Biopharmaceutical company Sirnaomics Inc disclosed on Thursday the receipt of approval from the US Food and Drug Administration (FDA) to launch the study of its first oncology IND lead product candidate, STP705, in patients with advanced cholangiocarcinoma (CCA).

Cholangiocarcinoma (CCA) is the second most common hepatic primary malignancy (accounting for 15-20% of liver cancer). CCA is also known as bile duct adenocarcinoma and biliary tract cancer.

According to the company, STP705 is an anti-cancer/anti-fibrosis siRNA (small interfering RNA) therapeutic. It takes advantage of a dual-targeted inhibitory property and a proprietary polypeptide nanoparticle (PNP)-enhanced delivery system to target cells in the liver. It acts by directly inhibiting tumorigenesis through down regulation of Cancer Associated Fibroblast (CAF) activity and cell proliferation by silencing both TGF-β1 and COX-2 gene expression within the tumor micro-environment.

The company said STP705 is composed of two siRNA oligonucleotides, targeting TGF-β1 and COX-2 mRNA and formulated in nanoparticles with Histidine-Lysine Co-Polymer (HKP) peptide. Each individual siRNA was demonstrated to inhibit the expression of their target mRNAs and combining the two siRNA's produces a synergistic effect that diminishes pro-fibrogenic and pro-inflammatory factors. Additional data suggests reductions in TGF-β1 and COX-2 led to proapoptotic effects in fibroblasts.