London, UK, September 9, 2026
Full-Life Technologies has announced that the U.S. Food and Drug Administration (FDA) has cleared its Investigational New Drug (IND) application for [²²⁵Ac]Ac-FL-261, while the program has also received Australian Human Research Ethics Committee (HREC) approval and completed the Clinical Trial Notification (CTN) process with the Therapeutic Goods Administration (TGA). The regulatory clearances enable the company to advance a Phase 1 clinical trial of FL-261 in patients with c-MET-expressing non-squamous non-small cell lung cancer (nsNSCLC) in the United States and Australia.
FL-261 Advances Toward First-in-Human Trial
The planned first-in-human Phase 1 clinical trial will evaluate the safety and tolerability of [²²⁵Ac]Ac-FL-261, as well as its pharmacokinetic profile and preliminary antitumor activity. Full-Life Technologies plans to conduct clinical development in the United States, Australia, and other key regions, marking an important transition for the investigational radiopharmaceutical from preclinical development into clinical evaluation. FL-261 is being developed as a potentially first-in-class c-MET-targeted alpha radioconjugate for multiple solid tumor indications, with an initial clinical focus on nsNSCLC. The investigational therapy is designed to selectively bind to tumors expressing c-MET and deliver alpha-particle radiation directly to tumor cells. The regulatory progress provides the company with an opportunity to begin generating human clinical data for FL-261. The Phase 1 study is expected to provide initial information on the therapy’s safety, tolerability, pharmacokinetics, and preliminary antitumor activity, which will help guide subsequent development of the program.
Targeted Alpha Radiation for Solid Tumors
[²²⁵Ac]Ac-FL-261 uses Actinium-225 (Ac-225) as the therapeutic radionuclide and is designed to combine tumor-specific targeting with the potent cell-killing effects of alpha-particle radiation. By targeting the c-MET receptor, the radioconjugate is intended to deliver radiation directly to cancer cells expressing the target. The company is developing FL-261 for multiple solid tumor indications, reflecting the potential applicability of c-MET targeting beyond a single cancer type. The initial clinical development in c-MET-expressing nsNSCLC will provide an important assessment of whether the targeted alpha radioconjugate can demonstrate an acceptable clinical profile in patients. The advancement into Phase 1 is particularly significant for the radiopharmaceutical field, where the ability to achieve effective tumor targeting while managing exposure to healthy tissues remains an important development challenge. Full-Life Technologies stated that FL-261 is designed to selectively target c-MET-expressing tumors and deliver alpha radiation at the tumor sites.
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UniRDC Platform Supports Radiopharmaceutical Pipeline
FL-261 was developed using Full-Life Technologies’ proprietary UniRDC™ discovery platform, which is designed to rapidly generate radiopharmaceutical development candidates with optimized therapeutic properties. The platform integrates synthetic chemistry and protein-engineering capabilities with the goal of achieving high and sustained tumor uptake while avoiding key safety organs. According to Full-Life Technologies, UniRDC™ supports an accelerated development pathway from target selection to a development candidate with human biodistribution data in less than 24 months. The platform has been dosed in more than 100 patients and has generated three clinical-stage assets to date, with validation through partnerships with strategic pharmaceutical companies. Full-Life Technologies is a clinical-stage actinium-based radiopharmaceutical company with an integrated development model spanning drug discovery, clinical development, Actinium-225 production, and manufacturing. Its clinical pipeline includes [²²⁵Ac]Ac-FL-020, a PSMA-targeted alpha radioconjugate being evaluated in a global Phase 1 study for metastatic castration-resistant prostate cancer, as well as an NTSR1-targeted small-molecule radioconjugate being evaluated in a Phase 1 trial through a strategic collaboration. The company has also completed construction of a GMP-compliant Actinium-225 manufacturing and radiolabeling facility in Belgium, supporting its efforts to develop and manufacture actinium-based radiopharmaceuticals. The FDA IND clearance and Australian regulatory milestones position FL-261 for clinical testing in patients with c-MET-expressing nsNSCLC. Data from the Phase 1 study will be important in determining the investigational therapy’s clinical safety, pharmacokinetics, and potential antitumor activity as Full-Life Technologies advances its targeted alpha therapy strategy across solid tumors.
Source: Full-Life Technologies press release
