Mayo's randomized Phase 2 trial across 11 sites tested low-dose (825 μg) against high-dose (2.5 mg) TPIV200, a multi-epitope folate-receptor-alpha peptide vaccine adjuvanted with GM-CSF, with or without cyclophosphamide pretreatment in early-stage triple-negative breast cancer. The low dose matched the full dose on immunogenicity, cyclophosphamide pretreatment had no impact, and vaccination induced persistent polyepitope immunity. Kathryn Ruddy, Keith Knutson, and Saranya Chumsri presented the data June 1.
Mayo Clinic researchers led by Dr. Kathryn Ruddy will present a randomized Phase 2 trial of the folate receptor alpha (FRα) peptide vaccine TPIV200 in early-stage triple-negative breast cancer at ASCO 2026 (Abstract 536, June 1, 1:30-4:30 PM CDT). The trial dosed 80 patients with vaccine; 58 were evaluable for immunogenicity. The TPIV200 multi-epitope FRα peptide vaccine was found safe and immunogenic using a single low-dose injection without cyclophosphamide priming. FRα is overexpressed on the cell surface in breast, ovarian, and lung cancers, making it a shared-antigen vaccine target distinct from personalized neoantigen approaches. The data supports combining TPIV200 with an immune checkpoint inhibitor to extend recurrence-free or progression-free survival in TNBC — the breast cancer subtype with the highest mortality risk and fewest targeted-therapy options. The vaccine adds to the peptide cancer vaccine cohort (BioVaxys MVP-S, Dana-Farber NeoVax, Greenwich GP2) at ASCO 2026.
Mikhail Kolonin's group at UTHealth Houston published preclinical data showing BLMP6, a peptide identified through AI-guided modeling, selectively binds fibulin-4 — a protein highly expressed on metastatic triple-negative breast cancer cells — and not on noninvasive breast cancer or normal breast tissue. A BLMP6 conjugate carrying monomethyl auristatin E suppressed metastasis and improved survival in mouse models, and BLMP6-based fluorescent imaging probes successfully detected metastatic lesions. The paper, published in Molecular Therapy Oncology, identifies fibulin-4 as a new theranostic target.