VitsGen Therapeutics announced that its proprietary radionuclide drug conjugate (RDC), 177Lu-FAP-VG11, received Orphan Drug Designation (ODD) from the U.S. Food and Drug Administration (FDA) on October 22, 2026, for the treatment of soft tissue sarcoma (STS). The designation marks an important milestone in the company's global development of FAP-targeted radiopharmaceutical therapies.

Soft tissue sarcomas are a heterogeneous group of malignancies encompassing multiple histological subtypes. Treatment options remain limited for patients with advanced disease, highlighting a substantial unmet medical need and the potential value of novel therapeutic approaches.

About 177Lu-FAP-VG11

177Lu-FAP-VG11 is an investigational radiopharmaceutical consisting of the FAP-targeting ligand FAP-VG11 chelated to lutetium-177 (177Lu). The ligand is designed to selectively bind to cells expressing fibroblast activation protein (FAP) within the tumor microenvironment. By leveraging FAP expression across multiple solid tumor types, the drug is designed to deliver therapeutic radiation to FAP-expressing tissues.

The beta particles emitted by 177Lu induce DNA damage in targeted cells, leading to cell death. Their tissue penetration also produces a crossfire effect, allowing radiation to damage neighboring tumor cells. Radiation-induced bystander effects and potential immune-mediated abscopal effects may further contribute to the antitumor response.

Preclinical studies have shown higher FAP-binding affinity, increased tumor uptake, prolonged tumor retention, and an improved tumor-to-kidney uptake ratio, along with enhanced tumor growth inhibition in vivo. These findings were accompanied by no apparent increase in healthy-tissue uptake, low renal accumulation, and a lower estimated absorbed radiation dose to red bone marrow, suggesting a potentially favorable safety profile.

Leveraging innovation and R&D resources in both China and the United States, VitsGen Therapeutics is focused on advancing next-generation radionuclide drug conjugates from molecular design and preclinical research through clinical translation.

The company is advancing targeted radiopharmaceutical programs focused on FAP, prostate-specific membrane antigen (PSMA), and carbonic anhydrase IX (CA9), while pursuing regulatory submissions and approvals in both China and the United States.

Following the FDA designation, the company will continue the clinical development of 177Lu-FAP-VG11, generate clinical evidence, and explore its therapeutic potential in soft tissue sarcoma and other difficult-to-treat solid tumors with high FAP expression.