Fit for purpose? A case study: validation of immunological endpoint assays for the detection of cellular and humoral responses to anti-tumour DNA fusion vaccines.
Clinical trials are governed by an increasingly stringent regulatory framework, which applies to all levels of trial conduct. Study critical immunological endpoints, which define success or failure in early phase clinical immunological trials, require formal pre-trial validation. In this case study, we describe the assay validation process, during which the sensitivity, and precision of immunological endpoint assays were defined. The purpose was the evaluation of two multicentre phase I/II clinical trials from our unit in Southampton, UK, which assess the effects of DNA fusion vaccines on immune responses in HLA-A2+ patients with carcinoembryonic antigen (CEA)-expressing malignancies and prostate cancer. Validated immunomonitoring is being performed using ELISA and IFNgamma ELISPOTs to assess humoral and cellular responses to the vaccines over time. The validated primary endpoint assay, a peptide-specific CD8+ IFNgamma ELISPOT, was tested in a pre-trial study and found to be suitable for the detection of low frequency naturally occurring CEA- and prostate-derived tumour-antigen-specific T cells in patients with CEA-expressing malignancies and prostate cancer.
Mander
Ann
A
Cancer Sciences Division, School of Medicine, Southampton General Hospital, University of Southampton, Tremona Road, Southampton, UK. amander@soton.ac.uk
Chowdhury
Ferdousi
F
Low
Lindsey
L
Ottensmeier
Christian H
CH
D000230:Adenocarcinoma / Q000276:immunology / Q000628:therapy; D000818:Animals; D000912:Antibodies, Neoplasm / Q000096:biosynthesis / Q000097:blood* / Q000276:immunology; D000951:Antigens, Neoplasm / Q000276:immunology*; D019496:Cancer Vaccines / Q000276:immunology*; D002272:Carcinoembryonic Antigen / Q000276:immunology*; D017322:Clinical Trials, Phase II as Topic / Q000592:standards*; D004797:Enzyme-Linked Immunosorbent Assay; D005500:Follow-Up Studies; D015789:HLA-A2 Antigen / Q000276:immunology*; D006801:Humans; D007111:Immunity, Cellular; D007371:Interferon-gamma / Q000097:blood*; D008297:Male; D051379:Mice; D015337:Multicenter Studies as Topic / Q000592:standards*; D009369:Neoplasms / Q000276:immunology / Q000628:therapy*; D010446:Peptide Fragments / Q000235:genetics / Q000276:immunology*; D017430:Prostate-Specific Antigen / Q000235:genetics / Q000276:immunology*; D011471:Prostatic Neoplasms / Q000276:immunology / Q000628:therapy; D011993:Recombinant Fusion Proteins / Q000276:immunology; D013601:T-Lymphocytes / Q000378:metabolism; D013744:Tetanus Toxin / Q000235:genetics / Q000276:immunology*; D006113:United Kingdom; D019444:Vaccines, DNA / Q000276:immunology*
D000912:Antibodies, Neoplasm; D000951:Antigens, Neoplasm; D019496:Cancer Vaccines; D002272:Carcinoembryonic Antigen; D015789:HLA-A2 Antigen; D010446:Peptide Fragments; D011993:Recombinant Fusion Proteins; D013744:Tetanus Toxin; D019444:Vaccines, DNA; C040635:tetanus toxin fragment C; D007371:Interferon-gamma; D017430:Prostate-Specific Antigen