Full Press Release Details
Melbourne (Australia) and Indianapolis, IN (U.S) | 6 October 2025
Telix today announces that its Fibroblast Activation Protein (FAP)-targeting therapy candidate, TLX400, has been published in the Journal of Nuclear Medicine . TLX400 demonstrated clinical antitumor activity with a manageable safety profile in subjects with advanced sarcoma, a patient population with limited treatment options [1] .
TLX400 ( 177 Lu-DOTAGA.Glu.(FAPi) 2 ) was in-licensed by Telix in March 2025 as part of a portfolio of next-generation therapeutic and diagnostic (“theranostic”) radiopharmaceutical candidates [2] . This peer-reviewed publication further validates the clinical and development potential of Telix’s lead FAP therapeutic candidate in solid tumors, including aggressive mesenchymal malignancies such as sarcoma.
In this retrospective analysis, Dr. Sanjana Ballal and colleagues report outcomes from 10 patients with histologically confirmed sarcoma who received a median of three treatment cycles of TLX400. The therapy demonstrated a manageable safety profile and clinical activity, with a disease control rate of 50% and a partial response rate of 33.3%, according to PERCIST criteria 1 . The median progression-free survival (PFS) was approximately 5 months and the median overall survival (OS) was 8 months 1 . The administration of TLX400 was well tolerated, with no immediate toxicity or new onset of anemia in any patient. Three patients with preexisting grade 2 anemia showed no worsening of the condition. One patient with a primary tumor in the stomach experienced rectal bleeding 1 month after treatment. No other grade 3 or 4 hematologic, renal, or hepatic toxicities or electrolyte imbalances were observed 1, [3] .
Dr. Sanjana Ballal, Senior Researcher at the All India Institute of Medical Sciences (AIIMS, New Delhi), investigator and lead author, commented, “This study highlights the potential of TLX400 for patients with advanced sarcoma, particularly those who have exhausted standard therapies. The favorable safety profile and early signs of disease control 1 support further investigation in larger, prospective trials.”
Sarcomas are a diverse group of malignancies with high recurrence rates and limited systemic treatment options. FAP-targeted radiopharmaceutical therapy has the potential to disrupt the tumor microenvironment and target both stromal and tumor cells. TLX400 is a next generation FAP-targeting therapeutic candidate, differentiated by a novel structure that aims to drive prolonged tumor retention while minimizing off-target uptake. TLX400 was designed to overcome the limitations seen with first-generation FAP compounds and has extensive pre-clinical and clinical data covering a range of tumors [4] . Telix is working with global key opinion leaders to commence clinical development for TLX400, including a pan-cancer basket study.
Dr. David N. Cade, Group Chief Medical Officer, Telix, added, “We are encouraged by these early data in sarcoma, which reinforce the scientific potential and versatility of our FAP-targeting platform. Both in this publication from New Delhi, and in ongoing clinical use at centers in Germany, TLX400 continues to demonstrate a favorable safety profile and potential efficacy across multiple tumor types, supporting our broader clinical development strategy.”
The Journal of Nuclear Medicine publication is available online at: https://jnm.snmjournals.org/content/early/2025/08/21/jnumed.125.270186
[1] Ballal et al. J Nucl Med. 2025. https://jnm.snmjournals.org/content/early/2025/08/21/jnumed.125.270186
[2] Telix ASX disclosure 12 March 2025.
[3] The data were collected as part of a compassionate use program covered by an overarching protocol, approved by the institutional ethics board.
[4] See Telix investor presentation lodged with the ASX on 19 November 2024; Ballal et al. Thyroid. 2025. https://www.liebertpub.com/doi/10.1089/thy.2024.0229
TLX400 has not received a marketing authorization in any jurisdiction