Glypican-3 targeted delivery of ⁸⁹Zr and ⁹⁰Y as a theranostic radionuclide platform for hepatocellular carcinoma.

ABSTRACT: Glypican-3 (GPC3) is a tumor associated antigen expressed by hepatocellular carcinoma (HCC) cells. This preclinical study evaluated the efficacy of a theranostic platform using a GPC3-targeting antibody ?GPC3 conjugated to zirconium-89 (⁸⁹Zr) and yttrium-90 (⁹⁰Y) to identify, treat, and assess treatment response in a murine model of HCC. A murine orthotopic xenograft model of HCC was generated. Animals were injected with ⁸⁹Zr-labeled ?GPC3 and imaged with a small-animal positron emission/computerized tomography (PET/CT) imaging system (immuno-PET) before and 30 days after radioimmunotherapy (RIT) with ⁹⁰Y-labeled ?GPC3. Serum alpha fetoprotein (AFP), a marker of tumor burden, was measured. Gross tumor volume (GTV) and SUV_max by immuno-PET was measured using fixed intensity threshold and manual segmentation methods. Immuno-PET GTV measurements reliably quantified tumor burden prior to RIT, strongly correlating with serum AFP (R²?=?0.90). Serum AFP was significantly lower 30 days after RIT in ⁹⁰Y-?GPC3 treated animals compared to those untreated (p?=?0.01) or treated with non-radiolabeled ?GPC3 (p?=?0.02). Immuno-PET GTV measurements strongly correlated with tumor burden after RIT (R²?=?0.87), and GTV of animals treated with ⁹⁰Y-?GPC3 was lower than in animals who did not receive treatment or were treated with non-radiolabeled ?GPC3, although this only trended toward statistical significance. A theranostic platform utilizing GPC3 targeted ⁸⁹Zr and ⁹⁰Y effectively imaged, treated, and assessed response after radioimmunotherapy in a GPC3-expressing HCC xenograft model.

SUBMITTER: Labadie KP 

PROVIDER: S-EPMC7881163 | biostudies-literature | 2021 Feb

REPOSITORIES: biostudies-literature