A tumor-specific vaccine combined with an immune checkpoint inhibitor shrank tumors in one-third of patients with incurable cancer related to the human papilloma virus (HPV) in a phase II clinical trial led by investigators at The University of Texas MD Anderson Cancer Center, Houston, and reported in JAMA Oncology.
'That encouraging response rate is about twice the rate produced by PD1 checkpoint inhibitors in previous clinical trials, so these results will lead to larger, randomized clinical trials of this combination," says principal investigator Bonnie Glisson, professor of thoracic, head, and neck medical oncology.
Vaccines specific to HPV antigens found on tumors had sparked a strong immune response, but had not, by themselves, been active against established cancers, Glisson relates.
"Vaccines are rewing up the immune system, but the immunosuppressive tumor microenvironment probably prevents them from working. Our thinking was that inhibition of PD1 would address one mechanism of...