Patient specific characteristics associated with T-cell expansion for HER2/neu vaccine-primed autologous adoptive T-cell therapy.

e15041Background: Adoptive T-cell therapy (ACT) using tumor infiltrating lymphocytes (TIL) has shown significant response rates for metastatic melanoma. The need to harvest TIL from a visceral metastatic source for ACT has prevented its further application to other types of cancers. Two prior Phase I/II trials from our group demonstrated the feasibility of expanding and infusing autologous HER2 specific T cells from peripheral blood into advanced HER2+ breast cancer patients who received HER2 vaccination. Given the resource-intensive nature of ex-vivo T cell culture, determining patient specific characteristics predictive of favorable T-cell expansion would allow more optimal patient selection for ACT clinical trials. Methods: Under IRB approved protocols, we collected patient demographics, prior cancer therapies, baseline cell counts, and pathology data from our prior ACT trials in advanced HER2+ breast cancer. Cell expansion was calculated by comparing fold expansion after 24 days of culture from baseli...