A biodegradable, lyophilized lipid nanoparticle (LNP) encapsulating small interfering ribonucleic acid (siRNA) directed against glutathione S-transferase P (GSTP), with potential antineoplastic activity. Upon administration of LNP encapsulating GSTP siRNA NBF-006, the LNP formulation delivers the siRNA particles to the tumor cells where the GSTP siRNA targets and binds to GSTP mRNA. This results in the inhibition of the translation and expression of GSTP and may inhibit proliferation of KRAS-overexpressing tumor cells. GSTP, an enzyme overexpressed in many tumor cell types, is involved in modulating MAP kinase-related cell-signaling pathways.