Several peptide vaccines have undergone phase I and II clinical trials and have shown promising results in immunological as well as clinical responses. The notable peptide vaccines that have undergone clinical trials include HER-2/neu immunodominant peptide, Mucin-1, Carcinoembryonic antigen, Prostate-specific membrane antigen, HPV-16 E7 peptide, Ras oncoprotein peptide, and Melanoma antigens.
A MHC class II peptide, probably consisting 13-20 amino acid units, with any structure (from single strand/double strand, circular/liner twisted/non-twisted, cross-linked/non-cross-linked), derived from the telomerase reverse transcriptase catalytic subunit, is currently undergoing phase II clinical trials for liver cancer and non-small-cell lung cancer as well as a phase III trial for pancreatic cancer. This peptide, or other non-MHC class II peptide with similar features, can be encapsulated in nanoparticles and microspheres. The particle or microspheres can be made of PLGA, HA, CMC, PEG or any other biocompatible polymers, delivered into liver via a catheter through hepatic portal vein or artery.