Cancer Peptide Vaccine Clinical Trial Registrations Increased 34% Year-Over-Year Through Mid-2026 With 78 Tracked Personalized Cancer Vaccine Trials (70 Phase 1, 8 Phase 2, of Which 56 Are Currently Active); Peptide Vaccines Represent the Most-Tested Modality at 31 Trials (Versus 15 Dendritic Cell Vaccines and 13 RNA Vaccines) and Target CD8+ or CD4+ T-Cell Responses Against Tumor-Associated Antigens (TAAs) or Tumor-Specific Antigens (TSAs); The Majority Target Solid Tumors Previously Considered Resistant to Peptide Therapies (Pancreatic, Colorectal, Triple-Negative Breast Cancer); Combination Trials Pairing Checkpoint Inhibitor Antibodies With Peptide Vaccine Regimens Are Enrolling Now, Converting Immunologically Cold Tumors to Hot Before Checkpoint Blockade
Cancer peptide vaccine clinical trial registrations increased 34% year-over-year through mid-2026 with 78 tracked personalized cancer vaccine trials (70 Phase 1, 8 Phase 2), of which 56 are currently active and 22 have been completed. Modality breakdown: peptide vaccines represent the most-tested category at 31 trials (39.7% of the field), followed by dendritic cell vaccines at 15 trials (19.2%) and RNA vaccines at 13 trials (16.7%). Peptide vaccines target CD8+ T-cell responses (cytotoxic T cells that directly kill tumor cells) or CD4+ T helper cell responses (immune coordination) against tumor-associated antigens (TAAs, proteins overexpressed in cancer versus normal tissue) or tumor-specific antigens (TSAs, mutation-derived neoantigens unique to individual patient tumors). Indication trend: the majority of newly-registered trials target solid tumors previously considered resistant to peptide therapies (pancreatic, colorectal, triple-negative breast cancer) rather than the historically peptide-friendly indications (melanoma, glioblastoma). Combination-therapy trend: paired regimens of checkpoint inhibitor antibodies (anti-PD-1, anti-PD-L1, anti-CTLA-4) with peptide vaccines are the fastest-growing category, based on the biology that peptide vaccines can convert immunologically cold tumors to hot (increased tumor-infiltrating lymphocytes) prior to checkpoint blockade, potentially expanding the checkpoint responder population.