted-fda-fast-track-designation-302117301.html

2. 131I-TLX-101 for Treatment of Newly Diagnosed Glioblastoma (IPAX-2) (IPAX-2).ClinicalTrials.gov identifier: NCT05450744. Updated July 19, 2023. Accessed April 17, 2024. https://clinicaltrials.gov/study/NCT05450744

3. PR Newswire. First Patient Dosed in Phase II 'IPAX-Linz' Study of TLX101 for Glioblastoma Therapy. News release. November 21, 2022. Accessed April 17, 2024. https://www.prnewswire.com/news-releases/first-patient-dosed-in-phase-ii-ipax-linz-study-of-tlx101-for-glioblastoma-therapy-301684336.html