BLA submitted to FDA for imaging agent TLX250-CDx in kidney cancer

A biologics license application (BLA) has been submitted to the FDA for TLX250-CDx for PET imaging of patients with clear cell renal cell carcinoma (ccRCC), announced Telix Pharmaceuticals, the developer of the agent, in a news release.¹

Overall, TLX250‑CDx PET/CT demonstrated a high degree of sensitivity (85.5%) and specificity (87.0%) in patients with an indeterminate renal mass.

In addition to the BLA, Telix has also requested priority review for TLX250-CDx. Currently, the agent has been granted a rolling review process based on a breakthrough therapy designation granted in July 2020.²

James Stonecypher, MSc, RAC, Chief Development Officer at Telix, said in the news release,"If approved by the FDA, TLX250-CDx will be the first targeted radiopharmaceutical imaging agent for kidney cancer to be commercially available to patients in the US. The collaborative approach shown by the FDA under the breakthrough therapy designation has been highly valuable as we work to bring this novel, non-invasive, first-in-class 89-zirconium-labeled monoclonal antibody (mAb) based imaging agent to market.”¹

The BLA submission is supported by findings from the phase 3 ZIRCON study (NCT03849118), which demonstrated high specificity and sensitivity of the agent for PET/CT imaging of ccRCC.

"The ZIRCON study demonstrated the superior sensitivity and specificity of this advanced diagnostic imaging agent, which, if approved, will be the first and only agent available to target carbonic anhydrase IX, a highly relevant target in kidney cancer. This delivers on a major unmet need to provide confidence in the diagnosis of ccRCC, the most aggressive and common form of kidney cancer,” said Brian M. Shuch, MD, in the news release.¹ Shuch is an associate professor of urology, the director of the kidney cancer program, and the Alvin & Carrie Meinhardt Endowed Chair in kidney cancer research at the University of California, Los Angeles Institute of Urologic Oncology.

In total, the open-label, multi-center ZIRCON study enrolled 300 adult patients with RCC who were scheduled for partial or total nephrectomy. Patients were given a single dose of TLX250-CDx IV (10 mg girentuximab) on day 0 and underwent PET/CT imaging on day 5 (± 2 days). Primary outcomes for analysis were sensitivity and specificity.

Overall, TLX250‑CDx PET/CT demonstrated a high degree of sensitivity (85.5%) and specificity (87.0%) in patients with an indeterminate renal mass. Positive predictive value was at least 91.7%, and negative predictive value was at least 73.7% among all patients. Accuracy was found to be higher than 85.6%.

A secondary outcome analysis of patients with small masses (defined as ≤ 4 cm) found sensitivity to be 85.5% and specificity to be 89.5%.

Regarding safety, there were 263 adverse events (AEs) experienced among 124 patients. Of those, 2 AEs of mild intensity were related to treatment.³

Currently, Telix is offering TLX250-CDx through an expanded access program in the US and a named patient program in Europe to patients outside of clinical trials for whom there is no comparable or satisfactory alternatives. The company said it hopes to have commercial availability of the agent in 2024.

References

1. Telix submits Biologics License Application (BLA) for TLX250-CDx (Zircaix) for imaging of kidney cancer. News release. Telix Pharamceuticals Limited. December 18, 2023. Accessed December 19, 2023. https://www.prnewswire.com/news-releases/telix-submits-biologics-license-application-bla-for-tlx250-cdx-zircaix-for-imaging-of-kidney-cancer-302018264.html

2. Telix granted FDA Breakthrough Therapy Designation for renal cancer imaging product. News release. Telix Pharmaceuticals. July 1, 2020. Accessed December 19, 2023. https://telixpharma.com/news-views/telix-granted-fda-breakthrough-therapy-designation-for-renal-cancer-imaging-product/

3. Mulders PFA, Shuch BM, Pantuck AJ, et al. 89Zr-DFO-girentuximab for PET/CT imaging of clear cell renal cell carcinoma – results from a phase 3 ZIRCON study. Presented at the 38th Annual European Association of Urology (EAU) Congress. Milan, Italy. March 11, 2023. Accessed December 19, 2023