The present disclosure relates to a method of treating cancer using a composition comprising Nelfinavir, Metformin, Rosuvastatin, optionally along with a pharmaceutically acceptable excipient. The said composition is used for the treatment of cancer caused due to aberration in PTEN gene, optionally along with aberration in TP53 gene and related genes selected from group comprising PI3K, CDKN2A, MDM2 and MDM4.