[90Y]Y-L4-Lipo/ ethyl esters of Iodized fatty acids of poppy seed oil (lipiodol® ultra-fluid), a new TARE formulation, designed from a lipophilic ligand for stability and safety.

Background: Despite recent therapeutic advances, managing liver cancer remains a significant medical and economic priority for many countries. Patients often present at an advanced stage, preventing them from benefiting from salvage surgery. Consequently, palliative treatments play a crucial role in managing these cancers. Interventional radiology techniques are well-known for providing significant benefits to patients. [⁹⁰Y]Y-L4-Lipo/Lipiodol^® Ultra-Fluid is a novel transarterial radioembolization formulation designed for selective arterial injection to deliver localized radiation treatment of advanced unresectable liver tumors. This study aimed to confirm the stability of [⁹⁰Y]Y-L4-Lipo/Lipiodol^® Ultra-Fluid, investigate its biodistribution in an animal model, and conduct an initial dosimetry evaluation.

Results: Less than 3% of ⁹⁰Y was released from the [⁹⁰Y]Y-L4-Lipo/Lipiodol^® Ultra-Fluid formulation in human serum. The tumor-to-liver activity ratio (T/NT) expressed in %ID/g tissue at 1 h, 24 h, 3 days, and 6 days (5.50 ± 2.42, 3.28 ± 1.94, 4.89 ± 3.41 and 4.77 ± 1.59, respectively) suggests effective targeting of tumor tissue compared to healthy liver tissue. The extrapolated absorbed doses in Gy in humans to the tumor, normal liver, lung, and red marrow per GBq of [⁹⁰Y]Y-L4-Lipo/Lipiodol^® Ultra-Fluid administered were 54.3, 16.2, 0.69 and 0.89, for males, and 54.3, 22.3, 0.84 and 0.89, respectively, for females.

Conclusion: With good in vitro stability at low activity lasting at least 3 half-lives and a T/NT ratio of 4 in vivo, [⁹⁰Y]Y-L4-Lipo/Lipiodol^® Ultra-Fluid is confirmed as a valid candidate treatment for transarterial radioembolization of hepatocellular carcinoma. High activity stability in both in vitro and in vivo studies is needed to complete the formulation's safety profile.