Personalised neoantigen vaccines for precision oncology in Southeast Asia: clinical opportunities, infrastructure challenges, and policy perspectives.

Personalised neoantigen vaccines are patient-specific immunotherapies designed to target tumour-restricted antigens arising from genomic and transcriptomic alterations, including single-nucleotide variants, insertions and deletions, frameshifts, gene fusions and aberrant splicing. Early clinical studies have established manufacturing feasibility and immunogenicity, while randomised phase 2b evidence in resected melanoma has provided a signal of clinical activity that requires confirmation in larger trials. Clinical development nevertheless remains concentrated in high-income academic centres, raising questions about equitable implementation in Southeast Asia. This narrative review evaluates the published clinical evidence and the documented health-system capacity of the 11 ASEAN member states. Regional capacity is heterogeneous: national or institutional genomic programmes and tertiary molecular services are documented in several countries, whereas routine nationwide availability, public reimbursement and equitable geographic access remain incompletely characterised. Potential implementation barriers include access to clinical-grade tumour-normal sequencing, bioinformatics and molecular pathology expertise, patient-specific GMP manufacturing, chain-of-identity control, product release testing, temperature-controlled distribution, financing and country-specific regulatory requirements. Current immunopeptidomic training datasets provide uneven HLA coverage, and published neoantigen-prediction tools have not undergone prespecified, prospective, allele-stratified validation across representative Southeast Asian HLA class I and class II repertoires. Their regional transportability should therefore be considered uncertain rather than assumed to be either equivalent or inferior. A staged hub-and-spoke model linking clinical centres, national genomic nodes and a limited number of regional GMP facilities could support prospective implementation studies. Whether personalised neoantigen vaccines reduce or widen existing cancer inequities will depend on evidence-based patient selection, health-system investment, sustainable financing and nationally appropriate regulatory oversight.